Stable Aqueous Anode‐Free Zinc Batteries Enabled by Interfacial Engineering

Abstract Anode‐free zinc batteries (AFZBs) are proposed as promising energy storage systems due to their high energy density, inherent safety, low cost, and simplified fabrication process. However, rapid capacity fading caused by the side reactions between the in situ formed zinc metal anode and electrolyte hinders their practical applications. To address these issues, aqueous AFZBs enabled by electrolyte engineering to form a stable interphase are designed. By introducing a multifunctional zinc fluoride (ZnF 2 ) additive into the electrolyte, a stable F‐rich interfacial layer is formed. This interfacial layer can not only regulate the growth orientation of zinc crystals, but also serve as an inert protection layer against side reactions such as H 2 generation. Based on these synergy effects, zinc deposition/dissolution with high reversibility (Coulombic efficiency > 99.87%) and stable cycling performance up to 600 h of are achieved in the electrolyte optimized by ZnF 2 . With this electrolyte, the cycling life of AFZBs is significantly improved. The work may initiate the research of AFZBs and be useful for the design of high energy, high safety, and low‐cost power sources.