NanoSrTiO3-filled PEO–P(VdF-HFP)–LiClO4 electrolytes with improved electrical and thermal properties

In the present work, PEO:P(VdF-HFP) polymer blend was prepared. The blend was complexed with lithium perchlorate (LiClO4), and nanosized strontium titanate (70.60 nm) SrTiO3 particles were dispersed into the complex in different weight ratios. Acetonitrile was used as solvent. The nanocomposite polymer blend electrolytes (NCPBEs) were prepared by the solvent-casting technique. Ionic conductivity of polymer blend electrolyte, PEO:P(VdF-HFP):LiClO4, was found to enhance at room temperature by the addition of nanoSrTiO3, and it was further confirmed through PL studies. Two ionic conductivity maxima, one at 2 wt% and another at 6 wt% of SrTiO3 were observed for NCPBEs. Out of the two peak maxima, the maximum ionic conductivity, 4.827 × 10−5 S cm−1, was obtained for 2 wt% SrTiO3. This is attributed to the increase in amorphicity of the polymer blend electrolytes, resulting from the polymer–salt–filler interactions. The crystalline and amorphous phases of the complex were identified through X-ray diffraction. The dielectric behavior was analyzed using complex dielectric permittivity (ε∗\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\varepsilon^{*}$$\end{document}), electric modulus (M∗\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$M^{*}$$\end{document}), and loss tangent. From the loss tangent spectra, relaxation times were evaluated, and the relaxation is found to be consistent with the conductivity of the samples. AFM and SEM analyses revealed significant changes in the surface morphology, which is in accordance with the ionic conductivity of the samples. The thermal stability was ascertained through TG/DTA studies.