Abstract: A fuel cell stack includes stacked single cells. The single cells each include a power generation portion and a pair of a first separator and a second separator. The first separator includes first passages. The first passages each include first reversal portions and first general portions. The second separator includes second passages. The second passages each include second reversal portions and second general portions. The first reversal portions of the first passages each extend to increase a flow resistance of a cooling medium flowing through a part of a cooling medium flow region that corresponds to the first reversal portion. The second reversal portions of the second passages each extend to increase the flow resistance of the cooling medium flowing through a part of the cooling medium flow region that corresponds to the second reversal portion.

Abstract: A separator for a fuel cell includes multiple gas passages arranged side by side on a facing surface, and multiple cooling passages provided on a cooling surface. Each cooling passage is located between adjacent ones of the gas passages. The gas passages include multiple upstream passages arranged side by side, a merging portion, and a downstream passage that extends from the merging portion. The cooling surface includes a downstream end portion and a groove. The downstream end portion is a section in one of the cooling passages. The section is located between adjacent ones of the upstream passages and at an end portion of the cooling passage on a downstream side in a flow direction of the coolant. The groove connects the downstream end portion to another one of the cooling passages that is adjacent to the downstream end portion with one of the gas passages in between.

Abstract: A fuel cell stack includes stacked cells. Each of the cells includes a plastic support frame that supports a membrane electrode assembly at a central portion of the support frame, and includes two separators that sandwich the support frame. The support frame and the two separators each have a through-hole that defines a passage through which fluid flows. An outer surface of each of the two separators in the stacking direction includes a rib. The rib protrudes from an outer edge of the separator and from a peripheral edge of the through-hole of the separator. A shape of the rib on one of the two separators is different from a shape of the rib on the other one of the two separators.

Abstract: A fuel cell stack includes stacked cells. Each cell includes a plastic support frame member that supports a membrane electrode assembly, and includes two separators that sandwich the support frame member. The support frame member and the two separators each have a through-hole that extends in a stacking direction of the cells and define a passage through which fluid flows. The support frame member includes a protrusion that protrudes from each separator in at least one of an outer edge of the support frame member and a peripheral edge of the through-hole. The protrusion is sandwiched by plastic frames in the stacking direction together with outer edges of the separators, peripheral edges of the through-holes of the separators, or both the outer edges and the peripheral edges.

Abstract: A separator for a fuel cell includes multiple main passages configured to face a power generating unit and allow reactant gas to flow through the main passages, a supply-side manifold hole configured to supply the reactant gas toward the main passages, a discharge-side manifold hole configured to discharge the reactant gas from the main passages, multiple supply-side connecting passages that connect the supply-side manifold hole and the main passages to each other, and multiple discharge-side connecting passages that connect the discharge-side manifold hole and the main passages to each other. At least one of the supply-side connecting passages and the discharge-side connecting passages has a protrusion that protrudes toward the power generating unit, the protrusion being partially provided in an extending direction of the connecting passage.

Abstract: A fuel cell stack includes power generation cells, which are stacked in a vertical direction. Each power generation cell is configured to generated power by using gas. Each power generation cell includes a first hole and a second hole. The first holes of the power generation cells form a gas manifold. The gas manifold extends in the vertical direction, and the gas flows through the gas manifold. The second holes of the power generation cells form a passage. The passage is adjacent to the gas manifold and extends in the vertical direction. The gas manifold and the passage are connected to each other at upper ends of the gas manifold and the passage.

Abstract: A fuel cell stack includes power generation cells stacked in a vertical direction and a discharge passage defining member extending in the vertical direction. Each of the power generation cells includes a gas hole. The gas holes of the power generation cells define a gas manifold which extends in the vertical direction and through which gas flows. Part of an upper wall surface of the gas manifold includes a water collection portion configured to collect water from the upper wall surface. The discharge passage defining member is located below the water collection portion of the gas manifold and defines a discharge passage out of which the water dropping from the water collection portion is discharged.

Abstract: A fuel cell stack includes a stack main body including stacked single cells, and sensing terminals made of metal. Two surfaces facing each other in any adjacent two of the single cells are respectively defined as a first facing surface and a second facing surface. The first facing surface is a surface of the first separator of one of the two single cells. The second facing surface is a surface of the second separator of the other single cell. The first facing surface is provided with at least one first engagement portion. Each sensing terminal includes a base portion, an arm portion, and at least one second engagement portion that is engaged with the at least one first engagement portion of the first facing surface. The arm portion is in contact with the second facing surface while being elastically deformed toward the first facing surface.

Abstract: A fuel cell stack includes stacked single cells. Each single cell includes a power generating unit, a first separator, and a second separator. The first separator includes a facing surface that faces the power generating unit. The facing surface includes first groove passages. The first groove passages include first main passages and first auxiliary passages. The second separator includes a facing surface that faces the power generating unit. The facing surface includes second groove passages. The second groove passages include second main passages and second auxiliary passages. Extending portions of at least one of a set of the first auxiliary passages or a set of the second auxiliary passages include a wavy section. The wavy section intersects with one of the extending portions of the other one of the set of the first auxiliary passages and the set of the second auxiliary passages with the power generating unit in between.

Abstract: A single cell for a fuel cell includes a power generating unit and two separators that hold the power generating unit in between. Each separator includes a facing surface, which faces the power generating unit. Each facing surface includes groove passages and ribs. Each of the ribs includes a top wall portion, two side wall portions, and corner portions. The top wall portion is in contact with the power generating unit. The side wall portions are located at the opposite sides of the top wall portion. Each corner portion is located between the top wall portion and one of the side wall portions. A restricting portion is provided at a section of each corner portion that faces the groove passage. The restricting portion restricts the gas diffusion layer from sinking into the groove passage. The restricting portion is a conductive porous body.

