Pre‐Established Ion Transport Pathways Through Electrolyte Initiator for High‐Efficiency Polymer Interface Enabling Ultra‐Stable Aqueous Zinc‐Metal Anodes

Abstract Achieving stable zinc‐metal anodes is pivotal to realizing high‐performance aqueous zinc‐metal batteries (AZMBs). The construction of a functional polymer interface layer on the zinc‐metal anode surface is confirmed as an effective strategy for mitigating dendrite growth and side reactions, thereby significantly enhancing the stability of zinc‐metal anode. However, polymers capable of withstanding electrolyte environments over the long term typically suffer from elevated interfacial impedance, which hinders Zn 2+ transport. Here, a pioneering zinc‐metal anode enabled by a functional polymer interface layer with high‐efficiency ion transport is introduced. This polymer layer is polymerized in situ on the zinc‐metal anode surface through an innovative redox initiation system, where zinc trifluoromethanesulfonate (Zn(OTf) 2 ) salts function as both reductant and ion transport pre‐pathways, ensuring high‐efficiency ion transport. The resultant interface layer achieves an ideal balance of ionic conductivity, water resistance, adhesion, and mechanical properties, effectively suppressing dendrite growth and side reactions. Symmetric cells assembled with this interface layer deliver an impressive lifespan of 8800 and 1600 h under 1 and 5 mA cm −2 , respectively. This interface layer further demonstrates exceptional feasibility and versatility in Zn‐NVO and Zn‐PANI batteries. This work provides groundbreaking insights into the strategic design of high‐performance polymer interface layers for AZMBs.