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  • 651.
    Rehnlund, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lindgren, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Bohme, Solveig
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Nordh, Tim
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry. Uppsala Univ, Angstrom Lab, Dept Chem, Box 538, SE-75121 Uppsala, Sweden..
    Zou, Yiming
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Pettersson, Jean
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Bexell, Ulf
    Dalarna Univ, Sch Technol & Business Studies Mat Technol, Falun, Sweden..
    Boman, Mats
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lithium trapping in alloy forming electrodes and current collectors for lithium based batteries2017In: Energy & Environmental Science, ISSN 1754-5692, E-ISSN 1754-5706, Vol. 10, no 6, p. 1350-1357Article in journal (Refereed)
    Abstract [en]

    Significant capacity losses are generally seen for batteries containing high-capacity lithium alloy forming anode materials such as silicon, tin and aluminium. These losses are generally ascribed to a combination of volume expansion effects and irreversible electrolyte reduction reactions. Here, it is shown, based on e.g. elemental analyses of cycled electrodes, that the capacity losses for tin nanorod and silicon composite electrodes in fact involve diffusion controlled trapping of lithium in the electrodes. While an analogous effect is also demonstrated for copper, nickel and titanium current collectors, boron-doped diamond is shown to function as an effective lithium diffusion barrier. The present findings indicate that the durability of lithium based batteries can be improved significantly via proper electrode design or regeneration of the used electrodes.

  • 652.
    Rehnlund, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lindgren, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Böhme, Solveig
    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.
    Zou, Yiming
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Pettersson, Jean
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Bexell, Ulf
    Dalarna University.
    Boman, Mats
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Improved cycling stability of conversion and alloying anodes through the use of nanomaterials2016Conference paper (Other academic)
    Abstract [en]

    In order to meet the growing need for portable energy storage future batteries need to provide improved energydensities. One major problem lies in the current use of intercalation based electrode materials which are typicallylimited to storing one lithium ion per formula unit. Improved energy storage can be achieved through the use ofconversion and alloying reactions where it is possible to store multiple lithium ions per formula unit. Eventhough impressive energy densities can be obtained through the use of conversion and alloying anode materials,only surpassed by the use of lithium metal itself, these systems are typically plagued by capacity fading duringcycling. The origin is generally ascribed to irreversible reactions with the electrolyte amplified by major volumeexpansion, causing the growth of a solid electrolyte interphase (i.e. SEI). One promising strategy to address thisissue is through the use of nanosized electrode materials (e.g. Si nanoparticles), as it has been shown thatnanoparticles and nanowires show better cycling stability than their bulk counterparts [1, 2]. Large particles (i.emicrometer sized) form cracks during cycling as opposed to smaller particles (i.e. < 150 nm) [3]. Even thoughthe use of nanoparticles can reduce crack formation and the accompanied SEI growth, capacity fading is stillobserved for these systems. Our work has focused on studying freestanding nanostructured conversion materials(e.g. Cu2O nanowires), which offer in depth analyses of the conversion reactions without disturbance frombinders or conducting additives. Contrary to previous understanding nanosized Cu2O thin films and multilayerednanostructures show an increase in capacity during cycling [4, 5]. This behaviour is caused by improvedaccess to the entire material when using the nanomaterials. The system has also shown improved performanceduring cycling likely caused by electrochemical milling of the particles thereby consistently reducing the particlesize and thus allowing more of the material to be accessible. With the successful use of nanosized conversionmaterials our research is now focused on addressing the stability problems of alloying materials by studying theeffect of nanomaterials.

    References

    1. A. Magasinski, et al.. Nat. Mater., 2010. 22: p. 353-3582.

    2 C.K. Chan, et al.. Nat. Nanotechnol., 2008. 3: p. 31-353.

    3 X. H. Liu, et al.. Adv. En. Mater., 2012. 2: p. 722-7414.

    4 D. Rehnlund, et al.. J. Mat. Chem. A., 2014. 2: p. 9574-95865.

    5 D. Rehnlund, et al.. Nanoscale, 2015. 7: p. 13591-13604

  • 653.
    Rehnlund, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lindgren, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Böhme, Solveig
    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.
    Zou, Yiming
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Pettersson, Jean
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Bexell, Ulf
    Dalarna University.
    Boman, Mats
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lithium trapping in alloy forming electrodes and current collectors for lithium based batteries2017Conference paper (Other academic)
  • 654.
    Rehnlund, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lindgren, Fredrik
    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.
    Böhme, Solveig
    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.
    Zou, Yiming
    Pettersson, Jean
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Bexell, Ulf
    Boman, Mats
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lithium trapping in alloy forming electrodes andcurrent collectors for lithium based batteries2017In: Energy & Environmental Science, ISSN 1754-5692, E-ISSN 1754-5706, Vol. 10, p. 1350-1357Article in journal (Refereed)
  • 655.
    Rehnlund, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lindgren, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Pettersson, Jean
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lithium Trapping in Alloy forming Electrodes and Current Collectors for Lithium based Batteries2018Conference paper (Other academic)
    Abstract [en]

    The next generation of lithium based batteries can be expected to be based on lithium alloy forming anode materials which can store up to ten times more charge than the currently used graphite anodes. This increase in the charge storage capability has motivated significant research towards the commercialization of anode materials such as Si, Sn and Al. These alloy forming anode materials are, however, known to exhibit significant capacity losses during cycling. This is typically ascribed to the volume expansion associated with the formation of the lithium alloys (the volume expansion is e.g. about 280 % for Li3.75Si) resulting in electrode pulverization as well as continuous solid electrolyte interphase (SEI) layer formation [1-3]. While significant progress has been made to decrease the volume expansion problems by the use of e.g. nanoparticles, nanorods and thin films, and/or capacity limitations [1-3], capacity losses are still generally seen [4,5]. This and previously published data suggest that the phenomenon may be due to another effect and that this in fact could stem from lithium trapping in the electrodes [6-8].

    In the present work it is demonstrated (based on e.g. elemental analyses of cycled Sn, Al and Si electrodes) that lithium trapping can account for the capacity losses seen when alloy forming anode materials are cycled versus lithium electrodes, see Figure 1. It is shown that small amounts of elemental lithium are trapped within the electrode material during the cycling as a result of a two-way diffusion process [8] causing the lithium to move into the bulk material even during the delithiation step. This phenomenon, which can be explained by the lithium concentration profiles in the electrodes, makes a complete delithiation process very time consuming. As a result of the lithium trapping effect, the lithium concentration in the electrode increases continuously during the cycling. The experimental results also show that a similar effect can be seen also for commonly used current collector metals such as Cu, Ni and Ti. The latter means that these metals are unsuitable as current collector materials for lithium alloy forming materials in the absence of a thin layer of boron doped diamond serving as a lithium diffusion barrier layer [8].

    References

    1    M. N. Obrovac and V. L. Chevrier, Chem. Rev., 2014, 114, 11444.

    2    X. Su, Q. Wu, J. Li, X. Xiao, A. Lott, W. Lu, B. W. Sheldon and J. Wu, Adv. Energy Mater., 2014, 4, 1300882.

    3    J. R. Szczech and S. Jin, Energy Environ. Sci., 2011, 4, 56.

    4    G. Zheng, S. W. Lee, Z. Liang, H-W. Lee, K. Yan, H. Yao, H. Wang, W. Li, S. Chu and Y. Cui, Nat. Nanotechnol., 2014, 9, 618.

    5    K. Yan, H-W. Lee, T. Gao, G. Zheng, H. Yao, H. Wang, Z. Lu, Y. Zhou, Z. Liang, Z. Liu, S. Chu and Y. Cui, Nano Letters, 2014, 14, 6016.

    6    G. Oltean, C-W. Tai, K. Edström and L. Nyholm, J. Power Sources, 2014, 269, 266.

    7    A. L. Michan, G. Divitini, A. J. Pell, M. Leskes, C. Ducati and C. P. Grey, J. Am. Chem. Soc., 2016, 138, 7918.

    8    D. Rehnlund, F. Lindgren, S. Böhme, T. Nordh, Y. Zou, J. Pettersson, U. Bexell, M. Boman, K. Edström and L. Nyholm, Energy Environ. Sci., 10 (2017) 1350.

     

  • 656.
    Rehnlund, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Pettersson, Jean
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Lithium trapping in microbatteries based on lithium- and Cu2O-coated copper nanorods2018In: ChemistrySelect, E-ISSN 2365-6549, Vol. 3, no 8, p. 2311-2314Article in journal (Refereed)
    Abstract [en]

    Microbatteries based on three-dimensional (3D) electrodes composed of thin films of Li and Cu2O coated on Cu nanorod current collectors by electrodeposition and spontaneous oxidation, respectively, are described and characterised electrochemically. High-resolution scanning electron microscopy (HR-SEM) data indicate that the Li electrodeposition resulted in a homogenous coverage of the Cu nanorods and elemental analyses were also used to determine the amount of lithium in the Li-coated electrodes. The results show that 3D Cu2O/Cu electrodes can be cycled versus 3D Li/Cu electrodes but that the capacity decreased during the cycling due to Li trapping in the Cu current collector of the 3D Li/Cu electrode. These findings highlight the problem of using copper current collectors together with metallic lithium as the formation of a solid solution yields considerable losses of electroactive lithium and hence capacity.

