Abstract
The demands for higher energy density of rechargeable batteries have been continuously increasing recently, and cationic redox based current cathodes have little scope to further increase energy density since they already exhibit near-theoretical specific capacities. In this regard, oxygen redox (OR) reactions have emerged as a promising breakthrough for sodium-ion battery (SIB) cathodes. Most OR-based layered oxides suffer from drastic hysteretic-oxygen capacities upon discharging after the first charging. In contrast, stable and nonhysteretic oxygen capacities are herein enabled via Al3+ incorporation into Li-excess Na layered oxide (NLMO). By combining experimental work and first-principles calculations, it is found that there is an additional stable phase during the oxygen redox for Al incorporated NLMO in comparison with bare NLMO, which is a critical factor in extending and stabilizing the discharge capacity in thermodynamics. In addition, the additional redox-inactive Al3+ leads to heterogeneous oxygen redox rather than homogeneous, which results in stabilization of the oxide framework with sensitively control of the oxygen participation upon cycling.
Original language | English |
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Article number | 2103384 |
Journal | Advanced Energy Materials |
Volume | 12 |
Issue number | 11 |
DOIs | |
Publication status | Published - 17 Mar 2022 |
Bibliographical note
Publisher Copyright:© 2022 Wiley-VCH GmbH.
Keywords
- Al substitution
- first-principles calculations
- layered oxides
- oxygen redox
- sodium-ion batteries