Various compositions of TiO2 dispersed PVA-PMMA-LiBF4-EC based electrolytes were prepared using solution casting technique. The prepared electrolytes were characterized using AC impedance, XRD, SEM, FTIR, etc. The ionic conductivity value is increased with the increase in filler content (up to 8 wt %) and then decreased with the increase in filler content. The results are described using Vogel-Tamman-Fulcher theory. The thermal and transport properties of the electrolyte exhibiting maximum conductivity have also been studied. (c) 2006 Wiley Periodicals, Inc.