Characteristics and Electrochemical Performance of Supercapacitors with Manganese Oxide-Carbon Nanotube Nanocomposite Electrodes

Abstract

Supercapacitor characteristics of manganese oxide/nickel (MnOx∕Ni)(MnOx∕Ni) and manganese oxide/carbon nanotubes/nickel (MnOx∕CNTs∕Ni)(MnOx∕CNTs∕Ni) nanocomposite electrodes were investigated in this study. The CNTs were deposited on the Ni substrate by electrophoresis in a 0.5mgCNT∕1mL0.5mgCNT∕1mL dimethylformamide solution, whereas the MnOxMnOx were synthesized by anodic deposition in a 0.16M0.16M manganese sulfate pentahydrate aqueous solution on substrates. The crystallinity and surface morphology of these electrodes were determined by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The capacitive properties of these electrodes were demonstrated by cyclic voltammetry with scan rates ranging from 5to100mV∕s5to100mV∕s . The specific capacitances of the MnOx∕CNT∕NiMnOx∕CNT∕Ni nanocomposite electrode were 415 and 388F∕g388F∕g with scan rates of 5 and 100mV∕s100mV∕s , respectively. After 1000cycles1000cycles of operation, this electrode can maintain 79% of its original capacitance. These MnOx∕CNT∕NiMnOx∕CNT∕Ni nanocomposite electrodes possessing good electrochemical reversibility and high capacitance may be appropriate for supercapacitor application in the future.