SOLVATION OF LITHIUM IONS IN MIXTURES OF TETRAETHYLENE GLYCOL DIMETHYL ETHER AND PROPYLENE CARBONATE

The effect of propylene carbonate (PC) on the solvation shell of lithium ions in solutions of lithium perchlorate and lithium picrate in tetraethylene glycol dimethyl ether (TEGDME) was studied as a function of PC content and temperature using C-13 NMR, conductance, and optical and infrared spectroscopy. The results show that while PC promotes the dissociation of the electrolyte into free ions, it is at the same time a relatively poor cation chelating agent, and most of the cations remain bound to TEGDME even up to 80 mass % (90 mol%) PC. The ramifications of these observations for PC-plasticized lithium-polymer electrolytes are discussed.