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MM: Fachverband Metall- und Materialphysik
MM 42: Functional Materials I
MM 42.1: Talk
Thursday, March 17, 2011, 17:45–18:00, IFW B
Correlation of structural properties and electrochemical characteristics of carbon aerogel electrodes — •Volker Lorrmann1, Gudrun Reichenauer1, Vladimir Dyakonov1,2, and Jens Pflaum1,2 — 1Bavarian Center of Applied Energy Research e.V. (ZAE Bayern), 97074 Würzburg — 2Experimental Physics VI, Julius-Maximillians-University of Würzburg, 97074 Würzburg
In electrochemical double-layer capacitors (EDLC) the energy is stored in the electrochemical double-layer interface between the electrode surface and the electrolyte solution. The capacitance of EDLCs and rate capability depend on the porous nanostructure of the electrodes. Carbon aerogels, based on sol-gel derived organic precursors, are promising candidates for EDLC electrodes because of their tunable nanostructure (e.g. pore- and particle size). For the same reason these materials also represent excellent model systems for the investigation of correlations between structural properties and electrochemical characteristics. We prepared carbon aerogel EDLC electrodes with different primary particle sizes using different catalyst concentration in the starting solution. Scanning electron microscopy measurements of the carbons show, that the particle size and hence the interparticular pores are varied between several ten nm up to some µ m. Electrochemical investigation was performed by cyclic voltammetry and impedance spectroscopy in different electrolyte solutions. The relationship between the nanostructure and the electrochemical performance of the carbon aerogel is discussed.