The Influence of Inert Oxide Fillers on Poly(ethylene oxide) and Amorphous Poly(ethylene oxide) Based Polymer Electrolytes

Abstract

An FT-Raman study was performed on lithium salt/polymer/nanosized inert oxide filler (SiO2, Al2O3) systems. Molecular spectroscopy suggests that there is little effect of the filler particles on the "free" anion/ion-pair/higher aggregate equilibria. Raman line widths indicate enhanced anion disorder when a small amount of filler is introduced. Similarly, DSC measurement indicates a reduction of crystallinity. By contrast, fully amorphous polymer samples display broader Raman line widths and higher glass transition temperatures as the filler concentration is increased, with concomitant lower ion conductivity. The influence of the fillers differs in proportion to the extent of crystallinity of the polymer−salt complex, but within our experimental range the particle size or composition of the filler has little influence on ionic conductivity.