Achieving a Deeply Desodiated Stabilized Cathode Material by the High Entropy Strategy for Sodium‐ion Batteries

Abstract

Abstract Manganese‐based layered oxides are currently of significant interest as cathode materials for sodium‐ion batteries due to their low toxicity and high specific capacity. However, the practical applications are impeded by sluggish intrinsic Na + migration and poor structure stability as a result of Jahn–Teller distortion and complicated phase transition. In this study, a high‐entropy strategy is proposed to enhance the high‐voltage capacity and cycling stability. The designed P2‐Na 0.67 Mn 0.6 Cu 0.08 Ni 0.09 Fe 0.18 Ti 0.05 O 2 achieves a deeply desodiation and delivers charging capacity of 158.1 mAh g −1 corresponding to 0.61 Na with a high initial Coulombic efficiency of 98.2 %. The charge compensation is attributed to the cationic and anionic redox reactions conjunctively. Moreover, the crystal structure is effectively stabilized, leading to a slight variation of lattice parameters. This research carries implications for the expedited development of low‐cost, high‐energy‐density cathode materials for sodium‐ion batteries.