Direct growth of vertically aligned single‐walled carbon nanotubes on conducting substrate and its electrochemical performance in ionic liquids
Direct growth of vertically aligned single‐walled carbon nanotubes on conducting substrate and its electrochemical performance in ionic liquids
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DOI：
10.1002/pssa.201228438
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发表时间：
2012-11
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影响因子：
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通讯作者：
M. Azam;Kazuki Isomura;A. Fujiwara;T. Shimoda
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文献类型：
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作者：
M. Azam;Kazuki Isomura;A. Fujiwara;T. Shimoda
我们报道了用一种简单、低成本的乙醇基单壁碳纳米管(SWCNT)生长系统制备用于对称电化学电容器的垂直定向单壁碳纳米管(VA-SWCNT)电极。通过碳纳米管直接生长技术，电极的制备简单，因此可以组装成电化学稳定的离子液体作为电解液。将Va-SWCNT直接生长在未将粘结剂材料掺入电容器结构的SUS 310S导电衬底上。用扫描和透射电子显微镜研究了原生碳纳米管的形貌。该电容器具有高达584F g−1的重量电容(在1 mV S−1扫描速率下)和高速率能力，可获得高达1 000 mV的S−1扫描速率。从循环伏安分析，电容不仅来自理想的双电层电容，还来自充放电过程中可能发生的法拉第/氧化还原过程。除了电容外，还通过频率响应(电化学阻抗)和充放电分析测试了VA-SWCNT电容器的电化学性能。
We report the fabrication of vertically aligned single‐walled carbon nanotube (VA‐SWCNT) electrodes for a symmetric electrochemical capacitor using a simple, low‐cost ethanol‐based SWCNT growth system. From the CNT direct growth technique, the electrode was easily prepared and consequently assembled with an electrochemically stable ionic liquid as electrolyte. VA‐SWCNTs were directly grown on conducting SUS 310S foils in which the binder material was not incorporated in the capacitor structure. The morphology of as‐grown CNTs was investigated using scanning and transmission electron microscopy. This capacitor demonstrated a gravimetric capacitance of up to 584 F g−1 (at 1 mV s−1 scan rate) and a high‐rate capability, with up to 1000 mV s−1 scan rate being obtained. From the cyclic voltammetric analysis, the capacitance was contributed not only from the ideal double‐layer capacitance, but also from faradaic/redox processes that might have occurred during charge–discharge. Other than the capacitance, the VA‐SWCNT capacitor electrochemical performance was also measured by using frequency response (electrochemical impedance) and charge–discharge analyses.