Integrating Anionic Chemistry in Cosolvent Electrolyte for High‐Performance Aqueous Zn Metal Batteries

ABSTRACT Low‐cost and highly safe aqueous zinc metal batteries (AZMBs) hold great promise as next‐generation energy storage systems. However, water‐induced side reactions and Zn dendrite growth are recognized as two major challenges hindering the commercial application of AZMBs. Here, we integrate anionic chemistry into a cost‐effective cosolvent strategy to address these issues. Specifically, N,N‐dimethylformamide (DMF), as a cosolvent, disturbs the hydrogen‐bond network among water and alters the Zn ²⁺ solvation structure, thereby reducing water‐induced side reactions. The sodium D‐gluconate (GAS) with the functional groups (─COO ⁻ and ─OH), as an anionic additive, can preferentially anchor onto the Zn surface. The synergistic effect of the GAS anion in DMF cosolvent can guide the Zn ²⁺ migration and protect the Zn anode. Consequently, with this designed electrolyte, the Zn anodes achieve a lifespan of over 2100 h and a high reversibility with Coulombic efficiency of 99.60%. Furthermore, both the Zn//I ₂ @AC and Zn//MnO ₂ full cells deliver extended cycling stability alongside superior capacities. This study elucidates the role of solvent chemistry from multi‐dimension, providing an insight into the regulation of interfacial kinetics in next‐generation aqueous batteries.