Preparation and characterization of manganese oxide/CNT composites as supercapacitive materials

Manganese oxide was synthesized and dispersed on carbon nanotube (CNT) matrix by thermally decomposing manganese nitrates. CNTs used in this paper were grown directly on graphite disk by chemical vapor deposition technique. The capacitive behavior of manganese oxide/CNT composites was investigated by cyclic voltammetry and galvanostatic charge–discharge method in 1 M Na2SO4 aqueous solutions. When the loading mass of MnO2 is 36.9 μg cm− 2, the specific capacitance of manganese oxide/CNT composite (based on MnO2) at the charge–discharge current density of 1 mA cm− 2 equals 568 F g− 1. Additionally, excellent charge–discharge cycle stability (ca. 88% value of specific capacitance remained after 2500 charge–discharge cycles) and power characteristics of the manganese oxide/CNT composite electrode can be observed. The effect of loading mass of MnO2 on specific capacitance of the electrode has also been investigated.