In-situ electrochemical preparation of polyaniline/activated carbon nanocomposite as modified electrode for hybrid supercapacitor

Abstract

A supercapacitor is a type of energy storage device with faster charging and dischargingcapacity, longer cycle life and higher power density. They are extensively used in energystoragesystems,transportation,aviation,consumerelectronics,industrialequipment,medical devices etc. Therefore, different electrode materials of supercapacitors are beinginvestigated to overcome conventional limitations and improve their efficiency. Activatedcarbon, an electrode active material with large surface area is regarded as a potential dopingmaterialforsupercapacitors.Inthiswork,nanocompositeelectrodematerialofpolyaniline/activated carbon was prepared through one step in-situ electrochemical processbyaddingminuteamountofactivatedcarbonwithpolyanilinetoenhancetheelectrochemicalcapacitivepropertiesofpolyanilineinaqueousH2SO4electrolyte.Thesurface morphology and composition of the prepared electrode materials were analyzed byX-raydiffraction(XRD),Fieldemissionscanningelectronmicroscopy(FESEM)andFourier-transforminfrared(FTIR)spectroscopy.Theelectrochemicalpropertiesandsupercapacitive behaviors of PANI and PANI/AC composite materials were investigated bycyclic voltammetry (CV), galvanostatic constant current charge/discharge analysis (GCCD)and electrochemical impedance spectroscopy (EIS). FTIR confirmed C-H, C=C, C=N bondin the PANI. XRD peak showed (002), (101) and (200) crystallographic planes.According toFESEM images, uniform distribution of PANI nanofibers and AC particles results in theformationofinterlinkedporousnetworks.GCCDmeasurementsshowedthatincorporationof AC, specific capacitance and energy density of PANI were increased from 907 Fg-1 to1125.00Fg-1and125.00WhKg-1to156.00WhKg-1respectivelyinaqueous1MH2SO4electrolytesolution.ItisenvisagedthatACenhancesSO42-iontransportation,forwardsastable and fast surface redox reactions, hence collectively improving the overall capacitiveperformance of supercapacitor electrode. Considering its high capacitive properties, low-cost, and ease of synthesis, PANI/AC seems to be a promising electrode material for nextgenerationsymmetricsupercapacitor.