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Edström, Kristina, ProfessorORCID iD iconorcid.org/0000-0003-4440-2952
Publications (10 of 265) Show all publications
Wang, Z., Pan, R., Xu, C., Ruan, C., Edström, K., Strømme, M. & Nyholm, L. (2018). Conducting polymer paper-derived separators for lithium metal batteries. Energy Storage Materials, 13, 283-292
Open this publication in new window or tab >>Conducting polymer paper-derived separators for lithium metal batteries
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2018 (English)In: Energy Storage Materials, ISSN 2405-8297, Vol. 13, p. 283-292Article in journal (Refereed) Published
Abstract [en]

Overoxidised polypyrrole (PPy) paper has been employed as a mesoporous separator for lithium metal batteries (LMBs) based on its narrow pore size distribution, good thermal stability, high ionic conductivity (1.1 mS cm−1 with a LP40 electrolyte) and high electrolyte wettability. The overoxidised PPy paper was produced from a PPy/cellulose composite using a combined base and heat-treatment process, yielding a highly interrupted pyrrole molecular structure including N-containing polar groups maintaining the readily adaptable mesoporous structure of the pristine PPy paper. This well-defined pore structure gave rise to a homogeneous current distribution which significantly increased the performance of a LiFePO4|Li cell. With the overoxidised PPy separator, a symmetric Li|Li cell could be cycled reversibly for more than 600 h without any short-circuits in a LP40 electrolyte. This approach facilitates the manufacturing of well-defined separators for fundamental investigations of the influence of the separator structure on the performance of LMBs.

Keywords
Conducting polymers, nanocellulose, separator, porosity, lithium metal, batteries
National Category
Inorganic Chemistry Engineering and Technology
Research subject
Chemistry with specialization in Inorganic Chemistry; Chemistry with specialization in Materials Chemistry; Engineering Science with specialization in Nanotechnology and Functional Materials
Identifiers
urn:nbn:se:uu:diva-355543 (URN)10.1016/j.ensm.2018.02.006 (DOI)000436924800033 ()
Funder
Swedish Energy Agency, TriLiSwedish Foundation for Strategic Research , RMA-110012Carl Tryggers foundation StandUp
Available from: 2018-07-01 Created: 2018-07-01 Last updated: 2018-09-13Bibliographically approved
Nilsson, V., Younesi, R., Brandell, D., Edström, K. & Johansson, P. (2018). Critical evaluation of the stability of highly concentrated LiTFSI - Acetonitrile electrolytes vs. graphite, lithium metal and LiFePO4 electrodes. Journal of Power Sources, 384, 334-341
Open this publication in new window or tab >>Critical evaluation of the stability of highly concentrated LiTFSI - Acetonitrile electrolytes vs. graphite, lithium metal and LiFePO4 electrodes
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2018 (English)In: Journal of Power Sources, ISSN 0378-7753, E-ISSN 1873-2755, Vol. 384, p. 334-341Article in journal (Refereed) Published
Abstract [en]

Highly concentrated LiTFSI - acetonitrile electrolytes have recently been shown to stabilize graphite electrodes in lithium-ion batteries (LIBs) much better than comparable more dilute systems. Here we revisit this system in order to optimise the salt concentration vs. both graphite and lithium metal electrodes with respect to electrochemical stability. However, we observe an instability regardless of concentration, making lithium metal unsuitable as a counter electrode, and this also affects evaluation of e.g. graphite electrodes. While the highly concentrated electrolytes have much improved electrochemical stabilities, their reductive decomposition below ca. 1.2 V vs. Li+/Li° still makes them less practical vs. graphite electrodes, and the oxidative reaction with Al at ca. 4.1 V vs. Li+/Li° makes them problematic for high voltage LIB cells. The former originates in an insufficiently stable solid electrolyte interphase (SEI) dissolving and continuously reforming – causing self-discharge, as observed by paused galvanostatic cycling, while the latter is likely caused by aluminium current collector corrosion. Yet, we show that medium voltage LiFePO4 positive electrodes can successfully be used as counter and reference electrodes.

Keywords
Highly concentrated electrolyte, Li-ion battery, SEI, Al corrosion, Self-discharge
National Category
Materials Chemistry
Research subject
Chemistry with specialization in Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-351302 (URN)10.1016/j.jpowsour.2018.03.019 (DOI)000430897700041 ()
Funder
Swedish Energy Agency, 39042-1
Available from: 2018-05-23 Created: 2018-05-23 Last updated: 2018-06-26Bibliographically approved
Björklund, E., Wikner, E., Younesi, R., Brandell, D. & Edström, K. (2018). Influence of state-of-charge in commercial LiNi0.33Mn0.33Co0.33O2/LiMn2O4-graphite cells analyzed by synchrotron-based photoelectron spectroscopy. Journal of Energy Storage, 15, 172-180
Open this publication in new window or tab >>Influence of state-of-charge in commercial LiNi0.33Mn0.33Co0.33O2/LiMn2O4-graphite cells analyzed by synchrotron-based photoelectron spectroscopy
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2018 (English)In: Journal of Energy Storage, ISSN 2352-152X, Vol. 15, p. 172-180Article in journal (Refereed) Published
Abstract [en]