  • 657.
    Rehnlund, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Pettersson, Jean
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Microbatteries based on 3D Li and Cu2O coated Cu nanorodsManuscript (preprint) (Other academic)
  • 658.
    Rehnlund, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Valvo, Mario
    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.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Electrodeposition of Vanadium Oxide/Manganese Oxide Hybrid Thin Films on Nanostructured Aluminum Substrates2014In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 161, no 10, p. D515-D521Article in journal (Refereed)
    Abstract [en]

    Electrodeposition of functional coatings on aluminum electrodes in aqueous solutions often is impeded by the corrosion of aluminum. In the present work it is demonstrated that electrodeposition of vanadium, oxide films on nanostructured aluminum substrates can be achieved in acidic electrolytes employing a novel strategy in which a thin interspacing layer of manganese oxide is first electrodeposited on aluminum microrod substrates. Such deposited films, which were studied using SEM, XPS, XRD, and surface enhances Raman scattering as well as chronopotentiometry, are shown to comprise a mixture of vanadium oxidation states (i.e. IV and V). As this all-electrochemical approach circumvents the problems associated with aluminum corrosion, the approach provides new possibilities for the electrochemical coating of nanostructured Al substrates with functional layers of metal oxides. The latter significantly facilitates the development of new procedures for the manufacturing of three-dimensional aluminum based electrodes for lithium ion microbatteries. (C) The Author(s) 2014. Published by ECS. All rights reserved.

  • 659.
    Rehnlund, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Valvo, Mario
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Tai, Cheuk-Wai
    Stockholm University.
    Ångstrom, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry. Stockholm University.
    Sahlberg, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Electrochemical fabrication and characterization of Cu/Cu2O multi-layered micro and nanorods in Li-ion batteries2015In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 7, no 32, p. 13591-13604Article in journal (Refereed)
    Abstract [en]

    Electrodes composed of freestanding nano- and microrods composed of stacked layers of copper and cuprous oxide have been fabricated using a straightforward one-step template-assisted pulsed galvanostatic electrodeposition approach. The approach provided precise control of the thickness of each individual layer of the high-aspect-ratio rods as was verified by SEM, EDS, XRD, TEM and EELS measurements. Rods with diameters of 80, 200 and 1000 nm were deposited and the influence of the template pore size on the structure and electrochemical performance of the conversion reaction based electrodes in lithium-ion batteries was investigated. The multi-layered Cu2O/Cu nano-and microrod electrodes exhibited a potential window of more than 2 V, which was ascribed to the presence of a distribution of Cu2O (and Cu, respectively) nanoparticles with different sizes and redox potentials. As approximately the same areal capacity was obtained independent of the diameter of the multi-layered rods the results demonstrate the presence of an electroactive Cu2O layer with a thickness defined by the time domain of the measurements. It is also demonstrated that while the areal capacity of the electrodes decreased dramatically when the scan rate was increased from 0.1 to 2 mV s(-1), the capacity remained practically constant when the scan rate was further increased to 100 mV s(-1). This behaviour can be explained by assuming that the capacity is limited by the lithium ion diffusion rate though the Cu2O layer generated during the oxidation step. The electrochemical performance of present type of 3-D multi-layered rods provides new insights into the lithiation and delithiation reactions taking place for conversion reaction materials such as Cu2O.

  • 660.
    Rehnlund, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Valvo, Mario
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Tai, Cheuk-Wai
    Stockholm University.
    Ångström, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Sahlberg, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Electrochemical fabrication of 3D Cu/Cu2O multilayered nanostructures2015Conference paper (Other academic)
    Abstract [en]

    The possibility of engineering multilayered nanostructures and coatings with a wide variety of compositions has in the last decades attracted a great deal of scientific interest. In fact, multilayered structures with tailored properties have been investigated for solar conversion [1], the semiconductor industry [2] and tribological systems [3].Electrochemical engineering has emerged as a particularly promising technique for fabrication of nanostructured electrodes with excellent control on morphology [4]. The technique shows great promise in the copper system as Cu/Cu2O multilayers have been produced by allowing spontaneous potential oscillations to dictate the deposition [5, 6].Although this natural phenomenon provides a simple route to obtain mixedcomposition, improved control is required to obtain fine detailed multilayers. The presented study has been focused on preventing spontaneous potential oscillations to provide controlled deposition of Cu/Cu2O multilayers. In addition copper based multilayers have hereby been transported into the world of 3D electrodes via a one-step electrodeposition fabrication.

    Figure 1: Multilayered Cu/Cu2O nanopillars fabricated through electrodeposition.

    References

    1. W. Wei, et al.. Advanced Materials, 2010. 22: p. 4770-4774.

    2. G. Binasch, et al.. Physical Review B, 1989. 39: p. 4828-4830.

    3. P. E. Hovsepian, et al.. Surface and Coatings Technology, 1999. 116-119: p.727-734.

    4. K. Edström, et al.. The Electrochemical Society Interface, 2011. 20: p. 41-46.

    5. J. Eskhult, et al.. Journal of Electroanalytical Chemistry, 2006. 594: p. 35-49.6. S. Leopold, et al.. Electrochimica Acta, 2002. 47

  • 661.
    Renault, Stevén
    et al.
    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.
    Gustafsson, Torbjörn
    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.
    Improving the electrochemical performance of organic Li-ion battery electrodes2013In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 49, no 19, p. 1945-1947Article in journal (Refereed)
    Abstract [en]

    Dilithium benzenediacrylate was prepared and investigated as an example of a readily available organic electrode material for lithium-ion batteries. Its poor conductive properties were overcome by a method of carbon-coating in the liquid state, resulting in enhanced cycling performance, displaying a reversible capacity of 180 mA h g(-1).

  • 662.
    Renault, Stevén
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Mihali, Viorica Alina
    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.
    Optimizing the electrochemical performance of water-soluble organic Li-ion battery electrodes2013In: Electrochemistry communications, ISSN 1388-2481, E-ISSN 1873-1902, Vol. 34, p. 174-176Article in journal (Refereed)
    Abstract [en]

    A method for improving the electrode formulation of organic Li-ion battery active materials is reported here. By combining freeze-drying and carbon-coating in the liquid state, an improved morphology of the electrode and the material can be achieved. The carbon content proved to be vital for the electrochemical performance due to its high dispersion when the active material particle size decreases. Reasonable capacity (>150 mAh/g) was shown for dilithium benzenediacrylate at 2C during 50 cycles. 

  • 663.
    Renault, Stevén
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Oltean, Viorica Alina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Ebadi, Mahsa
    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.
    Dilithium 2-aminoterephthalate as a negative electrode material for lithium-ion batteries2017In: Solid State Ionics, ISSN 0167-2738, E-ISSN 1872-7689, Vol. 307, p. 1-5Article in journal (Refereed)
    Abstract [en]

    This work presents the synthesis and characterization of a novel organic Li-battery anode material: dilithium 2-aminoterephthalate (C8H5Li2NO4). When investigated in Li half-cells, the resulting electrodes show stable capacities around ca. 180 mAh g− 1 and promising rate capabilities, with battery performance at 500 mA g− 1 and good capacity recovery, despite being an asymmetric compound. DFT calculations indicate a preferential lithiation on carboxylates close to the amino group.

  • 664.
    Renault, Stéven
    et al.
    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.
    Environmentally-Friendly Lithium Recycling From a Spent Organic Li-Ion Battery2014In: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 7, no 10, p. 2859-2867Article in journal (Refereed)
    Abstract [en]

    A simple and straightforward method using non-polluting solvents and a single thermal treatment step at moderate temperature was investigated as an environmentally-friendly process to recycle lithium from organic electrode materials for secondary lithium batteries. This method, highly dependent on the choice of electrolyte, gives up to 99% of sustained capacity for the recycled materials used in a second life-cycle battery when compared with the original. The best results were obtained using a dimethyl carbonate/lithium bis(trifluoromethane sulfonyl) imide electrolyte that does not decompose in presence of water. The process implies a thermal decomposition step at a moderate temperature of the extracted organic material into lithium carbonate, which is then used as a lithiation agent for the preparation of fresh electrode material without loss of lithium.

  • 665.
    Renault, Stéven
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Mihali, Viorica Alina
    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.
    Stability of organic Na-ion battery electrode materials: The case of disodium pyromellitic diimidate2014In: Electrochemistry communications, ISSN 1388-2481, E-ISSN 1873-1902, Vol. 45, p. 52-55Article in journal (Refereed)
    Abstract [en]

    A novel organic Na-salt is presented here for utilization as an active electrode material in rechargeable Na-ion batteries. The compound, disodium pyromellitic diimidate, is synthesized through a reaction by pyromellitic acid and sodium hydride and characterized using H-1-NMR. Na-batteries of the organic compound were able to obtain capacity values close to the theoretical during the first cycles, but a steady capacity decrease could be observed during cycling. The battery nevertheless delivered a capacity of ca 90 mAh/g after 100 cycles, rendering it a comparatively competitive organic Na-battery material. However, the results stress the importance of tailoring Na-compounds with a good chemical stability also at high levels of sodiation, since decomposition side-reactions can be probable. 

  • 666.
    Renault, Stéven
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Oltean, Viorica Alina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Araujo, C. Moyses
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Grigoriev, Anton
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    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.
    Superlithiation of Organic Electrode Materials: The Case of Dilithium Benzenedipropiolate2016In: Chemistry of Materials, Vol. 28, no 6, p. 1920-1926Article in journal (Refereed)
    Abstract [en]

    Dilithium benzenedipropiolate was prepared and investigated as a potential negative electrode material for secondary lithium-ion batteries. In addition to the expected reduction of its carbonyls, this material can reduce and reversibly oxidize its unsaturated carbon–carbon bonds leading to a Li/C ratio of 1/1 and a specific capacity as high as 1363 mAh g–1: the highest ever reported for a lithium carboxylate. Density functional theory calculations suggest that the lithiation is preferential on the propiolate carbons.

  • 667.
    Renman, Viktor
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry. Uppsala universitet.
    Structural and Electrochemical Relations in Electrode Materials for Rechargeable Batteries2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Rechargeable batteries have already conquered the market of portable electronics (i.e., mobile phones and laptops) and are set to further enable the large-scale deployment of electric vehicles and hybrid electric vehicles in a not too distant future. In this context, a deeper understanding of the fundamental processes governing the electrochemical behavior of electrode materials for batteries is required for further development of these applications. The aims of the work described in this thesis have been to investigate how electrochemical properties and structural properties of novel electrode materials relate to each other. In this sense, electrochemical characterization, structural analysis using XRD and their combined simultaneous use via in operando XRD experiments have played a crucial part.

