Solar reduced porous graphene incorporated within polyaniline network for high-performance supercapacitor electrode

A nanocomposite of solar reduced porous graphene (SRPG) and polyaniline network (PANI) have been successfully synthesized using in-situ oxidative polymerization. In composite, few sheets of SRPG have been successfully covered with the layers of PANI. Whereas, remaining SRPG sheets have been effectively incorporated inside the PANI network forming a unique PANI-SRPG composite. Detailed characterizations have been performed for PANI, SRPG, and PANI-SRPG composite to study their structure, surface area, elemental mapping, and morphology. Electrochemical investigations were carried out in aqueous and ionic liquid electrolytes under various potential windows. PANI electrodes achieved gravimetric charge storage capacity of 555.92 F/g with only 69.26 % of capacitance retention after 5000 galvanostatic charging-discharging (GCD) cycles. On the other hand, PANI-SRPG exhibited exceptionally high specific capacitance of 939.96 F/g with 98.46 % capacitance retention after 5000 GCD cycles. This is strongly attributed to the synergistic effect between the PANI and SRPG which improved the porosity, ionic diffusion and chemical stability of the resultant composite. Ragon plot for PANI-SRPG showed the highest energy and power density of 145 Wh/kg and 17578.13 W/kg respectively. Presence of SRPG in the PANI matrix resulted in high electrochemical performance due to its ability to provide in-plane as well as a cross-plane diffusion of electrolyte ions during the charging-discharging of supercapacitor.