Structural and electrochemical properties of PVP-CH3COOK based solid polymer electrolyte films

Abstract

Solid polymer electrolytes are widely used in several applications such as super capacitors, fuel cells, energy storage devices and sensors due to their excellent physical and chemical properties. The objective of the present investigation is to prepare solid polymer electrolyte films using PVP with different wt% ratios of CH3COOK by solution cast technique and subsequently characterized by structural studies and electrochemical properties. XRD pattern showed a broad peak at 24.5° ascribed to pure PVP which indicates its semicrystalline phase. The little agglomerations observed in SEM images are due to the dispersion of salt embedded in the polymer matrix. The peaks observed in FTIR spectra for pure PVP at 944.5, 1105.6 and 1569.2 cm−1 correspond to C–O bending, C–O stretching and C=O vibrations respectively. The peaks in Raman spectra observed at 760.5 and 451.3 cm−1 relate to the C–H stretching, the peaks at 1378.31 and 1054.3 cm−1 correspond to the C–H2 bending and the peaks at 1423.8 and 1688.3 cm−1 correspond to the CH2 wagging for mixed salt-polymer films respectively. The ionic conductivity was found to be maximum (2.12 × 10−5 S cm−1) for 80:20 wt% composition at room temperature. From electrochemical properties, it is observed that the voltage across the cell has been raised from 2.3 to 5.1 V. The performance of the cell capacity has been raised up to 1.2 h and becomes constant after certain time till 6.2 h. The storage aspect of the energy related issues is addressed by ion conducting polymer electrolytes and their applications in the field of rechargeable batteries.