Highly reversible zinc metal anodes enabled by a three-dimensional silver host for aqueous batteries

Abstract

Due to the inherent benefits of metallic Zn, aqueous Zn-based batteries have been deemed attractive candidates for next-generation energy storage devices with a high level of safety. Unfortunately, the reversibility of the zinc anode in mild electrolytes is still severely constrained by dendritic growth, undesirable hydrogen evolution, and the formation of inert “dead” zinc. Herein, we report the utilization of Ag mesh as a three-dimensional host for the development of highly reversible and dendrite-free Zn anodes. The in situ, spontaneously formed Ag–Zn alloys on Ag mesh surfaces result in no barrier Zn deposition and suppress the hydrogen evolution, enabling high-efficiency and dendrite-free Zn plating and stripping. Based on such surface-alloyed Ag mesh hosts, an asymmetric cell exhibits superior coulombic efficiency (99.5% for over 2000 cycles at a current density of 5 mA cm⁻² and a capacity of 1 mA h cm⁻²), and LiFePO₄//Zn hybrid-ion aqueous batteries with a limited amount of Zn exhibit improved specific capacities and capacity retention.