Porous carbon for electrochemical capacitors prepared from a resorcinol/formaldehyde-based organic aquagel with nano-sized particles

Abstract

We report a simplified method to prepare porous carbon with abundant mesopores and micropores by ambient drying from a resorcinol/formaldehyde-based organic aquagel. Needle-like nano-sized Mg(OH) 2 is introduced into the reaction system between resorcinol and formaldehyde, and slightly soluble Mg(OH) 2 in the solution acts as a catalyst of the reaction. Due to the divalent ion Mg 2+ catalysis and the presence of nano-sized particles, the gelation time of the resorcinol/formaldehyde reaction system is greatly reduced, from more than tens of hours generally to several minutes. The results of nitrogen adsorption at 77 K show that the prepared porous carbon possesses more larger micropores (>0.6 cm 3 g À1 ) than carbon aerogels, corresponding to high surface areas of more than 1100 m 2 g À1 , though there is no activation. The wet gel polymer shrinks seriously during ambient drying, but abundant mesopores smaller than 10 nm are formed in the carbon product after removing the MgO template. The columnar cactus-like pore texture with narrow multimodal distribution in the prepared porous carbon results in high capacitance and excellent power performance for electrochemical capacitor electrode materials in a 6 M KOH aqueous solution.

Ultrafast sol–gel synthesis of graphene aerogel materials

“…First synthesized in 1989 by Pekala and colleagues, [15] RF-derived aerogels have already been studied extensively as supercapacitor electrode materials. [16][17][18][19][20] Recently by Worsley et al, the pyrolysis of base (Na 2 CO 3 )-catalyzed RF gels loaded with graphene oxide (GO), a highly oxidized and exfoliated derivative of graphite, was shownprovided that the RF is sufficiently low in concentration-to yield extended three-dimensional graphene macroassemblies whereby the carbonized RF junctions were chemically crosslinked into the graphene framework. [21,22] These structures exhibited a bulk electrical conductivity more than two orders of magnitude higher than that of previously made 3D graphene assemblies with physical cross-links.…”

Facile synthesis of nitrogen-doped carbon nanosheets with hierarchical porosity for high performance supercapacitors and lithium–sulfur batteries

“…The CV curves exhibit nearly rectangular shapes, which are well retained even at high scan rate (100 mV s -1 ), demonstrating its fast ion transport at high charge/discharge rate and ideal capacitive behavior. 31 Whereas, the CV curves of N-MPCNS shows some distortion at high scan rates (Fig. S5), which should be ascribed to the lack of mesopore diffusion channels and thus slower ion transport at high rate operations.…”

Highly Monodisperse Microporous Polymeric and Carbonaceous Nanospheres with Multifunctional Properties

“…Generally, carbonization is an important approach to provide novel structures and properties to polymer-based materials, such as achieving conductive and electrochemical performances464748495051 and generating micropores525354, which greatly extends their applications. Therefore, we tried to produce MMCNSs by carbonization of MMPNSs.…”