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  • 1.
    Abdi, Zahra
    et al.
    Inst Adv Studies Basic Sci IASBS, Dept Chem, Zanjan 4513766731, Iran..
    Bagheri, Robabeh
    Soochow Univ, Sch Phys Sci & Technol, Coll Energy, Soochow Inst Energy & Mat Innovat, Suzhou 215006, Peoples R China.;Soochow Univ, Key Lab Adv Carbon Mat & Wearable Energy Technol, Suzhou 215006, Peoples R China..
    Reza Mohammadi, Mohammad
    Univ Sistan & Baluchestan, Dept Phys, Zahedan 9816745845, Iran..
    Song, Zhenlun
    Chinese Acad Sci, Ningbo Inst Mat Technol & Engn, Surface Dept, Surface Protect Res Grp, 519 Zhuangshi Rd, Ningbo 315201, Peoples R China..
    Görlin, Mikaela
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Dau, Holger
    Free Univ Berlin, Fachbereich Phys, Arnimallee 14, D-14195 Berlin, Germany..
    Najafpour, Mohammad Mahdi
    Inst Adv Studies Basic Sci IASBS, Dept Chem, Zanjan 4513766731, Iran..
    In Situ Synthesis of Manganese Oxide as an Oxygen-Evolving Catalyst: A New Strategy2021In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 27, no 4, p. 1330-1336Article in journal (Refereed)
    Abstract [en]

    All studies on oxygen-evolution reaction by Mn oxides in the presence of cerium(IV) ammonium nitrate (CAN) have been so far carried out by synthesizing Mn oxides in the first step. And then, followed by the investigation of the Mn oxides in the presence of oxidants for oxygen-evolution reaction (OER). This paper presents a case study of a new and promising strategy for in situ catalyst synthesis by the adding Mn-II to either CAN or KMnO4/CAN solution, resulting in the formation of Mn-based catalysts for OER. The catalysts were characterized by scanning electron microscopy, energy-dispersive spectroscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray absorption spectroscopy, and X-ray photoelectron spectroscopy. Both compounds contained nano-sized particles that catalyzed OER in the presence of CAN. The turnover frequencies for both catalysts were 0.02 (mmolO2 /mol(Mn).

  • 2.
    Abdi-Jalebi, Mojtaba
    et al.
    Univ Cambridge, Dept Phys, Cavendish Lab, JJ Thomson Ave, Cambridge, England.
    Pazoki, Meysam
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Philippe, Bertrand
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Dar, M. Ibrahim
    Ecole Polytech Fed Lausanne, Inst Chem Sci & Engn, Lab Photon & Interfaces, Lausanne, Switzerland.
    Alsari, Mejd
    Univ Cambridge, Dept Phys, Cavendish Lab, JJ Thomson Ave, Cambridge, England.
    Sadhanala, Aditya
    Univ Cambridge, Dept Phys, Cavendish Lab, JJ Thomson Ave, Cambridge, England.
    Diyitini, Giorgio
    Univ Cambridge, Dept Mat Sci & Met, Charles Babbage Rd, Cambridge, England.
    Imani, Roghayeh
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Lilliu, Samuele
    Univ Sheffield, Dept Phys & Astron, Sheffield, S Yorkshire, England; UAE Ctr Crystallog, Dubai, U Arab Emirates.
    Kullgren, Jolla
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Rensmo, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Gratzel, Michael
    Ecole Polytech Fed Lausanne, Inst Chem Sci & Engn, Lab Photon & Interfaces, Lausanne, Switzerland.
    Friend, Richard H.
    Univ Cambridge, Dept Phys, Cavendish Lab, JJ Thomson Ave, Cambridge, England.
    Dedoping of Lead Halide Perovskites Incorporating Monovalent Cations2018In: ACS Nano, ISSN 1936-0851, E-ISSN 1936-086X, Vol. 12, no 7, p. 7301-7311Article in journal (Refereed)
    Abstract [en]

    We report significant improvements in the optoelectronic properties of lead halide perovskites with the addition of monovalent ions with ionic radii close to Pb2+. We investigate the chemical distribution and electronic structure of solution processed CH3NH3PbI3 perovskite structures containing Na+, Cu+, and Ag+, which are lower valence metal ions than Pb2+ but have similar ionic radii. Synchrotron X-ray diffraction reveals a pronounced shift in the main perovskite peaks for the monovalent cation-based films, suggesting incorporation of these cations into the perovskite lattice as well as a preferential crystal growth in Ag+ containing perovskite structures. Furthermore, the synchrotron X-ray photoelectron measurements show a significant change in the valence band position for Cu- and Ag-doped films, although the perovskite bandgap remains the same, indicating a shift in the Fermi level position toward the middle of the bandgap. Such a shift infers that incorporation of these monovalent cations dedope the n-type perovskite films when formed without added cations. This dedoping effect leads to cleaner bandgaps as reflected by the lower energetic disorder in the monovalent cation-doped perovskite thin films as compared to pristine films. We also find that in contrast to Ag+ and Cu+, Na+ locates mainly at the grain boundaries and surfaces. Our theoretical calculations confirm the observed shifts in X-ray diffraction peaks and Fermi level as well as absence of intrabandgap states upon energetically favorable doping of perovskite lattice by the monovalent cations. We also model a significant change in the local structure, chemical bonding of metal-halide, and the electronic structure in the doped perovskites. In summary, our work highlights the local chemistry and influence of monovalent cation dopants on crystallization and the electronic structure in the doped perovskite thin films.

  • 3. Acker, Pascal
    et al.
    Rzesny, Luisa
    Marchiori, Cleber F. N.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Araujo, Carlos Moyses
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Esser, Birgit
    π-Conjugation Enables Ultra-High Rate Capabilities and Cycling Stabilities in Phenothiazine Copolymers as Cathode-Active Battery Materials2019In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 29, no 45, article id 1906436Article in journal (Refereed)
    Abstract [en]

    In recent years, organic battery cathode materials have emerged as an attractive alternative to metal oxide–based cathodes. Organic redox polymers that can be reversibly oxidized are particularly promising. A drawback, however, often is their limited cycling stability and rate performance in a high voltage range of more than 3.4 V versus Li/Li+. Herein, a conjugated copolymer design with phenothiazine as a redox‐active group and a bithiophene co‐monomer is presented, enabling ultra‐high rate capability and cycling stability. After 30 000 cycles at a 100C rate, >97% of the initial capacity is retained. The composite electrodes feature defined discharge potentials at 3.6 V versus Li/Li+ due to the presence of separated phenothiazine redox centers. The semiconducting nature of the polymer allows for fast charge transport in the composite electrode at a high mass loading of 60 wt%. A comparison with three structurally related polymers demonstrates that changing the size, amount, or nature of the side groups leads to a reduced cell performance. This conjugated copolymer design can be used in the development of advanced redox polymers for batteries.

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  • 4.
    Adamovic, Nadja
    et al.
    TU Wien, ISAS, Vienna, Austria..
    Asinari, Pietro
    Politecn Torino, Dept Energy, Turin, Italy..
    Goldbeck, Gerhard
    Goldbeck Consulting Ltd, St Johns Innovat Ctr, Cambridge, England..
    Hashibon, Adham
    Fraunhofer Inst Mech Mat IWM, Freiburg, Germany..
    Hermansson, Kersti
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Hristova-Bogaerds, Denka
    DPI, Eindhoven, Netherlands..
    Koopmans, Rudolf
    Koopmans Consulting GmbH, Zurich, Switzerland..
    Verbrugge, Tom
    Dow Benelux BV, Hoek, Netherlands..
    Wimmer, Erich
    Mat Design, Le Mans, France..
    European Materials Modelling Council2017In: Proceedings Of The 4Th World Congress On Integrated Computational Materials Engineering (Icme 2017) / [ed] Mason, P Fisher, CR Glamm, R Manuel, MV Schmitz, GJ Singh, AK Strachan, A, Springer Publishing Company, 2017, p. 79-92Conference paper (Refereed)
    Abstract [en]

    The aim of the European Materials Modelling Council (EMMC) is to establish current and forward looking complementary activities necessary to bring the field of materials modelling closer to the demands of manufacturers (both small and large enterprises) in Europe. The ultimate goal is that materials modelling and simulation will become an integral part of product life cycle management in European industry, thereby making a strong contribution to enhance innovation and competitiveness on a global level. Based on intensive efforts in the past two years within the EMMC, which included numerous consultation and networking actions with representatives of all stakeholders including Modellers, Software Owners, Translators and Manufacturers in Europe, the EMMC identified and proposed a set of underpinning and enabling actions to increase the industrial exploitation of materials modelling in Europe. EMMC will pursue the following overarching objectives in order to bridge the gap between academic innovation and industrial application: enhance the interaction and collaboration between all stakeholders engaged in different types of materials modelling, including modellers, software owners, translators and manufacturers, facilitate integrated materials modelling in Europe building on strong and coherent foundations, coordinate and support actors and mechanisms that enable rapid transfer of materials modelling from academic innovation to the end users and potential beneficiaries in industry, achieve greater awareness and uptake of materials modelling in industry, in particular SMEs, elaborate Roadmaps that (i) identify major obstacles to widening the use of materials modelling and (ii) elaborate strategies to overcome them.

  • 5.
    Agosta, Lorenzo
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Arismendi-Arrieta, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Dzugutov, Mikhail
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Hermansson, Kersti
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Origin of the Hydrophobic Behaviour of Hydrophilic CeO22023In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 62, no 35, article id e202303910Article in journal (Refereed)
    Abstract [en]

    The nature of the hydrophobicity found in rare-earth oxides is intriguing. The CeO2 (100) surface, despite its strongly hydrophilic nature, exhibits hydrophobic behaviour when immersed in water. In order to understand this puzzling and counter-intuitive effect we performed a detailed analysis of the water structure and dynamics. We report here an ab-initio molecular dynamics simulation (AIMD) study which demonstrates that the first water layer, in immediate contact with the hydroxylated CeO2 surface, is responsible for the effect behaving as a hydrophobic interface with respect to the rest of the liquid water. The hydrophobicity is manifested in several ways: a considerable diffusion enhancement of the confined liquid water as compared with bulk water at the same thermodynamic condition, a weak adhesion energy and few H-bonds above the hydrophobic water layer, which may also sustain a water droplet. These findings introduce a new concept in water/rare-earth oxide interfaces: hydrophobicity mediated by specific water patterns on a hydrophilic surface.

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  • 6.
    Agosta, Lorenzo
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Brandt, Erik G.
    Stockholm Univ, Dept Mat & Environm Chem, S-10691 Stockholm, Sweden..
    Lyubartsev, Alexander
    Stockholm Univ, Dept Mat & Environm Chem, S-10691 Stockholm, Sweden..
    Improved Sampling in Ab Initio Free Energy Calculations of Biomolecules at Solid-Liquid Interfaces: Tight-Binding Assessment of Charged Amino Acids on TiO2 Anatase (101)2020In: Computation, E-ISSN 2079-3197, Vol. 8, no 1, article id 12Article in journal (Refereed)
    Abstract [en]

    Atomistic simulations can complement the scarce experimental data on free energies of molecules at bio-inorganic interfaces. In molecular simulations, adsorption free energy landscapes are efficiently explored with advanced sampling methods, but classical dynamics is unable to capture charge transfer and polarization at the solid-liquid interface. Ab initio simulations do not suffer from this flaw, but only at the expense of an overwhelming computational cost. Here, we introduce a protocol for adsorption free energy calculations that improves sampling on the timescales relevant to ab initio simulations. As a case study, we calculate adsorption free energies of the charged amino acids Lysine and Aspartate on the fully hydrated anatase (101) TiO2 surface using tight-binding forces. We find that the first-principle description of the system significantly contributes to the adsorption free energies, which is overlooked by calculations with previous methods.

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  • 7.
    Agosta, Lorenzo
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Dzugutov, Mikhail
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Hermansson, Kersti
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Supercooled liquid-like dynamics in water near a fully hydrated titania surface: Decoupling of rotational and translational diffusion2021In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 154, no 9, article id 094708Article in journal (Refereed)
    Abstract [en]

    We report an ab initio molecular dynamics (MD) simulation investigating the effect of a fully hydrated surface of TiO2 on the water dynamics. It is found that the universal relation between the rotational and translational diffusion characteristics of bulk water is broken in the water layers near the surface with the rotational diffusion demonstrating progressive retardation relative to the translational diffusion when approaching the surface. This kind of rotation-translation decoupling has so far only been observed in the supercooled liquids approaching glass transition, and its observation in water at a normal liquid temperature is of conceptual interest. This finding is also of interest for the application-significant studies of the water interaction with fully hydrated nanoparticles. We note that this is the first observation of rotation-translation decoupling in an ab initio MD simulation of water.

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  • 8.
    Agosta, Lorenzo
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Metere, Alfredo
    Lawrence Livermore Natl Lab, Phys & Life Sci Directorate, Phys Div, Livermore, CA 94550 USA.
    Oleynikov, Peter
    Shanghai Tech Univ, Sch Phys Sci & Technol, Shanghai, Peoples R China.
    Dzugutov, Mikhail
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Self-assembly of a triply periodic continuous mesophase with Fddd symmetry in simple one-component liquids2020In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 152, no 19, article id 191101Article in journal (Refereed)
    Abstract [en]

    Triply periodic continuous morphologies (networks) arising as a result of the microphase separation in block copolymer melts have so far never been observed self-assembled in systems of particles with spherically symmetric interaction. We report a molecular dynamics simulation where two simple one-component liquids form upon cooling an equilibrium network with the Fddd space group symmetry. This complexity reduction in the liquid network formation in terms of the particle geometry and the number of components evidences the generic nature of this class of phase transition, suggesting opportunities for producing these structures in a variety of new systems.

  • 9.
    Ahlberg Tidblad, Annika
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström. Volvo Car Corp, SE-40531 Gothenburg, Sweden.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Hernández, Guiomar
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    de Meatza, Iratxe
    CIDETEC, Basque Res & Technol Alliance BRTA, P Miramon 196, Donostia San Sebastian 20014, Spain.
    Landa-Medrano, Imanol
    CIDETEC, Basque Res & Technol Alliance BRTA, P Miramon 196, Donostia San Sebastian 20014, Spain.
    Biendicho, Jordi Jacas
    Inst Recerca Energia Catalunya IREC, Barcelona 08930, Spain.
    Trilla, Lluís
    Inst Recerca Energia Catalunya IREC, Barcelona 08930, Spain.
    Buysse, Maarten
    Bax & Co, Barcelona 08013, Spain.
    Ierides, Marcos
    Bax & Co, Barcelona 08013, Spain.
    Perez Horno, Beatriz
    Bax & Co, Barcelona 08013, Spain.
    Kotak, Yash
    TH Ingolstadt, CARISSMA Inst Elect Connected & Secure Mobil C EC, Esplanade 10, D-85049 Ingolstadt, Germany.
    Schweiger, Hans-Georg
    TH Ingolstadt, CARISSMA Inst Elect Connected & Secure Mobil C EC, Esplanade 10, D-85049 Ingolstadt, Germany.
    Koch, Daniel
    TH Ingolstadt, CARISSMA Inst Elect Connected & Secure Mobil C EC, Esplanade 10, D-85049 Ingolstadt, Germany.
    Kotak, Bhavya Satishbhai
    TH Ingolstadt, CARISSMA Inst Elect Connected & Secure Mobil C EC, Esplanade 10, D-85049 Ingolstadt, Germany.
    Future Material Developments for Electric Vehicle Battery Cells Answering Growing Demands from an End-User Perspective2021In: Energies, E-ISSN 1996-1073, Vol. 14, no 14, article id 4223Article, review/survey (Refereed)
    Abstract [en]

    Nowadays, batteries for electric vehicles are expected to have a high energy density, allow fast charging and maintain long cycle life, while providing affordable traction, and complying with stringent safety and environmental standards. Extensive research on novel materials at cell level is hence needed for the continuous improvement of the batteries coupled towards achieving these requirements. This article firstly delves into future developments in electric vehicles from a technology perspective, and the perspective of changing end-user demands. After these end-user needs are defined, their translation into future battery requirements is described. A detailed review of expected material developments follows, to address these dynamic and changing needs. Developments on anodes, cathodes, electrolyte and cell level will be discussed. Finally, a special section will discuss the safety aspects with these increasing end-user demands and how to overcome these issues.

