A corrosion-resistant zincophilic film enables synergistic hydrogen evolution suppression and dendrite-free deposition toward highly reversible and durable Zn anodes

Zinc ion batteries have challenges originated from the Zn dendrite growth and hydrogen evolution reaction (HER) on Zn anodes. We design an all-in-one corrosion-resistant zincophilic film (CRZF) composed of zinc halide and Cu on Zn (CRZF@Zn) through the replacement reaction of copper halides with Zn metal. The in-situ formed zinc halide with high zincophilicity in the CRZF facilitates desolvation of [Zn(H 2 O) 6 ] 2+ clusters and boosts ions migration, with the conspicuously decreased nucleation potential of Zn. The formed chemically inert Cu improves the corrosion-resistivity of Zn anode and enhances the HER overpotential on Zn. The stimulated charge transfer supports uniform deposition of Zn to avoid the “tip effect”, which effectively restrains dendrites formation on Zn anode. Thus this artificial surface demonstrates synergistic effect on dendrite inhibition and HER suppression. The density functional theory (DFT) calculations show that with the increase of the electronegativity of halogen atoms in the zinc halide, the adsorption energy of Zn 2+ on the CRZF layer is enhanced, validating the positive correlation between ions migration and electronegativity of halogen atoms in CRZF. Our findings offer a deeper insight into the interface tuning chemistry of Zn anodes, providing opportunities for the development of dendrite-free and long-life Zn metal batteries.