Abstract
High-rate cathode materials for Li-ion batteries require fast Li transport kinetics, which typically rely on topotactic Li intercalation/de-intercalation because it minimally disrupts Li transport pathways. In contrast to this conventional view, here we demonstrate that the rate capability in a Li-rich cation-disordered rocksalt cathode can be significantly improved when the topotactic reaction is replaced by a non-topotactic reaction. The fast non-topotactic lithiation reaction is enabled by facile and reversible transition metal octahedral-to-tetrahedral migration, which improves rather than impedes Li transport. Using this concept, we show that high-rate performance can be achieved in Mn- and Ni-based cation-disordered rocksalt materials when some of the transition metal content can reversibly switch between octahedral and tetrahedral sites. This study provides a new perspective on the design of high-performance cathode materials by demonstrating how the interplay between Li and transition metal migration in materials can be conducive to fast non-topotactic Li intercalation/de-intercalations.
| Original language | English |
|---|---|
| Pages (from-to) | 706-714 |
| Number of pages | 9 |
| Journal | Nature Energy |
| Volume | 6 |
| Issue number | 7 |
| DOIs | |
| State | Published - Jul 2021 |
Funding
This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Vehicle Technologies Office, under the Applied Battery Materials Program of the US Department of Energy under contract no. DE-AC02-05CH11231. The XAS measurements were performed at the Advanced Photon Source at Argonne National Laboratory, which is supported by the US Department of Energy under contract no. DE-AC02-06CH11357. Work at the Advanced Light Source was supported by the US DOE Office of Science User Facility under contract no. DE-AC02-05CH11231. Work at the Molecular Foundry was supported by the Office of Science, Office of Basic Energy Sciences, of the US Department of Energy under contract no. DE-AC02-05CH11231. The computational analysis was performed using computational resources sponsored by the US Department of Energy\u2019s Office of Energy Efficiency and Renewable Energy and located at the National Renewable Energy Laboratory, as well as computational resources provided by the Extreme Science and Engineering Discovery Environment (XSEDE), supported by National Science Foundation grant no. ACI1053575, and the National Energy Research Scientific Computing Center (NERSC), a DOE Office of Science User Facility supported by the Office of Science and the US Department of Energy under contract no. DE-AC02-05CH11231. We thank H. Kim and Z. Lun for assistance with the XAS measurements.