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  • 10.
    Ahlgren, Per
    et al.
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Statistics. Uppsala University, University Administration, Planning Division.
    Jeppsson, Tobias
    KTH Biblioteket, KTH Royal Institute of Technology, Stockholm, Sweden.
    Stenberg, Esa
    Uppsala University, University Administration, Faculty Offices.
    Berg, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    A bibliometric analysis of battery research with the BATTERY 2030+ roadmap as point of departure2022Report (Other academic)
    Abstract [en]

    In this bibliometric study, we analyze the six battery research subfields identified in the BATTERY 2030+ roadmap: Battery Interface Genome, Materials Acceleration Platform, Recyclability, Smart functionalities: Self-healing, Smart functionalities: Sensing, and Manufacturability. In addition, we analyze the entire research field related to BATTERY 2030+ as a whole, using two operationalizations. We (a) evaluate the European standing in the subfields/the BATTERY 2030+ field in comparison to the rest of the world, and (b) identify strongholds of the subfields/the BATTERY 2030+ field across Europe. For each subfield and the field as a whole, we used seed articles, i.e. articles listed in the BATTERY 2030+ roadmap or cited by such articles, in order to generate additional, similar articles located in an algorithmically obtained classification system. The output of the analysis is publication volumes, field normalized citation impact values with comparisons between country/country aggregates and between organizations, co-publishing networks between countries and organizations, and keyword co-occurrence networks. For the results related to (a), the performance of EU & associated (countries) is similar to China and the aggregate Japan-South Korea-Singapore and well below North America regarding citation impact and with respect to the field as a whole. Exceptions are, however, the subfields Battery Interface Genome and Recyclability. For the results related to (b), there is a large variability in the EU & associated organizations regarding volume in the different subfields. For citation impact, examples of high-performing EU & associated organizations are ETH Zurich and Max Planck Society for the Advancement of Science.

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  • 11.
    Ahlgren, Per
    et al.
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Statistics.
    Jeppsson, Tobias
    KTH Royal Inst Technol KTH Lib, KTH Lib, S-10044 Stockholm, Sweden..
    Stenberg, Esa
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Berg, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    BATTERY 2030+ and its Research Roadmap: A Bibliometric Analysis2023In: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 16, no 21, article id e202300333Article in journal (Refereed)
    Abstract [en]

    In this bibliometric study, we analyze two of the six battery research subfields identified in the BATTERY 2030+ roadmap: Materials Acceleration Platform and Smart functionalities: Sensing. In addition, we analyze the entire research field related to BATTERY 2030+ as a whole. We (a) evaluate the European standing in the two subfields/the BATTERY 2030+ field in comparison to the rest of the world, and (b) identify strongholds of the two subfields/the BATTERY 2030+ field across Europe. For each subfield and the field as a whole, we used seed articles, i. e. articles listed in the BATTERY 2030+ roadmap or cited by such articles, in order to generate additional, similar articles located in an algorithmically obtained classification system. The output of the analysis is publication volumes, field normalized citation impact values with comparisons between country/country aggregates and between organizations, co-publishing networks between countries and organizations, and keyword co-occurrence networks.

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  • 12.
    Ahlstrand, Emma
    et al.
    Linnus Univ, Dept Chem & Biomed Sci, S-39182 Kalmar, Sweden.;Linnus Univ, Ctr Biomat Chem, S-39182 Kalmar, Sweden..
    Hermansson, Kersti
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Friedman, Ran
    Linnus Univ, Dept Chem & Biomed Sci, S-39182 Kalmar, Sweden.;Linnus Univ, Ctr Biomat Chem, S-39182 Kalmar, Sweden..
    Interaction Energies in Complexes of Zn and Amino Acids: A Comparison of Ab Initio and Force Field Based Calculations2017In: Journal of Physical Chemistry A, ISSN 1089-5639, E-ISSN 1520-5215, Vol. 121, no 13, p. 2643-2654Article in journal (Refereed)
    Abstract [en]

    Zinc plays important roles in structural stabilization of proteins, eniyine catalysis, and signal transduction. Many Zn binding sites are located at the interface between the protein and the cellular fluid. In aqueous solutions, Zn ions adopt an octahedral coordination, while in proteins zinc can have different coordinations, with a tetrahedral conformation found most frequently. The dynainics of Zn binding to proteins and the formation of complexes that involve Zn are dictated by interactions between Zn and its binding partners. We calculated the interaction energies between Zn and its ligands in complexes that mimic protein binding sites and in Zn complexes of water and one or two amino acid moieties, using quantum mechanics (QM) and molecular mechanics (MM). It was found that MM calculations that neglect or only approximate polarizability did not reproduce even the relative order of the QM interaction energies in these complexes. Interaction energies calculated with the CHARMM-Diode polarizable force field agreed better with the ab initio results,:although the deviations between QM and MM were still rather large (40-96 kcallmol). In order to gain further insight into Zn ligand interactions, the free energies of interaction were estimated by QM calculations with continuum solvent representation, and we performed energy decomposition analysis calculations to examine the characteristics of the different complexes. The ligand-types were found to have high impact on the relative strength of polarization and electrostatic interactions. Interestingly, ligand ligand interactions did not play a significant role in the binding of Zn. Finally) analysis of ligand exchange energies suggests that carboxylates could be exchanged with water molecules, which explains the flexibility in Zn:binding dynamics. An exchange between earboxylate (Asp/Glii) and imidazole (His) is less likely.

  • 13.
    Ahlstrand, Emma
    et al.
    Linnæus University Centre for Biomaterials Chemistry.
    Spångberg, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Hermansson, Kersti
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Friedman, Ran
    Interaction Energies Between Metal Ions (Zn2+ and Cd2+) and Biologically Relevant Ligands2013In: International Journal of Quantum Chemistry, ISSN 0020-7608, E-ISSN 1097-461X, Vol. 113, no 23, p. 2554-2562Article in journal (Refereed)
    Abstract [en]

    Interactions between the group XII metals Zn2+ and Cd2+ and amino acid residues play an important role in biology due to the prevalence of the first and the toxicity of the second. Estimates of the interaction energies between the ions and relevant residues in proteins are however difficult to obtain. This study reports on calculated interaction energy curves for small complexes of Zn2+ or Cd2+ and amino acid mimics (acetate, methanethiolate, and imidazole) or water. Given that many applications and models (e.g., force fields, solvation models, etc.) begin with and rely on an accurate description of gas-phase interaction energies, this is where our focus lies in this study. Four density functional theory (DFT)-functionals and MP2 were used to calculate the interaction energies not only at the respective equilibrium distances but also at a relevant range of ion–ligand separation distances. The calculated values were compared with those obtained by CCSD(T). All DFT-methods are found to overestimate the magnitude of the interaction energy compared to the CCSD(T) reference values. The deviation was analyzed in terms of energy components from localized molecular orbital energy decomposition analysis scheme and is mostly attributed to overestimation of the polarization energy. MP2 shows good agreement with CCSD(T) [root mean square error (RMSE) = 1.2 kcal/mol] for the eight studied complexes at equilibrium distance. Dispersion energy differences at longer separation give rise to increased deviations between MP2 and CCSD(T) (RMSE = 6.4 kcal/mol at 3.0 Å). Overall, the results call for caution in applying DFT methods to metalloprotein model complexes even with closed-shell metal ions such as Zn2+ and Cd2+, in particular at ion–ligand separations that are longer than the equilibrium distances.

  • 14.
    Ahmed, Taha
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Nanostructured ZnO and metal chalcogenide films for solar photocatalysis2023Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The increasing demand for clean energy and safe water resources has driven the development of efficient and sustainable technologies. Among these technologies, photocatalysis using semiconducting materials has emerged as a promising solution for both solar hydrogen generation and water purification. Low-dimensional ZnO, including nanorods, nanoparticles, and quantum confined particles (so called quantum dots), has demonstrated excellent photocatalytic properties due to their large surface area, high electron mobility, and tunable band gap.

    The work in this thesis aims to investigate the potential of low-dimensional ZnO alone and in combination with CdS and Fe2O3 for solar hydrogen generation and photocatalytic water purification. The thesis includes a comprehensive analysis of the synthesis, characterization, and optimization of low-dimensional ZnO-based photocatalyst systems for solar hydrogen generation and photocatalytic water purification. Additionally, the thesis will evaluate the performance of the ZnO-based photocatalysts under different experimental conditions, either as photoelectrodes or as distributed particle systems for water purification. The work includes detailed size control of ZnO by itself in dimensions below 10 nm using a hydrothermal method, to provide an increased total surface area and introduce quantum confinement effects that increase the band gap to enable degradation of chemical bonds in a model pollutant in a distributed system for water purification. The work also includes a relatively detailed study of the phonon–phonon and electron–phonon coupling as a function of dimension from 10 nm to 150 nm for ZnO using non-resonant and resonant Raman spectroscopy. Ultimately, the thesis aims to provide insight into the potential of low-dimensional ZnO alone and in combination with other inorganic materials for solar hydrogen generation and photocatalytic water purification and pave the way for the development of efficient and sustainable technologies for clean energy and safe water resources.

    List of papers
    1. A facile approach to ZnO/CdS nanoarrays and their photocatalytic and photoelectrochemical properties
    Open this publication in new window or tab >>A facile approach to ZnO/CdS nanoarrays and their photocatalytic and photoelectrochemical properties
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    2013 (English)In: Applied Catalysis B: Environmental, ISSN 0926-3373, E-ISSN 1873-3883, Vol. 138, p. 175-183Article in journal (Refereed) Published
    Abstract [en]

    ZnO nanorods were successfully deposited on Transparent Conductive Oxide (TCO) glass by electrochemical deposition, during which initial pulse potential proves important for the fast nucleation and even distribution of ZnO. CdS nanoparticles were coated outside the as-prepared ZnO nanorods by chemical-bath deposition forming ZnO/CdS nanoarrays. The nanoarrays were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), ultraviolet-visible (UV-vis) spectroscopy, and photoelectrochemistry. The short-circuit current density (J(sc)) of some ZnO/CdS sample showed over 3.3 mA/cm(2) under solar-simulated illumination. The ZnO/CdS nanoarrays showed promising photocatalytic activity with respect to the degradation of Eriochrome Black T (EBT). The relatively high photoelectrochemical properties and photocatalytic performance under visible light irradiation can be ascribed to the enhanced visible light harvest from CdS and charge separation by the coupling of the semiconductors. The combination of electrodeposition and chemical-bath deposition can provide a simple and facile approach to the fabrication of one-dimensional nanocomposites. 

    Keywords
    ZnO, CdS, Nanoarray, Photocatalysis, Photoelectrochemistry
    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:uu:diva-202887 (URN)10.1016/j.apcatb.2013.02.042 (DOI)000319087900021 ()
    Note

    De två (2) första författarna delar förstaförfattarskapet.

    Available from: 2013-07-01 Created: 2013-07-01 Last updated: 2023-10-30
    2. Preparation and characterisation of ZnO/Fe2O3 core–shell nanorods
    Open this publication in new window or tab >>Preparation and characterisation of ZnO/Fe2O3 core–shell nanorods
    Show others...
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    ZnO is a widely used semiconductor photocatalyst. However, the bandgap of ZnO is too large to utilise visible light or solar energy. Therefore, ZnO can couple with a narrow band gap semiconductor that is a visible-light-responsive photocatalyst. ZnO can help with charge seperation through attracting electrons or holes from the other semiconductor. In this work, ZnO nanorods were electrodeposited on FTO glass, and then coated with ultrathin layer of Fe2O3 via ALD.

    SEM, TEM, XPS, Raman and UV-Vis spectroscopies were used to characterise the prepared samples. Raman shows that ALD-coated Fe2O3 is hematite (α-Fe2O3). The prepared ZnO/Fe2O3 shows photocatalytic activity of EBT degradation under visible light illumination. The synthetic strategy can also beextended to prepare other heterostructured photocatalysts.

    National Category
    Inorganic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-515253 (URN)
    Available from: 2023-10-30 Created: 2023-10-30 Last updated: 2023-10-30
    3. Optical Quantum Confinement in Ultrasmall ZnO and the Effect of Size on Their Photocatalytic Activity
    Open this publication in new window or tab >>Optical Quantum Confinement in Ultrasmall ZnO and the Effect of Size on Their Photocatalytic Activity
    2020 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 124, no 11, p. 6395-6404Article in journal (Refereed) Published
    Abstract [en]

    Zinc oxide is a well-known metal oxide semiconductor with a wide direct band gap that offers a promising alternative to titanium oxide in photocatalytic applications. ZnO is studied here as quantum dots (QDs) in colloidal suspensions, where ultrasmall nanoparticles of ZnO show optical quantum confinement with a band gap opening for particles below 9 nm in diameter from the shift of the band edge energies. The optical properties of growing ZnO QDs are determined with Tauc analysis, and a system of QDs for the treatment and degradation of distributed threats is analyzed using an organic probe molecule, methylene blue, whose UV/vis spectrum is analyzed in some detail. The effect of optical properties of the QDs and the kinetics of dye degradation are quantified for low-dimensional ZnO materials in the range of 3-8 nm and show a substantial increase in photocatalytic activity compared to larger ZnO particles. This is attributed to a combined effect from the increased surface area as well as a quantum confinement effect that goes beyond the increased surface area. The results show a significantly higher photocatalytic activity for the QDs between 3 and 6 nm with a complete decolorization of the organic probe molecule, while QDs from 6 nm and upward in diameter show signs of competing reduction reactions. Our study shows that ultrasmall ZnO particles have a reactivity beyond that which is expected because of their increased surface area and also demonstrates size-dependent reaction pathways, which introduces the possibility for size-selective catalysis.

    Place, publisher, year, edition, pages
    AMER CHEMICAL SOC, 2020
    National Category
    Physical Chemistry Theoretical Chemistry
    Identifiers
    urn:nbn:se:uu:diva-410900 (URN)10.1021/acs.jpcc.9b11229 (DOI)000526396000057 ()
    Funder
    Swedish Research Council Formas, 2016-00908
    Available from: 2020-05-25 Created: 2020-05-25 Last updated: 2023-10-30Bibliographically approved
    4. Phonon–phonon and electron–phonon coupling in nano-dimensional ZnO
    Open this publication in new window or tab >>Phonon–phonon and electron–phonon coupling in nano-dimensional ZnO
    Show others...
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Thermal losses through vibrational coupling are critical bottlenecks limiting several materials classes from reaching their full potential. Altering the phonon–phonon and electron–phonon coupling by controlled suppression of vibrational degrees of freedom through low-dimensionality are promising but still largely unexplored approaches. Here we report a detailed study of the first- and second-order Raman processes as a function of size for low-dimensional ZnO. Wurtzite ZnO nanoparticles were synthesised into 3D frameworks of ZnO crystallites, with tailored crystallite diameters from 10 nm to 150 nm and characterised by electron microscopy, X-ray diffraction and non-resonant and resonant Raman spectroscopy.

    We present a short derivation of how resonance Raman and the relation between the longitudinal optical (LO) phonons can be utilised to quantify the electron–phonon coupling, its merits, and limitations. Theoretical Raman response using density functional theory is corroborating the experimental data in assigning first- and second-order Raman modes. The Lyddane-Sachs-Teller equation was applied to the measured LO–TO split and revealed no change in the ratio between the static and high-frequency dielectric constant with changing ZnO dimension from 10 nm to 150 nm. The second-order Raman revealed a phonon–phonon coupling that generally increased with particle size and markedly so for differential modes. Resonance Raman showed the fundamental LO mode and the 2nd, 3rd, and 4th overtones. The intensity relation between the fundamental LO mode and its overtones enabled the extraction of the change in electron–phonon coupling via the Huang-Rhys parameter as a function of particle size, which showed an increase with particle size.

    National Category
    Physical Chemistry
    Identifiers
    urn:nbn:se:uu:diva-515256 (URN)
    Available from: 2023-10-30 Created: 2023-10-30 Last updated: 2023-10-30
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  • 15.
    Ahmed, Taha
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Edvinsson, Tomas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics.
    Optical Quantum Confinement in Ultrasmall ZnO and the Effect of Size on Their Photocatalytic Activity2020In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 124, no 11, p. 6395-6404Article in journal (Refereed)
    Abstract [en]

    Zinc oxide is a well-known metal oxide semiconductor with a wide direct band gap that offers a promising alternative to titanium oxide in photocatalytic applications. ZnO is studied here as quantum dots (QDs) in colloidal suspensions, where ultrasmall nanoparticles of ZnO show optical quantum confinement with a band gap opening for particles below 9 nm in diameter from the shift of the band edge energies. The optical properties of growing ZnO QDs are determined with Tauc analysis, and a system of QDs for the treatment and degradation of distributed threats is analyzed using an organic probe molecule, methylene blue, whose UV/vis spectrum is analyzed in some detail. The effect of optical properties of the QDs and the kinetics of dye degradation are quantified for low-dimensional ZnO materials in the range of 3-8 nm and show a substantial increase in photocatalytic activity compared to larger ZnO particles. This is attributed to a combined effect from the increased surface area as well as a quantum confinement effect that goes beyond the increased surface area. The results show a significantly higher photocatalytic activity for the QDs between 3 and 6 nm with a complete decolorization of the organic probe molecule, while QDs from 6 nm and upward in diameter show signs of competing reduction reactions. Our study shows that ultrasmall ZnO particles have a reactivity beyond that which is expected because of their increased surface area and also demonstrates size-dependent reaction pathways, which introduces the possibility for size-selective catalysis.