    The investigations showed that: Two oxohalides, Ni3Sb4O6F6 and Mn2Sb3O6Cl, react with Li-ions in a complex manner involving different types of reaction mechanisms at low voltages in Li half cells. In operando XRD show that both of these materials are reduced in a conversion reaction via an in situ formation of nanocomposites, which proceed to react reversibly with Li-ions in a combination of alloying and conversion reactions.

    Carbon-coated Na2Mn2Si2O7 was synthesized and characterized as a possible positive electrode material for non-aqueous Na-ion batteries. DFT calculations point to a structural origin of the modest electrochemical behavior of this material. It is suggested that structural rearrangements upon desodiation are associated with large overpotentials.

    It is demonstrated via an in operando synchrotron XRD study that Fe(CN)6 vacancies in copper hexacyanoferrate (CuHCF) play an important role in the electrochemical behavior toward Zn2+ in an aqueous CuHCF/Zn cell. Furthermore, manganese hexacyanomanganate (MnHCM) is shown to react reversibly with Li+, Na+ and K+ in non-aqueous alkali metal half cells. In contrast to CuHCF, which is a zero-strain material, MnHCM undergoes a series of structural transitions (from monoclinic to cubic) during electrochemical cycling.

    List of papers
    1. Ni3Sb4O6F6 and Its Electrochemical Behavior toward Lithium-A Combination of Conversion and Alloying Reactions
    Open this publication in new window or tab >>Ni3Sb4O6F6 and Its Electrochemical Behavior toward Lithium-A Combination of Conversion and Alloying Reactions
    Show others...
    2016 (English)In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 28, no 18, p. 6520-6527Article in journal (Refereed) Published
    Abstract [en]

    A group of oxohalides, where Ni3Sb4O6F6 is one example, has been investigated with respect to its electrochemical reactions toward Li+/Li. In situ and ex situ XRD measurements reveal that the original structure collapses and the material becomes amorphous upon insertion of Li at low potentials versus Li+/Li. With continued cycling, a nanocrystalline phase of NiSb, which reacts reversibly with Li, appears and steadily grows more stable. Electrochemical experiments (i.e., chronopotentiometry and cyclic voltammetry) show that multiple reactions of both conversion- and alloying-type are active in the system. High storage capacities are achieved initially but with rapid fading as a consequence of a limited reversibility of the Ni2+/Ni redox process, as shown by X-ray absorption spectroscopy of the first discharge/charge cycle. Stable cycling can be achieved by optimizing the cutoff potentials (i.e., excluding poorly reversible reactions at high and low voltages, respectively), yielding long-term cycling with a practical gravimetric capacity of similar to 200 mAh g(-1).

    National Category
    Materials Chemistry
    Identifiers
    urn:nbn:se:uu:diva-307284 (URN)10.1021/acs.chemmater.6b01914 (DOI)000384399000015 ()
    Funder
    Swedish Research Council, 2011-6512
    Available from: 2016-11-11 Created: 2016-11-11 Last updated: 2017-11-29Bibliographically approved
    2. Investigation of the Structural and Electrochemical Properties of Mn2Sb3O6CI upon Reaction with Li Ions
    Open this publication in new window or tab >>Investigation of the Structural and Electrochemical Properties of Mn2Sb3O6CI upon Reaction with Li Ions
    Show others...
    2017 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 121, no 11, p. 5949-5958Article in journal (Refereed) Published
    Abstract [en]

    The structural and electrochemical properties of a quaternary layered compound with elemental composition Mn2Sb3O6Cl have been investigated upon reaction with lithium in Li half cells. Operando XRD was used to investigate the potential impact of this particular layered structure on the lithiation process. Although the results suggest that the material is primarily reacted through a conventional conversion mechanism, they also provide some hints that the space between the slabs may act as preferential entry points for lithium ions but not for the larger sodium ions. Cyclic voltammetry, galvanostatic cycling, HRTEM, SAED, and EELS analyses were performed to unravel the details of the reaction mechanism with the lithium ions. It is found that two pairs of reactions are mainly responsible for the reversible electrochemical cycling of this compound, namely, the alloying of Li-Sb and the conversion of MnxOy to metallic Mn with concomitant formation of Li2O upon lithium uptake. A moderate cycling stability is achieved with a gravimetric capacity of 467 mAh g(-1) after 100 cycles between 0.05 and 2.2 V vs Li+/Li despite the large particle sizes of the active material and its nonoptimal inclusion into composite coatings. The electrochemical activity of the title compound was also tested in Na half cells between 0.05 and 2 V vs Ne/Na. It was found that a prolonged period of electrochemical milling is required to fully gain access to the active material, after which the cell delivers a capacity of 350 mAh CI. These factors are demonstrated to clearly limit the ultimate performances for these electrodes.

    Place, publisher, year, edition, pages
    AMER CHEMICAL SOC, 2017
    National Category
    Nano Technology Materials Chemistry
    Identifiers
    urn:nbn:se:uu:diva-320200 (URN)10.1021/acs.jpcc.6b13092 (DOI)000397546300011 ()
    Funder
    Swedish Research Council, 2011-6512Swedish Research Council Formas, 245-2014-668Knut and Alice Wallenberg FoundationStandUp
    Available from: 2017-04-18 Created: 2017-04-18 Last updated: 2017-12-30
    3. Manganese Pyrosilicates as Novel Positive Electrode Materials for Na-Ion Batteries
    Open this publication in new window or tab >>Manganese Pyrosilicates as Novel Positive Electrode Materials for Na-Ion Batteries
    Show others...
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    A carbon-coated pyrosilicate, Na2Mn2Si2O7/C, was synthesized and characterized for use as a new positive-electrode material for sodium ion batteries. The material consists of primary 20-80 nm particles embedded in a ≈10 nm-thick conductive carbon matrix. Reversible insertion of Na+ ions is clearly demonstrated with ≈25% of its theoretical capacity (165 mAh/g) accessible at room temperature at a low cycling rate. The material yields an average potential of 3.3 V vs. Na+/Na on charge and 2.2 V on discharge. DFT calculations predict an equilibrium potential for Na2Mn2Si2O7 in the range of 2.8-3.0 V vs. Na+/Na, with a possibility of a complete flip in the connectivity of neighboring Mn-polyhedra – from edge-sharing to disconnected and vice versa. This significant rearrangement in Mn coordination  (≈2 Å) and large volume contraction (>10%) could explain our inability to fully desodiate the material, and illustrates well the need for a new electrode design strategy beyond the conventional “down-sizing/coating” procedure.

    National Category
    Inorganic Chemistry
    Research subject
    Chemistry
    Identifiers
    urn:nbn:se:uu:diva-334063 (URN)
    Funder
    StandUp
    Available from: 2017-11-20 Created: 2017-11-20 Last updated: 2018-01-08
    4. Structural-electrochemical relations in the aqueous copper hexacyanoferrate-zinc system examined by synchrotron X-ray diffraction
    Open this publication in new window or tab >>Structural-electrochemical relations in the aqueous copper hexacyanoferrate-zinc system examined by synchrotron X-ray diffraction
    Show others...
    2017 (English)In: Journal of Power Sources, ISSN 0378-7753, E-ISSN 1873-2755, Vol. 369, p. 146-153Article in journal (Refereed) Published
    Abstract [en]

    The storage process of Zn2+ in the Prussian blue analogue (PBA) copper hexacyanoferrate (Cu[Fe(CN)6]2/3-nH2O - CuHCF) framework structure in a context of rechargeable aqueous batteries is examined by means of in operando synchrotron X-ray diffraction. Via sequential unit-cell parameter refinements of time-resolved diffraction data, it is revealed that the step-profile of the cell output voltage curves during repeated electrochemical insertion and removal of Zn2+ in the CuHCF host structure is associated with a non-linear contraction and expansion of the unit-cell in the range 0.36 < x < 1.32 for Znx/3Cu[Fe(CN)6]2/3-nH2O. For a high insertion cation content there is no apparent change in the unit-cell contraction. Furthermore, a structural analysiswith respect to the occupancies of possible Zn2+ sites suggests that the Fe(CN)6 vacancies within the CuHCF framework play an important role in the structural-electrochemical behavior of this particular system. More specifically, it is observed that Zn2+ swaps position during electrochemical cycling, hopping between cavity sites to vacant ferricyanide sites.

    Keywords
    Prussian blue analogues, Copper hexacyanoferrate, Zinc, Aqueous electrochemical energy storage, In operando X-ray diffraction, Synchrotron radiation
    National Category
    Inorganic Chemistry
    Research subject
    Chemistry
    Identifiers
    urn:nbn:se:uu:diva-334062 (URN)10.1016/j.jpowsour.2017.09.079 (DOI)000413799900018 ()
    Funder
    Swedish Research Council, 2011-6512Swedish Research Council Formas, 245-2014-668
    Available from: 2017-11-20 Created: 2017-11-20 Last updated: 2018-02-05Bibliographically approved
    5. A comparative study of manganese hexacyanomanganate as a positive electrode for non-aqueous Li-, Na- and K-ion batteries
    Open this publication in new window or tab >>A comparative study of manganese hexacyanomanganate as a positive electrode for non-aqueous Li-, Na- and K-ion batteries
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Inorganic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-334075 (URN)
    Funder
    StandUp
    Available from: 2017-11-20 Created: 2017-11-20 Last updated: 2017-12-30
  • 668.
    Renman, Viktor
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Hu, Shichao
    Stockholm Univ, Dept Mat & Environm Chem, SE-10691 Stockholm, Sweden..
    Eriksson, Rickard
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Maibach, Julia
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Johnsson, Mats
    Stockholm Univ, Dept Mat & Environm Chem, SE-10691 Stockholm, Sweden..
    Gómez, Cesar Pay
    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.
    Ni3Sb4O6F6 and Its Electrochemical Behavior toward Lithium-A Combination of Conversion and Alloying Reactions2016In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 28, no 18, p. 6520-6527Article in journal (Refereed)
    Abstract [en]

    A group of oxohalides, where Ni3Sb4O6F6 is one example, has been investigated with respect to its electrochemical reactions toward Li+/Li. In situ and ex situ XRD measurements reveal that the original structure collapses and the material becomes amorphous upon insertion of Li at low potentials versus Li+/Li. With continued cycling, a nanocrystalline phase of NiSb, which reacts reversibly with Li, appears and steadily grows more stable. Electrochemical experiments (i.e., chronopotentiometry and cyclic voltammetry) show that multiple reactions of both conversion- and alloying-type are active in the system. High storage capacities are achieved initially but with rapid fading as a consequence of a limited reversibility of the Ni2+/Ni redox process, as shown by X-ray absorption spectroscopy of the first discharge/charge cycle. Stable cycling can be achieved by optimizing the cutoff potentials (i.e., excluding poorly reversible reactions at high and low voltages, respectively), yielding long-term cycling with a practical gravimetric capacity of similar to 200 mAh g(-1).

