Highly conductive poly(ethylene oxide)-poly(methyl methacrylate) blends complexed with alkali metal salts

Solid electrolytes of room temperature ionic conductivity exceeding 10^?5 S cm^?1 were obtained by complexing NaI, LiI, LiBF₄ and LiClO₄ with blends prepared by thermal polymerization of methyl methacrylate in the presence of high molecular weight poly(ethylene oxide). All of the studied samples were thermally stable up to at least 60°C. Differential scanning calorimetry studies indicated that these electrolytes contained amorphous phases with very low glass transition temperatures. This is due to the plasticizing effect of the grafted copolymers formed during the polymerization. This is supposed to lead to high mobility of the charge carriers in the systems studied.