Recent advances in Ni-rich layered oxide particle materials for lithium-ion batteries

Ni-rich layered oxides with chemical formula of LiNixCoyMnzO2 or LiNixCoyAl2O2(x+y+z=1,x≥0.6)have been considered as promising cathode materials for 1让hium-ion batteries(LIBs)because of their high specific capacity(≥180mAhg^-1)and acceptable manufacture cost.However,the problems associated with high Nicontent severely restrict their large-scale applications.In this review,we summarize the recent advances in Ni-rich layered oxide particle materials for LIBs.We begin with the introduction of the structure,redox mechanism,and problems of Ni-rich layered oxides,mainly including residual lithium compounds,gas evolution,rock-salt phase formation,microcrack of particles,dissolution of transitionmetal ions,and thermal runaway.Then,four strategies(primary particle engineering,surface coating,doping,concentration gradient design)toward solving the problems of Ni-rich layered oxides will be systematically discussed with the emphasis on structure-performa nee relati on ships.To achieve satisfied comprehensive performance and accelerate large-scale applications of Ni-rich layered oxides,the combination of two or more strategies(particle engineering and surface/bulk stabilization techniques)w让h synergistic effects is necessary in future works.This review would promote further research and application of high-performance Ni-rich layered oxide particle materials for LIBs.