In situ Fe K-edge X-ray absorption spectroscopy study during cycling of Li2FeSiO4 and Li2.2Fe0.9SiO4 Li ion battery materials

Brownrigg, Alexander W. and Mountjoy, Gavin and Chadwick, Alan V. and Alfredsson, Maria and Bras, Wim and Billaud, Juliette and Armstrong, A. Robert and Bruce, Peter G. and Dominko, Robert and Kelder, Erik M. (2015) In situ Fe K-edge X-ray absorption spectroscopy study during cycling of Li2FeSiO4 and Li2.2Fe0.9SiO4 Li ion battery materials. Journal of Materials Chemistry A, 3 (14). pp. 7314-7322. ISSN 2050-7488. (doi:https://doi.org/10.1039/c4ta06305h) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

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Official URL
http://www.dx.doi.org/10.1039/c4ta06305h

Abstract

In situ X-ray Absorption Spectroscopy (XAS) results are presented for Li2FeSiO4 and Li2.2Fe0.9SiO4, promising cathode materials for lithium-ion batteries. The aims are to establish the valence and local structure of Fe during charge and discharge to understand if the Fe3+/Fe4+ redox pair can be reached in the current battery design. It is found that the valence state changes between Fe2+ and Fe3+, with no evidence of Fe4+ before the onset of electrolyte degradation. There is a reversible contraction and extension of the Fe–O bond lengths during cycling while the Fe–Si distance remains constant, which underlines the stability of the Li2FeSiO4 material. The same observations apply to Li2.2Fe0.9SiO4 cathode material indicating that changing the stoichiometry does not provide any additional structural stability.

Item Type: Article
Uncontrolled keywords: Bond length, Cathodes, Electric batteries, Electrodes, Lithium, Lithium alloys, Lithium compounds, Secondary batteries, Stability, X ray absorption spectroscopy, Battery design, Cath-ode materials, Charge and discharge, Electrolyte degradations, In-situ X-ray absorption spectroscopy, Li-ion batteries, Local structure, Structural stabilities, Lithium-ion batteries
Subjects: Q Science > QD Chemistry > QD478 Solid State Chemistry
Divisions: Faculties > Sciences > School of Physical Sciences > Functional Materials Group
Depositing User: Giles Tarver
Date Deposited: 03 Aug 2015 10:18 UTC
Last Modified: 04 Aug 2015 09:09 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/49974 (The current URI for this page, for reference purposes)
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