Separator for fuel cell and single cell of fuel cell

Abstract

To provide a fuel battery separator and a single cell of a fuel battery that can suppress the sinking of a gas diffusion layer into a groove channel.SOLUTION: A fuel battery separator 30 has an inner facing surface 30a facing an MEA 10 of a fuel battery. A plurality of ribs 38 positioned between groove channels 37 and protruding toward the MEA 10 are provided on the inner facing surface 30a. The rib 38 is provided with a projection 40 projecting toward the MEA 10.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a separator for a fuel cell and a single cell of a fuel cell.

Background Art

[0002] Patent Document 1 discloses a fuel cell. This fuel cell includes a membrane electrode gas diffusion layer assembly (hereinafter referred to as MEGA) and a resin frame member disposed on the outer peripheral side of the MEGA.

[0003] The fuel cell also includes anode-side and cathode-side separators that sandwich the MEGA and the resin frame member. The MEGA includes a membrane electrode assembly (hereinafter referred to as MEA) and anode-side and cathode-side gas diffusion layers (hereinafter referred to as GDL) that sandwich the MEA.

[0004] The separator has a plurality of groove flow paths for supplying an oxidizing gas or a fuel gas (hereinafter referred to as a reaction gas) to the MEGA, and a plurality of ribs that are located between the groove flow paths and contact the GDL.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] By the way, in such a fuel cell, a portion of the GDL adjacent to the separator and facing the groove flow path may be bent and deformed and sink into the groove flow path. In this case, the sunken GDL becomes a resistance to the reaction gas flowing through the groove flow path, and thus there is a risk of increasing the pressure loss of the reaction gas.

[0007] An object of the present invention is to provide a separator for a fuel cell and a single cell of a fuel cell that can suppress the sinking of the gas diffusion layer into the groove flow path.

Means for Solving the Problems

[0008] A separator for a fuel cell for achieving the above object has a facing surface facing the power generation part of the fuel cell, and a plurality of groove flow paths through which reaction gas flows are provided side by side on the facing surface. A separator for a fuel cell, wherein a plurality of ribs are provided on the facing surface, the ribs being located between the groove flow paths and protruding toward the power generation part, and the ribs are provided with convex parts protruding toward the power generation part.

[0009] Further, a single cell of a fuel cell for achieving the above object includes a pair of separators, and a power generation part sandwiched between the pair of separators and having a pair of gas diffusion layers in contact with each of the pair of separators. At least one of the pair of separators is the above separator, and the power generation part is compressed in the facing direction between the power generation part and the separator by the convex part.

[0010] According to the same configuration, when the power generation part and the separator are laminated to manufacture a single cell of a fuel cell, a portion of the gas diffusion layer (hereinafter referred to as GDL) facing the convex part is compressed. Along with this, a portion of the GDL facing the groove flow path is in a stretched state. Therefore, the sinking of the GDL into the groove flow path can be suppressed.

Brief Description of the Drawings

[0011]

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Embodiments for Carrying Out the Invention

[0012] Hereinafter, with reference to FIGS. 1 to 22, each embodiment of a separator for a fuel cell and a single cell of a fuel cell will be described. In each drawing, for convenience of explanation, a part of the configuration is shown in an exaggerated or simplified manner, so the dimensional ratios of each configuration may be different from the actual ones. Also, in the following description, "orthogonal" includes not only the case of strict orthogonality but also the case of approximately orthogonal within the range where the effects of each embodiment are achieved.

[0013] <First Embodiment> First, with reference to FIGS. 1 to 6, a first embodiment of a separator for a fuel cell and a single cell of a fuel cell will be described.

[0014] <Overall Configuration of Single Cell 90 of Fuel Cell> As shown in FIG. 1, the single cell 90 of the fuel cell includes a membrane electrode assembly 10 (hereinafter, MEA 10), a frame member 20 that holds the MEA 10, and a pair of separators 30 and 50 that sandwich the MEA 10 and the frame member 20.

[0015] The single cell 90 is rectangular plate-shaped as a whole. Hereinafter, the stacking direction of the separator 30, the MEA 10, the frame member 20, and the separator 50 will be described as the first direction X.

[0016] Also, a direction that is the longitudinal direction of the single cell 90 and orthogonal to the first direction X is described as the second direction Y. Also, a direction orthogonal to both the first direction X and the second direction Y is described as the third direction Z.

[0017] The single cell 90 has introduction holes 91, 93, 95 for introducing a reaction gas or a cooling medium into the single cell 90, and discharge holes 92, 94, 96 for discharging the reaction gas and the cooling medium in the single cell 90 to the outside. In this embodiment, the introduction hole 91 and the discharge hole 92 are holes through which the fuel gas flows. Also, the introduction hole 93 and the discharge hole 94 are holes through which the cooling medium flows. Also, the introduction hole 95 and the discharge hole 96 are holes through which the oxidant gas flows. Here, the fuel gas is hydrogen gas. Also, the cooling medium is cooling water. Also, the oxidant gas is air.

