Self‐Adaptive Liquid Film: Dynamic Realization of Dendrite‐Free Zn Deposition Toward Ultralong‐Life Aqueous Zn Battery

Abstract The poor reversibility and stability of Zn metal anode (ZMA) caused by uncontrolled Zn deposition behaviors and serious side reactions severely impeded the practical application of aqueous Zn metal battery. Herein, a liquid‐dynamic and self‐adaptive protective layer (LSPL) was constructed on the ZMA surface for inhibiting dendrites and by‐products formation. Interestingly, the outer LSPL consists of liquid perfluoropolyether (PFPE), which can dynamically adapt volume change during repeat cycling and inhibit side reactions. Moreover, it can also decrease the de‐solvation energy barrier of Zn²⁺ by strong interaction between C–F bond and foreign Zn²⁺, improving Zn²⁺ transport kinetics. For the LSPL inner region, in‐situ formed ZnF₂ through the spontaneous chemical reaction between metallic Zn and part PFPE can establish an unimpeded Zn²⁺ migration pathway for accelerating ion transfer, thereby restricting Zn dendrites formation. Consequently, the LSPL‐modified ZMA enables reversible Zn deposition/dissolution up to 2000 h at 1 mA cm⁻² and high coulombic efficiency of 99.8% at 4 mA cm⁻². Meanwhile, LSPL@Zn||NH₄V₄O₁₀ full cells deliver an ultralong cycling lifespan of 100 00 cycles with 0.0056% per cycle decay rate at 10 A g⁻¹. This self‐adaptive layer provides a new strategy to improve the interface stability for next‐generation aqueous Zn battery.