Solid electrolyte composed of 95(0.6Li2S·0.4SiS2)·5Li4SiO4 glass and high molecular weight branched poly(oxyethylene)

Novel single ion-conductive inorganic/organic composites were prepared from 95(0.6Li2S·0.4SiS2)·5Li4SiO4 oxysulfide glass and a high molecular weight branched poly(oxyethylene) (POE). The ionic conductivity of the composites increased with an increase of the glass. The ionic conductivity of the composite with 1 wt.% branched poly(oxyethylene) was in the orders of 10−5 S/cm at 30 °C and 10−4 S/cm at 80 °C. The composite exhibited an electrochemical stability window up to ca. 4.5 V versus Li+/Li and thermal stability against lithium metal up to 200 °C. Addition of LiClO4 to the polymer matrix of the composite improved the ionic conductivity. In this case, the composite was a dual-ion conductor, i.e., both Li+ and ClO4− contributed to the conductivity.