High-performance electrochemical capacitors using electrodeposited MnO2 on carbon nanotube array grown on carbon fabric

Carbon fabric (CF)-carbon nanotube array (CNTA)/MnO2 composites with a 3D porous structure are prepared by the electrochemical deposition for high-performance electrochemical capacitors. MnO2 nanoflowers assembled with the petal-like nanosheets uniformly attach on the surface of CNTs. Electrochemical characterization indicates that the maximum specific capacitance of CF-CNTA/MnO2 reach to 740 F g(-1) (based on MnO2 alone) with a mass loading of 0.34 mg cm(-2) at the scan rate of 2 mV s(-1), which is much better than that of MnO2 electrodeposited on the stainless steel and the CF. And the specific capacitance can remain 326 F g(-1) even with a mass loading of 4.09 mg cm(-2). While a reasonable area-normalized capacitance of 2081 mF cm(-2) is achieved with this high mass loading at 0.1 mV s(-1). The rate capability measurement shows the CF-CNTA/MnO2 achieved a high retention of 70% with a scan rate range of 2-200 mV s(-1), which outperform others 3D porous MnO2-based electrodes reported previously. These excellent electrochemical performances are attributed to large surface area, 3D porous structure and aligned ion diffusion channels of the CF-CNTA/MnO2 composite electrodes. (C) 2012 Elsevier Ltd. All rights reserved.