Heterostructured Interface Enables Uniform Zinc Deposition for High-Performance Zinc-Ion Batteries

Zinc metal has considerable potential as a high-energy anode material for aqueous batteries due to its high theoretical capacity and environmental friendliness. However, dendrite growth and parasitic reactions at the electrode/electrolyte interface remain two serious problems for the Zn metal anode. Here, the heterostructured interface of ZnO rod array and CuZn₅ layer is fabricated on the Zn substrate (ZnCu@Zn) to address these two issues. The zincophilic CuZn₅ layer with abundant nucleation sites ensures the initial uniform Zn nucleation process during cycling. Meanwhile, the ZnO rod array grown on the surface of the CuZn₅ layer can guide the subsequent homogeneous Zn deposition via spatial confinement and electrostatic attraction effects, leading to the dendrite-free Zn electrodeposition process. Consequently, the derived ZnCu@Zn anode exhibits an ultra-long lifespan of up to 2500 h with symmetric cells at the current density and capacity of 0.5 mA cm^-2 /0.5 mA h cm^-2 . Besides, a remarkable cyclability (75% retention for 2500 cycles at 2 A g^-1 ) is achieved in the ZnCu@Zn||MnO₂ full cell with a capacity of 139.7 mA h g^-1 . This heterostructured interface with specific functional layers provides a feasible strategy for the design of high-performance metal anodes.