A ZnCl2 nonaqueous deep-eutectic-solvent electrolyte for zinc-ion hybrid supercapacitors

Abstract Zinc-ion hybrid supercapacitor (ZHS), as emerging electrochemical energy storage devices, was constructed deploying a non-aqueous deep eutectic solvent electrolyte (DES-E) containing ZnCl2 and ethylene glycol (EG). This nonaqueous deep-eutectic-solvent electrolyte can fulfill a wide operating voltage window, leading to a ZHS with a high capacity of 78.6 mA h g−1, an energy density of 52.8 W h kg−1 at a power density of 384.8 W kg−1. This work will take forward into the development of zinc-based energy storage field and affords a significant enlightenment for the invention of other analogous non-aqueous deep eutectic solvent electrolytes.