Electrochemical Characteristics of LiAsF6 Solutions in Mixed Solvents Based on Dimethyl Sulfoxide

Abstract

The electrochemical behaviors of lithium hexafluoroarsenate-based systems in the acetonitrile (AN)–dimethyl sulfoxide (DMSO) and propylene carbonate (PC)–DMSO binary mixtures were compared. The specific electric conductivity of LiAsF₆ solutions in the AN–DMSO mixed solvent with a molal concentration of ionophore of 0.2–1.8 mol/kg and DMSO contents of 0.24–0.68 mole fractions at temperatures of 253.15, 263.15, 273.15, 283.15, 293.15, 303.15, 313.15, 323.15, and 333.15 K was determined for the first time. The concentration dependence of the specific conductivity of the test solutions obeys the Castell–Amis equation. The solvent and ionophore contributions to the activation energy of ionic conductivity were determined based on the application of the transition state theory. In the PC–DMSO and AN–DMSO mixed solvents, LiAsF₆ solutions have a narrower electrochemical window compared to that in solutions of this ionophore in the individual solvents.