Electrical conductivity of solvent free PEO based polymer electrolytes

Films of polyethylene oxide (PEO) based polymer electrolyte were prepared by the technique of solution casting. Propylene carbonate ( PC) was employed as the plasticiser and lithium trifluoromethanesulfonate (LiCF3SO3) was used as the doping salt. The highest room temperature conductivity achieved in PC plasticised system is 8.12 x 10(-6) S cm(-1). The effects of PC on the frequency dependent dielectric properties of PEO based electrolytes were also investigated by impedance spectroscopy, in the temperature range from 300 to 343 K. The relaxation time for the ionic charge carriers tau was obtained from the variation of loss tangent (tan delta) as a function of frequency at various temperatures for sample with highest conductivity value. The linear behaviour of temperature dependence of tau with regression value 0.91 could be described by Arrhenius law. The results of ac conductivity were discussed with existing theoretical models to elucidate the mechanism of conductance in the prepared electrolyte system.