FT-IR and DSC studies of poly(vinylidene chloride-co-acrylonitrile) complexed with LiBF4

Poly(vinylidene chloride-co-acrylonitrile) (PVdC-co-AN) based solvent free electrolytes were prepared for different compositions of PVdC-co-AN and LiBF4 using solution casting technique. The ionic conductivity, thermal behavior, complexation and structure of polymer electrolytes have been investigated as a function of LiBF4 content at different weight ratios. DSC studies revealed that the glass transition temperature T-g decreases with the increase of salt concentration up to an optimum level. The change in the glass transition temperature (T-g) with respect to the LiBF4 concentration is reflected in the bulk resistance of the electrolytes and the sample containing 6 wt.% of LiBF4 exhibited minimum bulk resistance compared to other samples. FT-IR studies confirm the interaction of polymer and salt which is mainly between Li-cation and nitrogen atom of C N group. The crystalline phase of polymer host is completely changed on the addition of Li salt. (C) 2013 Elsevier B.V. All rights reserved.