Exploration of rGO-Polyaniline Composites for Supercapacitor Applications

The increased requirements for high-efficiency and low-cost energy storage devices have paced research nowadays. The present study explores the applications of reduced Graphene Oxide (rGO) and Polyaniline (Pani) composites (rGO-Pani) for supercapacitor devices. These composites offer improved electrical conductivity and high specific capacitance. The composites have been characterized for their optical, magnetic, and specific capacitance properties. The energy band gap and Urbach’s energy for the composites is observed to be lower than the pristine Pani sample. Three photoluminescence peaks have been observed for pristine Pani whose intensity increases with increasing concentration of rGO in the composite. The CIE coordinates also indicate the higher color temperature of the composites. The original samples of rGO and Polyaniline do not possess any magnetic properties, but the composites show slight retentivity and coercivity. Cyclic voltammetry and Galvanostatic Charge-Discharge techniques performed at different scan rates reveal higher specific capacitance for Polyaniline samples than the composites that may be attributed to the presence of defects or impurities as they can introduce additional energy levels within the band structure. Deep-level defects may trap charge carriers, which leads to reduced charge transport efficiency and lower electrochemical performance.