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Gustafsson, TorbjörnORCID iD iconorcid.org/0000-0003-2737-4670
Alternative names
Publications (10 of 147) Show all publications
Liu, C., Rehnlund, D., Brant, W. R., Zhu, J., Gustafsson, T. & Younesi, R. (2017). Growth of NaO2 in Highly Efficient Na–O2 Batteries Revealed by Synchrotron In Operando X-ray Diffraction [Letter to the editor]. ACS Energy Letters, 2, 2440-2444
Open this publication in new window or tab >>Growth of NaO2 in Highly Efficient Na–O2 Batteries Revealed by Synchrotron In Operando X-ray Diffraction
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2017 (English)In: ACS Energy Letters, E-ISSN 2380-8195, Vol. 2, p. 2440-2444Article in journal, Letter (Other academic) Published
Abstract [en]

The development of Na–O2 batteries requires understanding the formation of reaction products, as different groups reported compounds such as sodium peroxide, sodium superoxide, and hydrated sodium peroxide as the main discharge products. In this study, we used in operando synchrotron radiation powder X-ray diffraction (SR-PXD) to (i) quantitatively track the formation of NaO2 in Na–O2 cells and (ii) measure how the growth of crystalline NaO2 is influenced by the choice of electrolyte salt. The results reveal that the discharge could be divided into two time regions and that the formation of NaO2 during the major part of the discharge reaction is highly efficient. The findings indicate that the cell with NaOTf salt exhibited higher capacity than the cell with NaPF6 salt, whereas the average domain size of NaO2 particles decreases during the discharge. This fundamental insight brings new information on the working mechanism of Na–O2 batteries.

National Category
Materials Chemistry
Research subject
Chemistry with specialization in Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-330766 (URN)10.1021/acsenergylett.7b00768 (DOI)000415914200036 ()
Projects
Na-air batteries
Available from: 2017-10-03 Created: 2017-10-03 Last updated: 2018-02-26Bibliographically approved
Liu, J., Ma, Y., Roberts, M., Gustafsson, T., Edström, K. & Zhu, J. (2017). Highly efficient Ru/MnO2 nano-catalysts for Li-O2 batteries: Quantitative analysis of catalytic Li2O2 decomposition by operando synchrotron X-ray diffraction. Journal of Power Sources, 352, 208-215
Open this publication in new window or tab >>Highly efficient Ru/MnO2 nano-catalysts for Li-O2 batteries: Quantitative analysis of catalytic Li2O2 decomposition by operando synchrotron X-ray diffraction
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2017 (English)In: Journal of Power Sources, ISSN 0378-7753, E-ISSN 1873-2755, Vol. 352, p. 208-215Article in journal (Refereed) Published
Abstract [en]

In-situ or operando quantitative analysis is very important for Li-O2 batteries, in order to properly, accurately and comprehensively evaluate electrocatalysts and characterize Li-O2 electrochemistry in real-time. Synchrotron XRD can provide much higher X-ray intensity and time resolution than traditional in-house diffractometers, and therefore can contribute to quantitative analysis for Li-O2 batteries. Here, operando synchrotron XRD is further developed to quantitatively study Li-O2 batteries with nano catalysts, Ru/MnO2. The time-resolved oxygen evolution reaction (OER) kinetics for Li-O2 cells with Ru/MNT was systematically investigated using operando synchrotron radiation powder X-ray diffraction (SR-PXD). Li2O2 decomposition in the electrodes with Ru/MNT catalysts during galvanostatic and potentiostatic charge processes followed pseudo-zero-order kinetics and showed ideal Coulombic efficiency (close to 100%). Furthermore, it was found that the OER kinetics for a cell with 2 wt% Ru/MNT charged at a constant potential of 4.3 V was even faster than that for a cell with the same amount of pure Ru nanoparticles, which have been considered as a highly active catalyst for Li-O2 batteries. These results indicated that Ru/MNT with a special nanostructure represented a very efficient electrocatalyst for promoting the OER in Li-O2 batteries. We also demonstrate that synchrotron radiation XRD can "highlight" a way to quantitative analysis for Li-O2 batteries.

