Hydrothermal Synthesis of Dendritic NiCo2O4 Nanostructures and Carbon Nanotube Composite Electrodes for Supercapacitors
| Autor: | Lai, Yu-Sheng, 賴譽生 |
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| Rok vydání: | 2015 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 103 This study used a facile hydrothermal synthesis to prepare the nanodendritic NiCo2O4 spinel on the conductive substrate for supercapacitors. Generally, electrode structure with large surface area could effectively improve the electrochemical performance of electrode due to the increase in the contact area between the electrode material and electrolyte. Therefore, we used the stainless steel wire mesh (SS mesh) to replace the stainless steel sheet (SS) as an electrode substrate. The composite electrode composed of carbon nanotubes (CNTs) and active materials were prepared. Results indicated that the composite electrode exhibited an excellent capacitive behavior due to presence of 3D CNTs that considerably increase the electrical conductivity of composite electrode, making the transport of electron easier. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction, surface area analyzer, and thermal gravimetric analysis were used to characterize the physical properties of the electrodes. The results showed that nanodendritic NiCo2O4 could be successfully prepared on the conductive substrate. Electrochemical performance of electrodes was systematically investigated by cyclic voltammetry, galvanostatic charge/discharge, AC impedance, and cyclic life in 1 M KOH electrolyte. The result revealed that the CNT/NiCo2O4-SS mesh exhibited superior specific capacitance of 1213 F g-1 at a current density of 1 A g-1 and the better capacitance retention (about 92 % after 3000 cycles). Keywords: hydrothermal synthesis, NiCo2O4, nanodendritic structures, carbon nanotube, supercapacitors |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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