An electrolyzer or unitized regenerative fuel cell has a flow field with at least one channel, wherein the cross-sectional area of the channel varies along at least a portion of the channel length. In some embodiments the channel width decreases along at least a portion of the length of the channel according to a natural exponential function. The use of this type of improved flow field channel can improve performance and efficiency of operation of the electrolyzer device.

A fuel cell gas supply and diffusion layer includes a sheet-like porous body layer, and a plurality of gas passage grooves formed on one surface of the porous body layer in parallel and formed in a zigzag shape or a wave shape respectively. As viewed in a plan view, a first rectangular region where circumscribes one gas passage groove and a second rectangular region where circumscribes a gas passage groove adjacent to the one gas passage groove overlap along a region in contact each other. An overlapping region where the first rectangular region and the second rectangular region overlap exists at any depth position of the grooves. According to the fuel cell gas supply and diffusion layer, it is possible to increase a power generation efficiency of a fuel cell.

A separator for a fuel cell includes a separator base, crest sections, and trough sections. Regions surrounded by the respective trough sections and a corresponding electrode layer each constitute a passage that supplies oxidation gas or fuel gas to the electrode layer. A thin film having conductivity is placed at least on the top surface of each crest section. The thin film on the top surface of each crest section has a groove that connects the passages on the opposite sides of the crest section to each other. Each trough section has a flow resistance increasing portion on the downstream side of the groove in the flow direction of the gas. The flow resistance increasing portion reduces the cross-sectional flow area of the passage such that the cross-sectional flow area at the flow resistance increasing portion is smaller than that at the section to which the groove is connected.

The present disclosure relates to a fuel cell bipolar plate including a substrate. A surface of the substrate defines a first flow channel and a second flow channel adjacent to the first flow channel. A rib is formed between the first flow channel and the second flow channel. A top surface of the rib defines a groove or a second bore. One or both of the first flow channel and the second flow channel is in fluid communication with the groove or the second bore.

The present disclosure relates to a fuel cell bipolar plate including a substrate. A surface of the substrate defines a first flow channel and a second flow channel adjacent to the first flow channel. A rib is formed between the first flow channel and the second flow channel. A top surface of the rib defines a groove or a second bore. One or both of the first flow channel and the second flow channel is in fluid communication with the groove or the second bore.

Fuel cell assemblies comprising at least one thermally compensated coolant channel are provided. The thermally compensated coolant channel has a cross-sectional area that decreases in the coolant flow direction along at least a portion of the channel length. In some embodiments, such thermally compensated coolant channels can be used to provide substantially uniform heat flux, and substantially isothermal conditions, in fuel cells operating with substantially uniform current density.

Fuel cell assemblies comprising at least one thermally compensated coolant channel are provided. The thermally compensated coolant channel has a cross-sectional area that decreases in the coolant flow direction along at least a portion of the channel length. In some embodiments, such thermally compensated coolant channels can be used to provide substantially uniform heat flux, and substantially isothermal conditions, in fuel cells operating with substantially uniform current density.

The present disclosure provides a separator for a fuel cell, including a central part with a rectangular shape, and a surrounding part disposed to surround the central part, wherein the surrounding part includes an outlet manifold positioned at a pair of edges of the central part, which are opposed each other, and an inlet manifold positioned along a side of the central part to be adjacent to another edge except for the pair of edges at which the outlet manifold is positioned, and the central part includes a plurality of guide patterns that are spaced apart from each other to guide fluids introduced through the inlet manifold toward the outlet manifold.

An illustrative example fuel cell cooler plate includes a first side configured to be received adjacent a fuel cell component and a second side facing opposite the first side. The first side defines a first surface area of the plate. An edge is transverse to the first side and the second side. The edge has a surface area that is less than the first surface area. A first coolant passage within the plate is closer to the second side than the first side. A second coolant passage is between the first side and the first coolant passage. The second coolant passage is in a heat exchange relationship with the first coolant passage.

An illustrative example fuel cell cooler plate includes a first side configured to be received adjacent a fuel cell component and a second side facing opposite the first side. The first side defines a first surface area of the plate. An edge is transverse to the first side and the second side. The edge has a surface area that is less than the first surface area. A first coolant passage within the plate is closer to the second side than the first side. A second coolant passage is between the first side and the first coolant passage. The second coolant passage is in a heat exchange relationship with the first coolant passage.