Poly(ethylene oxide) electrolytes for operation at near room temperature

In an effort to improve the room temperature ionic conductivity of poly(ethylene oxide) doped with lithium salts, the effects of various additives were examined. Partial substitution of the high polymer by a poly(ethylene oxide) of low molecular weight had the effect of increasing the solubility of the crystalline polymer/salt complex in the liquid polymer as well as lowering the effective melting and glass transition temperatures of the polymer. An optimized composition had a much improved conductivity of 10−4 (Ω cm)−1 at 40 °C.