Keywords
Ru nanoparticle, MnO2 nanotube, Li-O-2 battery, Electrocatalyst, Oxygen evolution reaction, Operando synchrotron radiation powder X-ray diffraction (SR-PXD)
National Category
Materials Chemistry Other Chemical Engineering
Identifiers
urn:nbn:se:uu:diva-324237 (URN)10.1016/j.jpowsour.2017.03.127 (DOI)000401206100024 ()
Funder
Swedish Research Council, 2012-4681Swedish Energy Agency, 2010-000414StandUp
Available from: 2017-06-15 Created: 2017-06-15 Last updated: 2017-12-30
Blidberg, A., Sobkowiak, A., Tengstedt, C., Valvo, M., Gustafsson, T. & Björefors, F. (2017). Identifying the Electrochemical Processes in LiFeSO4F Cathodes for Lithium Ion Batteries. Chemelectrochem, 4(8), 1896-1907
Open this publication in new window or tab >>Identifying the Electrochemical Processes in LiFeSO4F Cathodes for Lithium Ion Batteries
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2017 (English)In: Chemelectrochem, Vol. 4, no 8, p. 1896-1907Article in journal (Other academic) Published
Abstract [en]

The electrochemical performance of tavorite LiFeSO4F can be considerably improved by coating the material with a conducting polymer (poly(3,4-ethylenedioxythiophene); PEDOT). Herein, the mechanisms behind the improved performance are studied systematically by careful electrochemical analysis. It is shown that the PEDOT coating improves the surface reaction kinetics for the Li-ion insertion into LiFeSO4F. For such coated materials no kinetic limitations remain, and a transition from solid state to solution-based diffusion control was observed at 0.6 mA cm−2 (circa C/2). Additionally, the quantity of PEDOT is optimized to balance the weight added by the polymer and the improved electrochemical function. Post mortem analysis shows excellent stability for the LiFeSO4F-PEDOT composite, and maintaining the electronic wiring is the most important factor for stable electrochemical cycling of LiFeSO4F. The insights and the methodology used to determine the rate-controlling steps are readily transferable to other ion-insertion-based electrodes, and the findings are important for the development of improved battery electrodes.

Keywords
Batteries; conducting polymers; electrochemistry; kinetics; lithium
National Category
Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-317003 (URN)10.1002/celc.201700192 (DOI)000410498700015 ()
Funder
Swedish Foundation for Strategic Research , EM11-0028VINNOVASwedish Research Council Formas, 245-2014-668
Available from: 2017-03-08 Created: 2017-03-08 Last updated: 2017-12-08Bibliographically approved
Xu, C., Renault, S., Ebadi, M., Wang, Z., Björklund, E., Guyomard, D., . . . Gustafsson, T. (2017). LiTDI: A Highly Efficient Additive for Electrolyte Stabilization in Lithium-Ion Batteries. Chemistry of Materials, 29(5), 2254-2263
Open this publication in new window or tab >>LiTDI: A Highly Efficient Additive for Electrolyte Stabilization in Lithium-Ion Batteries
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2017 (English)In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 29, no 5, p. 2254-2263Article in journal (Refereed) Published
Abstract [en]

The poor stability of LiPF6-based electrolytes has always been a bottleneck for conventional lithium-ion batteries. The presence of inevitable trace amounts of moisture and the operation of batteries at elevated temperatures are particularly detrimental to electrolyte stability. Here, lithium 2trifluoromethy1-4,5-dicyanoimidazole (LiTDI) is investigated as a moisture-scavenging electrolyte additive and can sufficiently suppress the hydrolysis of LiPF6. With 2 wt % LiTDI, no LiPF6 degradation can be detected after storage for 35 days, even though the water level in the electrolyte is enriched by 2000 ppm. An improved thermal stability is also obtained by employing the LiTDI additive, and the moisture-scavenging mechanism is discussed. The beneficial effects of the LiTDI additive on battery performance are demonstrated by the enhanced capacity retention of both the LiNi1/3Mn1/3Co1/3O2 (NMC)/Li and NMC/graphite cells at 55 degrees C. In particular, the increase in cell voltage hysteresis is greatly hindered when LiTDI is presented in the electrolyte. Further development of the LiTDI additive may allow the improvement of elevated-temperature batteries, as well as energy savings by reducing the amount of effort necessary for dehydration of battery components.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2017
National Category
Physical Chemistry
Identifiers
urn:nbn:se:uu:diva-319530 (URN)10.1021/acs.chemmater.6b05247 (DOI)000396639400040 ()
Funder
Swedish Energy Agency, 34191-1 39036-1Swedish Foundation for Strategic Research Carl Tryggers foundation StandUp
Available from: 2017-04-06 Created: 2017-04-06 Last updated: 2017-12-30
Mindemark, J., Sobkowiak, A., Oltean, G., Brandell, D. & Gustafsson, T. (2017). Mechanical Stabilization of Solid Polymer Electrolytes through Gamma Irradiation. Electrochimica Acta, 230, 189-195
Open this publication in new window or tab >>Mechanical Stabilization of Solid Polymer Electrolytes through Gamma Irradiation
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2017 (English)In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 230, p. 189-195Article in journal (Refereed) Published
Abstract [en]

