Construction of Interface Film with Well-Regulated Zn Ion Flux Enabled Long-Term and Dentrite-Free Zn Anode

Abstract

Aqueous zinc-ion batteries have been highly valued for their high safety and environmental friendliness. However, the notorious Zn dendrite growth derived from uneven distribution of electric fields and side reaction at the electrolyte–anode interface critically limited the lifespan of aqueous zinc-ion batteries. Herein, uniform zinc deposition were achieved by construction of interface film with prussian blue 3D open framework, which provide highly zincophilic channel with well-regulated Zn2+ flow tailored on Zn anode surface. The decorated Zn electrode displayed an ultralong plating/stripping cycling life over 4800 h with an ultralow voltage hysteresis (31 mV) at current density of 0.25 mA cm−2. Moreover, the modified Zn||Cu half cell delivers high average coulombic efficiency up to 99.2% for more than 1000 cycles at 0.5 mA cm-2. When coupled with MnO2 cathode, the full cells demonstrated significantly improved cycling stability with capacity retention of 85.09% after 200 cycles. The facile construction strategy of interface layer with well-regulated Zn2+ flow developed in this work provided promising perspective for the design of long term aqueous Zn battery.

Keywords: Zinc-ion batteries, Zinc anode, Interface film, Homogeneous deposition, Dendrite free.