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

Abstract

Lithium-ion conducting composite polymer electrolytes (CPE),(PEO)₈-LiCF₃SO₃ (PEO=polyethylene oxide) dispersed with a glass-ceramic, Li_1.4[Al_0.4Ge_1.6(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 E_a 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.