Mechanical degradation in layered oxide cathode materials during electrochemical cycling limits their long-term use by compromising structural stability and capacity retention. In a study on Ni-rich layered oxide cathodes (LiNi0.8Co0.1Mn0.1O2), researchers found that intra-granular cracking inside primary particles degrades performance. Density functional theory simulations revealed that these materials are more vulnerable to tensile than compressive deformation, especially in the out-of-plane direction. Delithiation further weakens mechanical properties, leading to accelerated intra-granular cracking compared to materials with lower nickel content.