Interphase‐Electrolyte Co‐Regulation by a Partially Soluble Zinc Acetate Interphase for Zinc Anodes

ABSTRACT Interfacial modification is a widely adopted strategy for stabilizing zinc metal anodes in aqueous zinc‐ion batteries. However, most reported designs rely on strictly insoluble interphases, largely due to routine path dependence in the prevailing assumption that soluble modification layers would rapidly dissipate and lose functionality. Herein, a partially soluble zinc acetate surface modification is constructed via temperature‐controlled etching, enabling simultaneous regulation of the electrode interface and the electrolyte environment. Upon electrolyte immersion, the residual interphase homogenizes the interfacial electric field and mitigates surface corrosion, while released acetate anions which dynamically reconstruct the Zn 2+ solvation structure by partially displacing coordinated water molecules. This cooperative regulation promotes uniform Zn deposition while suppressing parasitic corrosion reactions on Zn anode. As a result, the zinc modified Zn anode delivers stable dendrite‐free plating/stripping for over 2000 h at 10 mA cm −2 and maintains reversible cycling under a 30% depth of discharge for 600 h. Full cells with an ammonium vanadate cathode exhibit a capacity retention of 67.8% after 1500 cycles at 5 A g −1 . This work demonstrates that controlled interphase solubility can be intentionally leveraged as a viable parameter for interface engineering in aqueous zinc batteries.