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. A novel composite material is synthesized by coating the surface of O3 phase Li-rich Mn-based oxides with its isoform, the O2 phase. This composite combines the best attributes of both O3 and O2 phases, inheriting the high-capacity advantage of the O3 phase while exhibiting the reduced voltage decay of the O2 phase. image