Abstract: A fuel cell stack includes single cells stacked in a first direction. Each single cell includes a power generating unit, a first separator, and a second separator. The first separator and the second separator hold the power generating unit between the first separator and the second separator. The first separator of each single cell includes first protrusions that protrude toward the second separator of another single cell that is adjacent in the first direction. The first protrusions are in contact with the second separator. Each of the first protrusions includes a top wall portion and two side wall portions. At least one of the two side wall portions includes a step portion having a shape of a step in the first direction.

Abstract: A fuel cell stack includes single cells stacked in a first direction. Each single cell includes a power generating unit, a first separator, and a second separator. The first separator and the second separator hold the power generating unit between the first separator and the second separator. The first separator of each single cell includes first protrusions. The second separator of each single cell includes second protrusions. A distal end of each second protrusion includes a depression that is located at a center in a second direction and extends in a third direction. A length of the depression in the second direction is greater than a length of the first protrusion in the second direction. A distal end of each first protrusion is located inside the depression.

Abstract: A separator for a fuel cell includes a facing surface configured to face a power generating unit of the fuel cell. Groove passages are arranged side by side in the facing surface. Reactant gas flows through the groove passages. Ribs, which are located between the groove passages and protrude toward the power generating unit, are provided on the facing surface. At least one of the ribs includes at least one protrusion that protrudes toward the power generating unit.

Abstract: A separator for a fuel cell includes a contact surface. Groove passages are arranged side by side in the contact surface. The groove passages include a first groove passage and a second groove passage that are adjacent to each other in an arrangement direction of the groove passages. The contact surface includes a rib located between the first groove passage and the second groove passage. The rib includes at least one wide section. The first groove passage includes at least one first contiguous section that is adjacent to the at least one wide section. The second groove passage includes at least one second contiguous section that is adjacent to the at least one wide section. A cross-sectional flow area of the first contiguous section is less than a cross-sectional flow area of the second contiguous section.

Abstract: A separator for a fuel cell includes a facing surface configured to face a power generating unit of the fuel cell. Groove passages and ribs that protrude toward the power generating unit are provided on the facing surface. At least one of the ribs includes at least one recess in a center of the rib in an arrangement direction of the groove passages. The recess includes a bottom surface, which faces the power generating unit, and two inner side surfaces, which rise from opposite ends in the arrangement direction of the bottom surface. The two inner side surfaces are inclined such that a given point on each inner side surface separates further away from the bottom surface in the arrangement direction as that point approaches the power generating unit in a direction in which the power generating unit and the separator face each other.

Abstract: A fuel cell stack includes power generation cells, which are stacked in a vertical direction. Each power generation cell is configured to generated power by using gas. Each power generation cell includes a first hole and a second hole. The first holes of the power generation cells form a gas manifold. The gas manifold extends in the vertical direction, and the gas flows through the gas manifold. The second holes of the power generation cells form a passage. The passage is adjacent to the gas manifold and extends in the vertical direction. The gas manifold and the passage are connected to each other at upper ends of the gas manifold and the passage.

Abstract: A separator for a fuel cell includes a contact surface configured to contact a power generating unit of the fuel cell. Groove passages are arranged side by side in the contact surface. Reactant gas flows through the groove passages. At least one of the groove passages includes a wavy section that extends in a wavy shape in planar directions of the contact surface. An upstream portion and a downstream portion in a flow direction of the reactant gas in each groove passage are defined as an upstream portion and a downstream portion, respectively. A wavelength of the wavy section is smaller in the downstream portion than in the upstream portion.

Abstract: A fuel cell comprising a membrane electrode gas diffusion layer assembly, a frame member disposed around the membrane electrode gas diffusion layer assembly, and a pair of separators stacked on the frame member to sandwich the membrane electrode gas diffusion layer assembly and the frame member, wherein the separators include separator-side manifolds; wherein the frame member includes a skeleton connecting to the membrane electrode gas diffusion layer assembly, as opening for housing the membrane electrode gas diffusion layer assembly, frame member-side manifolds aligned and disposed to communicate with the separator-side manifolds, and a fluid introduction and derivation site between the opening and the frame member-side manifolds; wherein the fluid introduction and derivation site includes convexities to form a flow path for delivering a fluid in a horizontal direction of the frame member; and wherein a thickness of the convexities is larger than a thickness of the skeleton.

Abstract: A fuel cell stack in which unit cells are stacked, wherein the unit cell includes: a membrane electrode assembly; an insulating member; a first separator; a second separator; and a gasket, a hole penetrates through the insulating member and the first and second separators, the gasket extends around the hole on the insulating member, a flow path portion is formed in at least one of the first and second separators, the first and second separators define a communicating portion, one of the first and second separators includes: first and second protruding portions; and a recessed portion, at least a part of the communicating portion is defined by the first and second protruding portions, the recessed portion, and the other of the first and second separators, and the first separator includes a support portion contacting and supporting the insulating member on a back side of the gasket.

Abstract: A fuel cell stack includes: a membrane electrode assembly; and first and second separators joined to each other, wherein first and third fluid groove portions face each other in a stacking direction in which the membrane electrode assembly and the first and second separators are stacked, second and fourth fluid groove portions face each other in the stacking direction, and first and second coolant groove portions face each other in the stacking direction and define a common coolant flow path.