Ultra‐Stable Aqueous Zinc Anodes: Enabling High‐Performance Zinc‐Ion Batteries via a ZnSiF6‐Derived Protective Interphase

Zinc‐ion batteries (ZIBs) hold immense promise as next‐generation energy storage solutions, however, the practical application of zinc anodes is hindered by dendrite formation and parasitic side reactions. Engineering a stable solid‐ eletrolyte interphase (SEI) is crucial for addressing these issues. This study proposes a novel strategy to enhance Zn anode performance by incorporating a ZnSiF6 additive into a standard ZnSO4 (ZSO) electrolyte. The ZnSiF6 additive facilitates the formation of a stable, fluorine‐rich SEI on the Zn anode surface. Characterization reveals a hierarchical SEI structure, primarily composed of porous alkali zinc sulfate (ZHS) with embedded ZnF2. This unique architecture promotes rapid zinc ion desolvation and efficient transport, enhances corrosion resistance, and mitigates hydrogen evolution. Consequently, ZnSiF6‐modified cells exhibit exceptional cycling stability, exceeding 3000 hours at 0.5 mA cm−2 and 560 hours at 10 mA cm−2, significantly outperforming ZSO‐based cells. The modified cells also achieve high areal capacities (10 mAh cm−2), indicating superior zinc utilization. This work provides key insights for designing stable electrode/electrolyte interfaces, contributing to the development of high‐performance aqueous ZIBs. A ZnSiF6 additive in ZnSO4 (ZSO) electrolyte forms a fluorine‐rich, hierarchical solid‐electrolyte interphase (SEI) on Zn anodes, enhancing Zn‐ion battery (ZIB) performance. The SEI promotes uniform Zn deposition and suppresses side reactions, boosting cycling stability. Characterization reveals a porous ZHS framework with embedded ZnF2 within the SEI, contributing to high‐performance aqueous ZIBs.