“Co-solvent-in-salt” electrolyte for boosting Zn anode reversibility

Abstract

The “solvent-in-salt” electrolyte is considered as a technology of significance for rechargeable Zn metal batteries due to its non-flammable, moisture-tolerant and electrochemical stable merits. Particularly, the “co-solvent-in-salt” electrolyte with dual-solvent of water and acetonitrile is developed in this work. It possesses both the advantages of high-concentration and aqueous/organic hybrid solvent, such as, low cost, low water content, high concentration and impressive ion conductivity. The corresponding modulated solvation structure and chemical environmental in the optimized electrolyte system contribute to suppress the side reactions (hydrogen evolution reaction (HER), Zn corrosion, dendrites growth) significantly. And they further improve the homogeneous Zn deposition, the plating/stripping reversibility (∼99.8 %) and the stability (∼2900 h) of Zn metal anode even in the Zn//NH4V4O10 full battery (500 cycles).