Liquid Alloy Interlayer for Aqueous Zinc-Ion Battery

Ameliorating the interfacial issues of the zinc anode, particularly dendrite growth and electrode corrosion, is imperative for rechargeable zinc metal batteries. Herein, an electrochemical-inert liquid gallium–indium alloy coating is designed toward the zinc anode, inspired by the gallium–indium–zinc phase diagram. This unique liquid coating prefers an inward-deposition of Zn underneath the liquid coating assisted by ultrafast mass/charge transport when charging. Moreover, the corrosion of the modified zinc anode is improved as well, depiciting a hydrogen-evolution reaction overpotential higher than that of the reference zinc anode. Consequently, it enables a polarization of 24 mV, the lowest to the best of our knowledge, at 0.25 mA cm–2 with a prolonged lifespan (2100 h), which further enables the corresponding MnO2 full cells with improved capacity retention and stage of charge above 96% after 48 h. This effective approach provides a universal idea for the future development of rechargeable metal batteries beyond zinc-storage systems.