Electropolymerization of p-phenylenediamine films on carbon fiber fabrics electrode for flexible supercapacitors: surface and electrochemical characterizations

Supercapacitors are considered as one of the most efficient and reliable approaches to fulfill the specifications of the energy storage devices, owing to high-efficiency storage of energy, which makes supercapacitive electrode materials provoke large curiosity. In this work, we report the electropolymerization of poly(p-phenylenediamine) (PpPD) films on lightweight and inexpensive flexible carbon fiber fabrics by potentiostatic technique. The ladder structure of the electrochemically prepared PpPD was examined by Fourier transform infrared spectroscopy (FTIR). The surface characteristics and elemental composition studies were performed through field-emission scanning electron microscope (FESEM) and energy-dispersive X-ray spectroscopy (EDS), which confirmed the polymerization on the carbon fabrics. The electrochemical behavior of the fabricated supercapacitors was investigated by electrochemical analysis including cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The electrodes presented a good capacitive retention in a sweep rate range between 5 and 100 mV s(-1) using cyclic voltammetry. The coated electrode exhibited good electrochemical property with a high specific capacitance of 80 F g(-1) at the current density of 1 A g(-1). The high electrochemical performance is associated to the outstanding conductivity, high electrochemical stability, and superior flexibility of the carbon fiber fabrics. The accomplishment of such superior performance, lightweight, and mechanically flexible supercapacitor can stimulate the use in energy storage applications and wearable electronics.