Advances in synthesis and optimization of single-crystal Ni-rich cathode materials for lithium-ion batteries

Lithium-ion batteries, owing to their superior discharge capacity and relatively reasonable cycle life characteristics, have become the predominant energy storage solution in the field of electric vehicles. Single-crystal nickel-rich cathode materials (SC-NCM) are driving the development of lithium-ion battery technology due to their superior cycle stability and energy density . This review systematically examines the recent research progress of SC-NCM for lithium-ion batteries. We particularly emphasize the enhanced structural integrity, superior electrochemical performance, and reduced side reactions of single-crystal cathode materials (SC) compared to polycrystalline cathode material (PC). Subsequently, we studied various synthesis methods, including coprecipitation , hydrothermal, sol-gel, and other precursor synthesis methods, as well as high-temperature solid-state reactions and the molten salt method. We further discussed the effects of these synthesis methods on the grain morphology and electrochemical properties . Besides, we present the latest advances in optimization strategies and structural design to improve electrochemical performance. At last, we discuss the challenges of diffusion dynamics and cycle stability of lithium-ion batteries under high temperature and high voltage conditions, providing a strategic overview and target guidance for developing high energy density and long lifespan lithium-ion batteries. • Emphasize SC's better structural integrity, electrochemical performance, and fewer side reactions than PC. • Study synthesis methods: coprecipitation , hydrothermal, sol-gel, solid-state reactions, and molten salt. • Summarize SC-NRCMs modification strategies like doping, coating, and electrolyte adjustment for guidance. • Discuss challenges and prospects of rapidly developing SC-NRCMs.