Hexagonal Porous Zincophilic Alloy Interface for Ultrastable Zinc Metal Anode

The cycling stability of zinc metal anodes (ZMAs) is often hindered by issues including uncontrolled dendritic growth, nonuniform electric field distribution, and parasitic hydrogen evolution reaction (HER). Herein, we report a zinc anode protected by a zinc-tin (ZnSn) alloy layer with a hexagonal porous structure, fabricated via a simple electrochemical etching process in sodium citrate electrolyte followed by an elemental substitution treatment in stannous chloride solution (denoted as SC@ZnSn). This modified anode exhibits an enhanced electrochemical activity and superior corrosion resistance. When paired in an asymmetric cell configuration, the SC@ZnSn anode delivers remarkable cycling stability, maintaining an average Coulombic efficiency of 99.6% over 1800 cycles. Experimental investigations reveal that the hexagonal porous framework provides abundant Zn²⁺ adsorption sites and promotes uniform ion flux while the zincophilic ZnSn alloy surface effectively lowers the nucleation barrier. These synergistic effects jointly suppress dendrite growth and ensure excellent long-term reversibility. Furthermore, the SC@ZnSn||<i>I</i>₂ full cell demonstrates outstanding durability, achieving stable operation for over 4000 cycles at 1 A g^-1 while maintaining high capacity retention.