Conquering poor reversibility of zinc powder electrode through in-situ surface engineering towards long-life zinc-ion batteries

With the increasing popularity of aqueous zinc-ion batteries, extensive research has been dedicated to mitigating dendritic growth and parasitic reactions for zinc metal anodes. While zinc foil is currently used as a common anode, zinc powder (Zn-P) turns out to be a promising alternative. However, Zn-P is more prone to experience corrosion and induce hydrogen evolution due to its larger specific surface area, thereby resulting in poor cyclability for Zn-P-based batteries. In this study, a simple yet highly effective strategy is developed to modify Zn-P with in-situ formed indium metal protective layer that owns larger hydrogen evolution overpotential than zinc metal. The modified Zn-P is combined with nanocellulose and carbon black to form a composite electrode, which can effectively resist corrosion and hydrogen evolution, facilitate desolvation process, and promote zinc deposition kinetics. Thanks to that, the modified Zn-P realizes significantly improved cumulative zinc plating capacity of 500 mAh cm−2 during symmetric cell test and the assembled Zn//MnO2 battery achieves impressive capacity retention of 97.6% after 2000 cycles. Overall, the composite electrode not only outperforms its unmodified counterpart but also exhibits distinct advantages over previously reported Zn-P-based electrodes. This work reveals a universal pathway to modify metal powder electrodes towards high-performance batteries.