Gm Global Technolgoy Operations, Inc.

Ilona Busenbender

Youssef Morcos Mikhail

Gayatri Vyas

Hubert Gasteiger

In one aspect a substrate such as a sheet metal product, in particular for use as a bipolar plate in a fuel cell or in an electrolyzer, is characterized in that it has, on at least one side, a conductive and corrosion-resistant protective coating of a metal oxide having a treatment which ensures the conductivity. The coating can be produced by introducing a piece of sheet metal into a coating plant and providing it with the conductive and corrosion-resistant protective coating of the metal oxide. In another aspect, an electrochemical cell such as a fuel cell comprises an electrically conductive contact element having a first surface facing an electrode for conducting electrical current, and the contact element comprises an electrically conductive substrate and an electrically conductive coating comprising a doped metal oxide, desirably a doped tin oxide, and preferably a fluorine doped tin oxide.

Electrical contact element and bipolar plate

A fuel cell system with flow passages and/or flow chambers which conduct moist gases in operation is characterized in that at least a part of the flow passages and/or flow chambers is provided with a coating which takes up water in distributed form at low temperatures and releases the water again at least in part at higher temperatures. This coating makes it possible to operate the fuel cell system at pronounced temperatures below zero, such as, for example, &#x2212;40&#xb0; C., and to ensure an adequate humidification of the operating gases, which protects the membranes from damage and favors a faster starting up of the fuel cell system.

Fuel cell with a device for storing water

A method and apparatus for the operation of a fuel cell system to avoid the freezing of water resident in one or more fuel cells during periods of system inactivity. Each fuel cell includes at least an anode, a cathode and a membrane configured to establish electrolyte communication between reaction products formed at the anode and cathode. During fuel cell system operation, a portion of the water formed remains within the fuel cell; to avoid having the water freeze and inhibit subsequent system operation, a chemical compound introduced into the fuel cells mixes with the water still resident within the fuel cell to lower the temperature upon which the onset of water freezing occurs. The chemical compound can be introduced alone under pressure in the vapor phase, or in combination with the fuel, the incoming oxygen or an inert gas. In addition, system is configured such that the chemical compound can be introduced at numerous different locations.

Method of operating a fuel cell system

A method and apparatus for the operation of a fuel cell system to avoid the freezing of water resident in one or more fuel cells during periods of system inactivity. Each fuel cell includes at least an anode, a cathode and a membrane configured to establish electrolyte communication between reaction products formed at the anode and cathode. During fuel cell system operation, a portion of the water formed remains within the fuel cell; to avoid having the water freeze and inhibit subsequent system operation, a chemical compound introduced into the fuel cells mixes with the water still resident within the fuel cell to lower the temperature upon which the onset of water freezing occurs. The chemical compound can be introduced alone under pressure in the vapour phase, or in combination with the fuel, the incoming oxygen or an inert gas. In addition, system is configured such that the chemical compound can be introduced at numerous different locations.

Fuel cell system and method of operation in which temperatures in the freezing range of water can occur

A fuel cell system with flow passages and/or flow chambers which conduct moist gases in operation is characterized in that at least a part of the flow passages and/or flow chambers is provided with a coating which takes up water in distributed form at low temperatures and releases the water again at least in part at higher temperatures. This coating makes it possible to operate the fuel cell system at pronounced temperatures below zero, such as, for example, &minus;40&deg; C., and to ensure an adequate humidification of the operating gases, which protects the membranes from damage and favors a faster starting up of the fuel cell system.

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Rheinbreitbach, Germany

Ilona Busenbender