The Preparation Of Porous Carbon-Carbon Composites For Electrochemical Supercapacitors

Porous carbon with 1D micro/nanostructure has attracted significant attention, not only for its fundamental scientific interest, but also for many modern-day technological applications, owing to their unique structure characteristics including high length/diameter ratio, large pore volume and high surface area. A large number of advanced techniques have been developed to fabricate 1D porous carbon nanostructure with well-controlled morphology and chemical composition. In this paper, we prepare the ordered mesoporous carbon-carbon composites and porous carbon-carbon composites by the evaporation-induced self assembly and dip coating method. The details are as follows:(1)Nitrogen-doped mesoporous carbon microfibers(NMCMFs) were prepared via an evaporation-induced tri-consistent assembly of triblock copolymer, resols and prehydrolyzed tetraethoxy silane on the natural silk and following pyrolysis. The result NMCMFs inherit the advantages of both order mesoporous carbons(OMCs) and carbon microfibers(CMFs), such as uniform meso-channels, high surface area, high nitrogen content, excellent electronic conductivity as well as good flexibility. Owing to the well-designed nanostructure and the synergistic effects of the strongly coupled components, the binder-free electrodes based on NMCMFs exhibit enhanced capacity(189 F g-1 at 5 m V s-1), excellent rate capability(107 F g-1 at 100 m V s-1) and durability(maintained over 96 % of the initial capacitance after 10000 cycles) in electric double-layer capacitors, outperforming those from OMCs and CMFs derived from pristine silk.(2)Ordered mesoporous carbon/graphene aerogel(OMC/GA) were prepared by an evaporation-induced tri-consistent assembly route. The obtained OMC/GA possesses hierarchically porous structures with both macro- and mesopores and a high specific surface area of 715 m2 g-1. As the electrode in EC, the composite shows enhanced electrochemical performance such as high specific capacitance(177 F g-1 at 5 m V s-1), good rate capability(115 F g-1 at 100 m V s-1), and excellent cycling stability(maintained over 93 % of the initial capacitance after 10000 cycles).(3)Nitrogen-doped carbon microfibers/grapheme(NCMF) were prepared by an dip coating. The obtained NCMF possesses hierarchically porous structures with both macro- and mesopores and a high specific surface area. As the electrode in EC, the composite shows enhanced electrochemical performance such as high specific capacitance(196 F g-1 at 5 m V s-1), good rate capability(92 F g-1 at 300 m V s-1), and excellent cycling stability(maintained over 107 % of the initial capacitance after 10000 cycles).