  • 669.
    Renman, Viktor
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Ojwang, Dickson O.
    Stockholm Univ, Dept Mat & Environm Chem, SE-10691 Stockholm, Sweden.
    Gómez, Cesar Pay
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Gustafsson, Torbjörn
    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.
    Svensson, Gunnar
    Stockholm Univ, Dept Mat & Environm Chem, SE-10691 Stockholm, Sweden.
    Valvo, Mario
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Manganese Hexacyanomanganate as a Positive Electrode for Nonaqueous Li-, Na-, and K-Ion Batteries2019In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 123, no 36, p. 22040-22049Article in journal (Refereed)
    Abstract [en]

    K2Mn[Mn(CN)(6)] is synthesized, characterized, and evaluated as possible positive electrode material in nonaqueous Li-, Na-, and K-ion batteries. This compound belongs to the rich and versatile family of hexacyanometallates displaying distinctive structural properties, which makes it interesting for ion insertion purposes. It can be viewed as a perovskite-like compound in which CN-bridged Mn(CN)(6) octahedra form an open framework structure with sufficiently large diffusion channels able to accommodate a variety of insertion cations. By means of galvanostatic cycling and cyclic voltammetry tests in nonaqueous alkali metal half-cells, it is demonstrated that this material is able to reversibly host Li+, Na+, and K+ ions via electrochemical insertion/deinsertion within a wide voltage range. The general electrochemical features are similar for all of these three ion insertion chemistries. An in operando X-ray diffraction investigation indicates that the original monoclinic structure is transformed into a cubic one during charging (i.e., removal of cations from the host framework) and that such a process is reversible upon subsequent cell discharge and cation reuptake.

  • 670.
    Renman, Viktor
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Ojwang, Dickson O.
    Stockholm University, Stockholm, Sweden.
    Valvo, Mario
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Gómez, Cesar Pay
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Gustafsson, Torbjörn
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Svensson, Gunnar
    Stockholm University, Stockholm, Sweden.
    Structural-electrochemical relations in the aqueous copper hexacyanoferrate-zinc system examined by synchrotron X-ray diffraction2017In: Journal of Power Sources, ISSN 0378-7753, E-ISSN 1873-2755, Vol. 369, p. 146-153Article in journal (Refereed)
    Abstract [en]

    The storage process of Zn2+ in the Prussian blue analogue (PBA) copper hexacyanoferrate (Cu[Fe(CN)6]2/3-nH2O - CuHCF) framework structure in a context of rechargeable aqueous batteries is examined by means of in operando synchrotron X-ray diffraction. Via sequential unit-cell parameter refinements of time-resolved diffraction data, it is revealed that the step-profile of the cell output voltage curves during repeated electrochemical insertion and removal of Zn2+ in the CuHCF host structure is associated with a non-linear contraction and expansion of the unit-cell in the range 0.36 < x < 1.32 for Znx/3Cu[Fe(CN)6]2/3-nH2O. For a high insertion cation content there is no apparent change in the unit-cell contraction. Furthermore, a structural analysiswith respect to the occupancies of possible Zn2+ sites suggests that the Fe(CN)6 vacancies within the CuHCF framework play an important role in the structural-electrochemical behavior of this particular system. More specifically, it is observed that Zn2+ swaps position during electrochemical cycling, hopping between cavity sites to vacant ferricyanide sites.

  • 671.
    Renman, Viktor
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Ojwang, Dickson O.
    Stockholm University.
    Valvo, Mario
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Pay Gómez, Cesar
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Johnsson, Mats
    Stockholm University.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    A comparative study of manganese hexacyanomanganate as a positive electrode for non-aqueous Li-, Na- and K-ion batteriesManuscript (preprint) (Other academic)
  • 672.
    Renman, Viktor
    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.
    Tai, Cheuk-Wai
    Stockholm Univ, Dept Mat & Environm Chem, Stockholm, Sweden.
    Gómez, Cesar Pay
    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.
    Liivat, Anti
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Manganese pyrosilicates as novel positive electrode materials for Na-ion batteries2018In: SUSTAINABLE ENERGY & FUELS, ISSN 2398-4902, Vol. 2, no 5, p. 941-945Article in journal (Refereed)
    Abstract [en]

    A carbon-coated pyrosilicate, Na2Mn2Si2O7/C, was synthesized and characterized for use as a new positive-electrode material for sodium ion batteries. The material consists of 20–80 nm primary particles embedded in a ≈10 nm-thick conductive carbon matrix. Reversible insertion of Na+ ions is clearly demonstrated with ≈25% of its theoretical capacity (165 mA h g−1) being accessible at room temperature at a low cycling rate. The material yields an average potential of 3.3 V vs. Na+/Na on charge and 2.2 V on discharge. DFT calculations predict an equilibrium potential for Na2Mn2Si2O7 in the range of 2.8–3.0 V vs. Na+/Na, with a possibility of a complete flip in the connectivity of neighboring Mn-polyhedra – from edge-sharing to disconnected and vice versa. This significant rearrangement in Mn coordination (≈2 Å) and large volume contraction (>10%) could explain our inability to fully desodiate the material, and illustrates well the need for a new electrode design strategy beyond the conventional “down-sizing/coating” procedure.

  • 673.
    Renman, Viktor
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Valvo, Mario
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Tai, Cheuk-Wai
    Stockholm University.
    Pay Gómez, Cesar
    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.
    Liivat, Anti
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Manganese Pyrosilicates as Novel Positive Electrode Materials for Na-Ion BatteriesManuscript (preprint) (Other academic)
    Abstract [en]

    A carbon-coated pyrosilicate, Na2Mn2Si2O7/C, was synthesized and characterized for use as a new positive-electrode material for sodium ion batteries. The material consists of primary 20-80 nm particles embedded in a ≈10 nm-thick conductive carbon matrix. Reversible insertion of Na+ ions is clearly demonstrated with ≈25% of its theoretical capacity (165 mAh/g) accessible at room temperature at a low cycling rate. The material yields an average potential of 3.3 V vs. Na+/Na on charge and 2.2 V on discharge. DFT calculations predict an equilibrium potential for Na2Mn2Si2O7 in the range of 2.8-3.0 V vs. Na+/Na, with a possibility of a complete flip in the connectivity of neighboring Mn-polyhedra – from edge-sharing to disconnected and vice versa. This significant rearrangement in Mn coordination  (≈2 Å) and large volume contraction (>10%) could explain our inability to fully desodiate the material, and illustrates well the need for a new electrode design strategy beyond the conventional “down-sizing/coating” procedure.

  • 674.
    Renman, Viktor
    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.
    Tai, Cheuk-Wai
    Stockholm Univ, Dept Mat & Environm Chem, SE-10691 Stockholm, Sweden..
    Zimmermann, Iwan
    Stockholm Univ, Dept Mat & Environm Chem, SE-10691 Stockholm, Sweden.;EPFL Valais Wallis, EPFL SCI SB MN, Rue IIndustrie 17, CH-1951 Sion, Switzerland..
    Johnsson, Mats
    Stockholm Univ, Dept Mat & Environm Chem, SE-10691 Stockholm, Sweden..
    Gómez, Cesar Pay
    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.
    Investigation of the Structural and Electrochemical Properties of Mn2Sb3O6CI upon Reaction with Li Ions2017In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 121, no 11, p. 5949-5958Article in journal (Refereed)
    Abstract [en]

    The structural and electrochemical properties of a quaternary layered compound with elemental composition Mn2Sb3O6Cl have been investigated upon reaction with lithium in Li half cells. Operando XRD was used to investigate the potential impact of this particular layered structure on the lithiation process. Although the results suggest that the material is primarily reacted through a conventional conversion mechanism, they also provide some hints that the space between the slabs may act as preferential entry points for lithium ions but not for the larger sodium ions. Cyclic voltammetry, galvanostatic cycling, HRTEM, SAED, and EELS analyses were performed to unravel the details of the reaction mechanism with the lithium ions. It is found that two pairs of reactions are mainly responsible for the reversible electrochemical cycling of this compound, namely, the alloying of Li-Sb and the conversion of MnxOy to metallic Mn with concomitant formation of Li2O upon lithium uptake. A moderate cycling stability is achieved with a gravimetric capacity of 467 mAh g(-1) after 100 cycles between 0.05 and 2.2 V vs Li+/Li despite the large particle sizes of the active material and its nonoptimal inclusion into composite coatings. The electrochemical activity of the title compound was also tested in Na half cells between 0.05 and 2 V vs Ne/Na. It was found that a prolonged period of electrochemical milling is required to fully gain access to the active material, after which the cell delivers a capacity of 350 mAh CI. These factors are demonstrated to clearly limit the ultimate performances for these electrodes.