[0018] The introduction holes 91, 93, 95 and the discharge holes 92, 94, 96 are rectangular in plan view and long in the second direction Y, and penetrate the single cell 90 in the first direction X. The introduction hole 91 and the discharge holes 94, 96 are provided on one side of the single cell 90 in the second direction Y (the left side in the left - right direction of FIG. 1). The introduction hole 91 and the discharge holes 94, 96 are arranged at intervals in the third direction Z. The discharge hole 92 and the introduction holes 93, 95 are provided on the other side of the single cell 90 in the second direction Y (the right side of FIG. 1). The discharge hole 92 and the introduction holes 93, 95 are arranged at intervals in the third direction Z.

[0019] Hereinafter, each configuration will be described in detail. <mea10> As shown in FIG. 1, MEA10 has a rectangular shape in plan view that is long in the second direction Y.

[0020] MEA10 has a solid polymer electrolyte membrane (hereinafter referred to as the electrolyte membrane), not shown, and electrode 11A and 11B provided on both sides of the electrolyte membrane. In the present embodiment, the electrode joined to one side (the upper side in the vertical direction of FIG. 1) of the electrolyte membrane (not shown) in the first direction X is the cathode electrode 11A. Also, the electrode joined to the other side (the lower side in FIG. 1) of the electrolyte membrane in the first direction X is the anode electrode 11B.

[0021] Electrodes 11A and 11B have a catalyst layer (not shown) joined to the electrolyte membrane and a gas diffusion layer 12 (hereinafter referred to as GDL12) joined to the catalyst layer. Note that MEA10 corresponds to the power generation unit of the fuel cell according to the present invention.

[0022] <Frame member 20> As shown in FIG. 1, the frame member 20 has a rectangular frame shape that is long in the second direction Y. The frame member 20 is formed in a sheet shape from, for example, a synthetic resin material.

[0023] The frame member 20 has through holes 21, 22, 23, 24, 25, and 26 that constitute holes 91, 92, 93, 94, 95, and 96. The frame member 20 has an opening 27 that is rectangular in plan view and long in the second direction Y at the center. MEA10 is joined to the edge of the opening 27 from one side in the first direction X (the upper side in FIG. 1). That is, the frame member 20 is located on the outer peripheral side of MEA10.

[0024] <Separator 30> As shown in FIGS. 1 and 2, the separator 30 has a rectangular plate shape in plan view that is long in the second direction Y.

[0025] The separator 30 is formed by press molding a metal member such as titanium or stainless steel, for example. The separator 30 is provided on the anode electrode 11B side of the MEA 10 (see FIG. 1).

[0026] The separator 30 has an inner facing surface 30a facing the MEA 10 and an outer facing surface 30b facing the frame member 20. The separator 30 has through holes 31, 32, 33, 34, 35, 36 that form holes 91, 92, 93, 94, 95, 96. The through holes 31, 34, 36 are provided at positions corresponding to the through holes 21, 24, 26 of the frame member 20 in the third direction Z, respectively. Also, the through holes 32, 33, 35 are provided at positions corresponding to the through holes 22, 23, 25 of the frame member 20 in the third direction Z, respectively.

[0027] The separator 30 has a plurality of groove flow paths 37 through which fuel gas flows and a plurality of ribs 38 located between the groove flow paths 37. In FIG. 1, the outer edges of the portions where the plurality of groove flow paths 37 and the plurality of ribs 38 are formed are shown in a simplified manner.

[0028] <Groove flow path 37> As shown in FIG. 2, the plurality of groove flow paths 37 are grooves that communicate the through hole 31 and the through hole 32. In the present embodiment, six groove flow paths 37 are arranged at intervals in the third direction Z.

[0029] The groove width of the groove flow path 37, that is, the flow path cross-sectional area, is constant throughout the extending direction of the groove flow path 37. The groove widths of the respective groove flow paths 37 are the same as each other. The six groove flow paths 37 are composed of three first groove flow paths 71 and three second groove flow paths 72. The first groove flow paths 71 and the second groove flow paths 72 are alternately provided in the third direction Z.

[0030] The first groove flow path 71 has a wavy portion 73 provided on the inner facing surface 30a and an extending portion 75 extending from the wavy portion 73 to the outer facing surface 30b. The corrugated portion 73 extends in a corrugated shape in the plane direction of the inner opposing surface 30a. The wavelength λ and amplitude A of the corrugated portion 73 are constant throughout the extending direction of the corrugated portion 73. Also, the number of waves of the corrugated portion 73 is three.