Degradation mechanisms in 26 Ah commercial Li-ion battery cells comprising graphite as the negative electrode and mixed metal oxide of LiMn2O4 (LMO) and LiNi1/3Mn1/3Co1/3O2 (NMC) as the positive electrode are here investigated utilising extensive cycling at two different state-of-charge (SOC) ranges, 10–20% and 60–70%, as well as post-mortem analysis. To better analyze these mechanisms electrochemically, the cells were after long-term cycling reassembled into laboratory scale “half-cells” using lithium metal as the negative electrode, and thereafter cycled at different rates corresponding to 0.025 mA/cm2 and 0.754 mA/cm2. The electrodes were also analyzed by synchrotron-based hard x-ray photoelectron spectroscopy (HAXPES) using two different excitation energies to determine the chemical composition of the interfacial layers formed at different depth on the respective electrodes. It was found from the extensive cycling that the cycle life was shorter for the cell cycled in the higher SOC range, 60–70%, which is correlated to findings of an increased cell resistance and thickness of the SEI layer in the graphite electrode as well as manganese dissolution from the positive electrode.

Keywords
Li-ion battery, Commercial cells, Battery ageing, Photoelectron spectroscopy
National Category
Chemical Sciences
Identifiers
urn:nbn:se:uu:diva-338184 (URN)10.1016/j.est.2017.11.010 (DOI)000426619500015 ()
Available from: 2018-01-08 Created: 2018-01-08 Last updated: 2018-05-16Bibliographically approved
Rehnlund, D., Pettersson, J., Edström, K. & Nyholm, L. (2018). Lithium trapping in microbatteries based on lithium- and Cu2O-coated copper nanorods. ChemistrySelect, 3(8), 2311-2314
Open this publication in new window or tab >>Lithium trapping in microbatteries based on lithium- and Cu2O-coated copper nanorods
2018 (English)In: ChemistrySelect, E-ISSN 2365-6549, Vol. 3, no 8, p. 2311-2314Article in journal (Refereed) Published
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.

Keywords
lithium trapping, microbatteries, nanorods, Cu2O, copper
National Category
Inorganic Chemistry
Research subject
Chemistry with specialization in Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-343590 (URN)10.1002/slct.201800281 (DOI)000426495600015 ()
Funder
Swedish Research Council, 2012-4681, 2015-04421StandUpSwedish Energy Agency
Available from: 2018-02-28 Created: 2018-02-28 Last updated: 2018-05-31Bibliographically approved
Renman, V., Valvo, M., Tai, C.-W., Gómez, C. P., Edström, K. & Liivat, A. (2018). Manganese pyrosilicates as novel positive electrode materials for Na-ion batteries. SUSTAINABLE ENERGY & FUELS, 2(5), 941-945
Open this publication in new window or tab >>Manganese pyrosilicates as novel positive electrode materials for Na-ion batteries
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2018 (English)In: SUSTAINABLE ENERGY & FUELS, ISSN 2398-4902, Vol. 2, no 5, p. 941-945Article in journal (Refereed) Published
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.

National Category
Inorganic Chemistry Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-356076 (URN)10.1039/c7se00587c (DOI)000431422700003 ()
Funder
Swedish Research Council, 2011-6512Swedish Research Council, 2010-4824Swedish Research Council Formas, 245-2014-668Knut and Alice Wallenberg FoundationStandUp
Available from: 2018-07-13 Created: 2018-07-13 Last updated: 2018-10-05Bibliographically approved
Ma, Y., Tai, C.-W., Li, S., Edström, K. & Wei, B. (2018). Multiscale Interfacial Strategy to Engineer Mixed Metal-Oxide Anodes toward Enhanced Cycling Efficiency. ACS Applied Materials and Interfaces, 10(23), 20095-20105
Open this publication in new window or tab >>Multiscale Interfacial Strategy to Engineer Mixed Metal-Oxide Anodes toward Enhanced Cycling Efficiency
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2018 (English)In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 23, p. 20095-20105Article in journal (Refereed) Published
Abstract [en]

