To investigate the effects of salt concentration, LiBF4 was incorporated into a PVdF–PVC based polymer blend and thin electrolytes were prepared by solution casting technique. The obtained thin films were subjected to various characterizations such as FTIR, XRD and TG/DTA analysis to study their complex behaviour, amorphicity and thermal stability, respectively. The ionic conductivities of the electrolytes were measured by AC impedance. A PVdF (80)–PVC (20)–LiBF4 (8wt%) polymer electrolyte was found to have high conductivity compared to other complexes. Similar investigations were also repeated with a LiClO4 salt in the above blend and the electrical conductivity was found to be higher in the polymer complex having 8wt% of salt concentration.