Supercapacitors oxide-based

Jiang J, Kucemak A. Electrochemical supercapacitor material based on manganese oxide preparation and characterization. Electrochim. Acta 2002 47 2381-6. 

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. 

Fig. 5.4 Supercapacitor cell assembly, a Schematic illustration of the supercapacitor design based on two laterally offset double-gyroid structured electrodes, b Photograph of a fully transparent electrochromic supercapacitor consisting of an oxidized yellow top electrode, a laterally offset green/gray bottom electrode in the reduced state...

Wei, W, Cui, X., Chen, W, Ivey, D.G., 2011. Manganese oxide-based materials as electrochemical supercapacitor electrodes. Chem. Soc. Rev. 40,1697-1721. 

Yuan, C., L. Hou, D. Li, Y. Zhang, S. Xiong, and X. Zhang. 2013. Unusual electrochemical behavior of Ru-Cr binary oxide-based aqueous symmetric supercapacitors in KOH solution. Electrochimica Acta 88 654-658. 

Sun, D., X. Yan, J. Lang, and Q. Xue. 2013. High performance supercapacitor electrode based on graphene paper via flame-induced reduction of graphene oxide paper. Journal... 

Zhang, Q., K. Scrafford, M. T. Li et al. 2014. Anomalous capacitive behaviors of graphene oxide based solid-state supercapacitors. Nano Letters 14 1938-1943. 

Metal-oxide-based supercapacitors are characterized by a chemical reaction at the surface of the electrodes. This causes a charge transfer (pseudo-capacitance). The most widely-used metal oxide is ruthenium dioxide (RUO2). This technology uses H2SO4 as the electrolyte and presents a very low internal resistance. However, the very high cost of metal oxides restricts their use to mihtary or space apphcations. 

Metal oxide-based materials, carbon materials, and conducting polymers for electrochemical supercapacitor electrodes have been reviewed in detail (6). Two important future research directions have been summarized The development of composite and nano-structured electrochemical supercapacitor materials to overcome the problem of low energy density of electrochemical supercapacitors. 

Recently supercapacitors are attracting much attention as new power sources complementary to secondary batteries. The term supercapacitors is used for both electrochemical double-layer capacitors (EDLCs) and pseudocapacitors. The EDLCs are based on the double-layer capacitance at carbon electrodes of high specific areas, while the pseudocapacitors are based on the pseudocapacitance of the films of redox oxides (Ru02, Ir02, etc.) or redox polymers (polypyrrole, polythiophene, etc.). 

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