Polyaniline/Reduced Graphene Oxide Composite as an Electrode for Symmetric and Asymmetric Supercapacitors

ABSTRACT Polyaniline‐based composites with reduced graphene oxide (rGO) were synthesized using chemical polymerization. Characterization techniques, including X‐ray diffraction (XRD), ultraviolet–visible (UV–visible) absorption spectroscopy, Fourier transform infrared (FTIR), and Raman spectroscopy, confirmed that both polyaniline (Pani) and the Pani/rGO composite were in the emeraldine salt state. The synergistic effect of Pani and rGO increases the polaron band and improves the electrical conductivity, which is confirmed by spectroscopic analysis. Scanning electron microscopy revealed that Pani had a granular morphology, whereas the Pani/rGO composite had a layered morphology. This layered morphology indicates that adding rGO can enhance the conductivity and electrochemical activity. The electrochemical studies of the Pani/rGO composite electrode showed a specific capacitance of 261 F g −1 at a current density of 2.4 A g −1 . The electrochemical performance of the Pani/rGO composites for energy storage devices was examined via two‐electrode cell assembly. Pani/rGO was utilized as a cathode, whereas various carbon materials (CNFs, MWCNTs, AC) were used as anodes. A maximum energy density of 7.9 Wh kg −1 at a power density of 325 W kg −1 was observed in the Pani/rGO//PMAC asymmetric supercapacitor at a voltage of 1.4 V. The electrochemical performance results show that the Pani/rGO composite is an efficient supercapacitor electrode material.