Research Progress on the Failure Mechanisms and Modifications of Ni-Rich Ternary Layered Oxide Cathode Materials for Lithium-Ion Batteries

With the continuous increase in energy demand, lithium-ion batteries (LIBs) are extensively used in a variety of applications because of their high voltage, large specific capacity, and good cyclic performance. The cathode material is critical to determine the properties of LIBs. As one of the most commercialized cathode materials, Ni-rich ternary layered oxides encompass the triple advantages of Ni, Co, and Mn and are the preferred cathode materials for designing high-specific energy LIBs by increasing Ni content and reducing Co and Mn content to obtain higher specific capacity and lower cost. However, they also have some problems and challenges that must be overcome urgently to be more suitable for the future development of the LIB industry. In this paper, the main problems and failure mechanisms of Ni-rich ternary layered oxide cathode materials are reviewed in detail, including cation mixing, thermal stability, and microcracks. In view of the three major issues above, the advances in modification research in recent years are summarized, including doping, coating, doping and coating synergistic modification, and special structure design. Finally, the future developments and challenges are forecasted.