In a flange in the form of a flat plate inside a bead seal (e.g., fluid passage bead) around a fluid passage (e.g., an oxygen-containing gas supply passage) of a fuel cell metal separator (e.g., a first metal separator), a tunnel is provided in a straight segment adjacent to a curved segment of an inner marginal portion of the flange. The tunnel is formed by expansion in a separator thickness direction.

Various embodiments include fuel cell interconnects having a fuel distribution portion having an inlet opening, a fuel collection portion having an outlet opening, and a primary fuel flow field containing channels, wherein the fuel distribution portion comprises at least one raised feature defining a fuel distribution flow path, and the fuel distribution flow path is not continuous with the channels in the primary fuel flow field. The at least one raised feature may include, for example, a network of ribs and/or dots. Further embodiments include interconnects having a fuel distribution portion with a variable surface depth to provide variable flow restriction and/or a plenum with variable surface depth and raised a raised relief feature on the cathode side, and/or varying flow channel depths and/or rib heights adjacent a fuel hole.

A unit cell for a fuel cell is provided. The unit cell includes an insert including a Membrane-Electrode Assembly having a first pair of electrode layers formed on a first surface of a polymer electrolyte membrane and a second pair of electrode layers formed on a second surface of the polymer electrolyte membrane, an elastomer frame bonded at a rim of the insert in an outer area of the insert, the elastomer frame having a reaction surface through-hole in which the insert is disposed formed therein and having a plurality of frame manifold through-holes, through which a reactant gas can flow or be discharged, formed at both sides of and spaced apart from the reaction surface through-hole, and a pair of separators, each separator disposed on a respective side of the insert and the elastomer frame.

A unit cell for a fuel cell is provided. The unit cell includes an insert including a Membrane-Electrode Assembly having a first pair of electrode layers formed on a first surface of a polymer electrolyte membrane and a second pair of electrode layers formed on a second surface of the polymer electrolyte membrane, an elastomer frame bonded at a rim of the insert in an outer area of the insert, the elastomer frame having a reaction surface through-hole in which the insert is disposed formed therein and having a plurality of frame manifold through-holes, through which a reactant gas can flow or be discharged, formed at both sides of and spaced apart from the reaction surface through-hole, and a pair of separators, each separator disposed on a respective side of the insert and the elastomer frame.

A fuel cell includes a fuel cell stack having a stacked body with a plurality of stacked unit cells, an end plate unit, and a gas manifold penetrating the stacked body and the end plate unit in a stacking direction for a flow of reaction gas. The fuel cell also includes a valve that is provided between the end plate unit and gas piping and includes an in-valve flow path for communicating the gas manifold and the gas piping and a valve element. The gas manifold includes a stacked body manifold and an end plate unit flow path. When the fuel cell stack is arranged so that a manifold bottom portion is horizontal, a bottom portion of an opening on the valve side in the end plate unit flow path is arranged above the manifold bottom portion.

A fuel cell includes a fuel cell stack having a stacked body with a plurality of stacked unit cells, an end plate unit, and a gas manifold penetrating the stacked body and the end plate unit in a stacking direction for a flow of reaction gas. The fuel cell also includes a valve that is provided between the end plate unit and gas piping and includes an in-valve flow path for communicating the gas manifold and the gas piping and a valve element. The gas manifold includes a stacked body manifold and an end plate unit flow path. When the fuel cell stack is arranged so that a manifold bottom portion is horizontal, a bottom portion of an opening on the valve side in the end plate unit flow path is arranged above the manifold bottom portion.

A fuel flow groove formed in a fuel electrode current collector of a fuel electrode of a fuel cell includes a plurality of flow groove portions disposed in parallel, and a plurality of return groove portions connecting an end portion of one side edge portion or an end portion of the other side edge portion of the flow groove portions of two adjacent groups. Each of the return groove portions has an inner wall surface portion facing the end portion of the flow groove portions in the return groove portions. The inner wall surface portion has a curved surface shape in which a distance facing each other from the inner wall surface portion to the end portion of the flow groove portions, gradually decreases toward both end portions of the inner side wall surface portion in a direction orthogonal to an extending direction of the flow groove portions.

A fuel flow groove formed in a fuel electrode current collector of a fuel electrode of a fuel cell includes a plurality of flow groove portions disposed in parallel, and a plurality of return groove portions connecting an end portion of one side edge portion or an end portion of the other side edge portion of the flow groove portions of two adjacent groups. Each of the return groove portions has an inner wall surface portion facing the end portion of the flow groove portions in the return groove portions. The inner wall surface portion has a curved surface shape in which a distance facing each other from the inner wall surface portion to the end portion of the flow groove portions, gradually decreases toward both end portions of the inner side wall surface portion in a direction orthogonal to an extending direction of the flow groove portions.

The present invention relates to a bipolar plate (100, 200, 403, 405, 407, 409, 500) for a fuel cell, wherein the bipolar plate (100, 200, 403, 405, 407, 409, 500) comprises at least one fluid channel (101, 103, 105, 201, 203, 205, 207, 209, 501) for transporting operating fluids of the fuel cell, wherein the at least one fluid channel (101, 103, 105, 201, 203, 205, 207, 209, 501) comprises an inlet opening for introducing fluid into the at least one fluid channel (101, 103, 105, 201, 203, 205, 207, 209, 501) and an outlet opening for fluid exiting the at least one fluid channel (101, 103, 105, 201, 203, 205, 207, 209, 501), wherein the at least one fluid channel (101, 103, 105, 201, 203, 205, 207, 209, 501) comprises a first region (107, 211, 503) and at least one second region (109, 213, 507), and wherein the at least one second region (109, 213, 503) has a cross-section which is reduced compared to the first region (107, 211, 507) in order to adjust a volumetric flow of fluid which exits the outlet opening.

The present invention relates to a bipolar plate (100, 200, 403, 405, 407, 409, 500) for a fuel cell, wherein the bipolar plate (100, 200, 403, 405, 407, 409, 500) comprises at least one fluid channel (101, 103, 105, 201, 203, 205, 207, 209, 501) for transporting operating fluids of the fuel cell, wherein the at least one fluid channel (101, 103, 105, 201, 203, 205, 207, 209, 501) comprises an inlet opening for introducing fluid into the at least one fluid channel (101, 103, 105, 201, 203, 205, 207, 209, 501) and an outlet opening for fluid exiting the at least one fluid channel (101, 103, 105, 201, 203, 205, 207, 209, 501), wherein the at least one fluid channel (101, 103, 105, 201, 203, 205, 207, 209, 501) comprises a first region (107, 211, 503) and at least one second region (109, 213, 507), and wherein the at least one second region (109, 213, 503) has a cross-section which is reduced compared to the first region (107, 211, 507) in order to adjust a volumetric flow of fluid which exits the outlet opening.