Polymer-salt complex with poly(vinyl chloride) (PVC) and poly(acrylonitrile) (PAN) as host polymers blended with lithium bis-(trifluoro methanesulfonyl)imide, LiTFSI [LiN(CF(3)SO(2))(2)] as dopant salt were prepared in the form of thin film. Fourier transform infrared (FTIR) studies show the evidence of the complexation between PVC. PAN and LiTFSI. Ionic conductivity studies reveal that polymer electrolyte with 30 wt.% LiTFSI has the highest ionic conductivity of 4.39x10(-4) S/cm at room temperature. The polymer electrolytes are also found to be stable up to 315 degrees C before they decompose. Thermal stability of the polymer electrolytes was also found to increase with increase in salt content. This was proven through thermogravimetric studies. (C) 2010 Elsevier B.V. All rights reserved.