Studies on poly(vinylidene fluoride-co-hexafluoropropylene) based gel electrolyte nanocomposite for sodium-sulfur batteries

► Role of SiO2 on the properties of Na+ ion conducting gel electrolyte is studied. ► Ion-polymer interaction and structural changes are confirmed from XRD, FTIR and SEM. ► Gel nanocomposite offers the room temperature ionic conductivity of ~ 4.1 × 10-3 S cm-1. ► Dispersion of SiO2 nanopowder results in Na+ ion transport number enhancement. ► Gel nanocomposite films are found suitable as electrolytes in Na/S batteries.