Bare Ni foam electrode-ferricyanides redox electrolyte system with high capacitive performance

Abstract Efficient electrode-electrolyte interaction is vital prerequisite for capacitive performance of supercapacitor. Herein, a novel capacitive system is proposed based on bare Ni foam electrode and ferricyanides (equal molar K3Fe(CN)6/K4Fe(CN)6 pair) mediated alkali electrolyte free of any active electrode material. The efficient electrode-electrolyte interaction enables high faradic capacitance, considerable cycleability and slow self-discharge behavior. The hybrid supercapacitor based on the Ni foam electrode-ferricyanides electrolyte positive half-cell and activated carbon negative electrode delivers high energy, power and excellent cycleability, manifesting the significance of electrode-electrolyte interaction to capacitive performance.