Gm Global Technolgoy Operations, Inc.

James H Lee

George R Woody

James S Siepierski

Brian K Brady

Robert L Fuss

Glenn William Skala

Stephan Fell

Martin Wohr

Werner Lehnert

A fuel cell or electrochemical cell has a catalytic electrode and an electrically conductive contact element facing the electrode. The electrically conductive contact element conducts electrical current from the electrode and has a surface that includes a plurality of passivated regions and a plurality of non-passivated regions dispersed among the passivated regions. The surface is further coated with an electrically conductive, corrosion resistant coating. Methods include treating the electrically conductive contact element by passivation to resist corrosion while still maintaining electrical conductivity of the element.

Corrosion resistant plate for PEM fuel cell and methods of making same

A fuel cell system and process using an organic Rankine cycle to produce shaft work to operate a fuel cell system component such as an air compressor. The air compressor delivers compressed air to a fuel cell stack. The steps of the Rankine cycle include pumping a liquid working fluid to an elevated pressure, heating the fluid to a gas, expanding the high temperature and high-pressure gas through an expander to produce shaft work used to drive a fuel cell system component such as an air compressor, and then removing energy from the cooling fluid to change the gas back to a liquid, and repeating the cycle. The liquid fluid can be heated by an external boiler, or one of the components of the fuel cell system such as the combustor and/or the fuel cell stack.

Cogeneration system for a fuel cell

A bipolar plate assembly is provided for use in a fuel cell stack to supply reactants to the anode and cathode sides of fuel cells within the stack. The bipolar plate assembly includes first and second sub-plates, each including a first face surface having a coolant flow field formed therein and a second face surface having a reactant flow field formed therein. The coolant fields of the first and second sub-plates include regions of varying flow volume, having respective flow resistance therebetween. The regions of varying flow volume enable variable cooling across the fuel cell stack, thereby enabling a constant temperature to be achieved across the fuel cell stack.

Coolant flow field design for fuel cell stacks

The present invention relates to an electrochemical cell having a catalytic electrode and an electrically conductive contact element facing the electrode. The electrically conductive contact element conducts electrical current from the electrode and has a surface comprising a plurality of passivated regions, and a plurality of non-passivated regions dispersed among the passivated regions. The surface further is coated with an electrically conductive, corrosion resistant coating. Other preferred aspects of the present invention include methods of treating the electrically conductive contact element by passivation to resist corrosion while still maintaining electrical conductivity.

Corrosion resistant PEM fuel cell

A fuel cell cooling system is provided with a coolant pump for pumping fluid through coolant flow field passages in a fuel cell stack. A pressure control mechanism is provided for maintaining a pressure level within the fuel cell stack for causing a phase change of the coolant within the stack. Allowing the coolant to change phase to a gas inside the stack reduces the amount of coolant needed to cool the fuel cell stack and thereby reduces the energy needed to pump the coolant through the fuel cell stack.

Cooling system for a fuel cell stack

A fuel cell arrangement consisting of several fuel cells, arranged at least essentially in parallel, with cooling gaps formed between neighboring cells extending between an inlet and an outlet and through which a coolant flows, characterized by the fact that the specific surface, i.e. the area of the cooling surfaces emitting heat to the coolant, increases in the direction from the inlet to the outlet and/or that the local heat transfer coefficient of the cooling areas emitting heat to the coolant increases in the direction of flow from the inlet to the outlet and/or that the support materials of the fuel cells, i.e. the membrane-electrode assemblies, exhibit a coefficient of thermal conductivity above 200 W/(m&middot;K). In this way, a uniform temperature in the fuel cells can be assured to that the power density can be increased while avoiding hot spots and/or the service life can be increased.

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Rochester, NY, United States of America

James H Lee