Studies on mechanism of carbon nanotube and manganese oxide nanosheet self-sustained thin film for electrochemical capacitor

Multilayer films of multi-walled carbon nanotubes (MWCNTs) and manganese oxide nanosheets (MONSs) are assembled on ITO glass substrates by an electrostatic layer-by-layer assembly technique. Using scanning microscopy and atomic force microscopy, we demonstrate that the framework is composed of MWCNTs and MONSs self-sustained thin films with randomly interconnected network structure. In addition, the electrochemical performance of these films as electrodes has been investigated using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The roles of each monolayer including the dual character of PDDA, especially for the crucial effects of MWCNTs in the multilayer films are investigated. The present study indicates the potential of a new type of composite material for electrochemical capacitors with a high specific capacitance and energy density. (C) 2010 Elsevier B.V. All rights reserved.