Grain Morphology and Microstructure Control in High‐Stable Ni‐Rich Layered Oxide Cathodes

• Published in: Advanced functional materials Vol. 33; no. 31
• Main Authors: Wang, Lin, Zhu, Baofu, Xiao, Dongdong, Zhang, Xu, Wang, Boya, Li, Haifeng, Wu, Tianhao, Liu, Shiqi, Yu, Haijun
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01-08-2023
• Subjects: Cathodes; Electrochemical analysis; Electrode materials; Lithium-ion batteries; Materials science; Microcracks; Microstructure; nanosized crystal domains; Ni‐rich layered oxides; primary particles; Strain; structural degradation; Structural stability; W doping
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202212849

Ni‐rich layered oxides are promising cathode material for high‐energy‐density lithium‐ion batteries (LIBs). However, they suffer from poor capacity retention due to unstable structures. Herein, a strategy of high‐valence W doping is put forward to tune the nanometer‐sized crystal domains and reshape the primary particle textures, which can stabilize the structure against the formation of microcracks to improve the electrochemical performance. The Ni‐rich layered oxide with 0.5 mol% doped W delivers a high‐capacity retention of 91.6% up to 300 cycles under 1 C. Such an improved performance is ascribed to the pre‐introduced nanometer‐sized spinel and rock‐salt crystal domains, which remarkably improve the structure stability, and the radially alignment of primary particles, and effectively reduce the anisotropic mechanical strain in deep charge states. This study sheds light on the design of high‐performance Co‐less Ni‐rich cathode materials through the adjustment of microstructures via a small amount of suitable dopants.
A high‐valance W doping strategy is put forward to regulate and optimize microstructure on Co‐less Ni‐rich cathode materials including both the nanometer‐sized crystal domains and micro‐level structures of primary particles, to enhance the electrochemical stability. An optimal material can deliver a high‐capacity retention of 91.6% up to 300 cycles at 1 C.