Structural Degradation and Interfacial Failure of LiNi0.8Co0.1Mn0.1O2 Cathode: A Review of Mechanisms and Modification Strategies

The development of sustainable energy storage systems urgently demands rechargeable lithium-ion batteries with high specific capacity and enhanced safety. Among promising cathode candidates, LiNi0.8Co0.1Mn0.1O2 (NCM811) stands out for next-generation high-energy-density applications due to its high capacity and favorable cost. However, its commercial deployment is hindered by severe structural and interfacial degradation, leading to rapid capacity fading, mechanical failure, and safety risks. This review systematically examines the fundamental degradation mechanisms of NCM811, including residual lithium-induced side reactions, transition metal dissolution, lattice oxygen release, phase transitions, microcrack propagation, and thermal runaway. Furthermore, we comprehensively summarize and critically assess representative modification strategies, including bulk doping, microstructure design, surface coating, electrolyte engineering, and the adoption of solid-state electrolytes, in terms of their effectiveness in mitigating these degradation pathways and enhancing electrochemical stability. discuss future research directions aimed at integrating multiple stabilization approaches and advancing scalable, cost-effective synthesis and processing techniques to facilitate the practical implementation of high-performance NCM811 cathodes.