Abstract:
A supercapacitor is a type of energy storage device with faster charging and discharging capacity, longer cycle life and higher power density. They are extensively used in energy storage systems, transportation, aviation, consumer electronics, industrial equipment, medical devices etc. Therefore, different electrode materials of supercapacitors are being investigated to overcome conventional limitations and improve their efficiency. Activated carbon, an electrode active material with large surface area is regarded as a potential doping material for supercapacitors. In this work, nanocomposite electrode material of
polyaniline/activated carbon was prepared through one step in-situ electrochemical process by adding minute amount of activated carbon with polyaniline to enhance the electrochemical capacitive properties of polyaniline in aqueous H2SO4 electrolyte. The surface morphology and composition of the prepared electrode materials were analyzed by
X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM) and Fourier-transform infrared (FTIR) spectroscopy. The electrochemical properties and super capacitive behaviors of PANI and PANI/AC composite materials were investigated by cyclic voltammetry (CV), galvanostatic constant current charge/discharge analysis (GCCD)
and electrochemical impedance spectroscopy (EIS). FTIR confirmed C-H, C=C, C=N bond in the PANI. XRD peak showed (002), (101) and (200) crystallographic planes. According to FESEM images, uniform distribution of PANI nanofibers and AC particles results in the formation of interlinked porous networks. GCCD measurements showed that incorporation of AC, specific capacitance and energy density of PANI were increased from 907 Fg-1 to 1125.00 Fg-1 and 125.00 WhKg-1 to 156.00 WhKg-1 respectively in aqueous 1 M H2SO4 electrolyte solution. It is envisaged that AC enhances SO42- ion transportation,
forwards a stable and fast surface redox reactions, hence collectively improving the overall capacitive performance of supercapacitor electrode. Considering its high capacitive properties, low- cost, and ease of synthesis, PANI/AC seems to be a promising electrode
material for next generation symmetric supercapacitors.
