CNTs/SnO2 and CNTs/MNo2 nanocomposites for the fabrication of the electrodes for supercapacitors

Abstract

The development of next generation high-energy and high-power aqueous supercapacitors is vital in an era when power demand has peaked. In terms of engineering related issues at the micro level, the major area urgently requiring attention is the development of new nanocomposite materials. This article reports on nanocomposites which demonstrate superiority in terms of three-dimensional structure and which possess electrical conductivity equivalent to metallic conductors as a result of CNTs which complement the high redox-active properties of the transition metal oxides. Such combined contributions, when applied in supercapacitors, lead to increased charge storage capabilities and exceptional cycling stability. Two nanocomposites, namely, CNTs/SnO2 and CNTs/MnO2, were synthesised their physicochemical properties examined by X-ray diffraction, scanning electron microscopy, cyclic voltammetry and galvanostatic charge-discharge. The nanocomposites show superior results in terms of charge-storage mechanisms, cycle life, and electrochemical kinetics. Uniquely, in this paper, CNTs/SnO2 nanocomposites were also reported as an alternative negative electrode material to the commonly used activated carbon in asymmetrical supercapacitors.