China Nonferrous Metallurgy

Ultra-high nickel cathode material, as one of the development directions of nickel-rich layered oxide cathode materials, is expected to become the next generation of lithium-ion battery cathode material due to its high specific capacity and cost reduction. The ultra-high nickel cathode material has the highest nickel content, which can improve the energy density, but deteriorate the cycle performance and thermal stability. In this paper, the capacity decline mechanism of ultra-high nickel cathode material is briefly analyzed. Combined with the domestic and foreign literature, the modification means such as element doping, surface coating, morphology design and crystal design are summarized. It is pointed out that the current modification means can improve the cycle stability of ultra-high nickel cathode material to a certain extent. However, there are still the problems of mismatch between energy density and structural stability, and how to scale up the industrial production from the laboratory stage. It is necessary to deeply explore the impact mechanism of alternative elements, the doping amount range and its doping process, and combine with a variety of modification methods to solve the problem of mismatch between energy density and structural stability.