Interconnected macro/mesoporous structures of mixed metal oxide (MMO) are developed on nickel foam as freestanding anodes for Li-ion batteries. The sustainable production is realized via a wet chemical etching process with bio-friendly chemicals. By means of divalent iron doping during an in situ recrystallization process, the as-developed MMO anodes exhibit enhanced levels of cycling efficiency. Furthermore, this atomic-scale modification coherently synergizes with the encapsulation layer across a micrometer scale. During this step, we develop a quasi-gel-state tri-copolymer, i.e., F127-resorcinol-melamine, as the N-doped carbon source to regulate the interfacial chemistry of the MMO electrodes. Electrochemical tests of the modified FexN1-xO@NC-NiF anode in both half-cell and full-cell configurations unravel the favorable suppression of the irreversible capacity loss and satisfactory cyclability at the high rates. This study highlights a proof-of-concept modification strategy across multiple scales to govern the interfacial chemical process of the electrodes toward better reversibility.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2018
Keywords
iron doping, nickel oxide, interfacial chemistry, cycling efficiency, lithium-ion storage
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-358523 (URN)10.1021/acsami.8b02908 (DOI)000435525100089 ()29782146 (PubMedID)
Available from: 2018-09-03 Created: 2018-09-03 Last updated: 2018-09-03Bibliographically approved
Pan, R., Xu, X., Sun, R., Wang, Z., Lindh, J., Edström, K., . . . Nyholm, L. (2018). Nanocellulose Modified Polyethylene Separators for Lithium Metal Batteries. Small, 14(21), Article ID 1704371.
Open this publication in new window or tab >>Nanocellulose Modified Polyethylene Separators for Lithium Metal Batteries
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2018 (English)In: Small, ISSN 1613-6810, E-ISSN 1613-6829, Vol. 14, no 21, article id 1704371Article in journal (Refereed) Published
Abstract [en]

Abstract Poor cycling stability and safety concerns regarding lithium (Li) metal anodes are two major issues preventing the commercialization of high‐energy density Li metal‐based batteries. Herein, a novel tri‐layer separator design that significantly enhances the cycling stability and safety of Li metal‐based batteries is presented. A thin, thermally stable, flexible, and hydrophilic cellulose nanofiber layer, produced using a straightforward paper‐making process, is directly laminated on each side of a plasma‐treated polyethylene (PE) separator. The 2.5 µm thick, mesoporous (≈20 nm average pore size) cellulose nanofiber layer stabilizes the Li metal anodes by generating a uniform Li+ flux toward the electrode through its homogenous nanochannels, leading to improved cycling stability. As the tri‐layer separator maintains its dimensional stability even at 200 °C when the internal PE layer is melted and blocks the ion transport through the separator, the separator also provides an effective thermal shutdown function. The present nanocellulose‐based tri‐layer separator design thus significantly facilitates the realization of high‐energy density Li metal‐based batteries.

Place, publisher, year, edition, pages
Wiley-VCH Verlagsgesellschaft, 2018
Keywords
cellulose, current distribution, lithium dendrites, lithium metal batteries, separators
National Category
Materials Chemistry Engineering and Technology
Research subject
Engineering Science with specialization in Nanotechnology and Functional Materials
Identifiers
urn:nbn:se:uu:diva-349143 (URN)10.1002/smll.201704371 (DOI)000434173300006 ()29675952 (PubMedID)
Funder
Swedish Foundation for Strategic Research , RMA-110012Swedish Energy AgencyStandUp
Available from: 2018-04-22 Created: 2018-04-22 Last updated: 2018-09-28Bibliographically approved
Wang, Z., Pan, R., Sun, R., Edström, K., Strömme, M. & Nyholm, L. (2018). Nanocellulose Structured Paper-Based Lithium Metal Batteries. ACS Applied Energy Materials
Open this publication in new window or tab >>Nanocellulose Structured Paper-Based Lithium Metal Batteries
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2018 (English)In: ACS Applied Energy MaterialsArticle in journal (Refereed) Published
Place, publisher, year, edition, pages
American Chemical Society, 2018
National Category
Nano Technology
Research subject
Engineering Science with specialization in Nanotechnology and Functional Materials
Identifiers
urn:nbn:se:uu:diva-358031 (URN)10.1021/acsaem.8b00961 (DOI)
Available from: 2018-08-23 Created: 2018-08-23 Last updated: 2018-10-05
Doubaji, S., Ma, L., Asfaw, H. D., Izanzar, I., Xu, R., Alami, J., . . . Saadoune, I. (2018). On the P2-NaxCo1−y(Mn2/3Ni1/3)yO2 Cathode Materials for Sodium-Ion Batteries: Synthesis, Electrochemical Performance, and Redox Processes Occurring during the Electrochemical Cycling. ACS Applied Materials and Interfaces, 10(1), 488-501
Open this publication in new window or tab >>On the P2-NaxCo1−y(Mn2/3Ni1/3)yO2 Cathode Materials for Sodium-Ion Batteries: Synthesis, Electrochemical Performance, and Redox Processes Occurring during the Electrochemical Cycling
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2018 (English)In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 1, p. 488-501Article in journal (Refereed) Published
Abstract [en]

