%J Energy & Environmental Science %K Science & Technology, Physical Sciences, Technology, Life Sciences & Biomedicine, Chemistry, Multidisciplinary, Energy & Fuels, Engineering, Chemical, Environmental Sciences, Chemistry, Engineering, Environmental Sciences & Ecology, WATER %L discovery10170177 %I ROYAL SOC CHEMISTRY %O This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. %X Despite their cost-effectiveness and intrinsic safety, aqueous zinc-ion batteries have faced challenges with poor reversibility originating from various active water-induced side reactions. After systematically scrutinizing the effects of water on the evolution of solvation structures, electrolyte properties, and electrochemical performances through experimental and theoretical approaches, a hydrated deep eutectic electrolyte with a water-deficient solvation structure ([Zn(H2O)2(eg)2(otf)2]) and reduced free water content in the bulk solution is proposed in this work. This electrolyte can dramatically suppress water-induced side reactions and provide high Zn2+ mass transfer kinetics, resulting in highly reversible Zn anodes (∼99.6% Coulombic efficiency over 1000 cycles and stable cycling over 4500 h) and high capacity Zn//NVO full cells (436 mA h g−1). This work will aid the understanding of electrolyte solvation structure–electrolyte property–electrochemical performance relationships of aqueous electrolytes in aqueous zinc-ion batteries. %T A hydrated deep eutectic electrolyte with finely-tuned solvation chemistry for high-performance zinc-ion batteries %A Ruwei Chen %A Chengyi Zhang %A Jianwei Li %A Zijuan Du %A Fei Guo %A Wei Zhang %A Yuhang Dai %A Wei Zong %A Xuan Gao %A Jiexin Zhu %A Yan Zhao %A Xiaohui Wang %A Guanjie He %D 2023