Investigations on the effect of various plasticizers in PVA–PMMA solid polymer blend electrolytes

Solid polymer electrolyte films containing poly(vinyl alcohol) (PVA)/PMMA–LiBF4–X (X=EC, PC, DEC, GBL) were prepared by solvent casting technique. Complexation of the prepared electrolytes is studied by XRD, FTIR analyses. Ionic conductivities of the electrolytes have been determined by ac impedance studies in the temperature range 302–373 K. The temperature-dependent ionic conductivity plots seem to obey the VTF relation. Dielectric relaxation studies of the polymer electrolyte have been undertaken and the results are discussed. Thermal stability of the prepared electrolytes has been examined using TG/DTA analysis. Cyclic voltammetry has been performed for the electrolyte films to study their cyclability and reversibility. The ionic transport in the polymer electrolytes has been discussed on the basis of free volume theory. The maximum ionic conductivity (1.2886×10−3 S/cm) has been observed for EC-based complex because of the higher dielectric constant among the other plasticizers.