  • 16.
    Ahmed, Taha
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Fondell, Mattis
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Younesi, Reza
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Donzel-Gargand, Olivier
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solar Cell Technology.
    Boman, Mats
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Zhu, Jiefang
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Preparation and characterisation of ZnO/Fe2O3 core–shell nanorodsManuscript (preprint) (Other academic)
    Abstract [en]

    ZnO is a widely used semiconductor photocatalyst. However, the bandgap of ZnO is too large to utilise visible light or solar energy. Therefore, ZnO can couple with a narrow band gap semiconductor that is a visible-light-responsive photocatalyst. ZnO can help with charge seperation through attracting electrons or holes from the other semiconductor. In this work, ZnO nanorods were electrodeposited on FTO glass, and then coated with ultrathin layer of Fe2O3 via ALD.

    SEM, TEM, XPS, Raman and UV-Vis spectroscopies were used to characterise the prepared samples. Raman shows that ALD-coated Fe2O3 is hematite (α-Fe2O3). The prepared ZnO/Fe2O3 shows photocatalytic activity of EBT degradation under visible light illumination. The synthetic strategy can also beextended to prepare other heterostructured photocatalysts.

  • 17.
    Ahmed, Taha
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Thyr, Jakob
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics.
    Naim Katea, Sarmad
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Westin, Gunnar
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Edvinsson, Tomas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Phonon–phonon and electron–phonon coupling in nano-dimensional ZnOManuscript (preprint) (Other academic)
    Abstract [en]

    Thermal losses through vibrational coupling are critical bottlenecks limiting several materials classes from reaching their full potential. Altering the phonon–phonon and electron–phonon coupling by controlled suppression of vibrational degrees of freedom through low-dimensionality are promising but still largely unexplored approaches. Here we report a detailed study of the first- and second-order Raman processes as a function of size for low-dimensional ZnO. Wurtzite ZnO nanoparticles were synthesised into 3D frameworks of ZnO crystallites, with tailored crystallite diameters from 10 nm to 150 nm and characterised by electron microscopy, X-ray diffraction and non-resonant and resonant Raman spectroscopy.

    We present a short derivation of how resonance Raman and the relation between the longitudinal optical (LO) phonons can be utilised to quantify the electron–phonon coupling, its merits, and limitations. Theoretical Raman response using density functional theory is corroborating the experimental data in assigning first- and second-order Raman modes. The Lyddane-Sachs-Teller equation was applied to the measured LO–TO split and revealed no change in the ratio between the static and high-frequency dielectric constant with changing ZnO dimension from 10 nm to 150 nm. The second-order Raman revealed a phonon–phonon coupling that generally increased with particle size and markedly so for differential modes. Resonance Raman showed the fundamental LO mode and the 2nd, 3rd, and 4th overtones. The intensity relation between the fundamental LO mode and its overtones enabled the extraction of the change in electron–phonon coupling via the Huang-Rhys parameter as a function of particle size, which showed an increase with particle size.

  • 18.
    Aktekin, Burak
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    The Electrochemistry of LiNi0.5-xMn1.5+xO4-δ in Li-ion Batteries: Structure, Side-reactions and Cross-talk2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The use of Li-ion batteries in portable electronic products is today widespread and on-going research is extensively dedicated to improve their performance and energy density for use in electric vehicles. The largest contribution to the overall cell weight comes from the positive electrode material, and improvements regarding this component thereby render a high potential for the development of these types of batteries. A promising candidate is LiNi0.5Mn1.5O4 (LMNO), which offers both high power capability and energy density. However, the instability of conventional electrolytes at the high operating potential (~4.7 V vs. Li+/Li) associated with this electrode material currently prevents its use in commercial applications.

    This thesis work aims to investigate practical approaches which have the potential of overcoming issues related to fast degradation of LNMO-based batteries. This, in turn, necessitates a comprehensive understanding of degradation mechanisms. First, the effect of a well-known electrolyte additive, fluoroethylene carbonate is investigated in LNMO-Li4Ti5O12 (LTO) cells with a focus on the positive electrode. Relatively poor cycling performance is found with 5 wt% additive while 1 wt% additive does not show a significant difference as compared to additive-free electrolytes. Second, a more fundamental study is performed to understand the effect of capacity fading mechanisms contributing to overall cell failure in high-voltage based full-cells. Electrochemical characterization of LNMO-LTO cells in different configurations show how important the electrode interactions (cross-talk) can be for the overall cell behaviour. Unexpectedly fast capacity fading at elevated temperatures is found to originate from a high sensitivity of LTO to cross-talk.

    Third, in situ studies of LNMO are conducted with neutron diffraction and electron microscopy. These show that the oxygen release is not directly related to cation disordering. Moreover, microstructural changes upon heating are observed. These findings suggest new sample preparation strategies, which allow the control of cation disorder without oxygen loss. Following this guidance, ordered and disordered samples with the same oxygen content are prepared. The negative effect of ordering on electrochemical performance is investigated and changes in bulk electronic structure following cycling are found in ordered samples, accompanied by thick surface films on surface and rock-salt phase domains near surface.

    List of papers
    1. The Effect of the Fluoroethylene Carbonate Additive in LiNi0.5Mn1.5O4 - Li4Ti5O12 Lithium-Ion Cells
    Open this publication in new window or tab >>The Effect of the Fluoroethylene Carbonate Additive in LiNi0.5Mn1.5O4 - Li4Ti5O12 Lithium-Ion Cells
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    2017 (English)In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 164, no 4, p. A942-A948Article in journal (Refereed) Published
    Abstract [en]

    The effect of the electrolyte additive fluoroethylene carbonate (FEC) for Li-ion batteries has been widely discussed in literature in recent years. Here, the additive is studied for the high-voltage cathode LiNi0.5Mn1.5O4 (LNMO) coupled to Li4Ti5O12 (LTO) to specifically study its effect on the cathode side. Electrochemical performance of full cells prepared by using a standard electrolyte (LP40) with different concentrations of FEC (0, 1 and 5 wt%) were compared and the surface of cycled positive electrodes were analyzed by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The results show that addition of FEC is generally of limited use for this battery system. Addition of 5 wt% FEC results in relatively poor cycling performance, while the cells with 1 wt% FEC showed similar behavior compared to reference cells prepared without FEC. SEM and XPS analysis did not indicate the formation of thick surface layers on the LNMO cathode, however, an increase in layer thickness with increased FEC content in the electrolyte could be observed. XPS analysis on LTO electrodes showed that the electrode interactions between positive and negative electrodes occurred as Mn and Ni were detected on the surface of LTO already after 1 cycle. (C) The Author(s) 2017. Published by ECS. All rights reserved.

    Place, publisher, year, edition, pages
    ELECTROCHEMICAL SOC INC, 2017
    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:uu:diva-323509 (URN)10.1149/2.0231706jes (DOI)000400958600056 ()
    Available from: 2017-06-14 Created: 2017-06-14 Last updated: 2019-07-29Bibliographically approved
    2. Understanding the Capacity Loss in LiNi0.5Mn1.5O4-Li4Ti5O12 Lithium-Ion Cells at Ambient and Elevated Temperatures
    Open this publication in new window or tab >>Understanding the Capacity Loss in LiNi0.5Mn1.5O4-Li4Ti5O12 Lithium-Ion Cells at Ambient and Elevated Temperatures
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    2018 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 122, no 21, p. 11234-11248Article in journal (Refereed) Published
    Abstract [en]

    The high-voltage spinel LiNi0.5Mn1.5O4, (LNMO) is an attractive positive electrode because of its operating voltage around 4.7 V (vs Li/Li+) and high power capability. However, problems including electrolyte decomposition at high voltage and transition metal dissolution, especially at elevated temperatures, have limited its potential use in practical full cells. In this paper, a fundamental study for LNMO parallel to Li4Ti5O12 (LTO) full cells has been performed to understand the effect of different capacity fading mechanisms contributing to overall cell failure. Electrochemical characterization of cells in different configurations (regular full cells, back-to-back pseudo-full cells, and 3-electrode full cells) combined with an intermittent current interruption technique have been performed. Capacity fade in the full cell configuration was mainly due to progressively limited lithiation of electrodes caused by a more severe degree of parasitic reactions at the LTO electrode, while the contributions from active mass loss from LNMO or increases in internal cell resistance were minor. A comparison of cell formats constructed with and without the possibility of cross-talk indicates that the parasitic reactions on LTO occur because of the transfer of reaction products from the LNMO side. The efficiency of LTO is more sensitive to temperature, causing a dramatic increase in the fading rate at 55 degrees C. These observations show how important the electrode interactions (cross-talk) can be for the overall cell behavior. Additionally, internal resistance measurements showed that the positive electrode was mainly responsible for the increase of resistance over cycling, especially at 55 degrees C. Surface characterization showed that LNMO surface layers were relatively thin when compared with the solid electrolyte interphase (SEI) on LTO. The SEI on LTO does not contribute significantly to overall internal resistance even though these films are relatively thick. X-ray absorption near-edge spectroscopy measurements showed that the Mn and Ni observed on the anode were not in the metallic state; the presence of elemental metals in the SEI is therefore not implicated in the observed fading mechanism through a simple reduction process of migrated metal cations.

    Place, publisher, year, edition, pages
    American Chemical Society (ACS), 2018
    National Category
    Materials Chemistry
    Identifiers
    urn:nbn:se:uu:diva-357732 (URN)10.1021/acs.jpcc.8b02204 (DOI)000434236700007 ()
    Funder
    Swedish Energy Agency, 42031-1
    Available from: 2018-08-31 Created: 2018-08-31 Last updated: 2019-07-29Bibliographically approved
    3. Cation Ordering and Oxygen Release in LiNi0.5-xMn1.5+xO4-y (LNMO): In Situ Neutron Diffraction and Performance in Li Ion Full Cells
    Open this publication in new window or tab >>Cation Ordering and Oxygen Release in LiNi0.5-xMn1.5+xO4-y (LNMO): In Situ Neutron Diffraction and Performance in Li Ion Full Cells
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    2019 (English)In: ACS Applied Energy Materials, E-ISSN 2574-0962, Vol. 2, no 5, p. 3323-3335Article in journal (Refereed) Published
    Abstract [en]

    Lithium ion cells utilizing LiNi0.5Mn1.5O4 (LNMO) as the positive electrode are prone to fast capacity fading, especially when operated in full cells and at elevated temperatures. The crystal structure of LNMO can adopt a P4(3)32 (cation-ordered) or Fd (3) over barm (disordered) arrangement, and the fading rate of cells is usually mitigated when samples possess the latter structure. However, synthesis conditions leading to disordering also lead to oxygen deficiencies and rock-salt impurities and as a result generate Mn3+. In this study, in situ neutron diffraction was performed on disordered and slightly Mn-rich LNMO samples to follow cation ordering-disordering transformations during heating and cooling. The study shows for the first time that there is not a direct connection between oxygen release and cation disordering, as cation disordering is observed to start prior to oxygen release when the samples are heated in a pure oxygen atmosphere. This result demonstrates that it is possible to tune disordering in LNMO without inducing oxygen deficiencies or forming the rock-salt impurity phase. In the second part of the study, electrochemical testing of samples with different degrees of ordering and oxygen content has been performed in LNMO vertical bar vertical bar LTO (Li4Ti5O12) full cells. The disordered sample exhibits better performance, as has been reported in other studies; however, we observe that all cells behave similarly during the initial period of cycling even when discharged at a 10 C rate, while differences arise only after a period of cycling. Additionally, the differences in fading rate were observed to be time-dependent rather than dependent on the number of cycles. This performance degradation is believed to be related to instabilities in LNMO at higher voltages, that is, in its lower lithiation states. Therefore, it is suggested that future studies should target the individual effects of ordering and oxygen content. It is also suggested that more emphasis during electrochemical testing should be placed on the stability of samples in their delithiated state.

    Place, publisher, year, edition, pages
    AMER CHEMICAL SOC, 2019
    Keywords
    high-voltage spinel, neutron diffraction, LNMO, cation ordering, oxygen deficiency
    National Category
    Materials Chemistry
    Identifiers
    urn:nbn:se:uu:diva-387975 (URN)10.1021/acsaem.8b02217 (DOI)000469885300040 ()
    Funder
    Swedish Energy Agency, 42758-1Swedish Energy Agency, 39043-1StandUp
    Available from: 2019-06-27 Created: 2019-06-27 Last updated: 2020-12-15Bibliographically approved
    4. The role of anionic processes in Li1xNi0.44Mn1.56O4 studied by resonant inelastic X-ray scattering
    Open this publication in new window or tab >>The role of anionic processes in Li1xNi0.44Mn1.56O4 studied by resonant inelastic X-ray scattering
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    2023 (English)In: Energy Advances, E-ISSN 2753-1457, Vol. 2, no 3, p. 375-384Article in journal (Refereed) Published
    Abstract [en]

    We investigated the first lithiation cycle of the positive electrode material Li1−xNi0.44Mn1.56O4 (LNMO) using soft X-ray absorption spectroscopy (XAS) and resonant inelastic X-ray scattering (RIXS) at the transition metal L- and oxygen K-edges. Our XAS results show that charge compensation in LNMO takes place mostly within the Ni–O bonds, which is consistent with previous similar studies. O K- and Ni L-RIXS reveals how the holes that are created by removal of electrons during delithiation are distributed between the Ni- and O-ions. Non-trivial anionic activity is revealed by O K-RIXS features such as the appearance of low-energy intra-band excitations and re-hybridization with Ni 3d-states forming a new intense band close to the top of the oxygen valence band. At the same time, Ni L-RIXS compares more favorably with covalently than with ionically bonded Ni-oxide based compounds. Thus, a picture emerges where delithiation leads to a gradual transition of the ground state of LNMO from Ni 3d8 to one with non-negligible amounts of ligand holes, i.e. Ni 3d8−x 2−x (0 < x < 2, where stands for a ligand hole) instead of a highly ionic state e.g. Ni 3d6. Our observations highlight the importance of studying the anionic character of redox processes in lithium ion batteries.

    Place, publisher, year, edition, pages
    RSC Publishing, 2023
    National Category
    Materials Chemistry
    Identifiers
    urn:nbn:se:uu:diva-389847 (URN)10.1039/d2ya00321j (DOI)001105875900001 ()
    Funder
    Swedish Research Council, 2014-6019Swedish Research Council, 2016-03545Swedish Research Council, 2018-06465StandUpSwedish Energy Agency, 40495-1Swedish Energy Agency, 45518-1Swedish Energy Agency, 50745-1
    Available from: 2019-07-29 Created: 2019-07-29 Last updated: 2024-06-17Bibliographically approved
    5. How Mn/Ni ordering controls electrochemical performance in high-voltage spinel LiNi0.44Mn1.56O4 (LNMO) with fixed oxygen content
    Open this publication in new window or tab >>How Mn/Ni ordering controls electrochemical performance in high-voltage spinel LiNi0.44Mn1.56O4 (LNMO) with fixed oxygen content
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    (English)Manuscript (preprint) (Other academic)
    Keywords
    High voltage spinel, LNMO, cation ordering, oxygen deficiency, rock-salt, anionic redox activity
    National Category
    Materials Chemistry
    Identifiers
    urn:nbn:se:uu:diva-389799 (URN)
    Available from: 2019-07-28 Created: 2019-07-28 Last updated: 2019-08-13
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  • 19.
    Aktekin, Burak
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Brant, William
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Valvo, Mario
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Marzano, Fernanda
    Scania CV AB.
    Zipprich, Wolfgang
    Volkswagen AG.
    Brandell, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Cation Ordering and Oxygen Release in LiNi0.5-xMn1.5+xO4-y (LNMO)—In Situ Neutron Diffraction and Performance in Li-Ion Full Cells2018Conference paper (Refereed)
    Abstract [en]

    LiNi0.5Mn1.5O4 (LNMO) is a promising spinel-type positive electrode for lithium ion batteries as it operates at high voltage and possesses high power capability. However, rapid performance degradation in full cells, especially at elevated temperatures, is a problem. There has been a considerable interest in its crystal structure as this is known to affect its electrochemical performance. LNMO can adopt a P4332 (cation ordered) or Fd-3m (cation disordered) arrangement depending on the synthesis conditions. Most of the studies in literature agree on better electrochemical performance for disordered LNMO [1], however, a clear understanding of the reason for this behaviour is still lacking. This partly arises from the fact that synthesis conditions leading to disordering also lead to oxygen deficiency, rock-salt impurities and therefore generate some Mn3+ [2]. Most commonly, X-ray diffraction is used to characterize these materials, however, accurate structural analysis is difficult due to the near identical scattering lengths of Mn and Ni. This is not the case for neutron diffraction. In this study, an in-situ neutron diffraction heating-cooling experiment was conducted on slightly Mn-rich LNMO under pure oxygen atmosphere in order to investigate relationship between disordering and oxygen deficiency. The study shows for the first time that there is no direct relationship between oxygen loss and cation disordering, as disordering starts prior to oxygen release. Our findings suggest that it is possible to obtain samples with varying degrees of ordering, yet with the same oxygen content and free from impurities. In the second part of the study, highly ordered, partially ordered and fully disordered samples have been tested in LNMO∥LTO (Li4Ti5O12) full cells at 55 °C. It is shown that differences in their performances arise only after repeated cycling, while all the samples behave similarly at the beginning of the test. The difference is believed to be related to instabilities of LNMO at higher voltages, that is, in its lower lithiation states.

