Siemens Aktiengesellschaft

Ballard Power Systems Corporation

Behr Gmbh Co. Kg

Wolfram Kaiser

Robert Fleck

Richard Spaeh

Joerg Wind

Markus Watzlawski

Detlev Repenning

The invention relates to a metal bipolar plate for a fuel cell, provided with a low-ohmic chemically stable coating. According to the invention, said coating is a multi-phase coating, at least in the region of the contacting outer surface thereof. One phase is a metal phase and/or &#x3b1; phase belonging thereto and another phase is a compound phase consisting of one or several metals of the metal phase and one of the elements N,O,C,B.

Metal bipolar plate

In a high-temperature fuel cell, the problem exists that a series electrical resistance rises while the high-temperature fuel cell is operating. This rise is caused by oxidation of the fuel-gas-side surface of the bipolar plate. Oxidation of this nature is largely suppressed by an oxidation buffer that is disposed in the fuel gas chamber and takes up the oxygen.

High-temperature fuel cell

During operation of a high-temperature fuel cell the problem of corrosion of the interconnector on the anode side arises. Accordingly, this problem is substantially prevented by use of at least two metallic functional layers that are applied one above the other on the interconnector. A lower functional layer contains copper and an upper functional layer contains nickel. Functional layers of this type construct a potential threshold for oxygen ions toward the interconnector.

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Bonndorf, Germany

Wolfram Kaiser