(Invited) Effect of Carbonaceous Materials on the Performance of Supercapacitors

Abstract

Carbonaceous materials such as carbon blacks, activated carbons, multi walled/single walled carbon nanotubes (CNTs), graphene oxide (GO), reduced graphene oxide (rGO), and biochar are found to be useful for energy storage applications because of their large specific surface area, high conductivity, high mechanical strength, good thermal stability, and low cost.In order to optimize the concentration of MWCNT in MnO2/MWCNT nanocomposite, we have synthesized MnO2/MWCNT nanocomposite with varying concentration of MWCNT such as pure MnO2, 1mg/ml, 4 mg/ml, and 10 mg/ml MWCNT in reaction mixture. The samples were identified as MnO2, M-CNT 100, M-CNT 400, and M-CNT 1000. From cyclic voltammetric studies at various scan rate, we plotted a graph between peak current () versus the scanning rate () and found that the slope of anodic (cathodic) peak for MnO2, M-CNT 100, M-CNT 400, and M-CNT 1000 were found to be 0.48 (0.42), 0.70 (0.61), 0.60 (0.54), and 0.52 (0.47), respectively. We also found that at a current density of 0.5 A/g, pure MnO2 has a specific capacitance of 124 F/g. The addition of MWCNT initially increases the specific capacitance to 145 F/g for M-CNT 100 nanocomposite; however, at the 400-mg and 1000-mg concentrations the specific capacitance decreases to 135 F/g and 102 F/g, respectively.Besides this, we have also studied the effect of binder on capacitive performance of MnO2/CuS/rGO samples and found that the specific capacitance of the composite materials increased upon decreasing the binder. The detailed results of our recent investigations on carbonaceous materials for supercapacitor applications will be presented at 244th ECS meeting.