Sprayed polyaniline layer onto chemically reduced graphene oxide as electrode for high performance supercapacitor

• High electrochemical performance of graphene oxide/polyaniline.
• Spray coating method for different electrodes fabrication.
• Cyclic voltammetry dependence on synergetic effect between graphene and PANI.
• The maximum energy density of 127 kW Kg−1 using G/PANI.
• The maximum specific capacitance of 916 Fg−1.

In this work supercapacitors were fabricated from reduced graphene oxide (RGO), polyaniline (PANI) and graphene/PANI (G/PANI) electrodes. The fabricated electrodes were characterized using scanning electron microscope (SEM) and UV–vis spectroscopy. The electrochemical activities of supercapacitors were assessed using cyclic voltammetry (CV), electrical impedance spectroscopy (EIS), and charge-discharge measurements. Graphene electrodes were prepared by exposure the graphene oxide (GO) sheets to hydrazine to reduce and restore the conducting carbon network. A maximum specific capacitance of 292 F/g with energy density of 40.5 Wh/kg in an aqueous electrolyte solution had been obtained for this graphene supercapacitor. Supercapacitor of sprayed PANI electrodes produced specific capacitance of 595 F/g and energy density of 82.63 Wh/kg. Finally, a hybrid supercapacitor had been developed by spraying PANI layer onto the reduced graphene oxide sheet (G/PANI). It was found that G/PANI supercapacitor displayed a specific capacitance of 916 F/g and energy density of 127.19 Wh/kg, which is much higher than that of pristine graphene and PANI electrodes supercapacitor.