A bridge between battery and supercapacitor for power/energy gap by dual redox-active ions electrolyte

Capacitor-like and battery-like energy storage characteristics can be incorporated into a single cell to achieve optimal performance metrics through adding dual redox-active ions Bi3+/Br- to electrolyte. By adding dual redox-active ions to traditional electrolyte of carbon-based supercapacitor, redox reactions occur at each electrolyte/electrode interface simultaneously to store energy, exhibiting significant charge and discharge platforms which are battery-like energy storage characteristics. Moreover, a specific capacitance of 1150 F/g and an energy density of 61.8 Wh/kg are achieved at 2 A/g, surpassing most of the state-of-the-art work.