[0031] The extending portions 75 extend linearly from both ends in the extending direction of the corrugated portion 73 toward the through holes 31 and 32, respectively. The second groove flow path 72 has a corrugated portion 74 provided on the inner opposing surface 30a and an extending portion 76 extending from the corrugated portion 74 to the outer opposing surface 30b. In this embodiment, the corrugated portion 74 has the same waveform as the corrugated portion 73.

[0032] The extending portions 76 extend linearly from both ends in the extending direction of the corrugated portion 74 toward the through holes 31 and 32, respectively. Among the six groove flow paths 37, the groove flow path 37 located most outward in the third direction Z has a portion located outside the outer edge of the inner opposing surface 30a in the third direction Z.

[0033] <Rib 38> As shown in FIG. 3, the plurality of ribs 38 protrude on one side in the first direction X (the upper side in the vertical direction in FIG. 3).

[0034] As shown in FIG. 2, in this embodiment, five ribs 38 are arranged at intervals in the third direction Z. Each rib 38 has a corrugated portion 81 provided on the inner opposing surface 30a and an extending portion 84 extending from the corrugated portion 81 to the outer opposing surface 30b. In this embodiment, the corrugated portion 81 located most outward in the third direction Z among the five corrugated portions 81 has a portion located outside the outer edge of the inner opposing surface 30a.

[0035] The corrugated portion 81 has a narrow-width portion 83 with a width W in the third direction Z smaller than that of other portions (hereinafter, general portion 82) in the corrugated portion 81. In this embodiment, the narrow-width portion 83 is located between the vertices V1 and V2 of the corrugated portion 81 and between the vertices V2 and V3 of the corrugated portion 81 in the extending direction of the corrugated portion 81.

[0036] As shown in FIGS. 2 and 3, each of the five ribs 38 is provided with a convex portion 40 protruding toward the MEA 10 side. As shown in FIG. 3, the convex portion 40 has a top surface 41 extending in the plane direction of the MEA 10 and a pair of side surfaces 42a extending by bending from both ends of the top surface 41 in the third direction Z.

[0037] The protruding height H1 of the convex portion 40 is preferably in the range of 10 μm or more and 30 μm or less. Further, the height H1 is more preferably 20 μm or more and 30 μm or less. In the present embodiment, the height H1 is set to 20 μm or more and 30 μm or less.

[0038] The pair of side surfaces 42a are inclined so as to be separated from the top surface 41 in the third direction Z as they are separated from the MEA 10 in the first direction X. The inclination angle θ1 of the pair of side surfaces 42a with respect to the top surface 41 is preferably in the range of 1 degree or more and 5 degrees or less. Further, the inclination angle θ1 is more preferably 2 degrees or more and 5 degrees or less. Further, the inclination angle θ1 is still more preferably 3 degrees or more and 5 degrees or less. Further, the inclination angle θ1 is even more preferably 4 degrees or more and 5 degrees or less. In the present embodiment, the inclination angle θ1 is set to 4 degrees or more and 5 degrees or less.

[0039] As shown in FIG. 2, the convex portions 40 are provided at a plurality of locations (four locations in the present embodiment) in the extending direction of each rib 38. Two of the four convex portions 40 are provided on the corrugated portion 81 of the rib 38. Specifically, the convex portions 40 are provided on each of the two narrow portions 83. The remaining two convex portions 40 are provided on the extending portions 84 of the rib 38. Specifically, the convex portions 40 are provided on each of the extending portion 84 extending to the through hole 31 and the extending portion 84 extending to the through hole 32.

[0040] <Groove flow path 38A, rib 37A> As shown in FIGS. 1 and 3, the separator 30 has a surface 30c on the side opposite to the opposing surfaces 30a and 30b in the first direction X. On the surface 30c, a plurality of groove channels 38A through which a cooling medium flows and a plurality of ribs 37A located between the groove channels 38A are provided. The rib 37A is constituted by the back surface of the groove channel 37. Further, the groove channel 38A is constituted by the back surface of the rib 38. That is, the rib 37A and the groove channel 38A are in a front-back integral relationship with the groove channel 37 and the rib 38 of the opposing surfaces 30a and 30b (see FIG. 3). Note that in FIG. 1, the outer edge of the portion where the plurality of groove channels 38A and the plurality of ribs 37A are formed is shown in a simplified manner.

[0041] The plurality of groove channels 38A are grooves that communicate the through hole 33 and the through hole 34. Inside the groove channel 38A, the cooling medium flows in a direction opposite to the fuel gas flowing through the groove channel 37. <Separator 50> As shown in FIG. 1, the separator 50 is in the shape of a rectangular plate in plan view that is long in the second direction Y.

