Catalytic electrode-redox electrolyte supercapacitor system with enhanced capacitive performance

Nitrogen doped porous carbons (NCs) with high specific surface areas, moderate graphitization degree and high N contents were synthesized by pyrolysis of melamine sponge-polyaniline composite. The as-prepared NCs demonstrate considerable capacitive performances in acidic electrolyte. More importantly, the NCs demonstrated high catalytic activity for the redox reaction of iodides in acidic electrolyte, thus enabled prominent pseudo-capacitance via the faradic reaction of redox electrolyte. Under the optimal concentration of KI in acidic electrolyte, the electrode specific capacitance achieved 616 F g(-1), which is 3 folds higher over that in solely acidic electrolyte. High cycling performance was also maintained for the avoidance of volumetric variation of electrode during charge-discharge cycles. The current work proposed a viable way to ameliorate the capacitive performance via the catalytic NCs electrode-redox iodide electrolyte system.