Polyaniline and graphene oxide/polyaniline composite on activated carbon cum reduced graphene oxide supported supercapacitor electrodes are fabricated and electrochemically characterized in a 3-electrode cell assembly. Attractive supercapacitor performance, namely high-power capability and cycling stability for graphene oxide/polyaniline composite, is observed owing to the layered and porous-polymeric-structured electrodes. Based on the materials-characterization data in a 3-electrode cell assembly, 1 V supercapacitor devices are developed and performance tested. A comparative study has also been conducted for polyaniline and graphene oxide/polyaniline composite-based 1 V supercapacitors for comprehending the synergic effect of graphene oxide and polyaniline. Graphene oxide/polyaniline composite-based capacitor that exhibits about 100 F g-1 specific capacitance with faradaic efficiency in excess of 90 %, while its energy and power density values happen to be 14 Wh kg-1 and 72 kW kg-1, respectively. Cycle-life data over 1000 cycles suggest 10 % capacitance degradation for graphene oxide/polyaniline composite supercapacitor.