Fabrication of energy storage EDLC device based on self-synthesized TiO2 nanowire dispersed polymer nanocomposite films

In this work, a systematic study of titanium oxide (TiO2) nanowires incorporated polymer nanocomposite (PNC) films prepared by a standard solution cast technique is reported. The structural, morphological, dielectric, and electrochemical properties were investigated thoroughly. The polymer nanocomposite films demonstrated improved electrical and electrochemical properties as compared to polymer–salt complex film. The morphological and structural properties have been examined by the field emission scanning electron microscope, Fourier transform infrared spectroscopy, and X-ray diffraction. It is observed that the maximum ionic conductivity is of the order of 10–5 S cm−1 exhibited by 0.5 wt% nanowire added polymer nanocomposite film. The ion transference number was close to unity for optimized film and stability window of about ~ 5 V. The shift of loss tangent peak toward the high-frequency window with nanowire addition indicates a decrease of the relaxation time. The optimized TiO2 nanowire dispersed polymer nanocomposite film has been used to fabricate the electric double-layer capacitor cells. The fabricated cell demonstrates the specific capacitance of about 57.5 F/g (at 10 mV/s). The calculated energy density and power density are 1.38 Wh kg−1 and 0.709 kW kg−1, respectively. The Coulombic efficiency is 97.7% up to the 500 cycles for the fabricated cell. The prepared polymer nanocomposite has the potential to use it as electrolyte cum separator for solid-state electric double-layer capacitor applications.