Attaining sufficient mechanical stability is a challenge for high-performance solid polymer electrolytes, particularly at elevated temperatures. We have here characterized the viscoelastic properties of the nonpolyether host material poly(epsilon-caprolactone-co-trimethylene carbonate) with and without incorporated LiTFSI salt. While this electrolyte material performs well at room temperature, at 80 degrees C the material is prone to viscous flow. Through gamma-irradiation at a dose of 25 kGy, the material stabilizes such that it behaves as a rubbery solid even at low rates of deformation while retaining a high ionic conductivity necessary for use in solid-state Li batteries. The performance of the irradiated electrolyte was investigated in Li polymer half-cells (Li vs. LiFePO4) at both 80 degrees C and room temperature. In Contrast with the notably stable battery performance at low temperatures using the non-irradiated material, during cycling of the irradiated electrolytes detrimental instabilities were noted at both 80 degrees C and room temperature. The possible effects of both radiation damage to the electrolyte and impaired interfacial contacts due to the crosslinking indicate that a different procedure may be necessary in order to stabilize these electrolytes for use in battery cells capable of stable long-term operation.

Place, publisher, year, edition, pages
PERGAMON-ELSEVIER SCIENCE LTD, 2017
Keywords
polymer electrolytes, crosslinking, lithium batteries, mechanical properties, gamma irradiation
National Category
Chemical Sciences
Identifiers
urn:nbn:se:uu:diva-320250 (URN)10.1016/j.electacta.2017.02.008 (DOI)000395599900021 ()
Funder
Swedish Energy Agency, 37722-1Swedish Research Council, 20123837
Available from: 2017-04-19 Created: 2017-04-19 Last updated: 2017-04-19Bibliographically approved
Srivastav, S., Xu, C., Edström, K., Gustafsson, T. & Brandell, D. (2017). Modelling the morphological background to capacity fade in Si-based lithium-ion batteries. Electrochimica Acta, 258, 755-763
Open this publication in new window or tab >>Modelling the morphological background to capacity fade in Si-based lithium-ion batteries
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2017 (English)In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 258, p. 755-763Article in journal (Refereed) Published
Abstract [en]

Understanding the fundamental processes at the electrode/electrolyte interface during charge and discharge will aid the development of high-capacity Li-ion batteries (LIBs) with long lifetimes. Finite Element Methodology studies are here used to investigate the interplay between morphological changes and electrochemical performance in Si negative electrodes. A one-dimensional battery model including Solid Electrolyte Interphase (SEI) layer growth is constructed for porous Si electrodes in half-cells and used for simulating electrochemical impedance response during charge and discharge cycles. The computational results are then compared with experimental investigations. The SEI layer from the electrolyte decomposition products, different depending on the presence or absence of the fluoroethylene carbonate (FEC) additive, covers the electrode surface porous structure and is leading to an increasing polarization observed in the Nyquist plots during cycling. A continuous reformation of the SEI layer after each cycle can be observed, leading to consumption of Li-|. The electrolyte composition also results in a variation of electrode porosity, which affects the performance of the cell. A more stable porous network is formed when using the FEC additive, rendering a reduction in polarization due to improved Li diffusion inside the electrode composite.

Keywords
Si-electrode, Electrochemical impedance spectroscopy, Volume change, Porosity, Morphology, SEM
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-337666 (URN)10.1016/j.electacta.2017.11.124 (DOI)000418324800085 ()
Funder
EU, FP7, Seventh Framework Programme, 608575Swedish Energy AgencyStandUp
Available from: 2018-01-03 Created: 2018-01-03 Last updated: 2018-02-09Bibliographically approved
Blidberg, A., Gustafsson, T., Tengstedt, C., Björefors, F. & Brant, W. R. (2017). Monitoring LixFeSO4F (x = 1, 0.5, 0) Phase Distributions in Operando To Determine Reaction Homogeneity in Porous Battery Electrodes. Chemistry of Materials, 29(17), 7159-7169
Open this publication in new window or tab >>Monitoring LixFeSO4F (x = 1, 0.5, 0) Phase Distributions in Operando To Determine Reaction Homogeneity in Porous Battery Electrodes
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2017 (English)In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 29, no 17, p. 7159-7169Article in journal (Refereed) Published
Abstract [en]

