Abstract
Owing to its low cost and high safety, metallic zinc has received considerable attention as an anode material for zinc aqueous batteries (ZIBs). However, the Zn metal instability as a result ultrafast of obstinate dendrite formation, free-water-induced parasite reactions, and corrosive electrolytes has detrimental effects on the implementation of ZIBs. We present an alternative stable electrolyte for ZIBs based on a zinc chloride/ethylene glycol deep eutectic solvent (DES). This electrolyte consists of abundant low-cost materials and a utilizable Zn2+ concentration of approximately 1 M. It combines the advantages of the aqueous and DES media to provide safe and reversible Zn plating/stripping with a two-fold increase in the cycling life compared to that of conventional aqueous electrolytes. With these advantages, the Zn symmetric cell operates at 0.2 mA cm-2 for 300 h. Due to its high efficiency and compositional versatility, this electrolyte enables the investigation of a non-aqueous electrolyte family for ZIBs that fulfill grid-scale electrical energy storage requirements.