The reduced graphene oxide (rGO)/activated carbon (AC) composites are coated on the aluminum substrate using spray coating technique to fabricate nanocarbon-based supercapacitor. Polymer-based solid-state xanthan-gum/Na2SO4 electrolyte is also introduced to increase stability of the supercapacitor. The electrochemical properties of the supercapacitor are evaluated using cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge/discharge tests. The highest capacitance value of the rGO/AC composite-based supercapacitor is 120 F/g. The rGO/AC composite-based supercapacitor has also retained ~ 85% of its initial capacitance value after 3000 galvanostatic charge/discharge cycles.

    Abstract
    1 Introduction
    2 Experimental
        2.1 Materials
        2.2 Preparation of rGO, AC and rGOAC dispersion
        2.3 Preparation of the solid-state polymer electrolyte
        2.4 Fabrication of rGO, AC and rGOAC electrodes
        2.5 Preparation of nanocarbon-based supercapacitors
    3 Characterization
        3.1 Cyclic voltammetry (CV)
        3.2 Electrochemical impedance spectroscopy (EIS)
        3.3 Charge and discharge measurement
        3.4 Morphology study of the rGO, AC and rGOAC composite electrode
    4 Results and discussion
    5 Conclusions
    References

• Hwa Yong Jung(Division of Energy and Environmental Engineering, Daejin University)
• Yong Ryeol Kim(Division of Energy and Environmental Engineering, Daejin University)
• Hyeon Taek Jeong(Division of Energy and Environmental Engineering, Daejin University)