Spectroscopic and electrochemical properties of PVP based polymer electrolyte films

Abstract

Solid polymer electrolyte films were prepared with polyvinyl pyrrolidone and MgCl2·6H2O salt for different compositions using solution cast technique at room temperature. The obtained polymer films were characterized by different spectroscopic techniques such as X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transformation infrared spectroscopy (FTIR) and Differential scanning calorimetry (DSC). XRD confirmed the orthorhombic lattice structure indicating its semicrystalline nature for the prepared polymer film. SEM revealed the heterogeneous phase of polymer electrolyte system. The chemical complex nature and interaction between the polymer and salt was analyzed by FTIR. DSC revealed the glass transition temperature (T g) of 89 °C at which a glassy phase becomes amorphous phase on heating. Electrical conductivity measurements were also undertaken on to the prepared films using HIOKI 3532-50 in the frequency ranging from 42 Hz to 5 MHz. The ionic conductivity was found to be maximum (1.42 × 10−5 S/cm) for 85:15 wt% composition at room temperature. Cyclic Voltammetry studies were carried out on to the fabricated solid-state battery with the configuration Mg+/(PVP + MgCl2·6H2O)/(I 2 + C+electrolyte) and discharge characteristics were studied for a constant load of 100 kΩ.