Mixed polyether lithium-ion conductors

Abstract Polymeric membranes based on high molecular weight poly(ethylene oxide) doped with lithium salts have proved to be useful as solid electrolytes in lithium cells operating around 100 °C. At lower temperatures, the conductivity is impaired by poorly conducting crystalline phases as well as by reduced lithiumion concentration and mobility in the amorphous, conducting phase. The addition of dimethoxy poly(ethylene glycol) results in a large conductivity increase due to partial dissolution of the crystalline phases and plasticization of the amorphous phases. The associated increase in fluidity is acceptable at low temperatures, so that a suitable composition for operation at 40 ° C may be formulated with a conductivity of 10 −4 (Ω cm) −1 .