Identifying the Chemical Origin of Oxygen Redox Activity in Li-Rich Anti-Fluorite Lithium Iron Oxide by Experimental and Theoretical X-ray Absorption Spectroscopy
- Argonne National Lab. (ANL), Argonne, IL (United States)
Harnessing oxygen redox reactions is an intriguing route to increasing capacity in Li-ion batteries (LIBs). Despite numerous experimental and theoretical attempts to unravel the mechanism of oxygen redox behavior, the electronic origin of oxygen activities in energy storage of Li-rich LIB materials remains under intense debate. In this work, the onset of oxygen activity was examined using a Li-rich material that has been reported to exhibit oxygen redox, namely, Li5FeO4. By comparing experimental measurements and first-principles Bethe-Salpeter equation calculations of oxygen K-edge X-ray absorption spectra (XAS), it was found that experimentally-observed changes in XAS originate from the non-bonding oxygen states in cation-disordered delithiated Li5FeO4, and the spectral features of oxygen dimers were also determined. This combined experimental and theoretical study offers an effective approach to disentangle the intertwined signals in XAS and can be further utilized in broader contexts for characterizing other energy storage and conversion materials.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States); Energy Frontier Research Centers (EFRC) (United States). Center for Electrical Energy Storage (CEES)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
- Grant/Contract Number:
- AC02-06CH11357
- OSTI ID:
- 1510469
- Journal Information:
- Journal of Physical Chemistry Letters, Journal Name: Journal of Physical Chemistry Letters Journal Issue: 4 Vol. 10; ISSN 1948-7185
- Publisher:
- American Chemical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Eliminating Transition Metal Migration and Anionic Redox to Understand Voltage Hysteresis of Lithium‐Rich Layered Oxides
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