Zhang Yujie, Chen Junhong, Fan Huili, Chou Kuo-Chih, Hou Xinmei
School of Chemistry and Biological Engineering, University of Science & Technology Beijing, Beijing 100083, China.
School of Material Science and Engineering, University of Science & Technology Beijing, Beijing 100083, China.
Dalton Trans. 2015 Dec 14;44(46):19974-82. doi: 10.1039/c5dt02971f.
In this research, we demonstrate a simple route for preparing SiC@SiO2 core-shell nanocables and furthermore obtain SiC@SiO2 nanocables/MnO2 as hybrid electrodes for supercapacitors using various modified methods. The modified procedure consists of mild modifications using sodium hydroxide as well as UV light irradiation and deposition of MnO2. The morphology and microstructural characteristics of the composites are investigated using XRD, XPS, FE-SEM with EDS and TEM. The results indicate that the surfaces of modified SiC@SiO2 nanocables are uniformly coated with a MnO2 thin layer. The electrochemical behaviors of the hybrid electrodes are systematically measured in a three-electrode system using cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy. The resultant electrode presents a superb charge storage characteristic with a large specific capacitance of 276.3 F g(-1) at the current density of 0.2 A g(-1). Moreover, the hybrid electrode also displays a long cycle life with a good capacitance retention (∼92.0%) after 1000 CV cycles, exhibiting a promising potential for supercapacitors.
在本研究中，我们展示了一种制备SiC@SiO2核壳纳米电缆的简单方法，并进一步通过各种改性方法获得了用于超级电容器的SiC@SiO2纳米电缆/MnO2复合电极。改性过程包括使用氢氧化钠进行温和改性以及紫外线照射和MnO2沉积。使用XRD、XPS、带有能谱仪的场发射扫描电子显微镜和透射电子显微镜对复合材料的形貌和微观结构特征进行了研究。结果表明，改性后的SiC@SiO2纳米电缆表面均匀包覆有一层MnO2薄层。在三电极体系中，使用循环伏安法、恒电流充放电和电化学阻抗谱系统地测量了复合电极的电化学行为。所得电极在0.2 A g(-1)的电流密度下具有276.3 F g(-1)的大比电容，呈现出优异的电荷存储特性。此外，该复合电极在1000次循环伏安循环后还表现出长循环寿命和良好的电容保持率（约92.0%），在超级电容器方面展现出广阔的应用前景。
