Fast-growing multifunctional ZnMoO4 protection layer enable dendrite-free and hydrogen-suppressed Zn anode

Metallic zinc has become one of the most potential anodes for aqueous zinc-ion batteries (ZIBs) due to its high capacity and safety. However, uneven Zn deposition and hydrogen evolution at zinc anode severely limit the development and commercialization of aqueous ZIBs. Here, we directly formed a uniform ridge-like ZnMoO4 layer on the Zn anode (denoted as Zn@ZnMoO4) within 20 s by chemical deposition. Due to its special structure and strong binding energy to Zn adatoms, the modified layer can induce uniform zinc nucleation and inhibit dendrite growth. In addition, ZnMoO4 can significantly increase the adsorption free energy of H adatoms (Delta G( H*)), suppressing the evolution of hydrogen. With this synergy effect, Zn@ZnMoO4 delivers strong hydrogen suppression capability that increases the hydrogen evolution overpotential from 27 mV to 137 mV, achieves exciting cycling stability for 10,000 cycles at a high current density of 10 mA cm(-2). Meanwhile, the capacity retention rate of the Zn@ZnMoO4/alpha-MnO2 full battery reaches 87% after 1000 cycles under 1A g(-1).

Automated summary

In this study, a uniform ridge-like ZnMoO4 layer was directly formed on the zinc anode within 20 seconds by chemical deposition, improving the issues of uneven zinc deposition and hydrogen evolution in aqueous zinc-ion batteries. Zn@ZnMoO4 demonstrates strong hydrogen suppression capability, excellent cycling stability, and high capacity retention rate.