Study On The Preparation Of Porous Carbon Materials For Electrochemical Capacitance Performance

The aim of this research is to explore the use of cheap raw materials and novelsynthetic methods for preparing porous carbon materials, nitrogen-doped carbonnanowires and graphitic mesoporous carbon, which are used as the electrode materialsof super-capacitors. Various characterization methods are employed to analyze theirmorphology, structure and performance. The major contents can be summarized asfollows:（1） Metal-organic frameworks are conducted to synthesize porous carbon andball carbon nanofibers. Porous carbon materials are synthesized by usingmetal-organic frameworks （MOFs） as precursor, followed by carbonizating underdifferent high temperatures and the removal of impurities by HCl. After the structurecharacterization, the synthesis mechanism is discussed. The supercapacitorapplication of the carbon material is also researched. It shows that the carbon materialobtaind under700℃shows good area capacitance of17.65μF cm-2at100mA g^-1,and its specific capacitance reaches271F g^-1. Meanwhile, ball carbon nanofibers areobtained by Al-PCP as template, which shows uniform morphology.（2） Nitrogen-doped carbon nanowire is synthesized by a simple impregnationmethod under low carbonization temperature. L-arginine is adopted as carbonresources and nitrogen resources and SBA-15is employed as hard template. Theobtained carbon nanowires possess a wormlike micropores structure, uniform andultrafine diameter of around6.5nm, in good accord with the pore size of the SBA-15silica template. The formation mechanism is probably due to the fact that L-arginine iselongated to form long chains in the pore of SBA-15throughdehydration-condensation reaction. The obtained carbon nanowire has plateful ofnitrogen-containing and oxygen-containing groups, which is very beneficial to thepseudo-capacitance. The results demonstrate that nitrogen-doped carbon nanowireshave good electrochemical performances including161F g^-1at250mA g^-1and the89.9%retention of specific capacitance over5000cycles.（3） A novel synthetic strategy is developed to fabricate high graphitization degreeof mesoporous carbon materials involving mesoporous metal oxides as catalystprecursor templates and sucrose as cheap carbon source. The results show that thegraphitic mesoporous carbons synthesized from mesoporous metal oxides as templatehave higher degree of graphitization than these prepared from pure SBA-15as template, which could benefit from the nanoscale catalysis performance of metaloxide. In addition, the graphitic mesoporous carbon which is obtained frommesoporous NiO template shows higher graphitization and lower equivalent seriesresistance. Meanwhile, all these graphitic carbons exhibit mesoporous structure.