Abstract: An electrochemical fuel cell stack with improved reactant manifolding and sealing includes a pair of separator plates interposed between adjacent membrane electrode assemblies. Passageways fluidly interconnecting the anodes to a fuel manifold and interconnecting the cathodes to an oxidant manifold are formed between adjoining non-active surfaces of the pairs of separator plates. The passageways extend through one or more ports penetrating the thickness of one of the plates thereby fluidly connecting the manifold to the opposite active surface of that plate, and the contacted electrode. The non-active surfaces of adjoining separator plates in a fuel cell stack cooperate to provide passageways for directing both reactants from respective stack fuel and oxidant supply manifolds to the appropriate electrodes. The fuel and oxidant reactant streams passageways are fluidly isolated from each other, although they both traverse adjoining non-active surfaces of the same pair of plates.

Abstract: An electrochemical fuel cell stack with improved reactant man folding and sealing includes a pair of separator plates interposed between adjacent membrane electrode assemblies. Passageways fluidly interconnecting the anodes to a fuel manifold and interconnecting the cathodes to an oxidant manifold are formed between adjoining non-active surfaces of the pairs of separator plates. The passageways extend through one or more ports penetrating the thickness of one of the plates thereby fluidly connecting the manifold to the opposite active surface of that plate, and the contacted electrode. The non-active surfaces of adjoining separator plates in a fuel cell stack cooperate to provide passageways for directing both reactants from respective stack fuel and oxidant supply manifolds to the appropriate electrodes. The fuel and oxidant reactant streams passageways are fluidly isolated from each other, although they both traverse adjoining non-active surfaces of the same pair of plates.

Abstract: An electrochemical fuel cell stack with improved reactant man folding and sealing includes a pair of separator plates interposed between adjacent membrane electrode assemblies. Passageways fluidly interconnecting the anodes to a fuel manifold and interconnecting the cathodes to an oxidant manifold are formed between adjoining non-active surfaces of the pairs of separator plates. The passageways extend through one or more ports penetrating the thickness of one of the plates thereby fluidly connecting the manifold to the opposite active surface of that plate, and the contacted electrode. The non-active surfaces of adjoining separator plates in a fuel cell stack cooperate to provide passageways for directing both reactants from respective stack fuel and oxidant supply manifolds to the appropriate electrodes. The fuel and oxidant reactant streams passageways are fluidly isolated from each other, although they both traverse adjoining non-active surfaces of the same pair of plates.

Abstract: An electrochemical fuel cell stack with improved reactant manifolding and sealing includes a pair of separator plates interposed between adjacent membrane electrode assemblies. Passageways fluidly interconnecting the anodes to a fuel manifold and interconnecting the cathodes to an oxidant manifold are formed between adjoining non-active surfaces of the pairs of separator plates. The passageways extend through one or more ports penetrating the thickness of one of the plates thereby fluidly connecting the manifold to the opposite active surface of that plate, and the contacted electrode. The non-active surfaces of adjoining separator plates in a fuel cell stack cooperate to provide passageways for directing both reactants from respective stack fuel and oxidant supply manifolds to the appropriate electrodes. The fuel and oxidant reactant streams passageways are fluidly isolated from each other, although they both traverse adjoining non-active surfaces of the same pair of plates.

Abstract: An electrochemical fuel cell assembly comprises a pair of separator layers and a membrane electrode assembly interposed between the separator layers. The membrane electrode assembly comprises a pair of electrodes and an ion exchange membrane interposed therebetween, the electrodes having electrocatalyst associated therewith defining an electrochemically active area. Each of the separator layers comprises one or more reactant stream passages in fluid communication with one of the electrodes. At least one of the separator layers further comprises one or more coolant stream passages which do not superpose the electrochemically active area of the adjacent membrane electrode assembly, and are fluidly isolated from the reactant stream passages.

Abstract: A fuel cell assembly within an electrochemical fuel cell stack has a cooling jacket disposed adjacent the cathode layer. The cooling layer comprises a coolant stream inlet, a coolant stream outlet, and at least one channel for directing a coolant stream from the coolant stream inlet to the coolant stream outlet. The coolant stream channels extend such that the coolest region of the cooling layer substantially coincides with the region of the adjacent cathode layer having the highest concentration of oxygen (and also the lowest water content), and the warmest region of the cooling layer substantially coincides with the region of the adjacent cathode layer having the lowest concentration of oxygen (and also the highest water content).

Abstract: A fluid manifold assembly for an array of electrochemical fuel cell stacks has a substantially fluid impermeable housing. Inlet passages are formed within the housing for introducing at least one inlet fluid stream to each of the fuel cell stacks. Outlet passages are formed within the housing for exhausting at least one outlet fluid stream from each of the fuel cell stacks.

Abstract: An electrochemical fuel cell stack has a humidification section located upstream from the electrochemically active section. The inlet fuel and oxidant streams are introduced into the humidification section without first being directed through the electrochemically active section. The upstream location of the humidification section in the stack enables the number of manifold openings in the active section to be reduced, thereby increasing the area available for the electrochemical reaction.

Abstract: A membrane electrode and seal assembly for an electrochemical fuel cell comprises first and second layers of porous electrically conductive sheet material, such as carbon fiber paper. The sheet material layers have a solid polymer ion exchange membrane interposed therebetween. The sheet material layers cover and support the membrane over substantially its entire surface area. The sheet material layers are coated with a catalyst to render them electrochemically active, and are bonded together with the membrane to form a consolidated assembly. Openings are formed in the layers of sheet material and the membrane to accommodate the passage of fluids through the assembly. Channels formed in the layers of sheet material generally circumscribe the openings and the electrochemically active region of the sheet material. Solid preformed gaskets are disposed in the channels. The gasketing technique can also be applied to the membrane and seal assemblies of the humidification portion of fuel cell stacks.

Abstract: A coolant flow field plate for use in association with a solid polymer fuel cell comprises, in a major surface, a coolant inlet, a coolant outlet, at least one coolant distribution channel in fluid communication with the coolant inlet and disposed near the perimeter of the plate. At least one central exhaust channel extends along a diagonal of the coolant flow field plate. The central exhaust channel is proximate to the center of the plate and in fluid communication with the coolant outlet. A plurality of coolant flow channels extend from the coolant distribution channels to the central exhaust channel. In the preferred embodiment, the coolant flow channels form a rib-cage pattern with the central exhaust channel. The coolant flow field plate is designed to increase the lifetime of solid polymer fuel cells by imposing lower temperatures near the periphery of the cell plates, and thereby protect the integrity of the seal where the reactant gases are sealed against external leakage.