  • 675.
    Rickard, Eriksson
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Adam, Sobkowiak
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Jonas, Ångström
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Martin, Sahlberg
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Torbjörn, Gustafsson
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Kristina, Edström
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Fredrik, Björefors
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Formation of Tavorite-Type LiFeSO4F Followed by In Situ X-ray DiffractionManuscript (preprint) (Other academic)
  • 676.
    Riva, Michele
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry. Hong Kong University of Science and Technology.
    Phase field modelling of LLZO/LCO cathode-electrolyte interfaces in solid state batteries2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This work describes two phase field models for the simulation of the interface evolution between a LiCoO2 cathode (LCO) and a Li7La3Zr2O12 solid electrolyte (LLZO) in a Li-metal/LLZO/LCO battery during high temperature sintering. In these conditions atomic species tend to diffuse into the opposing material, creating an intermediate layer of mixed composition which resists the movement of lithium ions. This undesired effect prevents the resulting solid-state battery to achieve its theoretical performances and needs to be avoided. The first model is an adaptation of the work of J. M. Hu et alii [1] for a similar interface problem encountered between yttria-stabilized zirconia electrolytes (YSZ) and lanthanum-strontium-manganite cathodes (LSM) in solid oxide fuelcells (SOFC), while the second is based on the work of D. A. Cogswell [2][3] for phase separation in metal alloys, extended to include electrostatic effects due to internal charge unbalances and externally applied electric fields. Animplementation of the latter is however lacking, and the interested reader is encouraged to build one up on the theoretical framework presented in this paper. In the conclusion section it is possible to find insights on how to prevent the interfacial diffusion between LCO and LLZO with reference to experimental attempts and simulations, as well as future directions for the development of the models.

  • 677.
    Roberts, Matthew
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Biendicho, J. J.
    ISIS Rutherford Appleton Laboratory UK.
    Hull, S.
    ISIS Rutherford Appleton Laboratory UK.
    Beran, P.
    Gustafsson, Torbjörn
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Svensson, G.
    Stockholm University.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Design of a new lithium ion battery test cell for in-situ neutron diffraction measurements2013In: Journal of Power Sources, ISSN 0378-7753, E-ISSN 1873-2755, Vol. 226, p. 249-255Article in journal (Refereed)
    Abstract [en]

    This paper introduces a new cell design for the construction of lithium ion batteries with conventional electrochemical performance whilst allowing in situ neutron diffraction measurement. A cell comprising of a wound cathode, electrolyte and anode stack has been prepared. The conventional hydrogen-containing components of the cell have been replaced by hydrogen-free equivalents. The electrodes are fabricated using a PTFE binder, the electrolyte consists of deuterated solvents which are supported in a quartz glass fibre separator. Typical battery performance is reported using the hydrogen-free components with a specific capacity of 140 mA h g-1 being observed for LiFePO4 at a rate of 0.2 C. Neutron diffraction patterns of full cells were recorded with phase change reactions monitored. When aluminium packaging was used a better signal to noise ratio was obtained. The obtained atomic positions and lattice parameters for all cells investigated were found to be consistent with parameters refined from the diffraction pattern of a powder of the pure electrode material. This paper highlights the pertinent points in designing cells for these measurements and addresses some of the problems.

  • 678.
    Roberts, Matthew
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Huang, An Feng
    Johns, Phil
    Owen, John
    Dip-spin coating of reticulated vitreous carbon with composite materials to act as an electrode for 3D microstructured lithium ion batteries2013In: Journal of Power Sources, ISSN 0378-7753, E-ISSN 1873-2755, Vol. 224, p. 250-259Article in journal (Refereed)
    Abstract [en]

    This paper describes a new and economic route for the formation of three dimensional (3D) microstructured battery electrodes using our "in house" developed dip-spin coating technique for depositing layers of active material onto reticulated vitreous carbon (RVC) substrates. These coatings are optimized composite materials containing carbon black and polymer binder to facilitate good electronic and ionic conductivities through the electrode. The application process begins by immersing the substrate in an ink followed by rapid spinning to provide a uniform coating with a well controlled mass loading. The performance of the electrodes was investigated in lithium ion cells as a function of the composition of the inks used and the number of dip-spin coating cycles. Optimization of the ink composition, dip and spin parameters has improved the electrochemical performances of the electrodes to give state of the art footprint area specific capacities (>1000 mu A h cm(-2)) and high rate capabilities (nearly 50% degree of discharge at 25 C) in lithium half cells. This represents the first stage in the development of a full 3D microbattery system. Initial results have also shown the versatility of this approach in depositing other electrode materials by forming uniform layers of both TiO2 and LiMn2O4.

  • 679.
    Roberts, Matthew
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Johns, Phil
    University of Southampton UK.
    Owen, John
    University of Southampton UK.
    Brandell, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    El Enany, Gaber
    Guery, Claude
    LRCS Université de Picardie Amiens France.
    Golodnitsky, Diana
    Tel-Aviv University Israel.
    Lacey, Mattew
    University of Southampton UK.
    Lecoeur, Cyrille
    Mazor, Hadar
    Peled, Emanuel
    Tel Aviv University Israel.
    Perre, Emilie
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Structural Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Shaijumon, Manikoth M.
    Simon, Patrice
    Taberna, Pierre-Louis
    3D lithium ion batteries-from fundamentals to fabrication2011In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 21, no 27, p. 9876-9890Article in journal (Refereed)
    Abstract [en]

    3D microbatteries are proposed as a step change in the energy and power per footprint of surface mountable rechargeable batteries for microelectromechanical systems (MEMS) and other small electronic devices. Within a battery electrode, a 3D nanoarchitecture gives mesoporosity, increasing power by reducing the length of the diffusion path; in the separator region it can form the basis of a robust but porous solid, isolating the electrodes and immobilising an otherwise fluid electrolyte. 3D microarchitecture of the whole cell allows fabrication of interdigitated or interpenetrating networks that minimise the ionic path length between the electrodes in a thick cell. This article outlines the design principles for 3D microbatteries and estimates the geometrical and physical requirements of the materials. It then gives selected examples of recent progress in the techniques available for fabrication of 3D battery structures by successive deposition of electrodes, electrolytes and current collectors onto microstructured substrates by self-assembly methods.

  • 680.
    Roberts, Matthew
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Younesi, Reza
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Richardson, William
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Liu, Jia
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Gustafsson, Torbjorn
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Zhu, Jiefang
    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.
    Increased Cycling Efficiency of Lithium Anodes in Dimethyl Sulfoxide Electrolytes For Use in Li-O-2 Batteries2014In: ECS ELECTROCHEM LETT, ISSN 2162-8726, Vol. 3, no 6, p. A62-A65Article in journal (Refereed)
    Abstract [en]

    High lithium cycling efficiencies are required if a metal anode system is to be considered for use in Li-O-2 batteries. In this work electrolyte additives (0.3 M LiNO3 and 0.14 M VC) were used to increase the efficiency from 25 to 82.5% in the topical DMSO based electrolyte. Furthermore, we show that oxygen also acts to improve the cycling efficiency to 87%. This work highlights the importance of anode considerations in the development of metal O-2 batteries in alternative solvents (DMSO, Acetonitrile and DMA) and suggests realistic strategies for performance improvements. (C)The Author(s) 2014. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. All rights reserved.

  • 681. Röckert, Andreas
    et al.
    Pazoki, Meysam
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry. 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.
    Methylammonium lanthanide iodide perovskites as lead free alternatives for solar cell materials2017Conference paper (Other academic)
  • 682.
    Saadoune, Ismael
    et al.
    LCME, University Cadi Ayyad, Marrakech, Morocco.
    Dahbi, Mohammed
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Wikberg, Magnus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Gustafsson, Torbjörn
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Svedlindh, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Effect of the synthesis temperature on the structure and electrochemical behaviour of the LiNi0.65Co0.25Mn0.1O2 positive electrode material2008In: Solid State Ionics, ISSN 0167-2738, E-ISSN 1872-7689, Vol. 178, no 31-32, p. 1668-1675Article in journal (Refereed)
    Abstract [en]

    Three kinds of LiNi0.65Co0.25Mn0.1O2 samples were prepared using a combustion method at different synthetic conditions (C1: 900 °C/1 h; C2: 900 °C/12 h and C3: 1000 °C/12 h). The samples were characterized using X-ray diffraction, scanning electron microscopy and magnetization measurements before their use as positive electrode material in lithium-ion batteries. Sample C1 presents the most ordered structure with less than 3% of nickel ions in the lithium plane. Increasing synthesis temperature and/or time lead to an increase of the Li/Ni disorder. The amount of extra-nickel ions in the lithium plane strongly affects the magnetic behaviour and the electrochemical performances of the prepared material. LiNi0.65Co0.25Mn0.1O2 prepared at 900 °C for 1 h presents the best cycling properties.

  • 683.
    Saadoune, Ismael
    et al.
    Univ Cadi Ayyad, Lab Chim Mat & Environm, Ave A Khattabi,BP 549, Marrakech, Morocco..
    Lasri, Karima
    Univ Cadi Ayyad, Lab Chim Mat & Environm, Ave A Khattabi,BP 549, Marrakech, Morocco..
    Bezza, Ilham
    Univ Cadi Ayyad, Lab Chim Mat & Environm, Ave A Khattabi,BP 549, Marrakech, Morocco.;KIT, IAM, D-76344 Eggenstein Leopoldshafen, Germany..
    Indris, Sylvio
    KIT, IAM, D-76344 Eggenstein Leopoldshafen, Germany..
    Brandell, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry. Uppsala Univ, Dept Chem, Angstrom Lab, SE-75121 Uppsala, Sweden..
    Ehrenberg, Helmut
    KIT, IAM, D-76344 Eggenstein Leopoldshafen, Germany..
    Electrode Materials Based On Phosphates For Lithium Ion Batteries As An Efficient Energy Storage System2015In: Proceedings of the TMS Middle East - Mediterranean Materials Congress on Energy and Infrastructure Systems (MEMA 2015) / [ed] Karaman, I; Arroyave, R; Masad, E, WILEY-BLACKWELL , 2015, p. 343-349Conference paper (Refereed)
    Abstract [en]

    Co0.5TiOPO4 and LiFe0.4Mn0.6PO4 phosphates present the electrochemical features of anode and cathode of lithium ion batteries, respectively. The cobalt oxyphosphate exhibits a high capacity and a working potential around 1.5 V. During the first discharge, an irreversible lithiation reaction occurs while during the subsequent cycles, a good reversibility of the charge/discharge process was obtained with a stable specific capacity approaching 280 mAh/g even at high rate. For the LiFe0.4Mn0.6PO4 olivine, the electrochemical process occurs in two steps involving separately two redox couples: Mn3+/Mn2+ and Fe3+/Fe2+. The electrochemical lithiation/delithiation occur without significant changes in the structure. Even if the obtained capacity ( 110 mAh/g), is lower that the theoretical one, the coulombic storage efficiency is rather good ( 95%).

