Structure and Electrochemical Properties of PANI/ZrOX and PANI/SiOX Composites

Synthesis of polyaniline/ZrOX (PANI/ZrOX) and polyaniline/SiOX (PANI/SiOX) composites was carried out through chemical polymerization of aniline in the presence of hydrochloric acid. Scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy and ultraviolet–visible (UV–Vis) spectroscopy were used to determine the form of polyaniline, changes in the chemical structure and the morphology of nanocomposites in comparison with pure polyaniline. The specific surface area investigation revealed values of 85.50 m2/g and 146.05 m2/g for PANI/SiOX and PANI/ZrOX, respectively. It was determined that the thermal stability of the composites increased by 8.0°C and 74.5°C with the addition of silica and zirconium particles, respectively, in comparison with the pure polyaniline. The synthesized composites were used for the preparation of polyvinyl alcohol/PANI/SiOX (PVA/PANI/SiOX) and polyvinyl alcohol/PANI/ZrOX (PVA/PANI/ZrOX) flexible composite electrodes. Their electrochemical properties were compared in 3 M KOH electrolytes. The pseudocapacitive behavior of the flexible electrodes was demonstrated. The highest areal capacitance for the PVA/PANI electrode (36 mF/cm2) was observed at a current density of 0.125 mA/cm2, while for PVA/PANI/SiOX and PVA/PANI/ZrOX composite electrodes, it was 28 mF/cm2 and 39 mF/cm2 at 0.075 mA/cm2, respectively. It was found that zirconia addition resulted in better areal capacitance, but led to a decrease in electrode conductivity. Electrochemical studies indicated a faradaic type of energy storage mechanism.