Molecular Engineering of Hybrid Electrolytes for Aqueous Zinc Ion Batteries

Abstract Aqueous zinc‐ion batteries (AZIBs) offer compelling advantages owing to their inherent safety, cost‐effectiveness, and the exceptional electrochemical properties of the Zn metal anode. However, achieving highly reversible Zn (de)plating remains a formidable challenge. In this study, a molecularly engineered hybrid electrolyte is systematically investigated to modulate the Zn 2+ solvation environment and enhance the interfacial stability. A modified phosphate‐based co‐solvent, diethyl(difluoromethyl)phosphonate (DEDFP) is developed by substituting an ethoxy moiety in triethyl phosphate (TEP) with a difluoromethyl group. This fine‐tunes the de‐solvation kinetics, induces a favorable passivation layer, and further minimizes water‐based side reactions. Compared to the TEP‐based hybrid electrolyte, the DEDFP‐based electrolyte promotes laterally uniform Zn growth to achieve an unprece…