P2-type NaMO2sodiated layered oxides withmixed transition metals are receiving considerable attention foruse as cathodes in sodium-ion batteries. A study on solidsolution (1−y)P2-NaxCoO2−(y)P2-NaxMn2/3Ni1/3O2(y=0,1/3, 1/2, 2/3, 1) reveals that changing the composition of thetransition metals affects the resulting structure and the stabilityof pure P2 phases at various temperatures of calcination. For 0≤y≤1.0, the P2-NaxCo(1−y)Mn2y/3Niy/3O2solid-solutioncompounds deliver good electrochemical performance whencycled between 2.0 and 4.2 V versus Na+/Na with improved capacity stability in long-term cycling, especially for electrodematerials with lower Co content (y= 1/2 and 2/3), despite lower discharge capacities being observed. The (1/2)P2-NaxCoO2−(1/2)P2-NaxMn2/3Ni1/3O2composition delivers a discharge capacity of 101.04 mAh g−1with a capacity loss of only 3% after 100cycles and a Coulombic efficiency exceeding 99.2%. Cycling this material to a higher cutoffvoltage of 4.5 V versus Na+/Naincreases the specific discharge capacity to≈140 mAh g−1due to the appearance of a well-defined high-voltage plateau, but afteronly 20 cycles, capacity retention declines to 88% and Coulombic efficiency drops to around 97%. In situ X-ray absorption near-edge structure measurements conducted on composition NaxCo1/2Mn1/3Ni1/6O2(y= 1/2) in the two potential windows studiedhelp elucidate the operating potential of each transition metal redox couple. It also reveals that at the high-voltage plateau, all ofthe transition metals are stable, raising the suspicion of possible contribution of oxygen ions in the high-voltage plateau.

Keywords
Na-ion batteries, P2-type materials, energy storage, in situ XANES measurements, high-voltage plateau
National Category
Natural Sciences Inorganic Chemistry
Research subject
Chemistry with specialization in Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-337712 (URN)10.1021/acsami.7b13472 (DOI)000422814400053 ()29098854 (PubMedID)
Funder
StandUpSwedish Research Council, 2015-05106
Available from: 2018-01-03 Created: 2018-01-03 Last updated: 2018-02-28Bibliographically approved
Valvo, M., Doubaji, S., Saadoune, I. & Edström, K. (2018). Pseudocapacitive charge storage properties of Na2/3Co2/3Mn2/9Ni1/9O2 in Na-ion batteries. Electrochimica Acta, 276, 142-152
Open this publication in new window or tab >>Pseudocapacitive charge storage properties of Na2/3Co2/3Mn2/9Ni1/9O2 in Na-ion batteries
2018 (English)In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 276, p. 142-152Article in journal (Refereed) Published
Abstract [en]

The behaviour of Na2/3Co2/3Mn2/9Ni1/9O2 in composite electrodes is studied via Na half-cells utilizing a dedicated cyclic voltammetry approach. The application of increasing sweep rates enabled a detailed analysis of the red-ox peaks of this material. All peak currents due to cathodic/anodic processes demonstrated clear capacitive properties. This finding widens the picture of classical Na+ insertion/ extraction in this complex oxide, as purely diffusive processes of Na+ through its layers do not fully explain the pseudocapacitance displayed by its red-ox peaks, which are typically linked to concomitant oxidation state changes for its transition metal atoms and/or phase transitions. No phase transition was observed during in operando X-Ray diffraction upon charge to 4.2 V vs. Na+/Na, proving good structural stability for P2-NaxCo2/3Mn2/9Ni1/9O2 upon Na+ removal. The origin of such pseudocapacitive properties is likely nested in strong electrostatic interactions among the metal oxide slabs and a tendency to release Na+ from its crystallites, e.g. to form surface by-products upon air exposure. Such a reactivity induces defects (e.g. vacancies) in its lattice and charge compensation mechanisms are required to maintain an overall charge neutrality, thus ultimately influencing the electrochemical properties. Possible limiting factors for the performances of this compound in composite coatings are also discussed.

Place, publisher, year, edition, pages
PERGAMON-ELSEVIER SCIENCE LTD, 2018
Keywords
Na-ion batteries, Na2/3Co2/3Mn2/9Ni1/9O2, Layered oxides, Positive electrodes, Pseudocapacitance
National Category
Materials Chemistry Physical Chemistry
Identifiers
urn:nbn:se:uu:diva-356610 (URN)10.1016/j.electacta.2018.04.150 (DOI)000433042500016 ()
Funder
Swedish Research Council Formas, 245-2014-668
Available from: 2018-08-03 Created: 2018-08-03 Last updated: 2018-08-03Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0003-4440-2952

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