  • 684.
    Sahlberg, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Brant, William R.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Berger, Rolf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Real-time in situ monitoring of the topotactic transformation of TlCu5Se3 into metastable o-TlCu4Se32016In: Journal of Alloys and Compounds, ISSN 0925-8388, E-ISSN 1873-4669, Vol. 685, p. 436-441Article in journal (Refereed)
    Abstract [en]

    The transformation within the solid state of tetragonal TlCu5Se3 into the metastable orthorhombic form of TlCu4Se3 by oxidative copper leaching in concentrated ammonia solution has been studied in situ by conventional X-ray powder diffraction. The ease with which the reaction occurs illustrates a comparatively high diffusion coefficient typical of copper sulphides and selenides. The diffraction patterns of the parent phase as well as the product remain sharp during the process, indicating strong topotaxy in the first-order transformation that is effectuated by the access of oxygen while the accompanying released copper enters the liquid phase. The transformation was followed in a real-time mode, leading to a complete transformation of the amount probed.

  • 685.
    Sahlberg, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Ångström, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Zlotea, Claudia
    Beran, Premsyl
    Latroche, Michel
    Pay Gómez, Ceasar
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Structure and hydrogen storage properties of the hexagonal Laves phase Sc(Al1-xNix)22012In: Journal of Solid State Chemistry, ISSN 0022-4596, E-ISSN 1095-726X, Vol. 196, p. 132-137Article in journal (Refereed)
    Abstract [en]

    The crystal structures of hydrogenated and unhydrogenated Sc(Al 1-xNi x) 2 Laves phases have been studied by combining several diffraction techniques and it is shown that hydrogen is situated interstitially in the A 2B 2-sites, which have the maximum number of scandium neighbours. The hydrogen absorption/desorption behaviour has also been investigated. It is shown that a solid solution of hydrogen forms in the mother compound. The hydrogen storage capacity exceeds 1.7 H/f.u. at 374 K, and the activation energy of hydrogen desorption was determined to 4.6 kJ/mol H 2. It is shown that these compounds share the same local coordination as Frank-Kasper-type approximants and quasicrystals, which opens up the possibility of finding many new hydride phases with these types of crystal structures.

  • 686. Sala, Jonas
    et al.
    Guardia, Elvira
    Marti, Jordi
    Spångberg, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Masia, Marco
    Fitting properties from density functional theory based molecular dynamics simulations to parameterize a rigid water force field2012In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 136, no 5, p. 054103-Article in journal (Refereed)
    Abstract [en]

    In the quest towards coarse-grained potentials and new water models, we present an extension of the force matching technique to parameterize an all-atom force field for rigid water. The methodology presented here allows to improve the matching procedure by first optimizing the weighting exponents present in the objective function. A new gauge for unambiguously evaluating the quality of the fit has been introduced; it is based on the root mean square difference of the distributions of target properties between reference data and fitted potentials. Four rigid water models have been parameterized; the matching procedure has been used to assess the role of the ghost atom in TIP4P-like models and of electrostatic damping. In the former case, burying the negative charge inside the molecule allows to fit better the torques. In the latter, since short-range interactions are damped, a better fit of the forces is obtained. Overall, the best performing model is the one with a ghost atom and with electrostatic damping. The approach shown in this paper is of general validity and could be applied to any matching algorithm and to any level of coarse graining, also for non-rigid molecules.

  • 687. Samuelsson, Mattias
    et al.
    Lundin, Daniel
    Sarakinos, Kostas
    Björefors, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Walivaara, Bengt
    Ljungcrantz, Henrik
    Helmersson, U.
    Influence of ionization degree on film properties when using high power impulse magnetron sputtering2012In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 30, no 3, p. 031507-Article in journal (Refereed)
    Abstract [en]

    Chromium thin films are deposited by combining direct current magnetron sputtering and high power impulse magnetron sputtering (HiPIMS) on a single cathode in an industrial deposition system. While maintaining a constant deposition rate and unchanged metal ion energy distribution function, the fraction of the total power supplied by either deposition technique is altered, and thereby also the metal ion to metal neutral ratio of the deposition flux. It is observed that the required total average power needed to be proportionally increased as the HiPIMS fraction is increased to be able to keep a constant deposition rate. The influence on microstructure, electrical, and electrochemical properties of the films is investigated and shows improvements with the use of HiPIMS. However, considerable influence of the studied properties occurs already when only some 40% of the total power is supplied by the HiPIMS technique. Further increase of the HiPIMS power fraction results in comparatively minor influence of the studied properties yet significant deposition rate efficiency reduction. The results show that the degree of ionization can be controlled separately, and that the advantages associated with using HiPIMS can be obtained while much of the deposition rate reduction, often reported for HiPIMS, can be avoided.

  • 688.
    Sarman, Sten
    et al.
    Stockholm Univ, Arrhenius Lab, Dept Mat & Environm Chem, S-10691 Stockholm, Sweden.
    Wang, Yong-Lei
    Stanford Univ, Dept Chem, Stanford, CA 94305 USA.
    Laaksonen, Aatto
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry. Stockholm Univ, Arrhenius Lab, Dept Mat & Environm Chem, S-10691 Stockholm, Sweden;Petru Poni Inst Macromol Chem, Ctr Adv Res Bionanoconjugates & Biopolymers, Aleea Grigore Ghica Voda 41A, Iasi 700487, Romania.
    Shear flow simulations of smectic liquid crystals based on the Gay–Berne fluid and the soft sphere string-fluid2019In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 21, no 1, p. 292-305Article in journal (Refereed)
    Abstract [en]

    We have studied the shear flow of the smectic A phase of three coarse grained liquid crystal model systems, namely two versions of the Gay-Berne fluid and the soft sphere string-fluid. At low shear rates, the orientation where the smectic layers are parallel to the shear plane and the orientation parallel to the vorticity plane are both stable in all the systems. In one of the Gay-Berne fluids, there is a transition from the orientation parallel to the shear plane to the orientation parallel to the vorticity plane. At higher shear rates, a nonequilibrium nematic phase is obtained in all the systems in the same way as in linear alkanes under shear. If the initial configuration is an equilibrium smectic A phase or a nematic phase with the molecules parallel to the streamlines, the orientation parallel to the shear plane is attained at low shear rates in the Gay-Berne fluids. In order to analyze the stability of the different orientations, the torque acting on the liquid crystal is calculated. It consists of an elastic torque caused by deformations due to the shape of the simulation cell and the periodic boundary conditions and a shear-induced torque. The elastic torque stabilizes both the orientation parallel to the shear plane and the orientation parallel to the vorticity plane because the liquid crystal is deformed if it is turned away from these orientations. The shear-induced torque, on the other hand, always turns the liquid crystal to the orientation parallel to the vorticity plane where the viscosity and the irreversible energy dissipation rate are minimal. Since the latter torque is proportional to the square of the shear rate, rather high shear rates are required for it to overwhelm the elastic torque. However, the elastic torque decreases with the system size so that it is likely that the shear-induced torque will dominate in large systems and that the orientation parallel to the vorticity plane will be attained at low or even zero shear rate.

  • 689. Sarman, Sten
    et al.
    Wang, Yonglei
    Laaksonen, Aatto
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Variational Principle for Nonequilibrium Steady States Tested by Molecular Dynamics Simulation of Model Liquid Crystal Systems2018In: Non-Equilibrium Particle Dynamics [Working Title], InTech, 2018Chapter in book (Refereed)
  • 690.
    Sarman, Sten
    et al.
    Stockholm Univ, Dept Mat & Environm Chem, Arrhenius Lab, Stockholm, Sweden.
    Wang, Yong-Lei
    Stockholm Univ, Dept Mat & Environm Chem, Arrhenius Lab, Stockholm, Sweden; Stanford Univ, Dept Chem, Stanford, CA USA.
    Rohlmann, Patrick
    Royal Inst Technol, Dept Machine Design, Stockholm, Sweden.
    Glavatskih, Sergei
    Royal Inst Technol, Dept Machine Design, Stockholm, Sweden; Univ Ghent, Dept Elect Energy Met Mech Construct & Syst, Ghent, Belgium.
    Laaksonen, Aatto
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry. Stockholm Univ, Dept Mat & Environm Chem, Arrhenius Lab, Stockholm, Sweden.
    Rheology of phosphonium ionic liquids: a molecular dynamics and experimental study2018In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 20, no 15, p. 10193-10203Article in journal (Refereed)
    Abstract [en]

    We have studied the rheological behavior of the ionic liquid trihexyl(tetradecyl)phosphonium bis(mandelato)borate, [P66614][BMB], and compared it with that of another ionic liquid, namely trihexyl(tetradecyl)phosphonium chloride, [P66614][Cl]. The non-halogenated [P66614][BMB] has been selected as it is known to provide enhanced lubrication performance and is, consequently, of technological importance. The ionic liquid [P66614][Cl], despite its relatively simple anion, exhibits viscosities very similar to those of [P66614][BMB], making it an excellent reference fluid for the modeling study. The viscosities of the ionic liquids have been obtained by equilibrium atomistic simulations using the Green–Kubo relation, and by performing nonequilibrium shear flow simulations. The influence of the simulation system size and a reduction of the atomic charges on the viscosities of the ionic liquids are systematically studied. The atomic charges are reduced to mimic the temperature dependent charge transfer and polarization effects. It has been found that scaling the point charges with factors between 0.60 and 0.80 from full ion charges can provide reliable viscosities of [P66614][BMB], consistent with the experimentally measured viscosities within the studied temperature interval from 373 to 463 K. The viscosities of [P66614][Cl] have been obtained with scaling factors between 0.80 and 1.0 reflecting the lower polarizability and charge transfer effects of the chloride anion.

