Highly Conductive Siloxane Polymers

A series of double-comb, disubstituted polysiloxane polymers have been prepared containing oligoethylene oxide units, CH3(OCH2CH2)(n)(CH2)(3)-, in the side chains. These polymers were doped with LiN( SO2CF3)(2) (LiTFSI, 1), and conductivities of the polymer-salt complexes were determined as a function of temperature and doping level. Conductivities increase with n up to n = 6 and then decrease. The maximum conductivity of the polymer with n = 6 at 25 degreesC was 4.5 x 10(-4), the highest value yet recorded for a lithium-doped polymer electrolyte.