Research progress on core-shell heterostructure high-nickel cathode materials
The rapid development of new energy vehicles and low altitude economy has put forward increasingly high requirements for power supply systems.Existing lithium-ion batteries are difficult to meet the new market application needs in terms of energy density and safety.The high nickel material LiNi1-x-yCoxMnyO2(x>0.8)combines the advantages of high specific energy,high energy efficiency,and long cycle life,making it a highly promising cathode material for lithium-ion batteries.However,it is prone to cation mixing,microcracks inside the particles,oxygen evolution and transition metal dissolution,irreversible phase transition during the delithiation process,leading to a decrease in battery performance.This paper focuses on the surface interface issues and formation mechanisms of high-nickel materials,briefly introducing common material modification methods.It compares the effects of structural designs such as core-shell structures,semi-concentration gradients,full concentration gradients,and double concentration gradients on battery cycling and safety performance improvements.On this basis,the development direction of core-shell heterogeneous materials is forecasted.