Addition of redox additives—synergic strategy for enhancing the electrochemical activity of spinel Co ₃ O ₄ based supercapacitors

Abstract

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 Co 3 O 4 , 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 K 3 Fe(CN) 6 . As the 2 M KOH electrolyte is modified by varying concentrations of K 3 Fe(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.