Rational design of mechanically robust Ni-rich cathode materials via concentration gradient strategy

Mechanical integrity issues such as particle cracking are considered one of the leading causes of structural deterioration and limited long-term cycle stability for Ni-rich cathode materials of Li-ion batteries. This paper investigates the effect of Co and Mn on the mechanical properties of Ni-rich materials and successfully mitigates particle cracking in Ni-rich cathodes via rational concentration gradient design without sacrificing electrode capacity. A Co-enriched surface design suppresses particle cracking due to its low stiffness, while a Mn-enriched core limits internal expansion and improves structural integrity. The concentration gradient design promotes morphological stability and cycling performance.

Tongchao Liu, Lei Yu, Jun Lu, Tao Zhou, Xiaojing Huang, Zhonghou Cai, Alvin Dai, Jihyeon Gim, Yang Ren, Xianghui Xiao, Martin V. Holt, Yong S. Chu, Ilke Arslan, Jianguo Wen, Khalil Amine