[0042] The separator 50 is formed, for example, by press-molding a metal member such as titanium or stainless steel. The separator 50 is provided on the cathode electrode 11A side of the MEA 10. The separator 50 has a first surface 50a including an opposing surface facing the MEA 10 and a second surface 50b on the side opposite to the first surface 50a.

[0043] The separator 50 has through holes 51, 52, 53, 54, 55, 56 that constitute holes 91, 92, 93, 94, 95, 96. The through holes 51, 54, 56 are provided at positions corresponding to the through holes 21, 24, 26 of the frame member 20 in the third direction Z, respectively. Further, the through holes 52, 53, 55 are provided at positions corresponding to the through holes 22, 23, 25 of the frame member 20 in the third direction Z, respectively.

[0044] As shown in FIG. 1, the separator 50 has a plurality of groove channels 57 through which the oxidant gas flows and a plurality of groove channels 58 through which the cooling medium flows. In FIG. 1, the outer edges of the portions where the plurality of groove channels 57 are formed and the outer edges of the portions where the plurality of groove channels 58 are formed in the separator 50 are each shown in a simplified manner.

[0045] The plurality of groove channels 57 are grooves that communicate the through-hole 55 and the through-hole 56. Inside the groove channel 57, the oxidant gas flows in a direction opposite to the fuel gas flowing through the groove channel 37. The plurality of groove channels 58 are grooves that communicate the through-hole 53 and the through-hole 54. Inside the groove channel 58, the cooling medium flows in the same direction as the oxidant gas flowing through the groove channel 57.

[0046] Next, the operation of this embodiment will be described. As shown in FIGS. 4 and 5, when the separator 30, the MEA 10, and the frame member 20 are laminated to manufacture a single cell 90 of a fuel cell, at the inner opposing surface 30a of the separator 30, the portion of the GDL 12 that contacts the convex portion 40 is compressed. Along with this, the portion of the GDL 12 that faces the groove channel 37 is in a stretched state. In FIGS. 4 and 5, only the GDL 12 in the MEA 10 is shown.

[0047] On the other hand, as shown in FIG. 6, at the outer opposing surface 30b of the separator 30, the portion of the frame member 20 that contacts the convex portion 40 is compressed. Along with this, the portion of the frame member 20 that faces the groove channel 37 is in a stretched state.

[0048] Next, the effects of this embodiment will be described. (1-1) The separator 30 has an inner opposing surface 30a that faces the MEA 10 of the fuel cell. On the inner opposing surface 30a, a plurality of ribs 38 are provided that are located between the groove channels 37 and protrude toward the MEA 10. On the rib 38, a convex portion 40 that protrudes toward the MEA 10 is provided.

[0049] According to such a configuration, the above-described operation is achieved. Therefore, the sinking of the GDL12 into the groove flow path 37 can be suppressed. (1-2) The convex portion 40 has a top surface 41 extending in the plane direction of the MEA10 and a pair of side surfaces 42a extending by bending from both ends of the top surface 41 in the third direction Z. The pair of side surfaces 42a are inclined so as to be farther from the top surface 41 in the third direction Z as they are farther from the MEA10 in the first direction X.

[0050] According to such a configuration, since the GDL12 sinks along the pair of side surfaces 42a, the portion of the GDL12 facing the convex portion 40 is easily compressed. As a result, the portion of the GDL12 facing the groove flow path 37 is likely to be in a stretched state. Therefore, the sinking of the GDL12 into the groove flow path 37 can be further suppressed.

[0051] (1-3) The protruding height H1 of the convex portion 40 is 20 μm or more and 30 μm or less. The inclination angle θ1 of the pair of side surfaces 42a with respect to the top surface 41 is 4 degrees or more and 5 degrees or less. According to such a configuration, the effect of the invention according to (1-2) can be preferably exhibited, and the generation of a gap between the side surface 42a of the convex portion 40 and the GDL12 can be preferably suppressed.

[0052] (1-4) The convex portion 40 is provided at a plurality of locations in the extending direction of the rib 38 on the inner opposing surface 30a. According to such a configuration, the operation and effect of the invention according to (1-1) can be exhibited at a plurality of locations in the extending direction of the rib 38. Therefore, the sinking of the GDL12 into the groove flow path 37 can be more suppressed.

[0053] (1-5) The plurality of groove flow paths 37 each extend in a wavy shape in the surface direction of the inner facing surface 30a and have a first groove flow path 71 and a second groove flow path 72 adjacent to each other in the third direction Z. The plurality of ribs 38 have a wavy portion 81 located between the first groove flow path 71 and the second groove flow path 72. The wavy portion 81 has a narrow-width portion 83 in which the width W in the third direction Z is smaller than that of the general portion 82 in the wavy portion 81. The convex portion 40 is provided in the narrow-width portion 83.