    [1] A. Manthiram, K. Chemelewski, E.-S. Lee, Energy Environ. Sci. 7 (2014) 1339.

    [2] M. Kunduraci, G.G. Amatucci, J. Power Sources. 165 (2007) 359–367.

  • 20.
    Aktekin, Burak
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Hernández, Guiomar
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Younesi, Reza
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Brandell, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Concentrated LiFSI-€“Ethylene Carbonate Electrolytes and Their Compatibility with High-Capacity and High-Voltage Electrodes2022In: ACS Applied Energy Materials, E-ISSN 2574-0962, Vol. 5, no 1, p. 585-595Article in journal (Refereed)
    Abstract [en]

    The unusual physical and chemical properties of electrolytes with excessive salt contents have resulted in rising interest in highly concentrated electrolytes, especially for their application in batteries. Here, we report strikingly good electrochemical performance in terms of conductivity and stability for a binary electrolyte system, consisting of lithium bis(fluorosulfonyl)imide (LiFSI) salt and ethylene carbonate (EC) solvent. The electrolyte is explored for different cell configurations spanning both high-capacity and high-voltage electrodes, which are well known for incompatibilities with conventional electrolyte systems: Li metal, Si/graphite composites, LiNi0.33Mn0.33Co0.33O2 (NMC111), and LiNi0.5Mn1.5O4 (LNMO). As compared to a LiTFSI counterpart as well as a common LP40 electrolyte, it is seen that the LiFSI:EC electrolyte system is superior in Li-metal–Si/graphite cells. Moreover, in the absence of Li metal, it is possible to use highly concentrated electrolytes (e.g., 1:2 salt:solvent molar ratio), and a considerable improvement on the electrochemical performance of NMC111-Si/graphite cells was achieved with the LiFSI:EC 1:2 electrolyte both at the room temperature and elevated temperature (55 °C). Surface characterization with scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) showed the presence of thicker surface film formation with the LiFSI-based electrolyte as compared to the reference electrolyte (LP40) for both positive and negative electrodes, indicating better passivation ability of such surface films during extended cycling. Despite displaying good stability with the NMC111 positive electrode, the LiFSI-based electrolyte showed less compatibility with the high-voltage spinel LNMO electrode (4.7 V vs Li+/Li).

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  • 21.
    Aktekin, Burak
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Lacey, Matthew J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Nordh, Tim
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Younesi, Reza
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Tengstedt, Carl
    Scania CV AB, SE-15187 Sodertalje, Sweden.
    Zipprich, Wolfgang
    Volkswagen AG, D-38436 Wolfsburg, Germany.
    Brandell, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Understanding the Capacity Loss in LiNi0.5Mn1.5O4-Li4Ti5O12 Lithium-Ion Cells at Ambient and Elevated Temperatures2018In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 122, no 21, p. 11234-11248Article in journal (Refereed)
    Abstract [en]

    The high-voltage spinel LiNi0.5Mn1.5O4, (LNMO) is an attractive positive electrode because of its operating voltage around 4.7 V (vs Li/Li+) and high power capability. However, problems including electrolyte decomposition at high voltage and transition metal dissolution, especially at elevated temperatures, have limited its potential use in practical full cells. In this paper, a fundamental study for LNMO parallel to Li4Ti5O12 (LTO) full cells has been performed to understand the effect of different capacity fading mechanisms contributing to overall cell failure. Electrochemical characterization of cells in different configurations (regular full cells, back-to-back pseudo-full cells, and 3-electrode full cells) combined with an intermittent current interruption technique have been performed. Capacity fade in the full cell configuration was mainly due to progressively limited lithiation of electrodes caused by a more severe degree of parasitic reactions at the LTO electrode, while the contributions from active mass loss from LNMO or increases in internal cell resistance were minor. A comparison of cell formats constructed with and without the possibility of cross-talk indicates that the parasitic reactions on LTO occur because of the transfer of reaction products from the LNMO side. The efficiency of LTO is more sensitive to temperature, causing a dramatic increase in the fading rate at 55 degrees C. These observations show how important the electrode interactions (cross-talk) can be for the overall cell behavior. Additionally, internal resistance measurements showed that the positive electrode was mainly responsible for the increase of resistance over cycling, especially at 55 degrees C. Surface characterization showed that LNMO surface layers were relatively thin when compared with the solid electrolyte interphase (SEI) on LTO. The SEI on LTO does not contribute significantly to overall internal resistance even though these films are relatively thick. X-ray absorption near-edge spectroscopy measurements showed that the Mn and Ni observed on the anode were not in the metallic state; the presence of elemental metals in the SEI is therefore not implicated in the observed fading mechanism through a simple reduction process of migrated metal cations.

  • 22.
    Aktekin, Burak
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Lacey, Matthew
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Nordh, Tim
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Tengstedt, Carl
    Scania CV AB.
    Brandell, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Understanding the Rapid Capacity Fading of LNMO-LTO Lithium-ion Cells at Elevated Temperature2017Conference paper (Other academic)
    Abstract [en]

    The high voltage spinel LiNi0.5Mn1.5O4 (LNMO) has an average operating potential around 4.7 V vs. Li/Li+ and a gravimetric charge capacity of 146 mAh/g making it a promising high energy density positive electrode for Li-ion batteries. Additionally, the 3-D lithium transport paths available in the spinel structure enables fast diffusion kinetics, making it suitable for power applications [1]. However, the material displays large instability during cycling, especially at elevated temperatures. Therefore, significant research efforts have been undertaken to better understand and improve this electrode material.

    Electrolyte (LiPF6 in organic solvents) oxidation and transition metal dissolution are often considered as the main problems [2] for the systems based on this cathode material. These can cause a variety of problems (in different parts of the cell) eventually increasing internal cell resistance, causing active mass loss and decreasing the amount of cyclable lithium.

    Among these issues, cyclable lithium loss cannot be observed in half cells since lithium metal will provide almost unlimited capacity. Being a promising full cell chemistry for high power applications, there has also been a considerable interest on LNMO full cells with Li4Ti5O12 (LTO) used as the negative electrode. For this chemistry, for an optimized cell, quite stable cycling for >1000 cycles has been reported at room temperature while fast fading is still present at 55 °C [3]. This difference in performance (RT vs. 55 °C) is beyond most expectations and likely does not follow any Arrhenius-type of trend.

    In this study, a comprehensive analysis of LNMO-LTO cells has been performed at different temperatures (RT, 40 °C and 55 °C) to understand the underlying reasons behind stable cycling at room temperature and rapid fading at 55 °C. For this purpose, testing was made on regular cells (Figure 1a), 3-electrode cells (Figure 1b) and back-to-back cells [4] (Figure 1c). Electrode interactions (cross-talk) have been shown to exist in the LTO-LNMO system [5] and back-to-back cells have therefore been used to observe fading under conditions where cross-talk is impossible [4]. Galvanostatic cycling combined with short-duration intermittent current interruptions [6] was performed in order to separately observe changes in internal resistance for LNMO and LTO electrodes in a full cell. Ex-situ characterization of electrodes have also been performed using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge spectroscopy (XANES).

    Our findings show how important the electrode interactions can be in full cells, as a decrease in lithium inventory was shown to be the major factor for the observed capacity fading at elevated temperature. In this presentation, the effect of other factors – active mass loss and internal cell resistance – will be discussed together with the consequences of cross-talk.

    References

    [1] A. Kraytsberg et al. Adv. Energy Mater., vol. 2, pp. 922–939,2012.

    [2] J. H. Kim et al., ChemPhysChem, vol. 15, pp. 1940–1954, 2014.

    [3] H. M. Wu et al. J. E. Soc., vol. 156, pp. A1047–A1050, 2009.

    [4] S. R. Li et al., J. E. Soc., vol. 160, no. 9, pp. A1524–A1528, 2013.

    [5] Dedryvère et al. J. Phys. C., vol. 114 (24), pp. 10999–11008, 2010.

    [6] M. J. Lacey, ChemElectroChem, pp. 1–9, 2017.

  • 23.
    Aktekin, Burak
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Lacey, Matthew
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Nordh, Tim
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Younesi, Reza
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Tengstedt, Carl
    Scania CV AB.
    Zipprich, Wolfgang
    Volkswagen AG.
    Brandell, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Understanding the Capacity Loss in LiNi0.5Mn1.5O4 - Li4Ti5O12 Lithium-Ion Cells at Ambient and Elevated Temperatures2017Conference paper (Refereed)
    Abstract [en]

    The high voltage spinel LiNi0.5Mn1.5O(LNMO) is an attractive positive electrode due to its operating voltage around 4.7 V (vs. Li/Li+) arising from the Ni2+/Ni4+ redox couple. In addition to high voltage operation, a second advantage of this material is its capability for fast lithium diffusion kinetics through 3-D transport paths in the spinel structure. However, the electrode material is prone to side reactions with conventional electrolytes, including electrolyte decomposition and transition metal dissolution, especially at elevated temperatures1. It is important to understand how undesired reactions originating from the high voltage spinel affect the aging of different cell components and overall cycle life. Half-cells are usually considered as an ideal cell configuration in order to get information only from the electrode of interest. However, this cell configuration may not be ideal to understand capacity fading for long-term cycling and the assumption of ‘stable’ lithium negative electrode may not be valid, especially at high current rates2. Also, among the variety of capacity fading mechanisms, the loss of “cyclable” lithium from the positive electrode (or gain of lithium from electrolyte into the negative electrode) due to side reactions in a full-cell can cause significant capacity loss. This capacity loss is not observable in a typical half-cell as a result of an excessive reserve of lithium in the negative electrode.

    In a full-cell, it is desired that the negative electrode does not contribute to side reactions in a significant way if the interest is more on the positive side. Among candidates on the negative side, Li4Ti5O12 (LTO) is known for its stability since its voltage plateau (around 1.5 V vs. Li/Li+) is in the electrochemical stability window of standard electrolytes and it shows a very small volume change during lithiation. These characteristics make the LNMO-LTO system attractive for a variety of applications (e.g. electric vehicles) but also make it a good model system for studying aging in high voltage spinel-based full cells.

    In this study, we aim to understand the fundamental mechanisms resulting in capacity fading for LNMO-LTO full cells both at room temperature and elevated temperature (55°C). It is known that electrode interactions occur in this system due to migration of reaction products from LNMO to the LTO side3, 4. For this purpose, three electrode cells have been cycled galvanostatically with short-duration intermittent current interruptionsin order to observe internal resistance for both LNMO and LTO electrodes in a full cell, separately. Change of voltage curves over cycling has also been observed to get an insight into capacity loss. For comparison purposes, back-to-back cells (a combination of LNMO and LTO cells connected electrically by lithium sides) were also tested similarly. Post-cycling of harvested electrodes in half cells was conducted to determine the degree of capacity loss due to charge slippage compared to other aging factors. Surface characterization of LNMO as well as LTO electrodes after cycling at room temperature and elevated temperature has been done via SEM, XPS, HAXPES and XANES.

    References

    1. A. Kraytsberg, Y. Ein-Eli, Adv. Energy Mater., vol. 2, pp. 922–939, 2012.

    2. Aurbach, D., Zinigrad, E., Cohen, Y., & Teller, H. Solid State Ionics, 148(3), 405-416, 2002.

    3. Li et al., Journal of The Electrochemical Society, 160 (9) A1524-A1528, 2013.

    4. Aktekin et al., Journal of The Electrochemical Society 164.4: A942-A948. 2017.

    5. Lacey, M. J., ChemElectroChem. Accepted Author Manuscript. doi:10.1002/celc.201700129, 2017. 

  • 24.
    Aktekin, Burak
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Lacey, Matthew
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Nordh, Tim
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Younesi, Reza
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Tengstedt, Carl
    Scania CV AB.
    Zipprich, Wolfgang
    Volkswagen.
    Brandell, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Understanding the capacity loss in LNMO-LTO lithium-ion cells at ambient and elevated temperaturesManuscript (preprint) (Other academic)
    Abstract
  • 25.
    Aktekin, Burak
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Massel, Felix
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Ahmadi, Majid
    Delft University of Technology, Kavli Institute of Nanoscience, Faculty of Applied Sciences.
    Valvo, Mario
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Hahlin, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Zipprich, Wolfgang
    Volkswagen AG.
    Marzano, Fernanda
    Scania CV AB.
    Duda, Laurent
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Younesi, Reza
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Brandell, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    How Mn/Ni ordering controls electrochemical performance in high-voltage spinel LiNi0.44Mn1.56O4 (LNMO) with fixed oxygen contentManuscript (preprint) (Other academic)
  • 26.
    Aktekin, Burak
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Massel, Felix
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Ahmadi, Majid
    Delft Univ Technol, Fac Appl Sci, Kavli Inst Nanosci, NL-2628 CJ Delft, Netherlands..
    Valvo, Mario
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Hahlin, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Zipprich, Wolfgang
    Volkswagen AG, D-38436 Wolfsburg, Germany..
    Marzano, Fernanda
    Scania CV AB, SE-15187 Sodertalje, Sweden..
    Duda, Laurent
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Younesi, Reza
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Brandell, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    How Mn/Ni Ordering Controls Electrochemical Performance in High-Voltage Spinel LiNi0.44Mn1.56O4 with Fixed Oxygen Content2020In: ACS Applied Energy Materials, E-ISSN 2574-0962, Vol. 3, no 6, p. 6001-6013Article in journal (Refereed)
    Abstract [en]

    The crystal structure of LiNi0.5O4 (LNMO) can adopt either low-symmetry ordered (Fd (3) over barm) or high-symmetry disordered (P4(3)32) space group depending on the synthesis conditions. A majority of published studies agree on superior electrochemical performance of disordered LNMO, but the underlying reasons for improvement remain unclear due to the fact that different thermal history of the samples affects other material properties such as oxygen content and particle morphology. In this study, ordered and disordered samples were prepared with a new strategy that renders samples with identical properties apart from their cation ordering degree. This was achieved by heat treatment of powders under pure oxygen atmosphere at high temperature with a final annealing step at 710 degrees C for both samples, followed by slow or fast cooling. Electrochemical testing showed that cation disordering improves the stability of material in charged (delithiated) state and mitigates the impedance rise in LNMO parallel to LTO (Li4Ti5O12) and LNMO parallel to Li cells. Through X-ray photoelectron spectroscopy (XPS), thicker surface films were observed on the ordered material, indicating more electrolyte side reactions. The ordered samples also showed significant changes in the Ni 2p XPS spectra, while the generation of ligand (oxygen) holes was observed in the Ni-O environment for both samples using X-ray absorption spectroscopy (XAS) and resonant inelastic X-ray scattering (RIXS). Moreover, high-resolution transmission electron microscopy (HRTEM) images indicated that the ordered samples show a decrease in ordering near the particle surface after cycling and a tendency toward rock-salt-like phase transformations. These results show that the structural arrangement of Mn/Ni (alone) has an effect on the surface and "nearsurface" properties of LNMO, particularly in delithiated state, which is likely connected to the bulk electronic properties of this electrode material.

