Occidental Chemical Corporation

Pierre Fauvel

Bernard Warszawski

Sylvain Dupre

Bernard Warzawski

Jean Arlie

Fuel cell with improved separation

A single fuel cell (20) is built up from a plurality of plane members (21, 32, 42, 24). A plurality of such cells are stacked together to constitute a fuel cell structure. Each fuel cell in the structure requires access to three independent fluid circuits: an electrolyte circuit including an inlet orifice (88A, 98A) and an outlet orifice (88B, 98B); a gas fuel circuit including inlet and outlet orifices (108); and an oxidant circuit which may be constituted by inlets and outlets in communication with ambient air. In the final structure, these circuits must be effectively sealed from one another and from the surroundings (except for the special case of ambient air oxidant). This invention improves such sealing by preventing unwanted seepage between adjacent ones of the plane members (21, 32, 42, 24) due to defects in planeness and parallelism of the individual plane members. This is done by surrounding an area to be sealed off from another area by at least one rib which stands proud of the surface of the associated plane member and which is associated with at least one groove. When the stack is assembled the ribs are ideally deformed and received in the associated grooves, but in the vicinity of non-ideal portions of the plane members the ribs serve to block gaps through which the fluids would otherwise pass.

Fuel cell structures

The fuel cell structure is constituted by a plurality of cells disposed in electrical contact with one another, each cell comprising two porous electrodes, an electrolyte filling the gap between the said electrodes, and two impermeable bipolar current collectors. The bottom and top portions of the collectors (23) are provided on both faces thereof with grooves or hollows enabling the anode face of the collectors to be supplied with fuel and the cathode face to be supplied with oxidant. Elongate ribs (39, 37, 38) constitute distribution channels (35, 36) for the gas flows, the said channels supplying channels which run over the central conductive zones (24) of the collectors substantially vertically.

The fuel cell structure is constituted by a plurality of cells disposed in electrical contact with one another, each cell comprising first and second porous electrodes (1,2), an electrolyte filling the gap between the said electrodes and two impermeable bipolar current collectors. The electrodes are pressed against opposite faces of a frame (3) having a central orifice (4). One face (10) of the frame includes first and second grooves (11) for conveying electrolyte from an inlet orifice (8A) to a distributing manifold (12) which is in communication with the electrolyte chamber, and for conveying electrolyte away from the electrolyte chamber to an exit orifice (8B). The electrolyte distribution network on the frame (3) is sealed by a thin film (15) which extends over said network and which is fixed to the frame, that one of the electrodes (1) which overlaps the said film (15) being fixed thereto.

The fuel cell structure is constituted by a plurality of cells disposed in electrical contact with one another, each cell comprising two porous electrodes, an electrolyte filling the gap between the said electrodes, and two impermeable bipolar current collectors. One of the electrodes (2) is pressed against a frame (3) having a central orifice (4). One face of the said frame (3) includes grooves (11) for conveying electrolyte from an inlet orifice (8A) to a distribution manifold (12) which is in communication with the electrolyte compartment, and also for conveying electrolyte from the central compartment to an outlet orifice (8B). The electrolyte conveying network on the frame (3) is sealed by means of a second frame (55) made of insulating material and pressed over the said network. The frames are fixed together.

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Limours, France

Pierre Fauvel