Research Progress on Enhancing the Performance of High Nickel Single Crystal Cathode Materials for Lithium-Ion Batteries

In recent years, stricter standards for lithium-ion batteries have been proposed due to the rapid development of portable electronic devices and new energy vehicles. LiNi_xCo_yMn_zO₂ (NCM, x + y + z = 1) has gradually become the mainstream of cathode materials for powering lithium-ion batteries due to its advantages of high energy density, long cycle life, and high reliability. Furthermore, the energy density of the NCM ternary battery is proportional to the nickel content. Promoting high nickel batteries will realize their lightweight property and high commercial value. This research initially summarizes the properties of polycrystalline and single crystal high nickel cathode materials. Then, the problems of high nickel single crystal cathode materials are emphasized from cation mixing, structural degradation, microcracks, surface side reactions, and thermal stability. Moreover, the coping strategies of coating, surface coating, and additives are discussed in detail. Finally, a summary of high nickel single crystal cathode materials is given, and future research directions are discussed.