Impact of nano-titania and ultrasonic irradiation on the physical properties of polymer blend electrolytes

Nanocomposite polymer blend electrolytes (NCPBEs) consisting of poly(ethylene oxide) and poly(vinylidene fluoride-co-hexafluoropropylene) as polymers, lithium triflate (LiCF₃SO₃) as an electrolyte and nano-titania (TiO₂) as a filler were prepared by both conventional stirring and ultrasonic irradiation methods. Complex formation and an increase in the amorphicity of the sample were confirmed through X-ray diffraction analysis. From alternating current impedance spectroscopy studies, it was observed that the ultrasonically irradiated NCPBEs exhibited maximum ionic conductivity compared with the NCPBEs prepared through conventional mechanical stirring. The Arrhenius behavior was observed from temperature-dependent ionic conductivity studies. Wagner’s polarization studies revealed that the charge transport in the prepared NCPBEs was predominantly due to ions. The dielectric behavior was analyzed by complex dielectric permittivity (ε*) and loss tangent studies. Notable morphological changes of the samples were observed from scanning electron microscopy and atomic force microscopy studies. From thermogravimetry–differential thermal analysis, the sample with the maximum ionic conductivity was found to be thermally stable up to 300°C.