Stabilizing Dual‐Band Redox Process via Bidirectional Regulation Term in High‐Voltage Sodium Layered Oxide Cathodes

Manganese‐based layered oxides represent a promising cathode candidate for sodium‐ion batteries due to their natural abundance and high theoretical capacity. However, their practical application remains challenged by structure phase transitions and unstable redox behavior. Herein, we proposed a high entropy‐induced electronegativity strategy to stabilize dual‐band redox by tuning the balance between d‐d Coulomb interaction energy and the charge transfeduer term, which can enhance the covalency of metal‐oxygen bonds, weaken electronic localization at oxygen sites, and stabilize the oxidized lattice oxygen. Such a strategy further increases configurational entropy and structural tolerance, promoting a robust solid‐solution reaction mechanism across a wide voltage window. The obtained cathode exhibits a reversible capacity of 192.87 mAh g −1 and outstanding capacity retention of 95.98%, which offers a generalizable strategy to decrease the irreversible oxygen oxidation at high voltage and opens new avenues for next‐generation high‐energy‐density sodium‐ion batteries.