Synergistic Integration of
LiCF
3
SO
3
in
B. Praveen Kumar, P. Ajay Kumar, P. Missak Swarup Raju ABSTRACT
Solid polymer electrolyte (SPE) films based on a PVdF‐HFP/PVAc blend with lithium trifluoromethanesulfonate (LiCF 3 SO 3 ) were prepared by solution casting. Structural, morphological were investigated using X‐ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and Fourier transform infrared spectroscopy (FTIR). XRD exhibited a reduction in crystallinity index with salt addition. FESEM micrographs displayed smoother surfaces with tail‐like chain segments. Electrochemical impedance spectroscopy (EIS) was employed to study ionic conductivity and dielectric behavior with increasing LiCF 3 SO 3 content. A maximum value of 3.46 × 10 −4 S cm −1 at room temperature for the optimized film SP4 was obtained and was attributed to ionic conduction. Optical bandgaps and Urbach energies, obtained from UV–Visible spectroscopy measurements, indicate changes in electronic structure and disorder of the polymer matrix: with increasing salt concentration the direct and indirect bandgaps decreased, but Urbach energy increased, with SP4 showing eV and direct/indirect bandgaps of 4.78 and 4.37 eV, respectively. Thermogravimetric (TG) and differential thermal analysis (DTA) shows that SPE films are thermally stable up to 300°C, aiding suitability for energy‐storage applications. DSC investigations have validated the enhancement of polymer flexibility and amorphous phase growth which is favorable for ionic transport in solid polymer electrolytes.