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HL: Fachverband Halbleiterphysik
HL 17: Poster I
HL 17.3: Poster
Montag, 25. Februar 2008, 16:30–19:00, Poster D
Fibre reinforced carbon aerogels for application as electrochemical double layer capacitors — •Henning Lorrmann1, Volker Lorrmann1, Ingo Riedel1,2, Carsten Deibel2, Gudrun Reichenauer1, Matthias Wiener1, and Vladimir Dyakonov1,2 — 1Bavarian Center for Applied Energy Research (ZAE Bayern), Functional Materials for Energy Technology, Am Hubland, D-97074 Würzburg, Germany — 2Experimental Physics VI, Physical Institute, Julius-Maximilians University of Würzburg, Am Hubland, D-97074 Würzburg
Fibre-reinforced carbon aerogels have been prepared from resorcinol-formaldehyde (RF) for application as electrodes in electrochemical storage devices. Fibres allow ambient pressure drying without solvent exchange even for a molar ratio of resorcinol to catalyst as low as five. Accordingly, shrinkage of the precursor-aerogels during drying-process is not critical. Electrochemical properties have been investigated by means of impedance spectroscopy, cyclic voltammetry and galvanostatic charge/discharge cycles. Capacities of up to 200F/g have been reached. The Ragone-plot, calculated from the impedance-data, exhibits high power densities even for high energy densities due to high specific capacitance (energy) as well as low internal resistance (power). N2-sorption measurements reveal large micropore volumes. However, specific surface (area per mass) is relatively low compared to bulk aerogels, as fibers contain little surface. The particle size can be adjusted by variation of the resorcinol-to-catalyst-ratio, whereas the density mainly depends on the ratio of RF to the total mass.