Interfacial Engineering via Halide Anion Derived Specific Adsorption Toward Regulated Deposition Kinetics for Zn Metal Anodes

Aqueous rechargeable zinc‐ion batteries are attractive for large‐scale energy storage but suffer from concurrent dendritic Zn growth and water‐induced parasitic reactions at the Zn/electrolyte interface. To address the intrinsic instability of interfacial layers formed by conventional, weak‐interaction‐based additive engineering, a specific‐adsorption‐dominated strategy is proposed to stabilize Zn anodes. Driven by interactions between surface Zn atoms and anionic lone pairs, halide anions form short‐range surface bonds with partial charge transfer to Zn atoms, yielding a partially covalent Zn‐halide chemisorbed layer within the inner Helmholtz plane. In contrast to the nonspecific and weakly adsorbed layers, such a chemisorbed layer possesses enhanced cohesive strength and resistance against perturbation, enabling long‐term interfacial protection. The resulting interphase lowers the Zn 2+ desolvation barrier to enhance interfacial kinetics while constructing a water‐deficient interface that suppresses hydrogen evolution. Consequently, Zn//Zn symmetric cells with halide‐containing electrolyte operate stably for > 4900 h at 1.0 mA cm −2 /1.0 mAh cm −2 with a cumulative plating capacity of 2.45 Ah cm −2 , while Zn//Cu cells deliver an average Coulombic efficiency (CE) of 99.7%. When paired with a NaV 3 O 8 ·1.5H 2 O (NVO) cathode, full cells further demonstrate improved rate capability and prolonged cycling, confirming that halide–anion chemisorption is a robust and generalizable strategy for highly reversible Zn anodes.