Influence of Electron beam radiation on the properties of Surface-Modified Titania-Filled gel polymer electrolytes using vinyltriethoxysilane (VTES) for lithium battery application

Gel polymer electrolytes (GPEs) are regarded as a prospective alternative for traditional liquid electrolytes. The dispersion of nanofiller in GPEs has been proven to improve the electrolyte's properties, such as reduced reactivity and leakage, improved safety, better shape flexibility, as well as manufacturing integrity. Meanwhile, the introduction of Electron Beam (EB) radiation remarkably enhances the electrochemical properties of GPEs. Therefore, the aim of the present work was to investigate the properties of titania-filled 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4)-poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) upon in-situ surface modification using vinyltriethoxysilane (VTES) coupling agent and its response towards 8 MeV energy EB irradiation. Following the surface modification of titania using VTES at different weight percentages (10-40%) and EB radiation exposure (5-20 kGy), the physicochemical, thermal, morphological, and electrochemical characteristics of the GPE were analyzed via Fourier Transform Infrared spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM), and impedance analysis, respectively. Based on the results, the TGA analysis showed that the thermal stability of the GPE increased with the increment of residues, which indicate the successful ceramics attachment onto the silanol group from the silane in the VTES compound. After the surface modification on the ceramic particle, the obtained average size particle was 50 nm with further enhancement of the particle distribution was observed when exposed to EB radiation. Additionally, the impedance analysis showed that the modified surface of the titania system achieved an optimum ionic conductivity of 10(-2) S cm(-1) at room temperature. When the electrolytes were exposed to EB radiation, the ionic conductivity increased up to 10(-1) S cm(-1) with the lithium transference number calculated at 0.52. These remarkable findings indicate that the developed surface modification technique of titania together with EB radiation on GPEs is a promising electrolyte for lithium-ion battery application.