Berlin 2012 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 58: Poster Session III (Solid/liquid interfaces; Metals; Semiconductors; Oxides and insulators)

O 58.5: Poster

Mittwoch, 28. März 2012, 18:15–21:45, Poster B

Variations in backbone morphology of MnO_x infiltrated carbon xerogels — •Christian Weber¹, Volker Lorrmann¹, Gudrun Reichenauer¹, and Jens Pflaum^1,2 — ¹Bavarian Center for Applied Energy Research e.V. (ZAE Bayern), D-97074 Würzburg — ²Julius-Maximilians-University of Würzburg, Institute of Physics, Experimental Physics VI, D-97074 Würzburg

Electrochemical capacitors (EC) bridge the gap between conventional capacitors with high power but low energy density and batteries with high specific energy density but rather low power density. In this contribution we analyzed hybrid capacitor structures relying on charge storage by the electrochemical double-layer between electrolyte and porous carbon electrode and an additional pseudocapacitance caused by redox processes of manganese oxide (MnO_x) with the electrolyte’s ions. Variations in the structure of the carbon xerogel backbone and the amount of deposited MnO_x were characterized electrochemically and structurally. From MnO_x-mass uptake and its correlation with carbon particle size, we can conclude that the deposition of MnO_x preferably takes place on the external surface area of the carbon particles. As the amount of deposited MnO_x scales with the external surface area, a thinner layer will provide a more efficient use of the active material and lead to better electrode performance.

Financial support by Deutsche Bundesstifung Umwelt is thankfully acknowledged.