Insight of high nickel Li-rich cathode materials for wide temperature operation

Abstract

Tuning the anionic redox is an effective strategy to improve the electrochemical performance of the Li-rich materials. Here, the Li-rich material, 0.5Li2MnO3·0.5LiNi0.8Co0.1Mn0.1O2 (LR-811), was prepared by the nucleation and post-solvothermal method with high temperature calcination. Compared with the well-known Li-rich material, 0.5Li2MnO3·0.5LiNi1/3Co1/3Mn1/3O2 (LR-111), the LR-811 shows excellent cycling performance due to the Ni ions can improve the structural stability and mitigate the oxygen redox during charge/discharge processes at 25 °C. At the same time, wide-temperature range operation of LR-811 sample are also investigated, the results showed that the layered-to-spinel transition and rapid capacity decay became more serious at 55 °C, the reason for this is that the elevated operation temperature facilitates the dissolution of TM ions and the decomposition of the electrolyte. These insights will help us seek electrode modification methods and find suitable electrolyte to improve the wide temperature application of the LR-811 material.