Studying Possibilities of Poly(Benzoquinone-Hydrazine) for Electrochemical Energy Storage Application
Abstract
Poly(benzoquinone-hydrazine), a brown-colored polyazine polymer, was synthesized by the polycondensation of p-benzoquinone and hydrazine hydrate with a catalytic amount of ZnCl2 heated at 110-115 °C for about 13 hours. The obtained polymer was washed with 1M NH4OH to remove the excess catalyst and with chloroform and acetic acid for the removal of unconverted p-benzoquinone from the reaction mixture. The electrochemical performance of the resulting polymer was evaluated through electrochemical methods involving cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS) in 1M H2SO4 solution using carbon paste electrode (CPE) as a substrate. The GCD represents a specific capacitance of 31.8 F/g with an energy and power density of 4.41 Wh/Kg and 249.99 W/Kg, respectively, at 0.5 A/g. The specific capacitance (35.42 F/g at 10 mV/s) calculated through CV affirms the results obtained by GCD. Polyazine's significant electroactive performance is attributed to its extended conjugation and large surface area, which facilitates effective charge carrier interaction and improved charge transfer. The EIS studies and bode plot represent the usual behavior the conducting polymer shows with appreciable impedance and phase angle. The electrochemical studies represent the potential of prepared polyazine as a supercapacitor material. The structural characterizations were confirmed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM), while the thermal behavior was studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) studies.