Enhancing the cycling stability of Ni-rich cathodes via dual-site modification induced by slight Ti-rich doping

The Ni-rich cathode material LiNi_0.90Co_0.05Mn_0.05O₂ is a promising candidate for power lithium-ion batteries due to its high specific capacity. However, it suffers from inherent structural instability and severe interfacial side reactions, leading to rapid capacity degradation and thermal instability. In this study, we employed a slight Ti-rich doping strategy to enhance the structural and interfacial stability of the LiNi_0.90Co_0.05Mn_0.05O₂ cathode. The slight Ti-rich doping achieves dual-site modification (TM and Li), inhibits the anisotropic lattice changes, and improves the reversibility of electrochemical reactions. Additionally, it induces the formation of a Li₂TiO₃ coating on the particle surface, which inhibits interfacial side reactions, reduces the deposition of decomposition products, and enhances thermal stability. This strategy significantly improves the cycling stability of the LiNi_0.90Co_0.05Mn_0.05O₂ cathode, achieving a capacity retention rate of 94.4 % at 1C after 150 cycles. This effective approach paves the way for enhancing the electrochemical performance of Ni-rich cathodes.