PEO/PVDF-based gel polymer electrolyte by incorporating nano-TiO₂ for electrochromic glass

To develop high performance mixed matrix gel polymer electrolyte, the synergistic effect of blending PVDF (PEO/PVDF weigh ratio of 85:15) and adding nano-TiO₂ (0.5–2 wt.%) to traditional monomer poly (ethylene oxide) was investigated. Thermogravimetric analysis indicated that poly (ethylene oxide)/poly (vinylidene fluoride) blend had an excellent thermal performance. X-ray diffraction analysis revealed that poly (ethylene oxide)/poly (vinylidene fluoride) blend leads to lower crystallinity and the amorphicity of corresponding gel polymer electrolyte increases with increasing nano-TiO₂ concentration. The maximum ionic conductivity (2.12 × 10⁻⁶ and 6.37 × 10⁻⁶ S/cm) of poly (ethylene oxide)/-(TiO₂)_0.5 and poly (ethylene oxide)/poly (vinylidene fluoride)/-(TiO₂)_0.5 gel polymer electrolyte at room temperature (25 °C) were obtained, respectively. The prepared poly (ethylene oxide)/poly (vinylidene fluoride)-TiO₂ gel polymer electrolyte demonstrated about 2.6 and 1.8-fold increment in the fracture strength as compared to that of poly (ethylene oxide) gel polymer electrolyte and poly (ethylene oxide)-TiO₂ gel polymer electrolyte. The average transmittance of poly (ethylene oxide)/poly (vinylidene fluoride)-TiO₂ gel polymer electrolyte was about 90 % in the visible region. With good electrical, mechanical and optical performance, it is very suitable for being applied in electrochromic glass.