Exploring Degradation Mechanisms and Recent Developments in High-Nickel Layered Cathodes for Lithium Batteries
Guiquan Zhao, Yongjiang Sun, Hang Ma, Futong Ren, Wenjin Huang, Pujia Cheng, Genfu Zhao, Qing Liu, Qi An, Li Yang, Lingyan Duan, Mengjiao Sun, Kun Zeng, Xin Wang, Hong Guo
Abstract
Abstract The Ni-rich layered cathode materials LiNi x Co y Mn 1− x − y O 2 (NCM), which have a high energy density, are crucial in the strategic formulation of next-generation high-performance lithium-ion batteries (LIBs), particularly for cathode materials with Ni ⩾ 0.9. Although advances in NCM cathodes have made them competitive in terms of capacity and cost, persistent challenges such as surface chemical instability (electrolyte-driven surface degradation) and poor mechanical integrity (lattice oxygen evolution and anisotropic microcracking) of the cathodes remain. Addressing these limitations requires coordinated strategies spanning from atomic-level dopant engineering to macroscopic electrode architectural innovations to enable viable large-scale deployment. Extensive research has been conducted on the structural instability caused by an increase in the Ni content, but a comprehensive understanding of its underlying mechanisms and effective modification strategies for next-generation nickel-rich cathodes is lacking. Hence, we provide a thorough overview of the latest findings on microstructural degradation mechanisms in Ni-rich cathodes, delve into recent effective modification strategies and cutting-edge characterization methods, and finally, examine future research directions and limitations. This review elucidates the challenges facing ultrahigh-nickel cathodes and offers new insights into promising research avenues. Graphical Abstract