氧化石墨烯-单壁碳纳米管复合物的超电容性能研究

以氧化石墨烯(GO)作为表面活性剂分散原始的单壁碳纳米管(SWNT),采用超声、冷冻干燥的办法得到氧化石墨烯-单壁碳纳米管复合物,利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)和电化学测试对样品的形貌、结构、组成以及电化学性质进行表征.结果表明:氧化石墨烯-单壁碳纳米管复合物电化学性质得到了显著的提高,通过调节单壁碳管与GO的比例,发现SWNT质量为GO的10%时,得到的复合材料具有最好的超电容储能特性,在6mol·L~(-1)的KOH电解液中,0.5A·g~(-1)电流密度下其比电容可达155F·g~(-1),是相同条件下GO比电容(81.5F·g~(-1))的1.9倍,这种简单的方法获得的GO-SWNT复合材料在能量存储装置方面展现了广阔的应用前景.

Study on the Supercapacitance Performance of Graphene Oxide-pristine SWNT composites

Graphene Oxide-Pristine SWNT composites were fabricated using graphene oxide(GO) as a surfactant to directly disperse pristine SWNT, followed by a freeze-drying method of the sample. The morphology, structure, component and electrochemical property of the compounds were characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and electrochemical measurements. The results showed that the electrochemical properties of the compounds were significantly improved due to the insertion of SWNTs into a GO matrix. Through changing the ratio between SWNTs and graphene oxide, the sample corresponding to a SWNT ratio of 10% showed the best supercapacitor property. At such a optimized mixing ratio, the specific capacitance of the nanocomposite was 155 F·g-1 at a current of 0.5A·g-1 in the KOH aqueous electrolyte of 6 mol·L-1 , which was 1.9-fold higher than that of pure graphene oxide (81.5F·g-1). These results clearly demonstrate that GO-SWNT composites prepared by our present simple method is very promising for next generation high-performance energy storage devices.