Preparation and dielectric properties of PVP-based polymer electrolyte films for solid-state battery application

Solid polymer electrolyte has been prepared with the combination of PVP (poly vinyl pyrrolidone) and magnesium sulfate heptahydrate (MgSO₄·7H₂O) by solution cast technique and subsequently characterized for possible polymer battery application. Structural studies were carried out by XRD technique. DSC analysis revealed that the micro-porous polymer membrane is thermally stable up to 300 °C. The surface morphology of the films was analyzed by SEM. Electrical conductivity was performed using AC impedance analyzing technique in the frequency range from 4 kHz to 5 MHz. Complex impedance spectroscopy revealed that the enhancement in electrical conductivity by salt doping and the conductivity maximum was obtained for 15 wt% of MgSO₄·7H₂O salt concentration. Optical absorption studies were carried out on to the prepared films in the wavelength range 200–600 nm. Solid-state polymer battery has been fabricated with the configuration of Mg⁺/(PVP + MgSO₄·7H₂O)/(I₂ + C + electrolyte) and discharge characteristics were studied for a constant load of 100 kΩ. The cell parameters like open-circuit voltage, short circuit current, energy density and power density were calculated.