  • 691. Sassolini, Alessandro
    et al.
    Colozza, Noemi
    Papa, Elena
    Hermansson, Kersti
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Cacciotti, Ilaria
    Arduini, Fabiana
    Screen-printed electrode as a cost-effective and miniaturized analytical tool for corrosion monitoring of re-inforced concrete2019In: Electrochemistry communications, ISSN 1388-2481, E-ISSN 1873-1902, Vol. 98, p. 69-72Article in journal (Refereed)
    Abstract [en]

    Herein, we report the first electrochemical sensor based on a screen-printed electrode designed to evaluate the corrosion level in iron-reinforced concrete specimens. The combination of an Ag pseudoreference electrode with a gel polymeric electrolyte allows for fast, stable and cost-effective potentiometric measurements, suitable for evaluating the corrosion of iron bars embedded in concrete samples. The sensor was found to be capable of discriminating between a standard non-corroded sample and samples subject to corrosion due to the presence of chloride or carbonate in the concrete matrix. The potential in concrete-based specimens containing carbonate (pH 9, - 0.35 +/- 0.03 V) or chloride (4% w/w, - 0.52 +/- 0.01 V) was found to be more negative than in a standard concrete-based sample ( - 0.251 +/- 0.003 V), in agreement with the ASTM standard C876 method which uses a classical Cu/CuSO4 solid reference electrode. Our results demonstrate that a printed Ag pseudoreference electrode combined with KC1 agar provides an efficient and reliable electrochemical system for evaluating the corrosion of iron bars embedded in concrete-based structures.

  • 692.
    Sayer, Thomas
    et al.
    Univ Cambridge, Dept Chem, Cambridge CB2 1EW, England.
    Sprik, Michiel
    Univ Cambridge, Dept Chem, Cambridge CB2 1EW, England.
    Zhang, Chao
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Finite electric displacement simulations of polar ionic solid-electrolyte interfaces: Application to NaCl(111)/aqueous NaCl solution2019In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 150, no 4, article id 041716Article in journal (Refereed)
    Abstract [en]

    Tasker type III polar terminations of ionic crystals carry a net surface charge as well as a dipole moment and are fundamentally unstable. In contact with electrolytes, such polar surfaces can be stabilized by adsorption of counterions from the solution to form electric double layers. In a previous work [T. Sayer et al., J. Chem. Phys 147, 104702 (2017)], we reported on a classical force field based molecular dynamics study of a prototype model system, namely, a NaCl(111) slab interfaced with an aqueous NaCl solution on both sides. A serious hurdle in the simulation is that the finite width of the slab admits an electric field in the solid perturbing the theoretical charge balance at the interface of semi-infinite systems [half the surface charge density for NaCl(111)]. It was demonstrated that the application of a finite macroscopic field E canceling the internal electric field can recover the correct charge compensation at the interface. In the present work, we expand this method by applying a conjugate electric displacement field D. The benefits of using D instead of E as the control variable are two fold: it does not only speed up the convergence of the polarization in the simulation but also leads to a succinct expression for the biasing displacement field involving only structural parameters which are known in advance. This makes it feasible to study the charge compensating phenomenon of this prototype system with density functional theory based molecular dynamics, as shown in this work.

  • 693.
    Schneider, Simon F.
    et al.
    Paul Scherrer Inst, Electrochem Lab, CH-5232 Villigen, Switzerland; Paul Scherrer Inst, Lab Energy Syst Anal, CH-5232 Villigen, Switzerland.
    Bauer, Christian
    Paul Scherrer Inst, Lab Energy Syst Anal, CH-5232 Villigen, Switzerland.
    Novák, Petr
    Paul Scherrer Inst, Electrochem Lab, CH-5232 Villigen, Switzerland.
    Berg, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry. Paul Scherrer Inst, Electrochem Lab, CH-5232 Villigen, Switzerland.
    A modeling framework to assess specific energy, costs and environmental impacts of Li-ion and Na-ion batteries2019In: Sustainable Energy & Fuels, ISSN 2398-4902, Vol. 3, no 11, p. 3061-3070Article in journal (Refereed)
    Abstract [en]

    Li-ion batteries (LIBs) are among the most advanced technologies for energy storage. Due to the potential criticality of lithium raw materials, Na-ion batteries (NIBs) are frequently suggested as a low-cost, environmentally benign alternative to eventually complement or even replace LIBs. Herein, we present a holistic modeling framework to assess the potential of NIB cells from a performance, cost, and environmental impact perspective. To this end, we employ a physics-based battery cell model to project practical specific energies of LIB and NIB cells subjected to varying discharge rates. The derived performance metrics are subsequently used to parameterize a bottom-up battery cell cost model and to assess life cycle greenhouse gas (GHG) emission. Benchmarking model results obtained for NIBs (NaNi1/3Co1/3Mn1/3O2 vs. hard carbon) against state-of-the-art LIBs (LiNi1/3Co1/3Mn1/3O2 vs. graphite), we find that NIBs made from currently available active materials cannot compete with LIBs in terms of performance, costs, and environmental impact. Identifying battery performance as a key parameter driving manufacturing costs and GHG emissions, we argue that in order to make NIBs competitive to LIBs, one of the main priorities of NIB research should be the development of anode and cathode materials offering specific charges, voltages, and cycle life times comparable to or higher than for LIB active materials.

  • 694.
    Schwartz, Pierre-Olivier
    et al.
    Alsachim SAS, Strasbourg, France;Ulm Univ, Inst Organ Chem & Adv Mat 2, Albert Einstein Allee 11, D-89081 Ulm, Germany.
    Pejic, Marijana
    ZSW Zentrum Sonnenenergie & Wasserstoff Forsch Ba, Helmholtzstr 8, D-89081 Ulm, Germany.
    Wachtler, Mario
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry. ZSW Zentrum Sonnenenergie & Wasserstoff Forsch Ba, Helmholtzstr 8, D-89081 Ulm, Germany.
    Baeuerle, Peter
    Ulm Univ, Inst Organ Chem & Adv Mat 2, Albert Einstein Allee 11, D-89081 Ulm, Germany.
    Synthesis and characterization of electroactive PEDOT-TEMPO polymers as potential cathode materials in rechargeable batteries2018In: Synthetic metals, ISSN 0379-6779, E-ISSN 1879-3290, Vol. 243, p. 51-57Article in journal (Refereed)
    Abstract [en]

    Herein we report a novel series of conjugated polymers bearing stable nitroxide pendant groups for possible applications as cathode-active material in secondary batteries. The polymers comprise a 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) moiety immobilized on a poly(3,4-ethylenedioxythiophene) (PEDOT) backbone via ester groups (PEDOT-TEMPO P1 and PEDOT-diTEMPO P2). The multistep synthesis of the corresponding monomers and their chemical characterization are described. Furthermore, oxidative electrochemical and chemical polymerization were performed in order to synthesize polymers on gram-scale for battery tests and to investigate their electrochemical behaviour, respectively. In addition, the electrochemical properties of polymer P1 were studied by potentiodynamic and galvanostatic methods. The results demonstrate that the as-synthesized nitroxide radical polymers showed an electrochemically reversible redox reaction of the TEMPO radicals at 3.5 V vs Li/Li+. When used as cathode material in galvanostatic cycling tests, P1 exhibited a moderate initial specific capacity of 47 mA h g(-1) (62% of the theoretical capacity) which slowly fades to 38 mA h within 50 cycles.

  • 695.
    Schwarz, Rainer
    et al.
    ZSW - Zentrum für Sonnenenergie- und Wasserstoff-Forschung Baden-Württemberg.
    Jankowski, Piotr
    Chalmers University of Technology, Department of Physics.
    Johansson, Patrik
    Chalmers University of Technology, Department of Physics.
    Randon-Vitanova, Anna
    Honda R&D Europe (Deutschland) GmbH.
    Younesi, Reza
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Wachtler, Mario
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry. ZSW - Zentrum für Sonnenenergie- und Wasserstoff-Forschung Baden-Württtemberg.
    Electrochemical stability and speciation of a magnesocene / THF electrolyte2017Conference paper (Refereed)
    Abstract [en]

    Magnesium batteries are currently attracting a lot of interest as potential post Li-ion battery technology. One of the critical issues is to find a suitable electrolyte. Classical electrolytes based on simple salts, such as Mg(ClO4)2 or Mg(TFSI)2 (TFSI = bis(trifluoromethylsulfonyl)imide), result in a strong passivation of the Mg metal anode, which prevents reversible plating and stripping of Mg. With very few exemptions the typical Mg electrolyte is composed of metal chloride complexes or reactive chlorine-containing metal-organic compounds [1], and the contained chloride can cause problems with corrosion for several of the cell components.

