Boosting the Structural Reversibility of Layered Oxide Cathode for Realizing Long‐Term Cycle Life Through Electronic Structure Regulation

O3-type layered oxide cathode exhibits great application potential for practical sodium-ion batteries, due to its cost-effectiveness, abundant sodium and manganese resources, and high theoretical capacity. However, the irreversible phase transition, coupled with rapid capacity decay, which is primarily attributed to the Jahn-Teller effect of Mn