Investigation of structural and morphological studies of Na

Sodium- ion conducting solid polymer electrolytes are considered a safe and sustainable alternative to liquid electrolytes for next- generation rechargeable batteries. In this work, nanocomposite membranes based on Poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and poly (vinyl chloride) (PVC) blend complexed with sodium tetrafluoroborate (NaBF4) and reinforced with TiO2 nanoparticles were fabricated by solution casting method. The recorded X-ray diffraction (XRD) patterns of these films revealed a significant reduction in polymer crystallinity upon the incorporation of salt and nanofiller, indicating enhanced amorphous character, which is favourable for ion transport. Scanning electron microscopy (SEM) confirmed a uniform dispersion of TiO2 and the formation of a porous, interconnected microstructure at intermediate TiO2 loadings. At higher filler concentrations, agglomeration and reduced porosity were observed, correlating with diminished structural uniformity. In brief, the findings confirm that TiO2 nanofillers are capable of directing the morphology and chain packing of PVDF-HFP/PVC/NaBF4 electrolytes, thereby paving the way for their use as solid electrolytes in sodium-ion energy storage systems.