溶胶-凝胶法介孔沥青炭微球的制备及电化学性能研究

Preparation and electrochemical performance of pitch-based mesoporous carbon spheres via sol-gel method

以水性中间相沥青（AMP）为前驱体,阳离子表面活性剂（CTAB）为结构导向剂,通过控制AMP的凝胶化和自组装过程,采用溶胶-凝胶法来制备介孔沥青炭微球。利用SEM、HRTEM、SAXRD、FT-IR等分析手段,对产物的形貌及结构进行表征,并研究了介孔沥青炭微球的形成机理和电化学性能。结果表明：在制备介孔沥青炭微球的过程中,CTAB与离子化的AMP可通过S＋I-静电力作用形成凝胶球,经炭化后得到介孔沥青炭微球。当CTAB/AMP=1.2时（CTAB为2 g）,炭化后得到的介孔炭微球之间界面明显,表面光滑,球体粒径为300~500 nm,当增加CTAB胶束在溶液中的浓度时,炭化产物中得到纳米炭棒。所得介孔沥青炭微球C-AMP1.2-800有序度差、石墨化度低,球体为乱层石墨结构,其在50 mV.s-1下的比电容为103.5 F/g。

Using aqua mesophase pitch（AMP） as the precursor and cationic surfactant CTAB as the structure-directing agent, pitch- based mesoporous carbon spheres were synthesized utilizing sol-gel method. The morphology and structure of products were characterized by using SEM, HRTEM, SAXRD and FT-IR, and then the formation mechanism and electrochemical performance of pitch-based mesoporous carbon spheres were studied. The results showed that CTAB and ionized AMP formed gel spheres via S＋I- electrostatic force, and then pitch-basod mesoporous carbon spheres were obtained via the carbonization process. When the ration of CTAB to AMP was 1.2 （CTAB was 2 g）, the obtained mesoporous carbon spheres with diameters of 300-500 nm had smooth surface and apparent boundary. When the concentration of CTAB was increased, carbon nano-rods were obtained in the carbonized products. The obtained pitch-based mesoporous carbon spheres （C-AMP1.2-800） with turbostratic structure show low degree of graphitization and ordering of the carbon layers. The specific capacitance of the mesoporous carbon spheres at 50 mV-s-1 is 103.5 F/g.