Study of ion-molecule interaction in poly(methylmethacrylate) based gel electrolytes by raman spectroscopy

Abstract

Gel electrolytes based on polymethymetacrylate (PMMA) have been obtained using propylene carbonate and ethylene carbonate as gelating agents. They have a good mechanical stability, solvent retention and high electrical conductivity at room temperature (about 10 −3 Sem −1). In the aim of understanding the possible interactions of the mobile ions with polymer or solvent molecules, a comparative Raman study has been carried out on samples containing all the components of the gel electrolytes or some of them. The interaction with Li + ions induces appreciable modifications of the vibrational spectra of the solvent molecules; two new bands appear at 900cm −1 and 730cm −1, slightly upshifted with respect to the stretching and bending modes of the ethylene carbonate ring. The change in size and polarizability of the anion species does not affect such cation-solvent interaction.