Forschungszentrum Julich Gmbh

Rheinisch-Westfälisch-Technische Hochschule Aachen

Rheinisch-westfalische Technische Hochschule Aachen

Jürgen Mergel

Hendrik Dohle

Detlef Stolten

Birger Fricke

Andrei Kulikovsky

Heinz Schmitz

Thomas Bewer

Helmut Baltruschat

Jan Bringmann

Martin Müller

Tilman Sanders

Dirk Uwe Sauer

Klaus Wippermann

Uwe Sauer

Ayhan Egmen

Anne Bendzulla

Thomas Beckmann

Jan Stalling

Thorsten Wüster

There is provided a method for the activation of a fuel cell. An exemplary method comprises operating the fuel cell entirely or partially at least briefly in an electrolysis regimen during galvanic operation.

Method for electrochemical activation of fuel cells

In low-temperature fuel cells according to prior art, the problem often arises that the diffusion layer of the cathode is filled by water which is permeated or produced on the cathode, such that oxygen can no longer be transported to the catalyst layer of the cathode in a frictionless manner. As a result, said fuel cells are regularly used with a high excess of oxygen in order to reduce the cited transport problems for the oxygen. The inventive fuel cell enables said problem to be solved in that the arrangement of the diffusion layer and the catalyst layer of the cathode is inverted. The diffusion layer, which is embodied in such a way as to also conduct ions, is directly adjacent to the electrolyte membrane. The catalyst layer oriented towards the free cathode space can advantageously directly react with the supplied oxygen without further transport problems. A further advantage lies in the fact that the water produced on the catalyst layer of the cathode and/or permeated by the electrolyte membrane and the diffusion layer can be easily withdrawn via the free cathode space.

Cathode for a direct methanol fuel cell and method for operating the same

In a direct-methanol fuel cell stack with an at least partial circulation () of the fuel, according to the invention a means is arranged in this circulation for reducing the concentration of an undesired byproduct. This means is comprised especially of a further electrochemical cell () to which electric current is applied and which at least partly transforms the byproducts by an electrochemical reduction reaction again to methanol and water. Since the concentration of byproducts is small, the loss in electric current required for the additional reduction reaction has no noticeable effect on the efficiency of the fuel cell stack.

Fuel cell stack with circuit

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Jülich, Germany

Jürgen Mergel