Supercapacitor electrodes

In the sixth paper of this chapter, Kierzek et al., mainly focus on modeling of pore formation vs surface area growth phenomena upon activation of coal and pitch-derived carbon precursors. These authors briefly touch on other precursor carbons as well. The properties of newly synthesized materials are being looked at from the point of view of their application as active materials in the supercapacitor electrodes. Editors thought this work by the Institute of Chemistiy and Technology of Petroleum and Coal in Poland, could be of genuine interest to the practical developers of carbon materials for the supercapacitor industry. 

Frackowiak E., Metenier K., Bertagna V., Beguin F. Supercapacitor electrodes from multiwalled carbon nanotubes. Appl Phys Lett 2000 77 2421-3. 

G. Ning, Z. Fan, G. Wang, J. Gao, W. Qian, F. Wei, Gram-scale synthesis of nanomesh graphene with high surface area and its application in supercapacitor electrodes, Chemical Communications, 47 (2011) 5976. 

Electrostatic interactions have recently been exploited for the synthesis of gra-phene-CNT hybrids. For example, poly(ethyleneimine) (PEI) coated graphene has been mixed with acid treated CNTs in a layer-by-layer method to form high surface area electrodes for supercapacitors [90]. Furthermore, Lu et al. prepared a supercapacitor electrode by mixing PDDA coated CNT-Mn02 hybrid with RGO [91]. 

Lei, Z., F. Shi, and L. Lu, Incorporation of Mn02-coated carbon nanotubes between graphene sheets as supercapacitor electrode. ACS Applied Materials Interfaces, 2012. 4(2) p. 1058-1064. 

Dong, X., et al., Synthesis of a Mn02-graphene foam hybrid with controlled Mn02 particle shape and its use as a supercapacitor electrode. Carbon, 2012. 50(13) p. 4865-4870. 

Energy Storage—CNTs have a very high surface area (about 10 m /g), good electrical conductivity and can be made very linear (straight). They have been used to make lithium batteries with the highest reversible capacity of any carbon material and employed to make supercapacitor electrodes. CNTs are used in a variety of fuel cell applications where durability is important. 

The synthesis of nanostructured carbon using aliphatic alcohols as selfassembling molecules has demonstrated that this strategy can be extended beyond metal oxide-based materials [38]. Recently, we have reported the synthesis of a novel carbon material with tunable porosity by using a liquid-crystalline precursor containing a surfactant and a carbon-yielding chemical, furfuryl alcohol. The carbonization of the cured self-assembled carbon precursor produces a new carbon material with both controlled porosity and electrical conductivity. The unique combination of both features is advantageous for many relevant applications. For example, when tested as a supercapacitor electrode, specific capacitances over 120 F/g were obtained without the need to use binders, additives, or activation to increase surface area [38]. The proposed synthesis method is versatile and economically attractive, and allows for the precise control of the structure. 

FIGURE 1.8 Voltammogram of a carbon supercapacitor electrode. (Adapted from Toupin, M., etal., J. Power Sources, 140, 203, 2005.)... 

As d is of the order of lnm, the specific capacity is very high, e.g., 0.1 F nr2. Nanoporous carbons are ideal materials for supercapacitor electrodes [8], because of their low cost, good electrical conductivity, and very high specific surface area (between 1000 and 2500 m2 g-1). The values of capacity are generally ranging from 100 to 200 F g 1. 

Viswanathan S, Tokune T. Honda Motor and University Ohio. Functionalized nanotube material for supercapacitor electrodes. WO Patent /2007/047185. 

Toupin M., Brousse T., Belanger D. Influence of microtexture on the charge storage properties of chemically synthesized manganese dioxide, Chem Mater 2002 14 3946-52. Wu N.L. Nanocrystalline oxide supercapacitors. Mater Chem Phys 2002 75 6-11. Frackowiak E., Metenier K., Bertagna V., Beguin F. Supercapacitor electrodes from multiwalled carbon nanotubes. Appl Phys Lett 2000 77 2421-3. 

Despite the limited improvements in material development for supercapacitor electrodes, the specific capacitance and life cycle of the newly developed materials cannot be compared with those of Ru02. 

Vix-Guterl, C., SaadaUah, S., Jurewicz, K., et al. (2004). Supercapacitor electrodes from new ordered porous carbon materials obtained by a templating procedure. Mater. Sci. Eng. B, 108, 148-55. 

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