酸功能化碳纳米管对多孔碳材料储能活性及稳定性的增强作用

采用球磨法将酸功能化碳纳米管（AMWCNTs）与环糊精均匀混合。 酸功能化有利于增强碳管和环糊精间的相互作用，从而使二者形成均匀、有效的复合。 在N2气保护下碳化并经后续的ZnCl2活化处理，最终获得酸功能化碳纳米管/多孔碳(PC)复合体材料。 采用透射电子显微镜、X射线衍射和拉曼光谱等方法对材料结构进行了表征。 结果表明，碳纳米管在多孔碳骨架内均匀分布，并且复合体同时具有较高的比表面积和良好的导电性。 循环伏安及恒流充放电等电化学测试表明，由于二者的协同作用及碳纳米管在多孔碳骨架内均匀、有效的复合，材料具有较好的电化学储能性能和良好的电化学稳定性。 电流密度为0.5 A/g时，AMWCNTs/PC12-4（其中12代表β-环糊精和AMWCNTs的质量比，4代表酸化碳纳米管/β-环糊精碳与氯化锌的质量比）复合材料的质量比电容为156 F/g，远远高于AMWCNTs（43 F/g）和PC-4（87 F/g）。 经5000次循环后，电极比电容无明显衰减，而且每次恒流充放电的库仑效率均大于99.9%，说明复合材料具有良好的稳定性，是非常有前景的超级电容器电极材料。

Enhanced Activity and Stability of Porous Carbon for Storage Energy by Acid Functionalized-Carbon Nanotubes

In this paper, the acid-functionalized multi-wall carbon nanotubes/porous carbon(AMWCNTs/PC) composites were prepared by an effective method, and the application of the composites for electrochemical energy storage was also studied. In the synthesis, the AMWCNTs were mixed with cyclodextrin by a milling method. The acid treatment was favorable for the formation of a uniform and effective composite due to the enhancement of the interaction of AMWCNTs with cyclodextrin. After carbonization under N2 protection and activation with ZnCl2, the AMWCNTs/PC composites could be obtained. The materials were characterized by transmission electron microscopy, X-ray diffraction and Raman spectroscopy. The results indicate that the CNTs are uniformly distributed into the framework of the porous carbon, and the materials have a high BET specific surface area and good conductivity. Cyclic voltammetry(CV) and galvanostatic charge-discharge(GCD) measurements indicate that the composites have good performances for electrochemical energy storage and a high stability. The AMWCNTs/PC12-4(numbers 12 and 4 represent the mass ratios of cyclodextrin to AMWCNTs and AMWCNTs/PC to ZnCl2, respectively) exhibits a high specific capacitance of 156 F/g, much higher than the AMWCNTs(43 F/g) and PC-4(87 F/g) at 0.5 A/g. Also, the AMWCNTs/PC-12-4 shows superior cycle durability and columbic efficiency over 99.9% after 5000 cycles in KOH, indicating a promising potential for AMWCNTs/PC-12-4 to be used as electrodes materials in supercapacitor.