A stable dual LiAlO2/Li2SiO3 coating LiNi0.8Co0.1Mn0.1O2 cathode towards ultra-long-life and wide-temperature lithium-ion battery

Ni-rich layered LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode material offers great potential for widespread applica-tions due to its high capacity, non-toxicity, and low cost. However, the instability of the structure, large po-larization and occurrence of side reactions during charge-discharge cycles greatly restrict the performance of LiNi0.8Co0.1Mn0.1O2. The stability of NCM811 can be improved through surface coating, but single-phase coating cannot achieve both high electronic conductivity and enhanced Li+ diffusion. Herein, LiAlO2 and Li2SiO3 are applied to prepare dual coating NCM811 (AS-NCM811) and build 3D Li+ diffusion channels and surface pro-tection to improve both Li+ diffusion efficiency and electronic conductivity of NCM811. In addition, using LiAlO2 and Li2SiO3 in AS-NCM811 can enhance structural stability and reduce the likelihood of undesired side reactions occurring, which is verified by ex-situ X-ray diffraction and transmission electron microscopy. As a result, the AS-NCM811-based battery exhibits a remarkable cyclic ability and rate performance in widen temperature range (room temperature (RT) to 55 degrees C). AS-NCM811 shows an RT initial discharge capacity of 180.8 mAh g-1, while achieve a high-capacity retention of 92.6 % (100 cycles, 1C). Even at 55 degrees C, AS-NCM811 also retains 68.4 % of its capacity (143.5 mAh g-1) after 200 cycles under 1C. Overall, these findings pave a novel dual-coating way for the application of Ni-rich layered cathodes in high energy-density lithium-ions battery.