Preparation and electrochemical properties of glass-polymer composite electrolytes for lithium batteries

Abstract

Electrochemical behavior of a new class of glass-polymer composites (GPC), consisting of (100-cursive chi) vol% (0.56Li2S·0.19B2S3·0.25LiI) glass and cursive chi vol% (P(EO)6·LiN(CF3SO2)2) polymer with cursive chi = 7, 13 and 25, has been investigated in cells with different electrodes. Results show that the addition of the polymer to the glass powder increases not only the mechanical flexibility but also the ionic conductivity. The combination of impedance spectroscopy and 4-probe dc measurements indicates that the GPC with cursive chi = 13 vol% polymer exhibits the highest lithium ion conductivity, varying from 3 × 10-4 Ω-4 cm-1 at room temperature to 1.4 × 10-3 Ω-4 cm-1 at 80°C. In addition, the GPC electrolytes with cursive chi = 13 vol% seem to be relatively stable against Li, Licursive chiMn2O4, and carbon electrodes, since interfacial impedances between the electrolyte and the electrode materials are relatively constant at 70°C for up to 375 hours.