Abstract
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, Li 5 FeO 4 . 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 nonbonding oxygen states in cation-disordered delithiated Li 5 FeO 4 , 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.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 806-812 |
| Number of pages | 7 |
| Journal | Journal of Physical Chemistry Letters |
| Volume | 10 |
| Issue number | 4 |
| DOIs | |
| State | Published - Feb 21 2019 |
Funding
The authors thank Zhenpeng Yao and Chris Wolverton for providing the structural model of Li3FeO3.5 and John Vinson and Eric Shirley for critical reading of the manuscript. This work was supported as a part of the Center for Electrochemical Energy Science, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, under Award Number DE-AC02−06CH11. Use of the Center for Nanoscale Materials and the Advanced Photon Source, both Office of Science user facilities operated by Argonne National Laboratory, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. The computing resources provided on Bebop, a high-performance computing cluster operated by the Laboratory Computing Resource Center at Argonne National Laboratory, is gratefully acknowledged, as is the Extreme Science and Engineering Discovery Environment (XSEDE) supported by National Science Foundation Grant Number ACI-1053575.37 This research also used resources of the National Energy Research Scientific Computing Center (NERSC), a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy (DOE) under Contract No. DE-AC02-05CH11231.
ASJC Scopus subject areas
- General Materials Science
- Physical and Theoretical Chemistry