A highly reversible dendrite-free Zn anode via spontaneous galvanic replacement reaction for advanced zinc-iodine batteries

Rechargeable aqueous zinc-iodine batteries have received extensive attention due to their inherent advantages such as low cost, flame retardancy and safety. To address the safety concern associated with Zn dendrites, tin functional layer is introduced to the Zn surface via a spontaneous galvanic replacement reaction. This provides rapid deposition kinetics, thereby achieving the uniform Zn plating/stripping with a low overpotential (13.9 mV) and good stability for over 900 h. Importantly, the coupling of the advanced Zn anode with iodine in Zn-I₂ battery exhibits a high specific capacity of 196.4 mAh·g⁻¹ with high capacity retention (90.7%). This work provides a reliable strategy to regulate the reversible redox of zinc for advanced rechargeable batteries.