https://scholars.lib.ntu.edu.tw/handle/123456789/409002
Title: | Comparative study on nanostructured MnO2/carbon composites synthesized by spontaneous reduction for supercapacitor application | Authors: | Lin Y.-P. Tsai C.-B. Ho W.-H. Wu N.-L. |
Keywords: | Chemical synthesis;Composite materials;Nanostructures;Supercapacitor | Issue Date: | 2011 | Journal Volume: | 130 | Journal Issue: | 1-2 | Start page/Pages: | 367-372 | Source: | Materials Chemistry and Physics | Abstract: | MnO2 has been deposited onto two types of carbon (C) substrates, including a non-porous multi-wall carbon nano-tube (CNT) and a porous carbon black (CB) powder, by a solution reduction process where MnO4 - was reduced at 80 ¢XC by the C substrate so as to give nano-crystalline MnO2 directly at the C surface. The nature of the C substrate has profound effects on polymorphicity, microstructure and electrochemical properties, in terms of supercapacitor application, of the resulting oxide. Deposition on CNT produces meso/macro-porous layer containing predominantly spinel MnO2 strongly bonded to the CNTs and having a larger surface area, while that on CB results in birnessite granules with a lower surface area. In addition to having a higher specific capacitance (309 F g-1), the MnO2/CNT electrode exhibits superior power performance (221 F g-1 at 500 mV s-1 or ca. 20 Wh kg -1at 88 kW kg-1) to MnO2/CB due to reduced electronic and ion-diffusion resistances. Furthermore, the MnO2/CNT electrode also exhibits slower self-discharging rate and greater cycling stability. The results indicate that the MnO2 spinel/CNT holds promise for supercapacitor applications. ? 2011 Elsevier B.V. All rights reserved. |
URI: | https://scholars.lib.ntu.edu.tw/handle/123456789/409002 | ISSN: | 02540584 | DOI: | 10.1016/j.matchemphys.2011.06.050 |
Appears in Collections: | 化學工程學系 |
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