Multisegmented Au-MnO2/Carbon Nanotube Hybrid Coaxial Arrays for High-Power Supercapacitor Applications

The present work reports on synthesis and supercapacitor applications of multisegmented Au-MnO2/carbon nanotube (CNT) coaxial arrays. Multisegmented Au-MnO2/CNT coaxial arrays are fabricated inside porous alumina templates using a combination of electrodeposition, infiltration, and chemical vapor deposition methods. CNTs serve as an alternative additive for improving the electrical conductivity of the manganese oxide electrodes, in addition to its active electrode characteristics. The well-adhered interface between Au and MnO2/CNT hybrid segments leads to nanoscale electrical contacts between the electrode and current collectors. Electrochemical studies have been performed using cyclic voltammetry, galvanostatic charge−discharge, and impedance spectroscopy measurements. The results demonstrate that MnO2/CNT hybrid coaxial arrays are efficient electrodes for supercapacitor applications. Au-segmented MnO2/CNT hybrid coaxial electrodes showed further improvement in specific capacitance, energy, and power densities of a supercapacitor.