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.