Carbon foam fuel cell components
AssigneeUnited Technologies Corporation
InventorsDonald L. Maricle, Dennis C. Nagle
Life of this patent
Estimating the term…
Abstract
In an electrochemical cell, such as a fuel cell, the gas distribution layer, which is the layer of material disposed directly behind and contiguous with the catalyst layer, is made from gas porous open cell carbon foam. Vitreous carbon foam is preferred. Vitreous carbon foam is extremely corrision resistant to many of the very reactive chemicals which might be used as an electrolyte in a fuel cell, such as phosphoric acid. It also has low electrical resistivity, good thermal conductivity, and can be made very thin and inexpensively. Preferably the cell catalyst layer is applied directly to one surface of the foam layer.
Claims10
In a fuel cell comprising an anode catalyst layer spaced apart from a cathode catalyst layer, the space therebetween adapted to have electrolyte disposed therein, and wherein said fuel cell operates on gaseous reactants, the improvement comprising:
- a gas distribution layer having first and second opposing surfaces, said second surface being in substantially continuous contact with one of said catalyst layers, said gas distribution layer including a first layer of open cell vitreous carbon foam, said foam layer being gas porous, sufficiently thick and including enough pores sufficiently large to permit a substantially free flow of a reactant gas through said pores both perpendicular to and parallel to the planes of said surfaces, said first layer being at least 80% porous;
- and
- a gas impermeable separator layer in substantially continuous contact with said first surface of said gas distribution layer.
In a fuel cell comprising an anode catalyst layer spaced apart from a cathode catalyst layer, the space therebetween adapted to have electrolyte disposed therein, and wherein said fuel cell operates on gaseous reactants, the improvement comprising:
- a gas distribution layer having first and second opposing surfaces, said second surface being in substantially continuous contact with one of said catalyst layers, said gas distribution layer including a first layer of open cell vitreous carbon foam, said foam layer being gas porous, sufficiently thick and including enough pores sufficiently large to permit a substantially free flow of reactant gas through said pores both perpendicular to and parallel to the planes of said surfaces, said first layer being at least 80% porous;
- a hydrophilic reservoir layer, one side thereof being in substantially continuous contact with said first surface of said gas distribution layer;
- a gas impermeable separator layer in substantially continuous contact with the other side of said reservoir layer;
- and
- hydrophilic wicking paths extending from said one catalyst layer through said gas distribution layer to said reservoir layer at select, uniformly distributed locations.
Dependencies are inferred from the claim text.