Synthesis and Their Electrochemical Performance of Manganese Dioxide / Activated Carbon Composite Materials

In this paper, taking KMnO4 as manganese source, manganese doxides∕ activated carbon composite materials were syn-thesized by using hydrothermal method in the same system by controlling the quality of KMnO4 and activated carbon. Their morpholo-gies and phase structures were characterized by high resolution scanning electron microscopy and X-ray powder diffraction. The com-posite materials were prepared into electrode sheets, and the electrode sheets were assembled into a symmetric supercapacitor, thenconstant-current charge and discharge(GCD), cyclic voltammetry(CV) and AC impedance(EIS) were used to test their electrochemicalproperties under the two-electrode system. Study results indicated that the electrochemical property of composite materials is the bestwhen the mass ratio of δ-MnO2 and activated carbon is 2:1, and its specific capacitance was up to 251.92 F/g.