Mesoporous carbon nanospheres with an excellent electrocapacitive performance
Mesoporous carbon nanospheres with an excellent electrocapacitive performance
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DOI：
10.1039/c0jm03322g
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发表时间：
2011-01-01
影响因子：
--
通讯作者：
Zhao, X. S.
中科院分区：
文献类型：
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作者：
Lei, Zhibin;Christov, Nikolay;Zhao, X. S.
制备了粒径约为65 nm，初介孔直径约为2.7 nm的介孔碳纳米球（MCS），并将其用作超级电容器电极。以二茂铁为碳前驱体，介孔二氧化硅纳米球为模板。高分辨率透射电子显微镜显示，MCS由小域的石墨烯片组成，其比表面积和孔体积分别为2396 m(2) g（-1）和2.9 cm(3) g（-1）。采用循环伏安法、恒流充放电法和电化学阻抗谱技术研究了MCS电极在水、非水电解质中的电容性能。MCS电极的介孔和较短的长度有利于电解质离子的扩散。在1.5 mol L-1的四氟硼酸四乙基铵乙腈电解质中，以MCS为电极的对称超级电容器在0.16 kW kg（-1）和32 kW kg（-1）的功率密度下，比电容为180 F g(-1)，能量密度分别为62.8 W h kg（-1）和9.1 W h kg（-1）。此外，MCS超级电容器在3.0 a g（-1）的电流密度下，循环700次后仍能保持78%的能量密度和90%以上的功率密度。
Mesoporous carbon nanospheres (MCS) with particle size of about 65 nm and primary mesopores of about 2.7 nm in diameter were prepared and used as supercapacitor electrodes. Ferrocene was employed as the carbon precursor and mesoporous silica nanospheres were used as the template. High-resolution transmission electron microscopy revealed that the MCS consisted of graphene sheets in small domains and exhibited a specific surface area and pore volume of 2396 m(2) g(-1) and 2.9 cm(3) g(-1), respectively. The electrocapacitive performance of the MCS electrode was investigated by using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy techniques with both aqueous and non-aqueous electrolytes. The mesopores and short length of the MCS electrode were found to favor the diffusion of electrolyte ions. A symmetric supercapacitor with the MCS as the electrodes exhibited a specific capacitance of 180 F g(-1) and delivered energy densities of 62.8 W h kg(-1) and 9.1 W h kg(-1) at power densities of 0.16 kW kg(-1) and 32 kW kg(-1), respectively, in a 1.5 mol L-1 tetraethylammonium tetrafluoroborate in acetonitrile electrolyte. In addition, the MCS supercapacitor displayed a good cyclability, with 78% energy density and more than 90% power density remained after 700 cycles at a current density of 3.0 A g(-1).