Abstract
Anionic redox reactions in cathodes of lithium-ion batteries are allowing opportunities to double or even triple the energy density. However, it is still challenging to develop a cathode, especially with Earth-abundant elements, that enables anionic redox activity for real-world applications, primarily due to limited strategies to intercept the oxygenates from further irreversible oxidation to O2 gas. Here we report simultaneous iron and oxygen redox activity in a Li-rich anti-fluorite Li5FeO4 electrode. During the removal of the first two Li ions, the oxidation potential of O2- is lowered to approximately 3.5 V versus Li+/Li0, at which potential the cationic oxidation occurs concurrently. These anionic and cationic redox reactions show high reversibility without any obvious O2 gas release. Moreover, this study provides an insightful guide to designing high-capacity cathodes with reversible oxygen redox activity by simply introducing oxygen ions that are exclusively coordinated by Li+.
Original language | English (US) |
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Pages (from-to) | 963-971 |
Number of pages | 9 |
Journal | Nature Energy |
Volume | 2 |
Issue number | 12 |
DOIs | |
State | Published - Dec 1 2017 |
Funding
This work was supported by the Centre for Electrochemical Energy Science, an Energy Frontier Research Centre funded by the US Department of Energy, Office of Science, Office of Basic Energy Sciences under award number DE-AC02–06CH11. Use of the Advanced Photon Source and the Centre for Nanoscale Materials, both Office of Science user facilities operated for DOE, Office of Science by Argonne National Laboratory, was supported by the US DOE under Contract No. DE-AC02-06CH11357. The authors acknowledge C.-K. Lin and X. Wang for preparing the Li5FeO4 powders and electrodes. L.L. and M.K.Y.C. thank E. Shirley and J. Vinson for the use of and guidance with the OCEAN code. The computing resources are supported by the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the US Department of Energy under Contract DE-AC02-05CH11231, and Blues, a high-performance computing cluster operated by the Laboratory Computing Resource Center at Argonne National Laboratory.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Fuel Technology
- Energy Engineering and Power Technology