Preparation of Electric Double Layer Capacitor depended on the effect of edge sites of grapheme structure

从2005年4月到2007年3月这两年的结果如下：从2005年4月到2006年3月，第一年的目标是制备剥离的中碳微珠（Ex-MCMB）来制作矩形薄电极。(1)将插层的MCMB与硫酸和硝酸的混合酸以4/1的体积比在1000℃下快速热解得到手风琴状剥离的MCMB。(2) x射线粉末衍射结果观察到芳香碳层间的膨胀和无序。边缘地点的暴露是通过碳层的剥落过程进行的。(3)汞孔计测定的MCMB剥落前后的比表面积和孔径分布显示出中孔的形态。第二年（2006年4月- 2007年3月）的目的是通过降低碳集流器和碳矩形极化电极之间的内阻来评价双电层电容器的性能。(1)在2000或3000℃下石墨化MCMB，成功制备了MCMB的剥离。(2) 2000℃石墨化后的MCMB比表面积由0.8 m^2/g大幅增加到70 m^2/g。剥落试样的吸附等温线表现为微孔为主的I型吸附行为。(3)由Ex-MCMB极化电极和碳集流电极制成的电极的静电容量是由PTFE、炭黑和Ex-MCMB制成的电极的5倍。此外，接触电阻也减小了。(4) Ex-MCMB基极化电极的SEM图像显示，脱落的片层边缘表面覆盖有碳涂层。碳涂层似乎降低了静电容量。然而，电化学氧化将静电容量提高到50 F/g。

The following results were obtained for the past two years from April of 2005 to March of 2007.The aim of this first year from April of 2005 to March of 2006 was to prepare exfoliated mesocarbon microbeads(Ex-MCMB) to make a rectangular thin electrode.(1) Accordion-like exfoliated MCMB was obtained by rapid pyrolysis at 1000℃ of the intercalated MCMB with the mixed acid of sulfuric and nitric acids at the volume ratio of 4/1.(2) Expansion and disorder between aromatic carbon layers were observed from the results of X-ray powder diffraction profiles. The exposure of edge sites proceeded through exfoliation process of carbon layers.(3) Specific surface area and pore size distribution of the MCMB before and after exfoliation by Mercury Porosimeter showed the appearance of mesopore.The aim of the second year from April of 2006 to March of 2007 was to evaluate the performance as electric double layer capacitor by decrease of internal resistance between carbon current collector and carbon rectangular polarized electrode.(1) Exfoilation of MCMB successfully produced by use of MCMB graphitized at 2000 or 3000℃.(2) Specific surface area of MCMB graphitized at 2000℃ was largely increased from 0.8 m^2/g to 70 m^2/g by exfoliation. The adsorption isotherms of the exfoliated samples showed the behavior of type I dominated by micropore.(3) Electrostatic capacity of the electrode made from the Ex-MCMB based polarized electrode and carbon current collector showed five times as larger as the electrode made from PTFE, carbon black, and Ex-MCMB. In addition, contact resistance also decreased.(4) SEM images of the Ex-MCMB based polarized electrode showed that carbon coatings covered on the edge surface of exfoliated lamellar. The carbon coatings seemed to decrease the electrostatic capacity. Electrochemical oxidation, however, improved the electrostatic capacity up to 50 F/g.