Cation‐Anion Coordination for Covalent Anchoring of Manganese Oxides to Stabilize Mn Ion Valence and Suppress Jahn‐Teller Distortion and Dissolution
Xiao‐Jie Lu, Lei Chen, Wenxiao Li, Xiaoliang Zhang, Weili Chi, Shulong Li, Chunxia Wang, Yong Liu, Xiangwu Zhang
Abstract
The increasing demand for high‐capacity energy storage, spurred by the growth of renewable energy, has accelerated the pursuit of cost‐effective and sustainable aqueous zinc‐ion batteries as a viable alternative to traditional lithium‐ion batteries. In this study, a cation‐anion coordination cathode material (Zn‐MnO 2 F X ) is proposed, which regulates the central valence state of Mn ions by covalently anchoring manganese oxides with Zn ions and F ions to inhibit Jahn‐Teller distortion and manganese dissolution. Density Functional Theory calculations elucidate the intercalation of Zn 2+ extends the MnO 2 layer spacing, reduces ion diffusion barriers, and accelerates ion diffusion, while F − ions repair defects and enhance the electronic conductivity of MnO 2 , which stabilizes the cathodes and prolongs the life span of batteries. The co‐insertion of Zn 2+ /H + in MnO 2 and the auxiliary effect of Zn 4 SO 4 ·(OH) 6 ·xH 2 O on dissolution/deposition were elucidated by analyzing the changes in structure, morphology, and impedance during the cycling process. The Zn‐MnO 2 F x cathode exhibits a high reversible capacity of 365.5 mA h g −1 at 0.1 A g −1 , with remarkable capacity retention of 96.7% after 1000 cycles at 1 A g −1 . The initial specific capacity of the flexible yarn battery reaches 112.5 mA h g −1 at 0.1 A g −1 . This work adeptly addresses the kinetic‐stability balance in cathode materials, offering a pioneering strategy for sustainable and efficient large‐scale energy storage.