Effects of plasticiser on the lithium ionic conductivity of polymer electrolyte PVC-LiCF3SO3

Solid polymer electrolyte films based on poly(vinyl chloride)-lithium triflate (PVC-LiCF₃SO₃) have been prepared by the solution-cast technique in various concentrations. The film with the highest conductivity was used to prepare plasticised polymer electrolyte films by using poly(ethlene glycol) (PEG) of different molecular weights, i.e., 200, 400 and 600 gmol⁻¹. These films were prepared to study the effects of addition of low molecular weights PEG on the lithium ionic conduction of the PVC based polymer electrolyte. The films were characterised by electrochemical impedance spectroscopy (EIS) and Fourier transform infrared-spectroscopy (FTIR). Results indicate that the molecular weight has an inverse effect on the conductivity and this has been accounted for by FTIR. Paper presented at the International Conference on Functional Materials and Devices 2005, Kuala Lumpur, Malaysia, June 6 – 8, 2005.