Addition of redox additives—synergic strategy for enhancing the electrochemical activity of spinel Co3O4 based supercapacitors

Abstract

The supercapacitive performance in transition metal oxide(s) based supercapacitors is attributed to the enhanced redox activity at the electrode–electrolyte interface. In hierarchical nanorods of Co3O4, with high surface area and reasonable supercapacitive performance, the electrochemical capacitance can be doubled by the addition of a suitable redox additive viz. potassium ferricyanide K3Fe(CN)6. As the 2 M KOH electrolyte is modified by varying concentrations of K3Fe(CN)6, the specific capacitance shows an increasing trend up to an optimum concentration of redox additive. The fabricated device also show improvement in the cyclic and charge/discharge characteristics. The tremendous increase in the power and energy density values makes the devices quite useful for industrial applications.