Effect of glass–ceramic filler on properties of polyethylene oxide–LiCF3SO3 complex

Lithium-ion conducting composite polymer electrolytes (CPE),(PEO)8–LiCF3SO3 (PEO=polyethylene oxide) dispersed with a glass–ceramic, Li1.4[Al0.4Ge1.6(PO4)3] as a filler have been prepared as films and their thermal, mechanical, electrical and electrochemical properties have been studied. The glass transition temperature increases with filler addition reaches a maximum value of −39 °C for x=7.5 wt.%, and then decreases. Enhancement in the electrochemical stability of the films is noted; a maximum working voltage of 3.75 V is found at x=10 wt.%. Addition of filler decreases the ionic conductivity for x=7.5 wt.%, σ=1.6×10−7 S cm−1 which is a factor three lower than that for the PS complex. The Ea and log10(σ0) values of the composite polymer electrolytes consistently decrease with increasing x. The mechanical properties are enhanced with filler addition, a maximum tensile strength of 22.8 MPa, is obtained at x=7.5–10 wt.%, a value which is three times higher than that for the PS complex.