| Carbon composite material (CNTs/CAGs) with Carbon nanotubes (CNTs) and carbon aerogels (CAGs) is one kind of new carbon materials in recent years. It is an ideal electrode material of electric double-layer super-capacitors because of its excellent electrical conductivity and high energy storage efficiency. However, the bottleneck from its powder-molding has restricted its applications in electrochemistry. Accordingly, development of new method for macroscopic fabrication of CNTs/CAGs composites is the key to solve this problem.In this paper, large-area self-supported carbon composites of CAGs/CNTs/SMFNi were successfully prepared, with high CAGs content of up to 70% in the composites, by carbonizing the resol (RF), PF, and polyimide (PI) sols (their each or binary mixture) pre-coated on the CNTs/SMFNi. The home-made CNTs/SMFNi composite is characteristic of thin-sheet shape with entirely opened three-dimensional network. The CAGs/CNTs/SMFNi composites presented a hierarchical self-supported structure while the metal micro-fiber network, CNTs and CAGs acted as the current collector, the nano-wires and the ion reservoirs, respectively.The capacitance of RF-C/C (prepared with RF directly) was 257 F/g at 1 mV/s in 5.0 M KOH (360 F/g based on CAGs alone), which was 6.5 times higher than that of CNTs/SMFNi. For RF-C/C composite, micro-pore surface area (Smic) accounted 55.7% of the total surface area. Smaller pore size (-2 nm) made inorganic electrolyte ions a larger diffusion resistance in the CAGs, which made it difficult to form a stable double layer on the surface of carbon composite at the high scan rate. The attenuation of capacitance was up to 36.1% after 1000 cycles at 100 mV/s. Such composite delivered a small capacitance in the case of using organic electrolyte, one ninth that in 5.0 M KOH. This is due to the small aperture feature that significantly limited the large organic ions (>3 nm) to access into the narrow channels (～2 nm).P123 template or P123 and TEOS were added into the organic resin solution, and as a result, the pore size of the resulting CAGs was successfully increased. We have prepared three kinds of carbon composites using PF or the mixture of PF and RF as precursor with adding P123 template or P123 and TEOS. Larger mesoporous channels (4-10 nm) were generated in the corresponding carbon composites. This reduced the diffusion resistance of ions effectively and enhanced the electrochemical stability of carbon composites. All of these three carbon composites provided capacitance attenuation less than 13% after 1000 cycles. However, this approach is not success to prepare high-CAGs-loading composites thereby leading to lower capacitances on the basis of overall weight of composites. At the scan rate of 1 mV/s, the overall capacitances of these composites were 76,103,108 F/g (capacitances based on CAGs were 294,336,275 F/g). Not surprisingly, the aperture expansion facilitates the access of the larger organic electrolyte ions, and therefore, the capacitance in organic electrolyte was promoted markedly. The carbon composite PRF-C/C provided the highest capacitance (66 F/g) in 0.1 M N(C2H5)4PF6 at 1 mV/s (capacitance based on CAGs up to 167 F/g).Owing to the high carbonization temperature, the active groups on the surface of polyimide resin decomposed completely. Accordingly, no pseudo-capacitance effects were obtained yet, that could promote the capacitance of composites. Nevertheless, PI-C/C had certain ions storage efficiency in inorganic electrolyte with the capacitance of 133 F/g (359 F/g based on CAGs alone). In addition, a small capacitance of 35 F/g (94 F/g based on CAGs alone) was obtained on this composite because of its small pore size feature.
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