[0054] The sinking of the GDL12 into the groove flow path 37 is more likely to occur as the width W of the rib 38 adjacent to the groove flow path 37 in the third direction Z is smaller. In this regard, according to the above configuration, the convex portion 40 is provided in the narrow-width portion 83 of the rib 38. Therefore, in the portion of the first groove flow path 71 and the second groove flow path 72 adjacent to the narrow-width portion 83, that is, in the portion where the GDL12 is likely to sink into the groove flow path 37, the GDL12 facing the same portion can be put in a stretched state. Accordingly, the sinking of the GDL12 into the groove flow path 37 can be suppressed.

[0055] Also, according to the above configuration, the separator 30 has the first groove flow path 71 and the second groove flow path 72 extending in a wavy shape. Therefore, for example, when the plurality of groove flow paths 37 of the separator 30 extend linearly in the surface direction of the inner facing surface 30a, the contact portions between the separator 30 in one unit cell 90 and the separator 50 in the other unit cell 90 increase when the unit cells 90 are stacked. Accordingly, the stability of the contact structure between the adjacent separators 30 and 50, and thus the stability of the contact structure between the unit cells 90 can be improved.

[0056] (1-6) The convex portion 40 is provided on each of the plurality of ribs 38. According to such a configuration, for each of the plurality of groove flow paths 37, the sinking of the GDL12 into the groove flow path 37 can be suppressed.

[0057] (1-7) The separator 30 has an outer opposing surface 30b facing the frame member 20. The plurality of groove channels 37 and the plurality of ribs 38 each have extending portions 75, 76, 84 extending on the outer opposing surface 30b. The convex portion 40 is also provided on the extending portion 84 of the rib 38.

[0058] In the fuel cell, the MEA 10 is held by the frame member 20 located on the outer periphery of the MEA 10. When such a frame member 20 is formed of a synthetic resin material, the portion of the frame member 20 facing the groove channel 37 may be bent and deformed and sink into the groove channel 37. In this case, the sunken frame member 20, like the GDL 12, becomes a resistance to the fuel gas flowing through the groove channel 37, and thus there is a possibility of increasing the pressure loss of the fuel gas.

[0059] In this regard, according to the above configuration, since the same operation as that of the above invention is achieved, the sinking of the frame member 20 into the groove channel 37 can be suppressed. <Second Embodiment> Hereinafter, with reference to FIGS. 7 and 11, a second embodiment of the separator for a fuel cell will be described. In this embodiment, for the same or corresponding configurations as those in the first embodiment, the same reference numerals are given and the overlapping explanations are omitted.

[0060] As shown in FIG. 7, each of the five ribs 38 is provided with a convex portion 40 protruding toward the MEA 10 side. As shown in FIG. 9, the convex portion 40 has a pair of side surfaces 42b that bend and extend from both ends of the top surface 41 in the extending direction of the rib 38. In this embodiment, the inclination angles of the pair of side surfaces 42b with respect to the top surface 41 are set to be the same as the inclination angle θ1.

[0061] As shown in FIGS. 7 and 8, each corrugated portion 81 of the five ribs 38 is provided with a recess 43 that opens toward the MEA 10 side. The recess 43 is provided at the center of the rib 38 in the third direction Z.

[0062] As shown in FIG. 8, the recess 43 has a bottom surface 44 that extends in the plane direction of the MEA 10 and faces the MEA 10, and a pair of inner surfaces 45a that rise from both ends of the bottom surface 44 in the third direction Z. Further, the recess 43 has a pair of inner surfaces 45b that rise from the bottom surface 44 in the extending direction of the corrugated portion 81 (see FIG. 9).

[0063] The height H2 from the general surface 38a where the convex portion 40 and the concave portion 43 are not provided in the rib 38 to the bottom surface 44 is preferably in the range of 10 μm or more and 30 μm or less. Further, the height H2 is more preferably 20 μm or more and 30 μm or less. In the present embodiment, the height H2 is set to 20 μm or more and 30 μm or less.

[0064] The pair of inner surfaces 45a are inclined so as to be farther from the bottom surface 44 in the third direction Z as they approach the MEA 10 in the first direction X. The inclination angle θ2 of the pair of inner surfaces 45a with respect to the bottom surface 44 is preferably in the range of 1 degree or more and 5 degrees or less. Further, the inclination angle θ2 is more preferably 2 degrees or more and 5 degrees or less. Further, the inclination angle θ2 is still more preferably 3 degrees or more and 5 degrees or less. Further, the inclination angle θ2 is even more preferably 4 degrees or more and 5 degrees or less. In the present embodiment, the inclination angle θ2 is set to 4 degrees or more and 5 degrees or less.

