Nested‐Sphere Structure Stabilizes High‐Performance Lithium‐Rich Manganese‐Based Oxide Cathodes

ABSTRACT Lithium‐rich manganese‐based layered oxides (LMO) with high energy density are regarded as promising cathode candidates for next‐generation high‐specific‐energy batteries. However, during repeated lithium insertion and extraction, the accumulation of stress and strain can trigger cracking of secondary particles, compromise structural integrity, and accelerate electrochemical degradation. Here we tune the oxygen partial pressure during sintering to synthesize an LMO cathode with a nested‐sphere architecture. This architecture disperses the strain generated during cycling, while the interlayer voids buffer volume changes, thereby suppressing crack formation and improving cycling stability. Experimental results show that the cathode delivers high electrochemical reversibility, achieving a specific capacity of 261 mAh g −1 at 1°C and a voltage retention of 93.4% after 300 cycles. The mechanistic insight provided by this nested‐sphere design offers a practical route toward advanced lithium‐ion cathodes that combine high energy density with long‐term stability.