Advanced single-crystal layered Ni-rich cathode materials for next-generation high-energy-density and long-life Li-ion batteries

The studies of Ni-rich cathode materials have been the top priority of research because of the high energy density and fair cycling life. However, suffering from severe crack generations and side reactions, the traditional polycrystal (PC) Ni-rich material displayed structural/electrochemical fade during cycling. Compared with PC, single-crystal (SC) Ni-rich materials exhibited excellent structural stability and cycling performance, benefiting from the limited side reaction and gas generation. In this review, the authors not only compared the structural evolution and electrochemical failure mechanisms between PC and SC, but also summarized the synthesis methods and characterization techniques of SC, which provides universal insights into the development of Ni-rich cathode materials.