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In this paper, a proposed supercapacitor was fabricated using an electrode of graphene layer covered with polyaniline layer. Uniform polyaniline layer was deposited using spraying technique. Characterizations were performed using scanning electron microscope (SEM) and UV-visible spectroscopy. The electrochemical measurements were assessed using cyclicvoltammetry (CV), electrical impedance spectroscopy (EIS), and charge-discharge measurements. The results indicated that graphene/PANI double layers exhibited high porosity and large surface area. Polyaniline/graphene supercapacitor had a specific capacitance as high as 915.78 F/g at scan rate of 5 mV/s in the scanning potential window from - 0.8 to 0.8 V with 4 mg active material. The fabricated supercapacitor prototype has provided an energy density of 127.19 Wh/kg at potential difference of 1V using aqueous electrolyte of 6M potassium hydroxide. The effect of temperature on supercapacitor performance was investigated and it was found that the influence of temperature on specific capacitance was insignificant. It was observed that an improvement in the specific capacitance with about 1% in temperature range between 25 ˚C and 70 ˚C.