Redox-active alkaline electrolyte for carbon-based supercapacitor with pseudocapacitive performance and excellent cyclability

A simple method has been implemented to prepare a stable and effective redox-active alkaline electrolyte by doping m-phenylenediamine into a conventional KOH electrolyte for a carbon-based supercapacitor. The quick electron transfer and reversible Faradic process in the new electrolyte system results in additional pseudocapacitive contribution for a carbon-based supercapacitor. The specific capacitance of the supercapacitor based on the new electrolyte is 78.01 F g−1, which is an increase of 114.16% over that of a supercapacitor based on a conventional KOH electrolyte (36.43 F g−1). Additionally, the supercapacitor exhibits an excellent cyclical stability.