Understanding Solvation Dynamics and Electrochemical Behavior of Zinc-Based Deep Eutectic Solvents through Experimental and Computational Methods for Energy Storage Applications

Zinc-based energy storage devices offer a safer and cheaper pathway toward greener energy storage. Although their electrochemical performance is inferior to Li-based energy storage devices, their cost effectiveness and eco-friendliness make them potential candidates for next-generation energy storage devices. In this paper, we present the solvation study of two zinc-based DESs constituted of ethylene glycol and zinc chloride in molar ratios (1:4) and (1:6) with triethylmethylammonium tetrafluoroborate as the solute at different concentrations and different temperatures. The volumetric, acoustic, and thermodynamic properties were determined through experimental and computational methods. Spectroscopic investigation using FTIR spectroscopy, analyses of FMO, and plots of RDG and MEP obtained computationally provided visual insights into specific bonding regions. Further, by comparing the data of transport properties and cyclic voltammetry of ZEDES (1:4) and ZEDES (1:6), the latter showed higher ESW, higher ionic conductivity, and lower viscosity, indicating the high tunability of the studied systems.