High performance of active carbon-based supercapacitor introduced with NiSO4 and CoSO4 redox active electrolytes in acid media

The effects of incorporating NISO, and CoSO, as redox additives into an H ?SO, acid medium to improve the functionality of a capacitor that is based on active carbon were studied using impedance spectroscopy, galvanostatic charge-discharge, and cyclic voltammetry. The power density (432 W kg and 426 W kg). energy density (85.2 Wh kg and 49.8 Wh kg-1), and specific capacitance (924 F g and 842 F g-(1)) were achieved in electrolytes of NISO, H ?SO, and CoSO,H,SO,, respectively, assuming a density of 1 Ag-1. through diffusion controlled redox reactions at the negative electrode.