Systematic study of influencing parameters on the in-situ electrochemical growth of three-dimensional graphene on carbon cloth for supercapacitor applications

Abstract

A novel two-step electrophoretic deposition/reduction (EPD/red) technique was applied for the electrochemical growth of three-dimensional (3D) graphene on carbon cloth (CC) as electrode material in supercapacitors. The physicochemical and electrochemical characteristics of the electrodes prepared using this approach were compared with those prepared using common electrochemical deposition methods; i.e., galvanostatic and potentiostatic. In order to increase the compatibility of the CC surface with the electrochemical growth of 3D graphene, it was activated using three different methods of chemical, hydrothermal, and electrochemical oxidation. The structural and electrochemical influences of the activation method were followed using different characterization techniques. Further studies were carried out to optimize the potential magnitude and duration of the EPD step and to find the best reduction method as the key parameters influencing the efficiency of the EPD/red technique. All the synthesized electrodes were subjected to physicochemical and electrochemical analyses. The best electrode synthesized using the optimized EPD/red technique provided a high specific capacitance of 364.9 mF cm−2 at 1 mA cm−2 which can be considered as a good candidate for use in carbon-based supercapacitors. Moreover, this electrode can be utilized as a promising conductive substrate for the chemical or electrochemical deposition of pseudocapacitive materials due to its high specific surface area. The symmetric supercapacitor cell prepared based on the best electrode showed a high specific capacitance of 147.4 mF cm−2 at 0.5 mA cm−2, and the capacitance retention of 83% after 2000 cycles of charge/discharge at 5 mA cm−2. It also provided the highest energy density of 20.5 μWh cm−2 at power density of 250 μW cm−2.