Mitigating Capacity and Voltage Decay in Li‐Rich Cathode Via Dual‐Phase Design

High‐capacity O3‐type lithium‐rich manganese‐based (LRM) materials exhibit significant structural instability and severe voltage decay, which limit their practical applications. In contrast, the O2‐type LRM materials demonstrate remarkable structural stability despite offering lower capacity. In this study, a composite material, O3@O2‐LRM is designed, by coating the main structure of O3‐type LRM with a minor amount of O2‐type LRM to combine the high capacity of the O3 phase with the superior stability of the O2 phase. Electrochemical tests demonstrate that O3@O2‐LRM exhibits both high specific capacity and reduced voltage decay. Furthermore, a series of characterizations after different cycles confirm its enhanced structure stability compared to O3‐LRM. This novel structure holds great promise for developing advanced cathode materials capable of meeting the demanding requirements of next‐generation Li‐ion batteries.