Supercritical CO ₂ ‐Induced Surface Autogenous Mineralization Enabling Epitaxial Zn Electrodeposition on Weakly Conductive Crystalline Coating

Abstract

Abstract Regulating Zinc (Zn) nucleation and crystal growth on the anode surface is critical for reliable aqueous Zn metal batteries. However, achieving scalable and uniform surface modifications remains challenging. A Supercritical CO 2 ‐induced surface autogenous mineralization (SAM) strategy is introduced to fabricate a large‐area, uniform, and crystalline Smithsonite autogenous regulating layer (ARL) on Zn foil. SAM enables in situ generation of H 2 CO 3 and direct reactions with Zn under supercritical conditions, suppressing Zn 2+ hydrolysis and inducing in situ mineralization. The ARL well‐defined facets provide zincophilic sites, promoting single‐crystal Zn nucleation and facilitating dense epitaxial deposition, thereby mitigating dendrites and enhancing cycling stability. The modified electrodes achieve over 1200 h with 99.48% Coulombic efficiency in SZn‐4||Cu cells, over 3500 h in symmetrical cells, and over 8000 cycles in full cells at high current densities. This scalable SAM route offers a robust platform for high‐performance, long‐life Zn anodes in next‐generation aqueous energy storage.