Polyethylene oxide (PEO) – montmorillonite (MMT) composite electrolytes were synthesised by solution casting technique. The salt used for the study is Lithium perchlorate (LiClO4). The morphology and percentage of crystallinity data were obtained through X-ray Diffraction and Differential Scanning Caloriemetry. The ionic conductivity of the polymer electrolytes was studied by impedance spectroscopy. The addition of MMT resulted in an increase in conductivity over the temperature range of 25–60∘C. The ionic conductivity of a composite polymer electrolyte containing 1.2 wt% MMT was 1 × 10−5 S cm−1 at 25∘C, which is at least one order of magnitude higher than that of the polymer electrolyte (4 × 10−7S cm−1). The increase in ionic conductivity is explained on the basis of crystallinity of the polymer electrolyte.
