Surfactant-assisted hierarchical silver coating enhances the anode surface stability toward zinc stripping/plating

Abstract

Rechargeable aqueous zinc (Zn) batteries are promising for large energy storage due to their low cost, high safety, and environmental compatibility, but their commercialization is hindered by the severe irreversibility of Zn metal anodes as exemplified by water-induced side reactions (H2 evolution and Zn corrosion) and dendrite growth. In this work, hierarchical layered silver-coated zinc anode under the assistance of anionic surfactant (trisodium citrate) was prepared for long-time cycle stabilities of zinc stripping and plating, where Ag coating has a strong affinity to Zn adatoms and hierarchical structure exhibits a positive role in inducing the (002) plane preferred-orientation growth of Zn phase. Benefiting from these features, hierarchical Ag-coated zinc anode was able to operate stability for more than 1200 cycles compared with the pure zinc anode at 2 mA/cm2 for 1 mAh/cm2, and an asymmetric cell shows superior Coulombic efficiency of ∼99.6% over 800 cycles at a current density of 1 mA/cm2 and 0.5 mAh/cm2, as well as a long cycling stability of 500 cycles with capacity of 115 mAh/g in MnO2||H–Zn@Ag full batteries. This work provides a new insight to improve the performance of Zn-metal batteries.