Phase Behavior and Solvation of Lithium Trifluoromethanesulfonate in Propylene Carbonate

Presented here are data describing the phase behavior and solvation of lithium trifluoromethanesulfonate (LiCF3SO3) in propylene carbonate (PC). Data obtained from differential scanning calorimetry (DSC) and Raman spectroscopy of sample mixtures are correlated to enhance understanding of solvent-salt associations. A phase diagram will display the behavior of the solvent-salt interactions. The binary phase diagram constructed from thermal data acquired by DSC analyses indicated only glass transition temperatures for all mixtures of PC-LiCF3SO3 tested. Raman spectroscopy is applied to probe the liquid electrolyte and discover solvent-salt associations in solution. Results indicate that mixtures of PC-LiCF3SO3 do not readily form solvent-separated ion pairs but rather tend toward contact ion pair and more aggregated solvates. Overall, this study provided some insight into electrolyte solvation of these model battery electrolyte species.