[0065] As shown in FIG. 9, the inclination angle of the pair of inner surfaces 45b with respect to the bottom surface 44 is set to be the same as the inclination angle θ2. As shown in FIGS. 7 and 9, a plurality (four in the present embodiment) of recesses 43 are provided at positions that do not overlap with the convex portions 40 in the extending direction of each corrugated portion 81. Specifically, the recesses 43 are provided one on each side of each convex portion 40 in the extending direction. In the present embodiment, the recesses 43 are provided such that the inner surfaces 45b are continuous with the side surfaces 42b of the convex portions 40.

[0066] Next, the operation of the present embodiment will be described. As shown in FIGS. 10 and 11, when the separator 30, the MEA 10, and the frame member 20 are laminated to manufacture the single cell 90 of the fuel cell, on the inner facing surface 30a of the separator 30, the GDL 12 sinks into the recess 43 along the pair of inner surfaces 45a. Also, the GDL 12 comes into contact with the bottom surface 44 of the recess 43. On the other hand, the portion of the GDL 12 that contacts the convex portion 40 is compressed (see FIGS. 4 and 5). As a result, the portion of the GDL 12 that faces the groove flow path 37 is in a stretched state. In FIGS. 10 and 11, only the GDL 12 of the MEA 10 is shown.

[0067] Next, the effects of the present embodiment will be described. (2-1) The rib 38 is provided with a recess 43 located at the center of the rib 38 in the third direction Z. The recess 43 has a bottom surface 44 that extends in the plane direction of the MEA 10 and faces the MEA 10, and a pair of inner surfaces 45a that rise from both ends of the bottom surface 44 in the third direction Z. The pair of inner surfaces 45a are inclined so as to be farther from the bottom surface 44 in the third direction Z as they approach the MEA 10 in the first direction X. The recess 43 is provided at a position that does not overlap with the convex portion 40 in the extending direction of the rib 38.

[0068] According to such a configuration, the above-described operation is achieved. Therefore, the sinking of the GDL 12 into the groove flow path 37 can be further suppressed. <Third Embodiment> Hereinafter, with reference to FIGS. 12 to 16, a third embodiment of the separator for a fuel cell will be described. Among the configurations of the separator 30 of the third embodiment, for the configurations corresponding to the configuration of the convex portion 40 of the first embodiment, the symbols of the first embodiment "**" are added with "100" to obtain the symbols "1**", and redundant explanations are omitted. Also, in other configurations of the present embodiment, for the same or corresponding configurations as those of the first embodiment, the same symbols are used to omit redundant explanations.

[0069] As shown in FIG. 12, the separator 30 includes a base material 30A that constitutes the main body of the separator 30, and a contact member 140 formed separately from the base material 30A. <Base material 30A> The base material 30A is formed by press-molding a metal member such as titanium or stainless steel, for example.

[0070] The base material 30A has a plurality (six in this embodiment) of groove flow paths 37 through which fuel gas flows, and a plurality (five in this embodiment) of ribs 38 located between the groove flow paths 37. <Contact member 140> As shown in FIGS. 12 and 13, the contact member 140 contacts the GDL 12 of the MEA 10 and is formed of a conductive material different from the base material 30A. Specifically, the contact member 140 is formed of a conductive material including a binder made of a thermosetting resin such as an epoxy resin and conductive particles such as carbon.

[0071] The contact member 140 is joined to each of the five ribs 38 and protrudes toward the MEA 10. The contact member 140 has a top surface 141 extending in the plane direction of the MEA 10, and a pair of side surfaces 142a extending by bending from both ends of the top surface 141 in the third direction Z. Further, the contact member 140 has a joining surface 146a that is located on the side opposite to the top surface 141 in the first direction X and is joined to the tip surface 38b of the rib 38.

[0072] The protruding height H3 of the contact member 140 is preferably set in the same manner as the protruding height H1 (see FIG. 3) of the convex portion 40 in the first embodiment. In this embodiment, the same height H3 is set to be 20 μm or more and 30 μm or less.

[0073] The inclination angle θ3 of the pair of side surfaces 142a with respect to the top surface 141 is preferably set in the same manner as the inclination angle θ1 (see FIG. 3) of the pair of side surfaces 42a with respect to the top surface 41 in the first embodiment. In this embodiment, the same inclination angle θ3 is set to be 4 degrees or more and 5 degrees or less.

[0074] The contact member 140 is fixed on the base material 30A by both ends of the joint surface 146a in the third direction Z being adhered to the tip surface 38b of the rib 38 with an adhesive (not shown). As shown in FIG. 12, the contact members 140 are provided at a plurality of positions (four positions in this embodiment) in the extending direction of each rib 38. Two of the four contact members 140 are adhered to the corrugated portions 81 of the rib 38. Specifically, the contact members 140 are provided at each of the two narrow portions 83. The remaining two contact members 140 are adhered to the extending portions 84 of the rib 38. Specifically, the contact members 140 are adhered to the extending portion 84 extending into the through hole 31 and the extending portion 84 extending into the through hole 32, respectively.