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  • 27.
    Aktekin, Burak
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Valvo, Mario
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Smith, Ronald I.
    Rutherford Appleton Lab, ISIS Pulsed Neutron & Muon Source, Harwell Campus, Didcot OX11 0QX, Oxon, England.
    Sörby, Magnus H.
    Inst Energy Technol, Dept Neutron Mat Characterizat, POB 40, NO-2027 Kjeller, Norway.
    Marzano, Fernanda Lodi
    Scania CV AB, SE-15187 Sodertalje, Sweden.
    Zipprich, Wolfgang
    Volkswagen AG, D-38436 Wolfsburg, Germany.
    Brandell, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Brant, William
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Cation Ordering and Oxygen Release in LiNi0.5-xMn1.5+xO4-y (LNMO): In Situ Neutron Diffraction and Performance in Li Ion Full Cells2019In: ACS Applied Energy Materials, E-ISSN 2574-0962, Vol. 2, no 5, p. 3323-3335Article in journal (Refereed)
    Abstract [en]

    Lithium ion cells utilizing LiNi0.5Mn1.5O4 (LNMO) as the positive electrode are prone to fast capacity fading, especially when operated in full cells and at elevated temperatures. The crystal structure of LNMO can adopt a P4(3)32 (cation-ordered) or Fd (3) over barm (disordered) arrangement, and the fading rate of cells is usually mitigated when samples possess the latter structure. However, synthesis conditions leading to disordering also lead to oxygen deficiencies and rock-salt impurities and as a result generate Mn3+. In this study, in situ neutron diffraction was performed on disordered and slightly Mn-rich LNMO samples to follow cation ordering-disordering transformations during heating and cooling. The study shows for the first time that there is not a direct connection between oxygen release and cation disordering, as cation disordering is observed to start prior to oxygen release when the samples are heated in a pure oxygen atmosphere. This result demonstrates that it is possible to tune disordering in LNMO without inducing oxygen deficiencies or forming the rock-salt impurity phase. In the second part of the study, electrochemical testing of samples with different degrees of ordering and oxygen content has been performed in LNMO vertical bar vertical bar LTO (Li4Ti5O12) full cells. The disordered sample exhibits better performance, as has been reported in other studies; however, we observe that all cells behave similarly during the initial period of cycling even when discharged at a 10 C rate, while differences arise only after a period of cycling. Additionally, the differences in fading rate were observed to be time-dependent rather than dependent on the number of cycles. This performance degradation is believed to be related to instabilities in LNMO at higher voltages, that is, in its lower lithiation states. Therefore, it is suggested that future studies should target the individual effects of ordering and oxygen content. It is also suggested that more emphasis during electrochemical testing should be placed on the stability of samples in their delithiated state.

  • 28.
    Aktekin, Burak
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Younesi, Reza
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Zipprich, Wolfgang
    Volkswagen AG, Wolfsburg, Germany..
    Tengstedt, Carl
    Scania CV AB, Södertalje..
    Brandell, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    The Effect of the Fluoroethylene Carbonate Additive in LiNi0.5Mn1.5O4 - Li4Ti5O12 Lithium-Ion Cells2017In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 164, no 4, p. A942-A948Article in journal (Refereed)
    Abstract [en]

    The effect of the electrolyte additive fluoroethylene carbonate (FEC) for Li-ion batteries has been widely discussed in literature in recent years. Here, the additive is studied for the high-voltage cathode LiNi0.5Mn1.5O4 (LNMO) coupled to Li4Ti5O12 (LTO) to specifically study its effect on the cathode side. Electrochemical performance of full cells prepared by using a standard electrolyte (LP40) with different concentrations of FEC (0, 1 and 5 wt%) were compared and the surface of cycled positive electrodes were analyzed by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The results show that addition of FEC is generally of limited use for this battery system. Addition of 5 wt% FEC results in relatively poor cycling performance, while the cells with 1 wt% FEC showed similar behavior compared to reference cells prepared without FEC. SEM and XPS analysis did not indicate the formation of thick surface layers on the LNMO cathode, however, an increase in layer thickness with increased FEC content in the electrolyte could be observed. XPS analysis on LTO electrodes showed that the electrode interactions between positive and negative electrodes occurred as Mn and Ni were detected on the surface of LTO already after 1 cycle. (C) The Author(s) 2017. Published by ECS. All rights reserved.

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  • 29.
    Alcantara, Ricardo
    et al.
    Univ Cordoba, Dept Quim Inorgan Ingn Quim, Inst Quim Energia & Medioambiente IQEMA, Campus Rabanales,Edificio Marie Curie, E-14071 Cordoba, Spain..
    Lavela, Pedro
    Univ Cordoba, Dept Quim Inorgan Ingn Quim, Inst Quim Energia & Medioambiente IQEMA, Campus Rabanales,Edificio Marie Curie, E-14071 Cordoba, Spain..
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Fichtner, Maximilian
    Karlsruhe Inst Technol, Inst Nanotechnol, Hermann von Helmholtz Pl 1, D-76344 Eggenstein Leopoldshafen, Germany.;Helmholtz Inst Ulm HIU Electrochem Energy Storage, Helmholtzstr 11, D-89081 Ulm, Germany..
    Le, Top Khac
    Univ Sci, Fac Mat Sci & Technol, Ho Chi Minh City 700000, Vietnam.;Vietnam Natl Univ, Ho Chi Minh City 700000, Vietnam..
    Floraki, Christina
    Hellen Mediterranean Univ, Sch Engn, Dept Elect & Comp Engn, Iraklion 71410, Greece..
    Aivaliotis, Dimitris
    Hellen Mediterranean Univ, Sch Engn, Dept Elect & Comp Engn, Iraklion 71410, Greece..
    Vernardou, Dimitra
    Hellen Mediterranean Univ, Sch Engn, Dept Elect & Comp Engn, Iraklion 71410, Greece.;Hellen Mediterranean Univ Ctr, Inst Emerging Technol, Iraklion 71410, Greece..
    Metal-Ion Intercalation Mechanisms in Vanadium Pentoxide and Its New Perspectives2023In: Nanomaterials, E-ISSN 2079-4991, Vol. 13, no 24, article id 3149Article, review/survey (Refereed)
    Abstract [en]

    The investigation into intercalation mechanisms in vanadium pentoxide has garnered significant attention within the realm of research, primarily propelled by its remarkable theoretical capacity for energy storage. This comprehensive review delves into the latest advancements that have enriched our understanding of these intricate mechanisms. Notwithstanding its exceptional storage capacity, the compound grapples with challenges arising from inherent structural instability. Researchers are actively exploring avenues for improving electrodes, with a focus on innovative structures and the meticulous fine-tuning of particle properties. Within the scope of this review, we engage in a detailed discussion on the mechanistic intricacies involved in ion intercalation within the framework of vanadium pentoxide. Additionally, we explore recent breakthroughs in understanding its intercalation properties, aiming to refine the material's structure and morphology. These refinements are anticipated to pave the way for significantly enhanced performance in various energy storage applications.

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    FULLTEXT01
  • 30.
    Alipour, Mohammad
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Tavallaey, Shiva Sander
    ABB AB Corp Res, Forskargrand 7, SE-72178 Västerås, Sweden.;Sch Sci KTH, Dept Mech, SE-10044 Stockholm, Sweden..
    Andersson, Anna M.
    ABB AB Corp Res, Forskargrand 7, SE-72178 Västerås, Sweden..
    Brandell, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Improved Battery Cycle Life Prediction Using a Hybrid Data-Driven Model Incorporating Linear Support Vector Regression and Gaussian2022In: ChemPhysChem, ISSN 1439-4235, E-ISSN 1439-7641, Vol. 23, no 7, article id e202100829Article in journal (Refereed)
    Abstract [en]

    The ability to accurately predict lithium-ion battery life-time already at an early stage of battery usage is critical for ensuring safe operation, accelerating technology development, and enabling battery second-life applications. Many models are unable to effectively predict battery life-time at early cycles due to the complex and nonlinear degrading behavior of lithium-ion batteries. In this study, two hybrid data-driven models, incorporating a traditional linear support vector regression (LSVR) and a Gaussian process regression (GPR), were developed to estimate battery life-time at an early stage, before more severe capacity fading, utilizing a data set of 124 battery cells with lifetimes ranging from 150 to 2300 cycles. Two type of hybrid models, here denoted as A and B, were proposed. For each of the models, we achieved 1.1 % (A) and 1.4 % (B) training error, and similarly, 8.3 % (A) and 8.2 % (B) test error. The two key advantages are that the error percentage is kept below 10 % and that very low error values for the training and test sets were observed when utilizing data from only the first 100 cycles.The proposed method thus appears highly promising for predicting battery life during early cycles.

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    fulltext
  • 31.
    Alipour, Mohammad
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Yin, Litao
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Tavallaey, Shiva Sander
    ABB AB Corp Res, Forskargrand 7, SE-72178 Västerås, Sweden.;KTH, Dept Mech, Sch Sci, SE-10044 Stockholm, Sweden..
    Andersson, Anna Mikaela
    ABB AB Corp Res, Forskargrand 7, SE-72178 Västerås, Sweden..
    Brandell, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    A surrogate-assisted uncertainty quantification and sensitivity analysis on a coupled electrochemical-thermal battery aging model2023In: Journal of Power Sources, ISSN 0378-7753, E-ISSN 1873-2755, Vol. 579, article id 233273Article in journal (Refereed)
    Abstract [en]

    High-fidelity physics-based models are required to comprehend battery behavior at various operating condi-tions. This paper proposes an uncertainty quantification analysis on a coupled electrochemical-thermal aging model to improve the reliability of a battery model, while also investigating the impact of parametric model uncertainties on battery voltage, temperature, and aging. The coupled model's high computing cost, however, is a significant barrier to perform uncertainty quantification (UQ) and sensitivity analysis (SA). To address this problem, a surrogate model - i.e, by simulating the outcome of a quantity of interest that cannot be easily computed or measured - based on the Gaussian process regression (GPR) theory and principle component analysis (PCA) is built, using a small collection of finite element simulation results as synthetic training data. In total, 43 variable electrochemical-thermal parameters as well as 13 variable aging parameters are studied and estimated. Moreover, the trained surrogate model is also used in the parameterization of the electrochemical and thermal models. The results show that the uncertainties in the input parameters significantly affect the estimations of battery voltage, temperature, and aging. Based on this sensitivity analysis, the most influential parameters affecting the above mentioned battery outputs are reported. This approach is thereby helpful for developing robust and reliable high-fidelity battery aging models with potential applications in digital twins as well as for synthetic data generation.

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  • 32.
    Alvi, Muhammad Rouf
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Physical Organic Chemistry.
    Jahn, Burkhard O.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Tibbelin, Julius
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Baumgartner, Judith
    Institut für Anorganische Chemie, Technische Universität Graz, Stremayrgasse 9, A-8010 Graz, Austria.
    Gómez, Cesar Pay
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Ottosson, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Physical Organic Chemistry.
    Highly Efficient and Convenient Acid Catalyzed Hypersilyl Protection of Alcohols and Thiols by Tris(trimethylsilyl)silyl-N,N-dimethylmethaneamide2012Manuscript (preprint) (Other academic)
    Abstract [en]

    Tris(trimethylsilyl)silyl-N,N-dimethylmethaneamide, herein named hypersilylamide, is a convenient and efficient source of the hypersilyl group in the first widely applicable acid catalyzed protocol for silyl group protection of primary, secondary, tertiary alkyl as well as aryl alcohols and thiols in high yields. The sole by-product is N,N-dimethylformamide (DMF) and a range of solvents can be used, including DMF. A high selectivity in the protection of diols can be achieved, also for diols with very small differences in the steric demands at the two hydroxyl groups. Moreover, in the protection of equivalent alcohol and thiol sites the protection of the alcohol is faster, allowing for selective protection in high yields. Quantum chemical calculations at the M062X hybrid meta density functional theory level give insights on the mechanism for the catalytic process. Finally, the hypersilyl group is easily removed from all protected alcohols and thiols examined herein by irradiation at 254 nm.

  • 33.
    Amici, Julia
    et al.
    Politecn Torino, DISAT Dept Appl Sci & Technol, Corso Duca Abruzzi, 24, I-10129 Turin, Italy..
    Asinari, Pietro
    Politecn Torino, Dept Energy, Corso Duca Abruzzi, 24, I-10129 Turin, Italy.;Ist Nazl Ric Metrol INRiM, Str Cacce 91, I-10135 Turin, Italy..
    Ayerbe, Elixabete
    Basque Res & Technol Alliance BRTA, CIDETEC, Paseo Miramon 196, Donostia San Sebastian 20014, Spain..
    Barboux, Philippe
    PSL Res Univ, Chim ParisTech, CNRS, Inst Rech Chim Paris IRCP, F-75005 Paris, France..
    Bayle-Guillemaud, Pascale
    Univ Grenoble Alpes, CEA, CNRS, IRIG SyMMES, F-38000 Grenoble, France..
    Behm, R. Juergen
    Ulm Univ, Inst Theoret Chem, Albert Einstein Allee 11, D-89081 Ulm, Germany..
    Berecibar, Maitane
    Vrije Universiteit Brussel, MOBI Mobil Logist & Automot Technol Res Ctr, Pleinlaan 2, B-1050 Brussels, Belgium..
    Berg, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Bhowmik, Arghya
    Tech Univ Denmark, Dept Energy Convers & Storage, Anker Engelundvej Bldg 301, DK-2800 Lyngby, Denmark..
    Bodoardo, Silvia
    Politecn Torino, DISAT Dept Appl Sci & Technol, Corso Duca Abruzzi, 24, I-10129 Turin, Italy..
    Castelli, Ivano E.
    Tech Univ Denmark, Dept Energy Convers & Storage, Anker Engelundvej Bldg 301, DK-2800 Lyngby, Denmark..
    Cekic-Laskovic, Isidora
    Forschungszentrum Julich, Helmholtz Inst Munster HI MS IEK12, Correns Str 46, North Rhine Westphalia, D-48149 Munster, Germany..
    Christensen, Rune
    Tech Univ Denmark, Dept Energy Convers & Storage, Anker Engelundvej Bldg 301, DK-2800 Lyngby, Denmark..
    Clark, Simon
    SINTEF Ind, New Energy Solut, Sem Saelands Vei 12, N-7034 Trondheim, Norway..
    Diehm, Ralf
    Karlsruhe Inst Technol KIT, Inst Thermal Proc Engn, Thin Film Technol, Kaiser Str 12, D-76131 Karlsruhe, Germany..
    Dominko, Robert
    Federat Rech CNRS 3104, ALISTORE European Res Inst, Hub Energie,15 Rue Baudelocque, F-80039 Amiens, France.;Helmholtz Inst Ulm HIU, Elctrochm Energy Storage, Helmholtz Str 11, D-89081 Ulm, Germany..
    Fichtner, Maximilian
    Helmholtz Inst Ulm HIU, Elctrochm Energy Storage, Helmholtz Str 11, D-89081 Ulm, Germany..
    Franco, Alejandro A.
    Federat Rech CNRS 3104, ALISTORE European Res Inst, Hub Energie,15 Rue Baudelocque, F-80039 Amiens, France.;Univ Picardie Jules Verne, Lab React Chim Solides LRCS, CNRS UMR 7314, Hub Energie,15 Rue Baudelocque, F-80039 Amiens, France.;Fed Rech CNRS 3459, Reseau Stockage Electrochim Energie RS2E, Hub Energie,15 Rue Baudelocque, F-80039 Amiens, France..
    Grimaud, Alexis
    Fed Rech CNRS 3459, Reseau Stockage Electrochim Energie RS2E, Hub Energie,15 Rue Baudelocque, F-80039 Amiens, France.;Coll France, Chim Solide Energie, UMR 8260, F-75231 Paris 5, France..
    Guillet, Nicolas
    Univ Grenoble Alpes, Liten, CEA, Ines Campus, F-73375 Le Bourget Du Lac, France..
    Hahlin, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Hartmann, Sarah
    Univ Grenoble Alpes, Leti, CEA, F-38000 Grenoble, France..
    Heiries, Vincent
    Fraunhofer Inst Silicate Res ISC, Neunerplatz 2, D-97082 Wurzburg, Germany..
    Hermansson, Kersti
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Heuer, Andreas
    Forschungszentrum Julich, Helmholtz Inst Munster HI MS IEK12, Correns Str 46, North Rhine Westphalia, D-48149 Munster, Germany.;Univ Munster, Inst Phys Chem, D-48149 Munster, Germany..
    Jana, Saibal
    Karlsruhe Inst Technol, Inst Nanotechnol, Hermann Helmholtz Platz 1, D-76344 Eggenstein Leopoldshafen, Germany..
    Jabbour, Lara
    Univ Grenoble Alpes, Liten, CEA, F-38000 Grenoble, France..
    Kallo, Josef
    Ulm Univ, Inst Energy Convers & Storage, Albert Einstein Allee 47, D-89081 Ulm, Germany..
    Latz, Arnulf
    Helmholtz Inst Ulm HIU, Elctrochm Energy Storage, Helmholtz Str 11, D-89081 Ulm, Germany.;German Aerosp Ctr, Pfaffenwaldring 38-40, D-70569 Stuttgart, Germany.;Ulm Univ, Albert Einstein Allee 47, D-89081 Ulm, Germany..
    Lorrmann, Henning
    Fraunhofer Inst Silicate Res ISC, Neunerplatz 2, D-97082 Wurzburg, Germany..
    Lovvik, Ole Martin
    SINTEF Ind, Sustainable Energy Technol, Forskningsveien 1, N-0314 Oslo, Norway..
    Lyonnard, Sandrine
    Univ Grenoble Alpes, CEA, CNRS, IRIG SyMMES, F-38000 Grenoble, France..
    Meeus, Marcel
    EMIRI, Rue Ransbeek, 310, B-1120 Brussels, Belgium..
    Paillard, Elie
    Politecn Milan, Dept Energy, Via Lambruschini 4, I-20156 Milan, Italy..
    Perraud, Simon
    Univ Grenoble Alpes, Liten, CEA, F-38000 Grenoble, France..
    Placke, Tobias
    Univ Munster, Inst Phys Chem, MEET Battery Res Ctr, Correns Str 46, D-48149 Munster, Germany..
    Punckt, Christian
    Helmholtz Inst Ulm HIU, Elctrochm Energy Storage, Helmholtz Str 11, D-89081 Ulm, Germany..
    Raccurt, Olivier
    Univ Grenoble Alpes, Liten, CEA, F-38000 Grenoble, France..
    Ruhland, Janna
    Karlsruher Inst Technol, Inst Prod Sci, Kaiser Str 12, D-76131 Karlsruhe, Germany..
    Sheridan, Edel
    SINTEF Energy, Elect Power Technol, Sem Saelands Vei 11, N-7034 Trondheim, Norway..
    Stein, Helge
    Helmholtz Inst Ulm HIU, Elctrochm Energy Storage, Helmholtz Str 11, D-89081 Ulm, Germany..
    Tarascon, Jean-Marie
    Fed Rech CNRS 3459, Reseau Stockage Electrochim Energie RS2E, Hub Energie,15 Rue Baudelocque, F-80039 Amiens, France.;Coll France, Chim Solide Energie, UMR 8260, F-75231 Paris 5, France..
    Trapp, Victor
    Fraunhofer Inst Silicate Res ISC, Neunerplatz 2, D-97082 Wurzburg, Germany..
    Vegge, Tejs
    Tech Univ Denmark, Dept Energy Convers & Storage, Anker Engelundvej Bldg 301, DK-2800 Lyngby, Denmark.;Federat Rech CNRS 3104, ALISTORE European Res Inst, Hub Energie,15 Rue Baudelocque, F-80039 Amiens, France..
    Weil, Marcel
    Helmholtz Inst Ulm HIU, Elctrochm Energy Storage, Helmholtz Str 11, D-89081 Ulm, Germany.;Karlsruher Inst Technol, Inst Technol Assessment & Syst Anal, Hermann Helmholtz Platz 1, D-76344 Eggenstein Leopoldshafen, Germany..
    Wenzel, Wolfgang
    Karlsruhe Inst Technol, Inst Nanotechnol, Hermann Helmholtz Platz 1, D-76344 Eggenstein Leopoldshafen, Germany..
    Winter, Martin
    Forschungszentrum Julich, Helmholtz Inst Munster HI MS IEK12, Correns Str 46, North Rhine Westphalia, D-48149 Munster, Germany.;Univ Munster, Inst Phys Chem, MEET Battery Res Ctr, Correns Str 46, D-48149 Munster, Germany..
    Wolf, Andreas
    Fraunhofer Inst Silicate Res ISC, Neunerplatz 2, D-97082 Wurzburg, Germany.;Friedrich Alexander Univ Nurnberg Erlangen FAU, Egerland Str 1, D-91058 Erlangen, Germany..
    Edström, Kristina
    Vrije Universiteit Brussel, MOBI Mobil Logist & Automot Technol Res Ctr, Pleinlaan 2, B-1050 Brussels, Belgium.;Univ Ljubljana, Natl Inst Chem, Fac Chem & Chem Technol, Ljubljana 1000, Slovenia..
    A Roadmap for Transforming Research to Invent the Batteries of the Future Designed within the European Large Scale Research Initiative BATTERY 2030+2022In: Advanced Energy Materials, ISSN 1614-6832, E-ISSN 1614-6840, Vol. 12, no 17, article id 2102785Article, review/survey (Refereed)
    Abstract [en]

