Electrochemical-mechanical coupling failure of Ni-rich cathodes: Failure mechanisms and remedying strategies

Ni-rich layered oxide cathodes are considered paramount cathode materials for high-energy density lithium-ion batteries because of their outstanding capacity, enhanced working potentials, and economic advantages. Nonetheless, the inherent structural and interfacial instabilities significantly degrade electrochemical performance and poses serious safety risks during repetitive delithiation/lithiation processes, particularly when the nickel content exceeds 80 %. Herein, the electrochemical features and distinctive structural of advanced Ni-rich layered cathodes, as well as an exhaustive analysis of their bulk and surface failure mechanisms are summarized. Subsequently, remedying strategies to stabilize the structure/interface of Ni-rich cathode, including heteroatom doping, surface modification, concentration-gradient structure and microstructural engineering (single-crystal particle) are reviewed. Finally, outlook and perspectives aimed at encouraging the practical implementation of Ni-rich cathode materials in automotive applications are presented.