[0075] Next, the operation of this embodiment will be described. As shown in FIGS. 14 and 16, when the separator 30, the MEA 10, and the frame member 20 are laminated to manufacture the single cell 90 of the fuel cell, on the inner opposing surface 30a of the separator 30, the portion of the GDL 12 that faces the contact member 140 is compressed. Along with this, the portion of the GDL 12 that faces the groove flow path 37 is in a stretched state. In FIGS. 14 and 15, only the GDL 12 in the MEA 10 is shown.

[0076] On the other hand, as shown in FIG. 16, on the outer opposing surface 30b of the separator 30, the portion of the frame member 20 that faces the contact member 140 is compressed. Along with this, the portion of the frame member 20 that faces the groove flow path 37 is in a stretched state.

[0077] Next, the effects of this embodiment will be described. (3-1) The separator 30 includes a base material 30A having a plurality of groove flow paths 37 and a plurality of ribs 38, and a contact member 140 that is joined to the base material 30A and contacts the MEA 10. The contact member 140 protrudes toward the MEA 10.

[0078] According to such a configuration, by simply applying the contact member 140 to the base material 30A of the existing separator 30, the same operational effects as those of the invention described in the first embodiment can be achieved. As a result, it is possible to avoid the complication of the shape of the base material 30A of the separator 30, and thus avoid the difficulty in forming the base material 30A.

[0079] <Fourth Embodiment> Hereinafter, with reference to FIGS. 17 to 22, a fourth embodiment of the separator for a fuel cell will be described. Among the configurations of the separator 30 of the fourth embodiment, for the configurations corresponding to the configuration of the convex portion 40 of the first embodiment and the configuration of the concave portion 43 of the second embodiment, the symbols "2**" obtained by adding "200" to each symbol "**" of the first embodiment and the second embodiment are used, and duplicate explanations are omitted. In addition, in other configurations of the present embodiment, for the configurations identical or corresponding to those of the first embodiment and the third embodiment, the same symbols are used, and duplicate explanations are omitted.

[0080] As shown in FIGS. 17 to 19, the separator 30 includes a base material 30A that constitutes the main body of the separator 30, and a contact member 30B that is formed separately from the base material 30A. In the present embodiment, the height of the rib 38 of the base material 30A in the first direction X is smaller than the same height in the third embodiment (see FIGS. 13 and 18).

[0081] <Contact Member 30B> As shown in FIGS. 17 to 19, the contact member 30B contacts the GDL 12 of the MEA 10 and is formed of the same conductive material as the contact member 140 of the third embodiment.

[0082] The contact member 30B is joined to each of the five ribs 38. The contact member 30B has a base portion 246 joined to the rib 38, a convex portion 240 protruding from the base portion 246, and a concave portion 243 opening toward the MEA 10 side.

[0083] As shown in FIGS. 18 and 19, the base portion 246 is located on the side opposite to the convex portion 240 and the concave portion 243 in the first direction X and has a joint surface 246a that is joined to the tip surface 38b of the rib 38.

[0084] The base portion 246 covers the entire tip surface 38b of the rib 38 in the third direction Z. The contact member 30B is fixed on the base material 30A by adhering both ends of the joint surface 246a in the third direction Z to the tip surface 38b of the rib 38 with an adhesive (not shown).

[0085] As shown in FIG. 17, the base portion 246 is adhered to both the corrugated portion 81 and the extending portion 84. Specifically, the base portion 246 is provided over the entire extending direction of the rib 38.

[0086] As shown in FIG. 18, the convex portion 240 has a top surface 241 that extends in the plane direction of the MEA 10 and a pair of side surfaces 242a that bend and extend from both ends of the top surface 241 in the third direction Z. Further, the convex portion 240 has a pair of side surfaces 242b that bend and extend from both ends of the top surface 241 in the extending direction of the rib 38 (see FIG. 20).

[0087] The protruding height H4 of the convex portion 240 is preferably set in the same manner as the protruding height H1 of the convex portion 40 in the first embodiment (see FIG. 3). In this embodiment, the same height H4 is set to be 20 μm or more and 30 μm or less.

[0088] The inclination angle θ4 of the pair of side surfaces 242a with respect to the top surface 241 is preferably set in the same manner as the inclination angle θ1 of the pair of side surfaces 42a with respect to the top surface 41 in the first embodiment (see FIG. 3). In this embodiment, the same inclination angle θ4 is set to be 4 degrees or more and 5 degrees or less.