    This roadmap presents the transformational research ideas proposed by "BATTERY 2030+," the European large-scale research initiative for future battery chemistries. A "chemistry-neutral" roadmap to advance battery research, particularly at low technology readiness levels, is outlined, with a time horizon of more than ten years. The roadmap is centered around six themes: 1) accelerated materials discovery platform, 2) battery interface genome, with the integration of smart functionalities such as 3) sensing and 4) self-healing processes. Beyond chemistry related aspects also include crosscutting research regarding 5) manufacturability and 6) recyclability. This roadmap should be seen as an enabling complement to the global battery roadmaps which focus on expected ultrahigh battery performance, especially for the future of transport. Batteries are used in many applications and are considered to be one technology necessary to reach the climate goals. Currently the market is dominated by lithium-ion batteries, which perform well, but despite new generations coming in the near future, they will soon approach their performance limits. Without major breakthroughs, battery performance and production requirements will not be sufficient to enable the building of a climate-neutral society. Through this "chemistry neutral" approach a generic toolbox transforming the way batteries are developed, designed and manufactured, will be created.

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  • 34.
    Ammothum Kandy, Akshay Krishna
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Linear models for multiscale materials simulations: Towards a seamless linking of electronic and atomistic models for complex metal oxides2021Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Multiscale modelling approaches, connecting data from electronic structure calculations all the way towards engineering continuum models, have become an important ingredient in modern materials science. Materials modelling in a broader sense is already amply used to address complex chemical problems in academic science, but also in many industrial sectors. As far as multiscale modelling is concerned, however, many challenges remain, in particular when it comes to coupling and linking the various levels along the multiscale ladder in a seamless and efficient fashion.        

    This thesis focusses on the development of new and efficient linear models to improve the quality and parameterisation processes of the two-body potentials used in empirical and semi-empirical methods within a multiscale materials modelling framework. In this regard, a machinery called curvature constrained splines (CCS) based on cubic splines to approximate general two-body potentials has been developed. The method is linear, and parameters can be easily solved in a least-square sense using a quadratic programming approach. Moreover, the objective function is  convex, implying that global minima can be readily found. This makes the optimisation process easy to handle and requires little to no human effort. Initial tests to validate the method were performed on molecular and bulk neon systems. Later, the method was extended to incorporate long-range interactions by including atomic charges. The capability of the method was demonstrated for ZnO polymorphs, and at the same time benchmarked towards the conventional  Buckingham potentials applied to the same problem. The results indicate that the CCS+Q method performs on par with the Buckingham approach, but is much faster and easier to parameterise. The merits of the method is further demonstrated with an exploration of size and shape dependent stability of CeO2 nanoparticles.

    Having established the framework of the CCS methodology, the method was further used to develop repulsive potentials for the semi-empirical self-consistent charge density functional tight binding (SCC-DFTB) method. The generation of the repulsive potentials is normally a tedious and time-consuming task. The  CCS methodology  makes this process significantly more efficient, and further provides new opportunities to explore the limits of the SCC-DFTB method. The development of repulsive potentials for bulk Si polymorphs showed that it is possible to retrieve a good description of each individual polymorph, but impossible to obtain an acceptable joint description of all polymorphs. The results indicated that a transferable repulsive potential needs to have coordination dependence, and by the  use of a many-body artificial neural network representation for the repulsive potential, it was indeed possible to obtain a global transferability. The CCS methodology was finally used to model a system of considerable chemical diversity and complexity, namely reduced CeO2 within the SCC-DFTB formalism. Here, the CCS framework facilitated the development of an efficient workflow that yielded a harmonized description of Ce ions in different oxidation states. In short, the introduced CCS-based workflow proved to extend the applicability of SCC-DFTB to complex oxide systems with correlated electronic states.               

    To conclude, the CCS methodology is demonstrated to be a versatile tool for efficient linking between (and within) electronic and atomistic models.

    List of papers
    1. CCS: A software framework to generate two-body potentials using Curvature Constrained Splines
    Open this publication in new window or tab >>CCS: A software framework to generate two-body potentials using Curvature Constrained Splines
    Show others...
    2021 (English)In: Computer Physics Communications, ISSN 0010-4655, E-ISSN 1879-2944, Vol. 258, article id 107602Article in journal (Refereed) Published
    Abstract [en]

    We have developed an automated and efficient scheme for the fitting of data using Curvature Constrained Splines (CCS), to construct accurate two-body potentials. The approach enabled the construction of an oscillation-free, yet flexible, potential. We show that the optimization problem is convex and that it can be reduced to a standard Quadratic Programming (QP) problem. The improvements are demonstrated by the development of a two-body potential for Ne from ab initio data. We also outline possible extensions to the method. Program summary Program Title: CCS CPC Library link to program files: http://dx.doi.org/10.17632/7dt5nzxgbs.1 Developer's repository link:gttp://github.com/aksam432/CCS Licensing provisions: GPLv3 Programming language: Python External routines/libraries: NumPy, matplotlib, ASE, CVXOPT Nature of problem: Ab initio quantum chemistry methods are often computationally very expensive. To alleviate this problem, the development of efficient empirical and semi-empirical methods is necessary. Two-body potentials are ubiquitous in empirical and semi-empirical methods. Solution method: The CCS package provides a new strategy to obtain accurate two body potentials. The potentials are described as cubic splines with curvature constraints.

    Place, publisher, year, edition, pages
    ElsevierELSEVIER, 2021
    Keywords
    Two-body potential, Force field, Quadratic programming, Cubic splines, Python
    National Category
    Computer Sciences Condensed Matter Physics
    Identifiers
    urn:nbn:se:uu:diva-426306 (URN)10.1016/j.cpc.2020.107602 (DOI)000587360000039 ()
    Funder
    Swedish Research CouncileSSENCE - An eScience Collaboration
    Available from: 2020-11-30 Created: 2020-11-30 Last updated: 2024-01-15Bibliographically approved
    2. Development of efficient linearly parametrized force fields for ionic materials
    Open this publication in new window or tab >>Development of efficient linearly parametrized force fields for ionic materials
    (English)In: Article in journal (Other academic) In press
    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:uu:diva-434542 (URN)
    Available from: 2021-02-10 Created: 2021-02-10 Last updated: 2021-02-10
    3. Curvature Constrained Splines for DFTB Repulsive Potential Parametrization
    Open this publication in new window or tab >>Curvature Constrained Splines for DFTB Repulsive Potential Parametrization
    Show others...
    2021 (English)In: Journal of Chemical Theory and Computation, ISSN 1549-9618, E-ISSN 1549-9626, Vol. 17, no 3, p. 1771-1781Article in journal (Refereed) Published
    Abstract [en]

    The Curvature Constrained Splines (CCS) methodology has been used for fitting repulsive potentials to be used in SCC-DFTB calculations. The benefit of using CCS is that the actual fitting of the repulsive potential is performed through quadratic programming on a convex objective function. This guarantees a unique (for strictly convex) and optimum two-body repulsive potential in a single shot, thereby making the parametrization process robust, and with minimal human effort. Furthermore, the constraints in CCS give the user control to tune the shape of the repulsive potential based on prior knowledge about the system in question. Herein, we developed the method further with new constraints and the capability to handle sparse data. We used the method to generate accurate repulsive potentials for bulk Si polymorphs and demonstrate that for a given Slater-Koster table, which reproduces the experimental band structure for bulk Si in its ground state, we are unable to find one single two-body repulsive potential that can accurately describe the various bulk polymorphs of silicon in our training set. We further demonstrate that to increase transferability, the repulsive potential needs to be adjusted to account for changes in the chemical environment, here expressed in the form of a coordination number. By training a near-sighted Atomistic Neural Network potential, which includes many-body effects but still essentially within the first-neighbor shell, we can obtain full transferability for SCC-DFTB in terms of describing the energetics of different Si polymorphs.

    Place, publisher, year, edition, pages
    American Chemical Society (ACS), 2021
    National Category
    Materials Chemistry
    Identifiers
    urn:nbn:se:uu:diva-434543 (URN)10.1021/acs.jctc.0c01156 (DOI)000629135700038 ()33606527 (PubMedID)
    Funder
    Swedish Research CouncileSSENCE - An eScience CollaborationSwedish National Infrastructure for Computing (SNIC)German Research Foundation (DFG), RTG 2247
    Available from: 2021-02-10 Created: 2021-02-10 Last updated: 2024-01-15Bibliographically approved
    4. Accurate description of Ce 4f states in reduced ceria using SCC-DFTB+U simulations
    Open this publication in new window or tab >>Accurate description of Ce 4f states in reduced ceria using SCC-DFTB+U simulations
    (English)In: Article in journal (Other academic) In press
    National Category
    Materials Chemistry
    Identifiers
    urn:nbn:se:uu:diva-434544 (URN)
    Available from: 2021-02-10 Created: 2021-02-10 Last updated: 2021-02-10
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  • 35.
    Ammothum Kandy, Akshay Krishna
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Wadbro, Eddie
    Aradi, Bálint
    Broqvist, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Kullgren, Jolla
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Curvature Constrained Splines for DFTB Repulsive Potential Parametrization2021In: Journal of Chemical Theory and Computation, ISSN 1549-9618, E-ISSN 1549-9626, Vol. 17, no 3, p. 1771-1781Article in journal (Refereed)
    Abstract [en]

    The Curvature Constrained Splines (CCS) methodology has been used for fitting repulsive potentials to be used in SCC-DFTB calculations. The benefit of using CCS is that the actual fitting of the repulsive potential is performed through quadratic programming on a convex objective function. This guarantees a unique (for strictly convex) and optimum two-body repulsive potential in a single shot, thereby making the parametrization process robust, and with minimal human effort. Furthermore, the constraints in CCS give the user control to tune the shape of the repulsive potential based on prior knowledge about the system in question. Herein, we developed the method further with new constraints and the capability to handle sparse data. We used the method to generate accurate repulsive potentials for bulk Si polymorphs and demonstrate that for a given Slater-Koster table, which reproduces the experimental band structure for bulk Si in its ground state, we are unable to find one single two-body repulsive potential that can accurately describe the various bulk polymorphs of silicon in our training set. We further demonstrate that to increase transferability, the repulsive potential needs to be adjusted to account for changes in the chemical environment, here expressed in the form of a coordination number. By training a near-sighted Atomistic Neural Network potential, which includes many-body effects but still essentially within the first-neighbor shell, we can obtain full transferability for SCC-DFTB in terms of describing the energetics of different Si polymorphs.

