Exploration on nano-composite fumed silica-based composite polymer electrolytes with doping of ionic liquid

Fumed silica (SiO2)-based composite polymer electrolytes were prepared by means of solution casing technique. Horizontal attenuated total reflectance-Fourier Transform Infrared (HATR-FTIR) study shows the complexation between polymer matrix and SiO2. The highest ionic conductivity of (4.11 ± 0.01) × 10− 3 Scm− 1 is achieved upon inclusion of 8 wt.% of SiO2. Three different regions have been observed in the frequency dependence–ionic conductivity study. The conductivity rises sharply with frequency at low frequency regime. It is followed by a frequency independent plateau region and sharp decrease in the conductivity at high frequency range. The dielectric permittivity (ε') and dielectric loss (ε") are decreased with increasing the frequency. This phenomenon is mainly attributed to the electrode polarization effect. The formation of electrical double layer has been proven in these dielectric permittivity studies. This indicates the non-Debye properties of the nano-composite polymer electrolytes.

► Highest ionic conductivity of (4.11 ± 0.01) × 10− 3 Scm− 1 is achieved with 8 wt.% of SiO2. ► Effective conducting pathway is formed between the grain boundaries. ► HATR–FTIR study verifies the complexation between gel polymer matrix and silica.