Experimental study of a carbon-based planar supercapacitor in an aqueous electrolyte

One of the remarkable characteristics of supercapacitors is their ability to rapidly charge/discharge compared to a battery. The increase in the charging rate adversely affects the capacitance reduction. To address this issue, a planar interdigitated electrode that provides a good rate capability is implemented. In this paper, leveraging cyclic voltammetry, we investigate the specific capacitance of three difference patterns of carbon-based planar electrodes and conventional sandwich supercapacitors using two electrodes system of cyclic voltammetry technique. The capacitance of all planar samples reach the maximum peak, which is higher than its initial value even after increasing the scan rate by 50-fold. The narrow planar electrode fringe has a strong electric field and enhances the capacitance. The optimum applied scan rate can be manipulated by varying the electrolyte concentration. Thus, a simplified model of charge storage behavior is proposed. Furthermore, the influence of electrolyte concentration and applied scan rate on the total capacitance is discussed. The excellent rate capability observed herein demonstrates the superior electrochemical performance of supercapacitor with planar electrode configuration beyond the conventional sandwich structure.