摘要
This paper reports a novel strategy for preparing redox-active electrolyte through introducing a redox-mediator(p-phenylenediamine,PPD) into KOH electrolyte for the application of ball-milled MnO 2-based supercapacitors.The morphology and compositions of ball-milled MnO 2 were characterized using scanning electron microscopy(SEM) and X-ray diffraction(XRD).The electrochemical properties of the supercapacitor were evaluated by cyclic voltammetry(CV),galvanostatic charge-discharge(GCD),and electrochemical impedance spectroscopy(EIS) techniques.The introduction of p-phenylenediamine significantly improves the performance of the supercapacitor.The electrode specific capacitance of the supercapacitor is 325.24 F g-1,increased by 6.25 folds compared with that of the unmodified system(44.87 F g-1) at the same current density,and the energy density has nearly a 10-fold increase,reaching 10.12 Wh Kg-1.In addition,the supercapacitor exhibits good cycle-life stability.
This paper reports a novel strategy for preparing redox-active electrolyte through introducing a redox-mediator （p-phenylenediamine, PPD） into KOH electrolyte for the application of ball-milled MnO2-based supercapacitors. The morphology and compositions of ball-milled MnO2 were characterized using scanning electron microscopy （SEM） and X-ray diffraction （XRD）. The electrochemical properties of the supercapacitor were evaluated by cyclic voltammetry （CV）, galvanostatic charge-discharge （GCD）, and electrochemical impedance spectroscopy （EIS） techniques. The introduction of p-phenylenediamine significantly improves the performance of the supercapacitor. The electrode specific capacitance of the supercapacitor is 325.24 F g-1, increased by 6.25 folds compared with that of the unmodified system （44.87 F g-1） at the same current density, and the energy density has nearly a 10-fold increase, reaching 10.12 Wh Kg-1. In addition, the supercapacitor exhibits good cycle-life stability.
基金
supported by the National High Technology Research and Development Program of China (2009AA03Z217)
the National Natural Science Foundation of China (90922028,50842027)
the Key Project of Ministry of Education of China (211204)
