A simple and efficient strategy to construct Li-rich layered materials with surface layered/spinel heterostructures

In Li-rich layered oxides cathode materials (LR materials), spinel structure was widely introduced to sup-press the structure attenuation and voltage decline during cycling. In this study, LR materials with surface layered/spinel heterostructures have been fabricated by a simple high-temperature post-treatment method. The existence of the surface spinel structure in synthesized materials was verified via X-ray diffraction, Raman spectra, and transmission electron microscopy. Moreover, the synthesized materials demonstrated remarkable electrochemical performance, especially their cycling performance. After optimization, the LR-850 samples showed the best electrochemical performances, that is, the capacity retentions are 126.97% at 1 C after 200 cycles and 92.2% at 5 C after 700 cycles, and the discharge-specific capacities are 139.6 mAhmiddotg-1 at 5 C and 111 mAhmiddotg-1 at 10 C, respectively. These electrochemical properties improvements are attributed to the introduction of the surface spinel structure in LR materials which could enhance the structural stability and provide 3D lithium ion diffusion paths.(c) 2022 Elsevier B.V. All rights reserved.