    Recently, we have introduced bis(cyclopentadienyl)magnesium (magnesocene, MgCp2) in tetrahydrofuran (THF) as a new chlorine-free electrolyte for low-voltage Mg batteries [2]. Unlike ferrocene, magnesocene behaves as a weak electrolyte and shows some minor dissociation in electron-donating solvents, thus exhibiting low conductivities in the order of 10-5 S/cm [3,4]:

    MgCp2 ↔ MgCp+ + Cp; MgCp2 + Cp ↔ MgCp3; MgCp2 + MgCp+ ↔ Mg2Cp3+

    Despite the low conductivity, high Mg plating / stripping current densities can be observed (Figure 1), which are comparable to those of other Mg electrolytes, such as Mg(BH4)2 / THF [2]. The plating / stripping process shows high reversibility for many cycles, which suggests that the Mg metal anode is not overly passivated in the MgCp2-based electrolyte. X-ray photoelectron spectroscopy (XPS) characterization of the surface of the cycled Mg electrode does not reveal any significant amounts of decomposition products or passivation films (Figure 2), and indicates that the electrolyte is rather stable at the working potential of the Mg metal electrode. The anodic stability has been investigated by linear sweep voltammetry, and values of approx. 1.5, 1.7, and 1.8 V vs. Mg2+/Mg0 have been observed on Pt, Cu, and stainless steel, respectively (Figure 3).

    The experimental findings are corroborated by density functional theory (DFT) calculations performed for various hypothetical Mg-Cp-THF species, using implicit (C-PCM) THF solvation. The cathodic stability of these species is well below 0 V vs. Mg2+/Mg0, indicating that they should not be reduced at the potentials of the Mg plating / stripping reactions. The overall anodic stability of the electrolyte is limited by the Cp species, which is oxidized at 1.86 V vs. Mg2+/Mg0. The DFT calculations, furthermore, show MgCp2THF2 to be the most stable neutral species, wherein one Cp moiety is η5-coordinated, the other one is η1-coordinated, and the THF molecules are coordinated via their oxygen atoms (Figure 4). The structure previously resolved for solid MgCp2THF2 crystals by X-ray diffraction [5] is thus preserved in THF solution.

  • 696.
    Scipioni, Roberto
    et al.
    Tech Univ Denmark, Dept Energy Convers & Storage, DTU Energy, Frederiksborgvej 399, DK-4000 Roskilde, Denmark;Northwestern Univ, Dept Mat Sci & Engn, 2220 Campus Dr, Evanston, IL 60208 USA.
    Jorgensen, Peter S.
    Tech Univ Denmark, Dept Energy Convers & Storage, DTU Energy, Frederiksborgvej 399, DK-4000 Roskilde, Denmark.
    Stroe, Daniel I.
    Aalborg Univ, Dept Energy Technol, Fredrik Bajers Vej 5, DK-9100 Aalborg, Denmark.
    Younesi, Reza
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Simonsen, Soren B.
    Tech Univ Denmark, Dept Energy Convers & Storage, DTU Energy, Frederiksborgvej 399, DK-4000 Roskilde, Denmark.
    Norby, Poul
    Tech Univ Denmark, Dept Energy Convers & Storage, DTU Energy, Frederiksborgvej 399, DK-4000 Roskilde, Denmark.
    Hjelm, Johan
    Tech Univ Denmark, Dept Energy Convers & Storage, DTU Energy, Frederiksborgvej 399, DK-4000 Roskilde, Denmark.
    Jensen, Soren H.
    Tech Univ Denmark, Dept Energy Convers & Storage, DTU Energy, Frederiksborgvej 399, DK-4000 Roskilde, Denmark.
    Complementary analyses of aging in a commercial LiFePO4/graphite 26650 cell2018In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 284, p. 454-468Article in journal (Refereed)
    Abstract [en]

    In this work we investigate the electrode degradation mechanisms in a commercial 2.5 Ah LiFePO4/ graphite 26650 cylindrical cell. Aged and fresh electrode samples were prepared by cycling two cells respectively five and 22 k times. Subsequently the cells were disassembled in a glovebox and the electrode samples were prepared for electrochemical testing in a 3-electrode setup, and for characterization with XRD, XPS and low-kV FIB/SEM tomography. A 1 mu m thick CEI (cathode electrolyte interface) layer was observed at the electrode/electrolyte interface of the aged LiFePO4 electrode. Relative to the fresh LiFePO4 electrode, the aged electrode exhibited a larger series resistance which indicates the observed degradation layer increases the ionic resistance. In addition, micron-sized agglomerates, probably a mixture of carbonaceous material and decomposition products from the electrolyte, were observed at the electrode/electrolyte interface of the aged graphite electrode. These layers may contribute significantly to the loss of lithium inventory (LLI) in the cell, and to the loss of active material (LAM) in the graphite electrode. Low-voltage FIB/SEM tomography was used to detect local charging effects of graphite particles in the carbon electrode, an effect of poor dissipation of the electric charge to the ground after the sample interaction with the electron beam. The charging effects were primarily observed in the aged electrode and most of the locally charged particles were found to be close to the electrode/electrolyte interface, indicating a poorly percolating graphite network near this interface.

  • 697.
    Sen, Anik
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Mitev, Pavlin D.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Eriksson, Anders
    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.
    H-bond and electric field correlations for water in highly hydrated crystals2016In: International Journal of Quantum Chemistry, ISSN 0020-7608, E-ISSN 1097-461X, Vol. 116, no 2, p. 67-80Article in journal (Refereed)
    Abstract [en]

    We present periodic plane-wave density functional theory (DFT) Perdew-Burke-Ernzerhof (PBE-D2) calculations for four highly hydrated crystals, Na2CO3 center dot 10H(2)O, MgSO4 center dot 7H(2)O, MgSO4 center dot 11H(2)O, and Al(NO3)(3)center dot 9H(2)O, containing 37 structurally unique water molecules and 74 unique hydrogen bonds. The calculated R(H center dot center dot center dot O) distances lie in the range 1.60-2.05 angstrom, the anharmonic OH frequencies in the range 2570-3425 cm(-1), and the water dipole moments lie in the range 2.9-4.3 Debye, as calculated from the Wannier function centers and the nuclei. We present the following findings. (i) Our optimized intramolecular r(OH) distances are always larger than the gasphase value and thus more accurate than those derived from neutron diffraction experiments; (ii) The local in situ electric field over the molecule, calculated from the positions of the nuclei and the Wannier centers in the surrounding crystal, appears to be a good descriptor of the pertturbation from the water molecule's surroundings as the internal molecular properties (r(e), nu, mu) are found to correlate well with the crystal-generated electric field; (iii) We have added DFT-calculated data points to the well-known experimental 'OH frequency versus R(H center dot center dot center dot O) correlation curve in a region where the experimental data points are scarce; (iv) For all 37 water molecules, the Wannier centers located in the lone-pair region, and those located in the OH bonds, displace about equally much due to the polarizing environment. Finally, we propose that our resulting 'OH frequency versus Wannier-type electric field' correlation curve may constitute a useful tool for predicting OH vibrational frequencies from snapshots from PBE-D2-based ab initio molecular dynamics simulations of water-containing systems.

  • 698.
    Shao, Yunqi
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Hellström, Matti
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Mitev, Pavlin D.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Knijff, Lisanne
    Zhang, Chao
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    PiNN: A Python library for building atomic neural networks of molecules and materials2019Conference paper (Other academic)
  • 699. Sharifi, Tiva
    et al.
    Valvo, Mario
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Gracia-Espino, Eduardo
    Sandstrom, Robin
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Wagberg, Thomas
    Hierarchical self-assembled structures based on nitrogen-doped carbon nanotubes as advanced negative electrodes for Li-ion batteries and 3D microbatteries2015In: Journal of Power Sources, ISSN 0378-7753, E-ISSN 1873-2755, Vol. 279, p. 581-592Article in journal (Refereed)
    Abstract [en]

    Hierarchical structures based on carbon paper and multi-walled nitrogen-doped carbon nanotubes were fabricated and subsequently decorated with hematite nanorods to obtain advanced 3D architectures for Li-ion battery negative electrodes. The carbon paper provides a versatile metal-free 3D current collector ensuring a good electrical contact of the active materials to its carbon fiber network. Firstly, the nitrogen-doped carbon nanotubes onto the carbon paper were studied and a high footprint area capacity of 2.1 mAh cm(-2) at 0.1 mA cm(-2) was obtained. The Li can be stored in the inter-wall regions of the nanotubes, mediated by the defects formed on their walls by the nitrogen atoms. Secondly, the incorporation of hematite nanorods raised the footprint area capacity to 2.25 mAh cm(-2) at 0.1 mA cm(-2). However, the repeated conversion/de-conversion of Fe2O3 limited both coulombic and energy efficiencies for these electrodes, which did not perform as well as those including only the N-doped carbon nanotubes at higher current densities. Thirdly, long-cycling tests showed the robust Li insertion mechanism in these N-doped carbonaceous structures, which yielded an unmatched footprint area capacity enhancement up to 1.95 mAh cm(-2) after 60 cycles at 0.3 mA cm(-2) and an overall capacity of 204 mAh g(-1) referred to the mass of the entire electrode. 

  • 700.
    Sharma, Sangeeta
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Condensed Matter Theory.
    Fransson, Linda
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Sjöstedt, Elisabeth
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Condensed Matter Theory.
    Nordström, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Condensed Matter Theory.
    Johansson, Börje
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics, Condensed Matter Theory.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    A theoretical and experimental study of the lithiation of η'-Cu6Sn5 in a lithium-ion battery2003In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 150, no 3, p. A330-A334Article in journal (Refereed)
    Abstract [en]

    Themechanism of Li insertion in -Cu6Sn5 to form Li2CuSn isdiscussed in detail, based on both theoretical calculations and experimentalresults. The mechanism is investigated by means of first principlescalculations, with the full potential linearized augmented plane wave method,in combination with in situ X-ray diffraction experiments. The -Cu6Sn5structure, as well as its lithiated products, were optimized andthe electronic charge density calculated in order to study thechange in bond character on lithiation. The average insertion voltageof the -Cu6Sn5-Li2CuSn transformation has been calculated to be 0.378V, in good agreement with the experimental value.                            

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