Highly efficient corrosion inhibitor for low charge voltage and long lifespan rechargeable aqueous zinc-air battery

Abstract

Hydrogen evolution, passivation and dendrite growth problems faced by zinc anodes of aqueous zinc-air batteries greatly reduce their cycle life and hinder their application in energy storage devices. Herein, a reversible, corrosion-resistant, and long-term stable cycle-life zinc anode is achieved by introducing zinc acetate and zinc gluconate into an alkaline electrolyte as corrosion inhibitors. Zinc acetate adsorbed on the surface of the zinc anode could be able to regulate the anode/electrolyte interface and thus inhibit the growth of dendrites, and zinc gluconate can reduce the charge voltage on the cathode to regulate the oxidation reaction and then prolong the cycle life, which eventually inhibit zinc anode corrosion. The additive package of zinc acetate and zinc gluconate provides a better performance. With addition of corrosion inhibitors, Zn||Cu cells show a high average coulombic efficiency about 94 %, and zinc-air batteries achieve a cycling lifespan of 297 h and low charge voltage of 1.7 V. This work provides a simple but practical guideline for high-performance zinc-air batteries.