Flow field plates for fuel cells may include an interior region bounded by an interior boundary that contains openings which, when the flow field plates are stacked, form plural headers extending along a fuel cell stack. A flow field may surround the interior boundary. The headers may include headers for fuel, oxidant and coolant for example. The flow field may include elements that direct flow of a reactant in a radial direction and/or in a circumferential direction. A fuel cell stack may be enclosed in a housing that compresses the stack. In some embodiments plural fuel cells are combined in a power unit in which the fuel cell stacks are received within a fuel cell block equipped with a fluid manifolding stack interface that provides fluid interfaces to the headers of the fuel cell stack.

Flow field plates for fuel cells may include an interior region bounded by an interior boundary that contains openings which, when the flow field plates are stacked, form plural headers extending along a fuel cell stack. A flow field may surround the interior boundary. The headers may include headers for fuel, oxidant and coolant for example. The flow field may include elements that direct flow of a reactant in a radial direction and/or in a circumferential direction. A fuel cell stack may be enclosed in a housing that compresses the stack. In some embodiments plural fuel cells are combined in a power unit in which the fuel cell stacks are received within a fuel cell block equipped with a fluid manifolding stack interface that provides fluid interfaces to the headers of the fuel cell stack.

A collector insert is configured to be inserted into a collector of an electrochemical reactor by defining a main conduit therein, which has a cross-sectional area that decreases from a first end to a second end of the main conduit, the collector insert including a connecting wall including a first face adapted to delimit the main conduit and a second face and a plurality of channels, each extending between a first opening located on the first face and a second opening located on the second face, the first openings being distributed along the main conduit and each second opening facing a connection port of the fluid chamber of a respective electrochemical cell when the collector insert is inserted in the collector.

A fuel cell stack is provided comprising membrane electrode assemblies and bipolar plates for supplying the membrane electrode assemblies with operating media and coolant, wherein a first bipolar plate comprises flow pathways having path depths that are different from path depths of corresponding flow pathways of a second bipolar plate. Moreover, a vehicle with a fuel cell system having such a fuel cell stack is provided.

An electrochemical cell stack having a plurality of electrochemical cells stacked along a longitudinal axis. The electrochemical cells include a membrane electrode assembly having an anode plate and a cathode plate with the membrane electrode assembly interposed therebetween. The electrochemical cells also include an anode plate and a cathode plate with the membrane electrode assembly interposed therebetween, and the anode plate defines a plurality of channels that form an anode flow field facing the anode catalyst layer. The electrochemical cells further include a cathode flow field positioned between the cathode plate and the cathode catalyst layer, wherein the cathode flow field comprises a porous structure.

An electrochemical cell stack having a plurality of electrochemical cells stacked along a longitudinal axis. The electrochemical cells include a membrane electrode assembly having an anode plate and a cathode plate with the membrane electrode assembly interposed therebetween. The electrochemical cells also include an anode plate and a cathode plate with the membrane electrode assembly interposed therebetween, and the anode plate defines a plurality of channels that form an anode flow field facing the anode catalyst layer. The electrochemical cells further include a cathode flow field positioned between the cathode plate and the cathode catalyst layer, wherein the cathode flow field comprises a porous structure.

An electrochemical cell includes a porous support substrate and a power generation element portion. The support substrate includes at least one first gas channel and at least one second gas channel. The first gas channel extends from a first end portion toward a second end portion and is connected to a gas supply chamber. The second gas channel is connected to the first gas channel on the second end portion side. The second gas channel extends from the second end portion toward the first end portion and is connected to a gas collection chamber. A ratio (p0/L) of a pitch p0 of a first gas channel and a second gas channel that are adjacent to each other to a distance L between the power generation element portion and a first end surface of the support substrate located on the first end portion side is 3.3 or less.

A fuel cell system includes a first fluid flow plate including a first plurality of first channels for flow of an oxidant or a fuel. The plurality of first channel has first channel cross-sectional flow areas. A second fluid flow plate includes a second plurality of second channels for flow of an oxidant or a fuel. The plurality of second channels has second channel cross-sectional flow areas. A membrane electrode assembly is located between the first plate and the second plate. The first flow plate includes a passage for a flow of a fluid entirely on a seam side of the first flow plate as the first plurality of first channels. The passage has a cross-sectional area for flow of the fluid smaller than the first channel cross-sectional flow area.

A fuel cell stack includes stacked cells, each including a sheet-shaped power generation portion, two separators, a gas passage defining plate that includes a gas passage portion through which reactant gas flows, and a frame member that includes a supply port and a discharge port. The gas passage portion includes opposing portions extended in a flow direction of the reactant gas and arranged in parallel in an orthogonal direction and wavy portions each having a wavy cross- sectional shape orthogonal to the orthogonal direction. The gas passage portion includes a first passage portion adjacent to the supply port in the flow direction and a second passage portion adjacent to the first passage portion in the orthogonal direction. The connection passages of the second passage portion each have a larger cross-sectional flow area than the connection passages of the first passage portion.

A fuel cell stack includes stacked cells, each including a sheet-shaped power generation portion, two separators, a gas passage defining plate that includes a gas passage portion through which reactant gas flows, and a frame member that includes a supply port and a discharge port. The gas passage portion includes opposing portions extended in a flow direction of the reactant gas and arranged in parallel in an orthogonal direction and wavy portions each having a wavy cross- sectional shape orthogonal to the orthogonal direction. The gas passage portion includes a first passage portion adjacent to the supply port in the flow direction and a second passage portion adjacent to the first passage portion in the orthogonal direction. The connection passages of the second passage portion each have a larger cross-sectional flow area than the connection passages of the first passage portion.