Uniform Zn Deposition Achieved by Ag Coating for Improved Aqueous Zinc-Ion Batteries

Aqueous zinc-ion batteries (ZIBs) are considered as a promising energy storage system due to their low cost and high safety merits. However, they suffer from the challenge of uncontrollable dendrite growth due to a non-uniform zinc deposition, which increases internal resistance and causes battery failure. Herein, Ag coating fabricated by a facile surface chemistry route on zinc metal was developed to guide uniform zinc deposition. Ag-coated Zn shows improved electrolyte wettability, a small zinc deposition overpotential, and fast kinetics for zinc deposition/dissolution. Direct optical visualization and scanning electron microscopy images show uniform zinc deposition due to the introduction of Ag coating. As a result, the Ag-coated Zn anode can sustain up to 1450 h of repeated plating/stripping with a low overpotential in symmetric cells at a current density of 0.2 mA cm(-2), while an improved performance is realized for full cells paired with a V2O5-based cathode. This work provides a facile and effective approach to improve the electrochemical performance of ZIBs.

Automated summary

A facile surface chemistry route has been developed to create an Ag coating on zinc metal, guiding uniform zinc deposition and improving electrochemical performance of ZIBs. Direct visualization and microscopy images confirm uniform zinc deposition on Ag-coated Zn anodes, enabling sustained plating/stripping cycles and improved performance in full cells paired with a V2O5-based cathode.