    Download full text (pdf)
    fulltext
  • 36. Ammothum kandy, Akshay
    et al.
    Wadbro, Eddie
    Broqvist, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Kullgren, Jolla
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Development of efficient linearly parametrized force fields for ionic materialsIn: Article in journal (Other academic)
  • 37.
    Anaraki, Elham Halvani
    et al.
    Ecole Polytech Fed Lausanne, Inst Chem Sci & Engn, Lab Photomol Sci, CH-1015 Lausanne, Switzerland;Isfahan Univ Technol, Dept Mat Engn, Esfahan 8415683111, Iran.
    Kermanpur, Ahmad
    Isfahan Univ Technol, Dept Mat Engn, Esfahan 8415683111, Iran.
    Mayer, Matthew T.
    Ecole Polytech Fed Lausanne, Lab Photon & Interfaces, Inst Chem Sci & Engn, CH-1015 Lausanne, Switzerland;Helmholtz Zentrum Berlin, Young Investigator Grp Electrochem Convers CO2, Hahn Meitner Pl 1, D-14109 Berlin, Germany.
    Steier, Ludmilla
    Ecole Polytech Fed Lausanne, Lab Photon & Interfaces, Inst Chem Sci & Engn, CH-1015 Lausanne, Switzerland;Imperial Coll London, Dept Chem, London SW7 2AZ, England.
    Ahmed, Taha
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Turren-Cruz, Silver-Hamill
    Ecole Polytech Fed Lausanne, Inst Chem Sci & Engn, Lab Photomol Sci, CH-1015 Lausanne, Switzerland.
    Seo, Jiyoun
    Ecole Polytech Fed Lausanne, Lab Photon & Interfaces, Inst Chem Sci & Engn, CH-1015 Lausanne, Switzerland.
    Luo, Jingshan
    Ecole Polytech Fed Lausanne, Lab Photon & Interfaces, Inst Chem Sci & Engn, CH-1015 Lausanne, Switzerland.
    Zakeeruddin, Shaik Mohammad
    Ecole Polytech Fed Lausanne, Inst Chem Sci & Engn, Lab Photomol Sci, CH-1015 Lausanne, Switzerland;Ecole Polytech Fed Lausanne, Lab Photon & Interfaces, Inst Chem Sci & Engn, CH-1015 Lausanne, Switzerland.
    Tress, Wolfgang Richard
    Ecole Polytech Fed Lausanne, Inst Chem Sci & Engn, Lab Photomol Sci, CH-1015 Lausanne, Switzerland;Ecole Polytech Fed Lausanne, Lab Photon & Interfaces, Inst Chem Sci & Engn, CH-1015 Lausanne, Switzerland.
    Edvinsson, Tomas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Graetzel, Michael
    Ecole Polytech Fed Lausanne, Lab Photon & Interfaces, Inst Chem Sci & Engn, CH-1015 Lausanne, Switzerland.
    Hagfeldt, Anders
    Ecole Polytech Fed Lausanne, Inst Chem Sci & Engn, Lab Photomol Sci, CH-1015 Lausanne, Switzerland.
    Correa-Baena, Juan-Pablo
    Ecole Polytech Fed Lausanne, Inst Chem Sci & Engn, Lab Photomol Sci, CH-1015 Lausanne, Switzerland;MIT, Dept Mech Engn, 77 Massachusetts Ave, Cambridge, MA 02139 USA.
    Low-Temperature Nb-Doped SnO2 Electron-Selective Contact Yields over 20% Efficiency in Planar Perovskite Solar Cells2018In: ACS Energy Letters, E-ISSN 2380-8195, Vol. 3, no 4, p. 773-778Article in journal (Refereed)
    Abstract [en]

    Low-temperature planar organic inorganic lead halide perovskite solar cells have been at the center of attraction as power conversion efficiencies go beyond 20%. Here, we investigate Nb doping of SnO2 deposited by a low-cost, scalable chemical bath deposition (CBD) method. We study the effects of doping on compositional, structural, morphological, and device performance when these layers are employed as electron-selective layers (ESLs) in planar-structured PSCs. We use doping concentrations of 0, 1, 5, and 10 mol % Nb to Sn in solution. The ESLs were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, atomic force microscopy, and ultraviolet visible spectroscopy. ESLs with an optimum 5 mol % Nb doping yielded, on average, an improvement of all the device photovoltaic parameters with a champion power conversion efficiency of 20.5% (20.1% stabilized).

  • 38.
    Andersson, Anna M
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry.
    Henningsson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics.
    Siegbahn, Hans
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics.
    Jansson, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Electrochemically lithiated graphite characterised by photoelectron spectroscopy2003In: Journal of Power Sources, ISSN 0378-7753, E-ISSN 1873-2755, Vol. 119-121, p. 522-527Article in journal (Refereed)
    Abstract [en]

    X-ray photoelectron spectroscopy (XPS) has been used to study the depth profile of the solid–electrolyte interphase (SEI) formed on a graphite powder electrode in a Li-ion battery. The morphology of the SEI-layer, formed in a 1 M LiBF4 EC/DMC 2:1 solution, consists of a 900 Å porous layer of polymers (polyethylene oxide) and a 15–20 Å thin layer of Li2CO3 and LiBF4 reduction–decomposition products. Embedded LiF crystals as large as 0.2 μm were found in the polymer matrix. LiOH and Li2O are not major components on the surface but rather found as a consequence of sputter-related reactions. Monochromatised Al Kα XPS-analysis based on the calibration of Ar+ ion sputtering of model compounds combined with a depth profile analysis based on energy tuning of synchrotron XPS can describe the highly complex composition and morphology of the SEI-layer.

  • 39.
    Andersson, Edvin K. W.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Wu, Liang-Ting
    Natl Taiwan Univ Sci & Technol, Dept Chem Engn, Taipei 106, Taiwan..
    Bertoli, Luca
    Dipartimento Chim Materiali & Ingn Chim Giulio Nat, Dipartimento Chim Mat & Ingn Chim Giulio Natta, Via Luigi Mancinelli 7, I-20131 Milan, Italy..
    Weng, Yi-Chen
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Condensed Matter Physics of Energy Materials.
    Friesen, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Elbouazzaoui, Kenza
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Bloch, Sophia
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Ovsyannikov, Ruslan
    Helmholtz Zentrum Berlin Mat & Energie, Inst Methods & Instrumentat Synchrotron Radiat Res, Albert Einstein Str 15, D-12489 Berlin, Germany..
    Giangrisostomi, Erika
    Helmholtz Zentrum Berlin Mat & Energie, Inst Methods & Instrumentat Synchrotron Radiat Res, Albert Einstein Str 15, D-12489 Berlin, Germany..
    Brandell, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Mindemark, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Jiang, Jyh-Chiang
    Natl Taiwan Univ Sci & Technol, Dept Chem Engn, Taipei 106, Taiwan..
    Hahlin, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Condensed Matter Physics of Energy Materials.
    Initial SEI formation in LiBOB-, LiDFOB- and LiBF4-containing PEO electrolytes2024In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 12, no 15, p. 9184-9199Article in journal (Refereed)
    Abstract [en]

    A limiting factor for solid polymer electrolyte (SPE)-based Li-batteries is the functionality of the electrolyte decomposition layer that is spontaneously formed at the Li metal anode. A deeper understanding of this layer will facilitate its improvement. This study investigates three SPEs – polyethylene oxide:lithium tetrafluoroborate (PEO:LiBF4), polyethylene oxide:lithium bis(oxalate)borate (PEO:LiBOB), and polyethylene oxide:lithium difluoro(oxalato)borate (PEO:LiDFOB) – using a combination of electrochemical impedance spectroscopy (EIS), galvanostatic cycling, in situ Li deposition photoelectron spectroscopy (PES), and ab initio molecular dynamics (AIMD) simulations. Through this combination, the cell performance of PEO:LiDFOB can be connected to the initial SPE decomposition at the anode interface. It is found that PEO:LiDFOB had the highest capacity retention, which is correlated to having the least decomposition at the interface. This indicates that the lower SPE decomposition at the interface still creates a more effective decomposition layer, which is capable of preventing further electrolyte decomposition. Moreover, the PES results indicate formation of polyethylene in the SEI in cells based on PEO electrolytes. This is supported by AIMD that shows a polyethylene formation pathway through free-radical polymerization of ethylene.

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  • 40.
    Andersson, Edvin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Sångeland, Christofer
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Berggren, Elin
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Condensed Matter Physics of Energy Materials.
    Johansson, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Kühn, Danilo
    Lindblad, Andreas
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Condensed Matter Physics of Energy Materials.
    Mindemark, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Polymer Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Hahlin, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Early-Stage Decomposition of Solid Polymer Electrolytes in Li-Metal Batteries2021In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 9, no 39Article in journal (Refereed)
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  • 41.
    Andersson, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Synthesis of polycarbonate polymer electrolytes for lithium ion batteries and study of additives to raise the ionic conductivity2015Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Polymer electrolyte films based on poly(trimethylene carbonate) (PTMC) mixed with LiTFSI salt in different compositions were synthesized and investigated as electrolytes for lithium ion batteries, where the ionic conductivity is the most interesting material property. Electrochemical impedance spectroscopy (EIS) and DSC were used to measure the ionic conductivity and thermal properties, respectively. Additionally, FTIR and Raman spectroscopy were used to examine ion coordination in the material. Additives of nanosized TiO2 and powders of superionically conducting Li1.3Al0.3Ti1.7(PO4)3 were investigated as enhancers of ionic conductivity, but no positive effect could be shown. The most conductive composition was found at a [Li+]:[carbonate] ratio of 1, corresponding to a salt concentration of 74 percent by weight, which showed an ionic conductivity of 2.0 × 10–6 S cm–1 at 25 °C and 2.2 × 10–5 S cm–1 at 60 °C, whereas for even larger salt concentrations, the mechanical durability of the polymeric material was dramatically reduced, preventing use as a solid electrolyte material. Macroscopic salt crystallization was also observed for these concentrations. Ion coordination to carbonyls on the polymer chain was examined for high salt content compositions with FTIR spectroscopy, where it was found to be relatively similar between the samples, possibly indicating saturation. Moveover, with FTIR, the ion-pairing was found to increase with salt concentration. The ionic conductivity was found to be markedly lower after 7 weeks of aging of the materials with highest salt concentrations.

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  • 42.
    Andersson, Linnéa
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Zhang, Chao
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Molecular dynamics simulations of metal-electrolyte interfaces under potential control2023In: Current Opinion in Electrochemistry, E-ISSN 2451-9103, Vol. 42, article id 101407Article, review/survey (Refereed)
    Abstract [en]

    The interfaces between metal electrodes and liquid electro-lytes are prototypical in electrochemistry. That is why it is crucial to have a molecular and dynamical understating of such interfaces for both electrical properties and chemical re-activities under potential control. In this short review, we will categorize different schemes for modeling electrified metal-electrolyte interfaces used in molecular dynamics simulations. Our focus is on the similarities between seemingly different methods and their conceptual connections in terms of relevant electrochemical quantities. Therefore, it can be used as a guideline for developing new methods and building modular-ized computational protocols for simulating electrified interfaces.

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  • 43.
    Andersson, Matilda
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Högström, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Urbonaite, Sigita
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Furlan, Andrej
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Jansson, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Deposition and characterization of magnetron sputtered amorphous Cr-C films2012In: Vacuum, ISSN 0042-207X, E-ISSN 1879-2715, Vol. 86, no 9, p. 1408-1416Article in journal (Refereed)
    Abstract [en]

    Thin films in the Cr-C system with carbon content of 25-85 at.% have been deposited using non-reactive DC magnetron sputtering from elemental targets. Analyses with X-ray diffraction and transmission electron microscopy confirm that the films are completely amorphous. Also, annealing experiment show that the films had not crystallized at 500 degrees C. Furthermore, X-ray spectroscopy and Raman spectroscopy show that the films consist of two phases, an amorphous CrCx phase and an amorphous carbon (a-C) phase. The presence of two amorphous phases is also supported by the electrochemical analysis, which shows that oxidation of both chromium and carbon contributes to the total current in the passive region. The relative amounts of these amorphous phases influence the film properties. Typically, lower carbon content with less a-C phase leads to harder films with higher Young's modulus and lower resistivity. The results also show that both films have lower currents in the passive region compared to the uncoated 316L steel substrate. Finally, our results were compared with literature data from both reactively and non-reactively sputtered chromium carbide films. The comparison reveals that non-reactive sputtering tend to favour the formation of amorphous films and also influence e.g. the sp(2)/sp(3) ratio of the a-C phase. 

  • 44.
    Andersson, Matilda
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Urbonaite, Sigita
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Lewin, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Jansson, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Magnetron sputtering of Zr-Si-C thin films2012In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 520, no 20, p. 6375-6381Article in journal (Refereed)
    Abstract [en]

    The phase composition and chemical bonding of Zr-C and Zr-Si-C films deposited by magnetron sputtering has been studied. The results show that the binary Zr-C films at higher carbon contents form nanocrystallites of ZrC in an amorphous carbon matrix. The addition of Si induces a complete amorphization of the films above a critical concentration of about 15 at.%. X-ray diffraction and transmission electron microscopy confirm that the amorphous films contain no nanocrystallites and therefore can be described as truly amorphous carbides. The amorphous films are thermally stable but start to crystallize above 500 degrees C. Analysis of the chemical bonding with X-ray photoelectron spectroscopy suggests that the amorphous films exhibit a mixture of different chemical bonds such as Zr-C, Zr-Si and Si-C and that the electrical and mechanical properties are dependent on the distribution of these bonds. For higher carbon contents, strong Si-C bonds are formed in the amorphous Zr-Si-C films making them harder than the corresponding binary Zr-C films.

  • 45.
    Andersson, Rassmus
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Discovering new ground in ion transport: Exploring coordination effects in polymer electrolytes: – From method development to battery implementation2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The exponentially increasing demand for portable and stationary energy storage devices is pushing the development of lithium-ion batteries (LIBs).  This requires safer and more sustainable electrolytes where solid polymer electrolytes (SPEs) are a viable alternative to the flammable liquid electrolytes used nowadays. However, SPEs are characterized by poor ionic conductivity compared to their liquid equivalents, preventing large-scale implementation. Furthermore, to meet the increasing production rate of batteries, alternative battery chemistries based on more abundant resources than Li are explored. To address these matters, a fundamental understanding of ion transport in SPEs for a range of relevant cations is vital in the development process.

    In the thesis, the ion transport is explored on a fundamental level for Li+ in addition to cations “beyond Li” such as Na+, K+ and Mg2+ in polyether-, polyester- and polycarbonate-based SPEs, where the core encompasses the connection between the ion coordination strength and the transference number (T+). New methods to investigate these properties have been developed especially targeting these more challenging cations. To study the ion coordination strength, two qualitative and one quantitative methods based on NMR and FTIR, are presented. In addition, eNMR and EIS have been combined to determine T+.

    Regardless of the cation investigated, the strongest coordination was observed for polyethylene oxide, stemming from its chelating effect on the cations. In contrast, poly(trimethylene carbonate) exhibited the weakest coordination, while poly(ε-caprolactone) fell in between. A direct correlation between the coordination strength and the T+ was also recognized, where strong interactions are accompanied by low T+ and vice versa. Moreover, the divalent Mg2+ displayed particularly interesting transport characteristics, where the [MgTFSI]+ speciation appears to be a large contributor to the net Mg mobility. 

    Lastly, the outcome of incorporating an ion-conducting polymer as the soft segment in polyurethanes is that the transport mechanism of the pure SPE remains. In combination with sustained long-term cycling in lithium metal batteries, the polyurethanes illustrate opportunities for new designs by adjusting the soft segments.  Similarly, the properties of poly(1-oxoheptamethylene) can be controlled by tuning its saturation degree, which is crucial for the ion conduction and mechanical properties in lithium metal batteries, since it highly affects the crystallinity and the crosslinking of the systems.

    In summary, this thesis contributes toward the understanding of ion transport in systems belonging to “next-generation” batteries, where SPEs for lithium-metal batteries as well as for cations “beyond Li” are considered to play an important part.

    List of papers
    1. Coordination Effects in Polymer Electrolytes: Fast Li+ Transport by Weak Ion Binding
    Open this publication in new window or tab >>Coordination Effects in Polymer Electrolytes: Fast Li+ Transport by Weak Ion Binding
    2020 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 124, no 43, p. 23588-23596Article in journal (Refereed) Published
    Abstract [en]

    In view of the limited ionic conductivity and low lithium transference number in classical poly(ethylene oxide) (PEO)-based salt-in-polymer electrolytes, employing alternative polymer architectures, e.g., polyester homopolymers or copolymers, is a promising approach. To shed light on the influence of the coordination properties of different polymer architectures and to identify their influence on Li ion transport, different polymeric structures are compared, i.e., poly(e-caprolactone) (PCL), poly(trimethylene carbonate) (PTMC), and a PCL-co-PTMC random copolymer, combined with lithium bis(trifluoromethanesulfonyl)amide (LiTFSA) at varying Li+/monomer ratios r. Electrophoretic NMR (H-1 and F-19 eNMR) is applied to determine the electrophoretic mobilities of both ionic species, from which partial conductivities and Li transference numbers are calculated. In comparison to PEO-based electrolytes, the ester-based systems show a much higher lithium transference number (similar to 0.5 compared to similar to 0.2), while the total ionic conductivity is lower. However, the partial lithium conductivities are found to be almost equal in PEO- and PCL-based electrolytes. The results show how via modifying the coordination strength, the competition of Li+-polymer coordination and Li+ ion pair formation can be finely tuned to yield either systems with a maximized total conductivity or maximized Li transference number. Thus, for the promising class of polyester-based polymer electrolytes, showing excellent lithium conduction properties, a molecular level-based understanding of the electrochemical transport parameters is derived, complementing the segmental motion-based description of ion transport with the additional effects of ion coordination.

