Study On The Structure And Electrochemical Performance Of Porous Carbons Made From Pitch-precursors

Activated carbon is an important branch of carbonaceous materials. Activated carbon products made with traditional activation methods were used in chemical engineering, environment protection and food purification. Meanwhile, new activated carbons with high surface area or high mesopore content had more potential for development, which play an important role in catalytic support, electrical double-layer capacitor and hydrogen storage. It is significant for theory and practice to study on the mechanism of etching, preparation conditions and application of activated carbons.In this paper, relationship between performance of activated carbon and structure of precursors was investigated from the structural characteristics. Isotropic precursor with more noncrystal or edge carbons can be etched by KOH easily and became high surface (2913m2/g) activated carbon with double peaks type pore size distribution. Mesocarbon microbeads were utilized to be precursors for activation and the impersonality among structure characteristics of precursors, heat treatment conditions and microstructure and adsorption abilities of activated carbons was discussed. Electrical double-layer capacitors using activated mesocarbon microbeads as electrode were taken shape and the max specific capacitance reached 271F/g. Activation mechanism was explained by structural defects and chemical etching. Activated carbon with high surface area (2412m2/g) and high mesopore content (41.5%) was gained under lower KOH/C ratio (2:1) from anisotropic precursor. Activated mesocarbon microbeads/expanded graphite composites were prepared and specific capacitance was discussed. Conductivity was increased through establishing the solid-network without changing the adsorption abilities of activated mesocarbon microbeads. The specific capacitances of pure porous carbons were increased about 20-30F/g, respectively.In this paper, chemical activation took advantage of man-made structural defects and porous carbon with higher performance was gained with novel chemical-catalytic activation method. Activated carbons made from mesocarbon microbeads were put into the investigating of electric double layer capacitor and the application of mesocarbon microbeads was widened.