Enhancement structural stability of LiNi0.8Co0.1Mn0.1O2 via S2− doping combine with Li2SO4 coating co-modification

During the charging and discharging process of Ni-rich cathode, the rapid fade of capacity is caused by interface side reactions and bulk structure degradation, which seriously hinders its development and application. In order to address these problems, we synthesized the S2− doping combine with Li2SO4 coating of LiNi0.8Co0.1Mn0.1O2 by one-step co-modification strategy, which consumed the lithium impurity and improved the stability of the surface structure and bulk structure simultaneously. The co-modified LiNi0.8Co0.1Mn0.1O2 not only exhibits outstanding cycling stability at 1 C of 154.3 mAh g−1, the capacity retention rate is 85.4% after 500 cycles, but also exhibits excellent rate performance at 10 C of 150 mAh g−1. The Li2SO4 coating formed can effectively consume oxygen vacancies on the surface of the material. And S2- doping forms a stable O-TM-S bond to prevent Oα- (α<2) migrate outwards, which can effectively improve the stability of the layered structure and surface structure. The research provides a design idea for stabilizing the surface/bulk structure of advanced cathodes for high-performance Li-ion batteries.