Increasing the energy and power density simultaneously remains a major challenge for improving electrochemical energy storage devices such as Li-ion batteries. Understanding the underlying processes in operating electrodes is decisive to improve their performance. Here, an extension of an in operando X-ray diffraction technique is presented, wherein monitoring the degree of coexistence between crystalline phases in multiphase systems is used to investigate reaction homogeneity in Li-ion batteries. Thereby, a less complicated experimental setup using commercially available laboratory equipment could be employed. By making use of the intrinsic structural properties of tavorite type LiFeSO4F, a promising cathode material for Li-ion batteries, new insights into its nonequilibrium behavior are gained. Differences in the reaction mechanism upon charge and discharge are shown; the influence of adequate electronic wiring for the cycling stability is demonstrated, and the effect of solid state transport on rate performance is highlighted. The methodology is an alternative and complementary approach to the expensive and demanding techniques commonly employed for time-resolved studies of structural changes in operating battery electrodes. The multiphase behavior of LiFeSO4F is commonly observed for other insertion type electrode materials, making the methodology transferable to other new energy storage materials. By expanding the possibilities for investigating complex processes in operating batteries to a larger community, faster progress in both electrode development and fundamental material research can be realized.

Place, publisher, year, edition, pages
American Chemical Society, 2017
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-338351 (URN)10.1021/acs.chemmater.7b01019 (DOI)000410868600017 ()
Available from: 2018-01-08 Created: 2018-01-08 Last updated: 2018-01-25Bibliographically approved
Edström, K., Gustafsson, T., Aktekin, B., Nordh, T., Lacey, M. & Liivat, A. (2017). Reach MAX: Reach maximum volymetric capacity for lithium batteries with high voltage cathodes. In: : . Paper presented at Energirelaterad fordonsforskning 2017, Enrgimyndigheten (Swedish Energy Agency).
Open this publication in new window or tab >>Reach MAX: Reach maximum volymetric capacity for lithium batteries with high voltage cathodes
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2017 (English)Conference paper, Oral presentation only (Other academic)
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-338172 (URN)
Conference
Energirelaterad fordonsforskning 2017, Enrgimyndigheten (Swedish Energy Agency)
Projects
ReachMAX
Available from: 2018-01-08 Created: 2018-01-08 Last updated: 2018-01-11Bibliographically approved
Renman, V., Ojwang, D. O., Valvo, M., Gómez, C. P., Gustafsson, T. & Svensson, G. (2017). Structural-electrochemical relations in the aqueous copper hexacyanoferrate-zinc system examined by synchrotron X-ray diffraction. Journal of Power Sources, 369, 146-153
Open this publication in new window or tab >>Structural-electrochemical relations in the aqueous copper hexacyanoferrate-zinc system examined by synchrotron X-ray diffraction
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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
Liu, C., Brant, W., Younesi, R., Dong, Y., Edström, K., Gustafsson, T. & Zhu, J. (2017). Towards an Understanding of Li2O2 Evolution in Li-O2 Batteries: An In-operando Synchrotron X-ray Diffraction Study. ChemSusChem, 10(7), 1592-1599
Open this publication in new window or tab >>Towards an Understanding of Li2O2 Evolution in Li-O2 Batteries: An In-operando Synchrotron X-ray Diffraction Study
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2017 (English)In: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 10, no 7, p. 1592-1599Article in journal (Refereed) Published
Abstract [en]

One of the major challenges in developing high-performance Li-O-2 batteries is to understand the Li2O2 formation and decomposition during battery cycling. In this study, this issue was investigated by synchrotron radiation powder X-ray diffraction. The evolution of Li2O2 morphology and structure was observed under actual electrochemical conditions of battery operation. By quantitatively tracking Li2O2 during discharge and charge, a two-step process was suggested for both growth and oxidation of Li2O2 owing to different mechanisms during two stages of both oxygen reduction reaction and oxygen evolution reaction. From an observation of the anisotropic broadening of Li2O2 in XRD patterns, it was inferred that disc-like Li2O2 grains are formed rapidly in the first step of discharge. These grains can stack together so that they facilitate the nucleation and growth of toroidal Li2O2 particles with a LiO2-like surface, which could cause parasitic reactions and hinder the formation of Li2O2. During the charge process, Li2O2 is firstly oxidized from the surface, followed by a delithiation process with a faster oxidation of the bulk by stripping the interlayer Li atoms to form an off-stoichiometric intermediate. This fundamental insight brings new information on the working mechanism of Li-O-2 batteries.

National Category
Chemical Sciences
Identifiers
urn:nbn:se:uu:diva-313451 (URN)10.1002/cssc.201601718 (DOI)000398838600037 ()28247542 (PubMedID)
Funder
Swedish Research CouncilSwedish Energy AgencyÅForsk (Ångpanneföreningen's Foundation for Research and Development)StandUp
Available from: 2017-01-19 Created: 2017-01-19 Last updated: 2018-01-03
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ORCID iD: ORCID iD iconorcid.org/0000-0003-2737-4670

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