Long cycle life zinc-air batteries achieved with Zn@Sn-cu anodes of varying architectures

Rechargeable aqueous zinc-air batteries (ZABs) are promising candidates for next-generation energy storage due to their high safety, substantial energy density, and low cost. However, their practical adoption is impeded by inherent issues of conventional zinc anodes, such as dendrite formation, volume expansion, and low zinc utilization during repeated electroplating and stripping. To address these challenges, this study fabricates stable Sn Cu current collectors as anode substrates from Sn-plated copper bases with varying architectures. Electrochemical characterization confirms that the Zn@Sn-Cu electrode inherits the high ionic conductivity of the copper substrate while effectively suppressing hydrogen evolution and reducing the local corrosion current density. Post-cycling scanning electron microscopy (SEM) further reveals that the introduced Sn layer mitigates zinc dendrite growth during deposition/stripping cycles, facilitating the formation of a highly dense and uniform zinc layer on the Sn Cu substrate. Consequently, ZABs assembled with Zn@Sn-2DCu and Zn@Sn-3DCu anodes deliver high specific energy densities of 783 and 800 mAh·g −1 , respectively. Notably, the Zn@Sn-3DCu battery achieves an extended cycle life of over 1800 cycles at a current density of 1 mA·cm −2 .