    Place, publisher, year, edition, pages
    AMER CHEMICAL SOC, 2020
    National Category
    Polymer Chemistry
    Identifiers
    urn:nbn:se:uu:diva-426302 (URN)10.1021/acs.jpcc.0c08369 (DOI)000587720300013 ()
    Funder
    StandUp
    Available from: 2020-11-30 Created: 2020-11-30 Last updated: 2024-03-24Bibliographically approved
    2. Quantifying the ion coordination strength in polymer electrolytes
    Open this publication in new window or tab >>Quantifying the ion coordination strength in polymer electrolytes
    2022 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 24, no 26, p. 16343-16352Article in journal (Refereed) Published
    Abstract [en]

    In the progress of implementing solid polymer electrolytes (SPEs) into batteries, fundamental understanding of the processes occurring within and in the vicinity of the SPE are required. An important but so far relatively unexplored parameter influencing the ion transport properties is the ion coordination strength. Our understanding of the coordination chemistry and its role for the ion transport is partly hampered by the scarcity of suitable methods to measure this phenomenon. Herein, two qualitative methods and one quantitative method to assess the ion coordination strength are presented, contrasted and discussed for TFSI-based salts of Li+, Na+ and Mg2+ in polyethylene oxide (PEO), poly(epsilon-caprolactone) (PCL) and poly(trimethylene carbonate) (PTMC). For the qualitative methods, the coordination strength is probed by studying the equilibrium between cation coordination to polymer ligands or solvent molecules, whereas the quantitative method studies the ion dissociation equilibrium of salts in solvent-free polymers. All methods are in agreement that regardless of cation, the strongest coordination strength is observed for PEO, while PTMC exhibits the weakest coordination strength. Considering the cations, the weakest coordination is observed for Mg2+ in all polymers, indicative of the strong ion-ion interactions in Mg(TFSI)(2), whilst the coordination strength for Li+ and Na+ seems to be more influenced by the interplay between the cation charge/radius and the polymer structure. The trends observed are in excellent agreement with previously observed transference numbers, confirming the importance and its connection to the ion transport in SPEs.

    Place, publisher, year, edition, pages
    Royal Society of Chemistry, 2022
    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:uu:diva-481181 (URN)10.1039/d2cp01904c (DOI)000817088300001 ()35762165 (PubMedID)
    Note

    Correction in: Physical Chemistry Chemical Physics, vol. 24, issue 5, page 17361

    DOI: 10.1039/d2cp90117j

    Available from: 2022-08-05 Created: 2022-08-05 Last updated: 2024-03-24Bibliographically approved
    3. Influence of molecular weight and end groups on ion transport in weakly and strongly coordinating polymer electrolytes
    Open this publication in new window or tab >>Influence of molecular weight and end groups on ion transport in weakly and strongly coordinating polymer electrolytes
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Polymer Chemistry
    Identifiers
    urn:nbn:se:uu:diva-525238 (URN)
    Available from: 2024-03-21 Created: 2024-03-21 Last updated: 2024-03-24
    4. Seeing the unseen: Mg2+, Na+ and K+ transference numbers in post-Li battery electrolytes by electrophoretic nuclear magnetic resonance
    Open this publication in new window or tab >>Seeing the unseen: Mg2+, Na+ and K+ transference numbers in post-Li battery electrolytes by electrophoretic nuclear magnetic resonance
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Physical Chemistry
    Identifiers
    urn:nbn:se:uu:diva-525242 (URN)
    Available from: 2024-03-23 Created: 2024-03-23 Last updated: 2024-03-24
    5. Ion Coordination and Transport in Magnesium Polymer Electrolytes Based on Polyester-co-Polycarbonate
    Open this publication in new window or tab >>Ion Coordination and Transport in Magnesium Polymer Electrolytes Based on Polyester-co-Polycarbonate
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    2021 (English)In: Energy Material Advances, E-ISSN 2692-7640, Vol. 2021, p. 1-14, article id 9895403Article in journal (Refereed) Published
    Abstract [en]

    Magnesium-ion-conducting solid polymer electrolytes have been studied for rechargeable Mg metal batteries, one of the beyond-Li-ion systems. In this paper, magnesium polymer electrolytes with magnesium bis(trifluoromethane)sulfonimide (Mg(TFSI)2) salt in poly(ε-caprolactone-co-trimethylene carbonate) (PCL-PTMC) were investigated and compared with the poly(ethylene oxide) (PEO) analogs. Both thermal properties and vibrational spectroscopy indicated that the total ion conduction in the PEO electrolytes was dominated by the anion conduction due to strong polymer coordination with fully dissociated Mg2+. On the other hand, in PCL-PTMC electrolytes, there is relatively weaker polymer–cation coordination and increased anion–cation coordination. Sporadic Mg- and F-rich particles were observed on the Cu electrodes after polarization tests in Cu|Mg cells with PCL-PTMC electrolyte, suggesting that Mg was conducted in the ion complex form (MgxTFSIy) to the copper working electrode to be reduced which resulted in anion decomposition. However, the Mg metal deposition/stripping was not favorable with either Mg(TFSI)2 in PCL-PTMC or Mg(TFSI)2 in PEO, which inhibited quantitative analysis of magnesium conduction. A remaining challenge is thus to accurately assess transport numbers in these systems.

    Place, publisher, year, edition, pages
    American Association for the Advancement of Science (AAAS)American Association for the Advancement of Science (AAAS), 2021
    Keywords
    polymer electrolytes, magnesium battery, ion coordination, ionic conductivity
    National Category
    Polymer Chemistry
    Research subject
    Chemistry with specialization in Polymer Chemistry
    Identifiers
    urn:nbn:se:uu:diva-464462 (URN)10.34133/2021/9895403 (DOI)000865925200031 ()
    Funder
    StandUp
    Available from: 2022-01-14 Created: 2022-01-14 Last updated: 2024-03-24Bibliographically approved
    6. Transference number and Ion coordination strength for Mg2+, Na+ and K+ in solid polymer electrolytes
    Open this publication in new window or tab >>Transference number and Ion coordination strength for Mg2+, Na+ and K+ in solid polymer electrolytes
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Physical Chemistry
    Identifiers
    urn:nbn:se:uu:diva-525239 (URN)
    Available from: 2024-03-21 Created: 2024-03-21 Last updated: 2024-03-24
    7. Designing Polyurethane Solid Polymer Electrolytes for High-Temperature Lithium Metal Batteries
    Open this publication in new window or tab >>Designing Polyurethane Solid Polymer Electrolytes for High-Temperature Lithium Metal Batteries
    Show others...
    2022 (English)In: ACS Applied Energy Materials, E-ISSN 2574-0962, Vol. 5, no 1, p. 407-418Article in journal (Refereed) Published
    Abstract [en]

    Potentially high-performance lithium metal cells in extreme high-temperature electrochemical environments is a challenging but attractive battery concept that requires stable and robust electrolytes to avoid severely limiting lifetimes of the cells. Here, the properties of tailored polyester and polycarbonate diols as the soft segments in polyurethanes are investigated and electrochemically evaluated for use as solid polymer electrolytes in lithium metal batteries. The polyurethanes demonstrate high mechanical stability against deformation at low flow rates and moreover at temperatures up above 100 degrees C, enabled by the hard urethane segments. The results further indicate transferrable ion transport properties of the pure polymers when incorporated as the soft segments in the polyurethanes, offering designing opportunities of the polyurethane by tuning the soft segment ratio and composition. Long-term electrochemical cycling of polyurethane-containing cells in lithium metal batteries at 80 degrees C proves the stability at elevated temperatures as well as the compatibility with lithium metal with stable cycling maintained after 2000 cycles.

    Place, publisher, year, edition, pages
    American Chemical Society (ACS), 2022
    Keywords
    polymer electrolytes, high-temperature batteries, polyurethane, lithium metal batteries, long-term cycling
    National Category
    Materials Chemistry Polymer Chemistry
    Identifiers
    urn:nbn:se:uu:diva-473183 (URN)10.1021/acsaem.1c02942 (DOI)000743235300001 ()
    Funder
    StandUp
    Available from: 2022-04-27 Created: 2022-04-27 Last updated: 2024-03-24Bibliographically approved
    8. Implementation of Highly Crystalline Polyketones as Solid Polymer Electrolytes in high-temperature Lithium Metal Batteries
    Open this publication in new window or tab >>Implementation of Highly Crystalline Polyketones as Solid Polymer Electrolytes in high-temperature Lithium Metal Batteries
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Chemical Engineering
    Identifiers
    urn:nbn:se:uu:diva-525240 (URN)
    Available from: 2024-03-21 Created: 2024-03-21 Last updated: 2024-03-24
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  • 46.
    Andersson, Rassmus
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Silicon-based graphite electrodes for Li-ion batteries2018Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The cycling performance of silicon containing graphite electrodes as the anode in lithium-ion batteries has been investigated. Different electrode compositions of silicon, graphite, carbon black, sodium carboxymethylcellulose (CMC-Na), styrene–butadiene rubber (SBR) and using water as the solvent have been prepared and evaluated electrochemically by constant-current-constant-voltage (CCCV) cycling. To understand the impact on the cycling performance of the electrodes, the process parameters in the coating process have been evaluated by rheological measurements of the electrode slurries.

    The highest and most stable capacity was found for the electrode containing 5 wt% silicon (vs. graphite), 3 wt% binder, equal amount of the binders CMC-Na and SBR and 70 wt% solvent in the initial electrode slurry. It showed a stable capacity retention of 360 mAh/g after 315 cycles, before it faded. It was found that the CMC-Na and the solvent have a strong impact on the properties of the electrode slurry and the processing parameters. CMC-Na, the solvent and SBR were also found to be important for the adhesion of the electrode coating on the current collector. The worst cycling performance was obtained for electrodes containing 15 wt% silicon, a solvent amount below 65 wt% and a binder ratio of CMC-Na:SBR below 1:1. Different rheological behaviour for different silicon particles was found to depend on the surface area of the particles.

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    Report - Rassmus Andersson
  • 47.
    Andersson, Rassmus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Hernández, Guiomar
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Mindemark, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Micro versus Nano: Impact of Particle Size on the Flow Characteristics of Silicon Anode Slurries2020In: ENERGY TECHNOLOGY, ISSN 2194-4288, Vol. 8, no 7, article id 2000056Article in journal (Refereed)
    Abstract [en]

    Silicon is interesting for use as a negative electrode material in Li-ion batteries due to its extremely high gravimetric capacity compared with today's state-of-the-art material, graphite. However, during cycling the Si particles suffer from large volume changes, leading to particle cracking, electrolyte decompositions, and electrode disintegration. Although utilizing nm-sized particles can mitigate some of these issues, it would instead be more cost-effective to incorporate mu m-sized silicon particles in the anode. Herein, it is shown that the size of the Si particles not only influences the electrode cycling properties but also has a decisive impact on the processing characteristics during electrode preparation. In water-based slurries and suspensions containing mu m-Si and nm-Si particles, the smaller particles consistently give higher viscosities and more pronounced viscoelastic properties, particularly at low shear rates. This difference is observed even when the Si particles are present as a minor component in blends with graphite. It is found that the viscosity follows the particle volume fraction divided by the particle radius, suggesting that it is dependent on the surface area concentration of the Si particles.

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  • 48.
    Andersson, Rassmus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Hernández, Guiomar
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Mindemark, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Quantifying the ion coordination strength in polymer electrolytes2022In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 24, no 26, p. 16343-16352Article in journal (Refereed)
    Abstract [en]

    In the progress of implementing solid polymer electrolytes (SPEs) into batteries, fundamental understanding of the processes occurring within and in the vicinity of the SPE are required. An important but so far relatively unexplored parameter influencing the ion transport properties is the ion coordination strength. Our understanding of the coordination chemistry and its role for the ion transport is partly hampered by the scarcity of suitable methods to measure this phenomenon. Herein, two qualitative methods and one quantitative method to assess the ion coordination strength are presented, contrasted and discussed for TFSI-based salts of Li+, Na+ and Mg2+ in polyethylene oxide (PEO), poly(epsilon-caprolactone) (PCL) and poly(trimethylene carbonate) (PTMC). For the qualitative methods, the coordination strength is probed by studying the equilibrium between cation coordination to polymer ligands or solvent molecules, whereas the quantitative method studies the ion dissociation equilibrium of salts in solvent-free polymers. All methods are in agreement that regardless of cation, the strongest coordination strength is observed for PEO, while PTMC exhibits the weakest coordination strength. Considering the cations, the weakest coordination is observed for Mg2+ in all polymers, indicative of the strong ion-ion interactions in Mg(TFSI)(2), whilst the coordination strength for Li+ and Na+ seems to be more influenced by the interplay between the cation charge/radius and the polymer structure. The trends observed are in excellent agreement with previously observed transference numbers, confirming the importance and its connection to the ion transport in SPEs.

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  • 49.
    Andersson, Rassmus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Hernández, Guiomar
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    See, Jennifer
    Brewer Sci, Rolla, MO 65401 USA..
    Flaim, Tony D.
    Brewer Sci, Rolla, MO 65401 USA..
    Brandell, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Mindemark, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Designing Polyurethane Solid Polymer Electrolytes for High-Temperature Lithium Metal Batteries2022In: ACS Applied Energy Materials, E-ISSN 2574-0962, Vol. 5, no 1, p. 407-418Article in journal (Refereed)
    Abstract [en]

    Potentially high-performance lithium metal cells in extreme high-temperature electrochemical environments is a challenging but attractive battery concept that requires stable and robust electrolytes to avoid severely limiting lifetimes of the cells. Here, the properties of tailored polyester and polycarbonate diols as the soft segments in polyurethanes are investigated and electrochemically evaluated for use as solid polymer electrolytes in lithium metal batteries. The polyurethanes demonstrate high mechanical stability against deformation at low flow rates and moreover at temperatures up above 100 degrees C, enabled by the hard urethane segments. The results further indicate transferrable ion transport properties of the pure polymers when incorporated as the soft segments in the polyurethanes, offering designing opportunities of the polyurethane by tuning the soft segment ratio and composition. Long-term electrochemical cycling of polyurethane-containing cells in lithium metal batteries at 80 degrees C proves the stability at elevated temperatures as well as the compatibility with lithium metal with stable cycling maintained after 2000 cycles.

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  • 50.
    Anuar, S. A.
    et al.
    Univ Kebangsaan Malaysia, Fac Engn & Built Environm, Bangi Ukm 43600, Selangor, Malaysia..
    Loh, K. S.
    Univ Kebangsaan Malaysia, Fuel Cell Inst, Bangi Ukm 43600, Selangor, Malaysia..
    Samad, S.
    Univ Kebangsaan Malaysia, Fuel Cell Inst, Bangi Ukm 43600, Selangor, Malaysia..
    Abidin, A. F. Zainul
    Univ Kebangsaan Malaysia, Fuel Cell Inst, Bangi Ukm 43600, Selangor, Malaysia..
    Wong, W. Y.
    Univ Kebangsaan Malaysia, Fuel Cell Inst, Bangi Ukm 43600, Selangor, Malaysia..
    Mohamad, A. B.
    Univ Kebangsaan Malaysia, Fac Engn & Built Environm, Bangi Ukm 43600, Selangor, Malaysia.;Univ Kebangsaan Malaysia, Fuel Cell Inst, Bangi Ukm 43600, Selangor, Malaysia..
    Lee, T.K.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry. Univ Kebangsaan Malaysia, Fac Engn & Built Environm, Bangi Ukm 43600, Selangor, Malaysia..
    Effect of Carbon Supports on Oxygen Reduction Reaction of Iron/Cobalt Electrocatalyst2020In: International Journal of Nanoelectronics and Materials, ISSN 1985-5761, Vol. 13, no Special Issue, p. 225-232Article in journal (Refereed)
    Abstract [en]

    Dual metal FeCo has great potential as Pt-free catalyst in various applications, such as cathodic catalyst for fuel cells, in order to reduce the cost significantly and make fuel cell commercialization, viable. In this study, dual metal FeCo catalyst supported on carbon Vulcan XC-72, carbon nanotubes (CNT), and reduced graphene oxide (rGO) were successfully prepared via facile co-precipitation method with varying weight ratios of Fe and Co. The structure of the as-prepared catalysts was characterized by powder X-ray diffraction (XRD), scanning electron micrographs (SEM), and X-ray photoelectron spectroscopy (XPS). The XPS analysis revealed that CoFe2O4 were present on the catalyst particle surface with different Fe to Co ratio. The emergence of the new peak at 530.5 eV is assigned to the deposition of CoFe2O4, which is enabled via Fe-O-Co bonds. The FeCo/rGO catalyst with weight ratio of 2:1 exhibited the optimum performance for oxygen reduction reaction (ORR), with reduction peak of 0.163 mA cm(-2) at 0.385 V vs. Ag/AgCl in an acidic media. The experimental result suggested that the dual metal FeCo catalyst display favourable electrocatalytic activity towards ORR and appears to be a promising cathodic electrocatalyst for an acidic fuel cell.

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