Recent progress in coatings and methods of Ni-rich LiNi0.8Co0.1Mn0.1O2 cathode materials: A short review

摘要

LiNi0.8Co0.1Mn0.1O2 (NCM811) is a typical nickel (Ni)-rich ternary cathode material with several advantages, such as high specific capacity, low-cost, and environmentally friendly, making it a good candidate for use in lithium-ion batteries. However, its Ni content is as high as 80%; therefore, several new problems have emerged with gradually increasing applications. In this review, Li-Ni disorder and corresponding modification methods are first briefly reviewed, and then the origin of complex surface defect, which has a crippling effect on diffusion processes of Li+ at electrolyte/cathode interface, is discussed in detail. Analyses showed the importance of selecting appropriate surface modification material/technique for enhancing electrochemical properties. Therefore, popular surface coating materials and methods including metal oxides, fluorides, phosphates, fast ion conductors, and other compounds/elements used for the development of NCM811 are subjected to extensive and thorough research. Finally, several new perspectives and insights related to stability and safety at high voltages and temperatures, and the optimization of production process are also proposed.