Influence of graphene oxide reduction and solvent effect on the performance of graphene oxide based supercapacitor

Supercapacitors (SCs) hold significant promise as a key component in energy storage systems due to their unique combination of high-power density, rapid charge/discharge rates and long cycle life. Unlike traditional batteries, SCs can efficiently handle frequent charge/discharge cycles without significant degradation, making them ideal for applications requiring rapid energy delivery. Graphene oxide (GO) and reduced graphene oxide (RGO) are gaining significant attention as electrode materials for SCs due to their unique properties. The solvents, HNO 3 acid and DMF not only facilitate the dispersion of graphene-based materials but also impact the morphology, surface chemistry, and structural properties of the resulting thin films. The present research explores the suitability of GO and RGO-based composite electrodes prepared using 0.1 M HNO 3 acid and DMF for SCs. The reported work mainly focused on comparing the performance of RGO-based SCs with that of GO-based (control) using HNO 3 and DMF as solvents. The maximum specific capacitance obtained was 146 F g −1 at 2 mV s −1 for RGO – DMF-based SC at room temperature. The maximum gravimetric energy density of 21.58 Wh kg −1 and gravimetric power density of 81.55 kW kg −1 were exhibited for GO – DMF and RGO – DMF-based SCs, respectively. Electrochemical impedance analysis was used to characterize the device. Investigation of solvent influence on electrode preparation is unique and can provide insights into optimizing the electrode preparation process. The study uncovers that DMF is a better solvent for preparing GO and RGO-based electrodes. In addition, the study reveals that RGO-based SC shows higher performance compared to that of GO-based one. ● Modified Hummers' method used to synthesize GO and RGO from vein graphite for SCs. ● DMF found to be a superior solvent for graphene-based electrode preparation for SCs. ● 2 M H2SO electrolyte-based SC showed enhanced performance due to high ion transport. ● RGO-based SCs outperform GO-based SCs in energy and power density. ● SC based on RGO -DMF electrode shows the highest capacitance of 146 Fg-1 at 2 mV-1.