[0089] As shown in FIG. 20, the inclination angle of the pair of inner side surfaces 245b with respect to the top surface 241 is set to be the same as the inclination angle θ4. As shown in FIG. 17, the convex portions 240 are provided at a plurality of locations (four locations in this embodiment) in the extending direction of each rib 38. Two of the four convex portions 240 are provided on the corrugated portion 81 of the rib 38. Specifically, the convex portions 240 are provided at positions corresponding to each of the two narrow portions 83 of the base portion 246. The remaining two convex portions 240 are provided on the extending portions 84 of the rib 38. Specifically, the convex portions 240 are provided at positions corresponding to each of the extending portion 84 extending to the through hole 31 and the extending portion 84 extending to the through hole 32 of the base portion 246.

[0090] As shown in FIG. 19, the recess 243 has a bottom surface 244 that extends in the plane direction of the MEA 10 and faces the MEA 10, and a pair of inner surfaces 245a that rise from both ends of the bottom surface 244 in the third direction Z. The recess 243 also has a pair of inner surfaces 245b that rise from the bottom surface 244 in the extending direction of the corrugated portion 81 (see FIG. 20).

[0091] The height H5 from the general surface 246b of the base portion 246 where the convex portion 240 and the recess 243 are not provided to the bottom surface 244 is preferably set in the same manner as the height H2 (see FIG. 8) from the general surface 38a of the rib 38 to the bottom surface 44 of the recess 43 in the second embodiment. In this embodiment, the same height H5 is set to be 20 μm or more and 30 μm or less.

[0092] The inclination angle θ5 of the pair of inner surfaces 245a with respect to the bottom surface 244 is preferably set in the same manner as the inclination angle θ2 (see FIG. 8) of the pair of inner surfaces 45a with respect to the bottom surface 44 in the second embodiment. In this embodiment, the same inclination angle θ5 is set to be 4 degrees or more and 5 degrees or less.

[0093] As shown in FIG. 20, the inclination angle of the pair of inner surfaces 245b with respect to the bottom surface 244 is set to be the same as the inclination angle θ5. The plurality (four in this embodiment) of concave portions 243 are provided at positions that do not overlap with the convex portions 240 in the extending direction of the corrugated portion 81. Specifically, one concave portion 243 is provided on each side of each convex portion 240 in the extending direction. In this embodiment, the concave portion 243 is provided such that the inner surface 245b is continuous with the side surface 242b of the convex portion 40.

[0094] Next, the operation of this embodiment will be described. As shown in FIGS. 21 and 22, when the separator 30, the MEA 10, and the frame member 20 are laminated to manufacture the single cell 90 of the fuel cell, on the inner opposing surface 30a of the separator 30, the GDL 12 sinks into the concave portion 243 along the pair of inner surfaces 245a. Also, the GDL 12 comes into contact with the bottom surface 244 of the concave portion 243. On the other hand, although not shown, the portion of the GDL 12 that contacts the convex portion 240 is compressed by the convex portion 240 acting in the same manner as the contact member 140 of the third embodiment (see FIGS. 14 and 15). As a result, the portion of the GDL 12 that faces the groove flow path 37 is in a stretched state. In FIGS. 21 and 22, only the GDL 12 of the MEA 10 is shown.

[0095] Next, the effects of this embodiment will be described. (4-1) The contact member 30B includes a base portion 246 joined to the rib 38. The convex portion 240 protrudes from the base portion 246.

[0096] According to such a configuration, the above-described operation is achieved. Therefore, the sinking of the GDL 12 into the groove flow path 37 can be suppressed. Also, according to the above configuration, since the contact member 30B has the base portion 246, the protruding height of the rib 38 of the base material 30A can be reduced by the height of the base portion 246. Therefore, the molding of the base material 30A of the separator 30, and thus the manufacture of the separator 30, can be facilitated.

[0097] (4-2) The base portion 246 is provided with a recess 243 located at the center of the base portion 246 in the third direction Z. The recess 243 has a bottom surface 244 that extends in the plane direction of the MEA 10 and faces the MEA 10, and a pair of inner side surfaces 245a that rise from both ends of the bottom surface 244 in the third direction Z. The pair of inner side surfaces 245a are inclined so as to be farther from the bottom surface 244 in the third direction Z as they approach the MEA 10 in the first direction X. The recess 243 is provided at a position that does not overlap with the convex portion 240 in the extending direction of the rib 38.

[0098] According to such a configuration, the same operational effects as those of the invention according to (2-1) of the second embodiment can be achieved. Therefore, the sinking of the GDL 12 into the groove flow path 37 can be further suppressed.

[0099] <Modification Example> The above embodiment can be implemented with the following modifications. The above embodiment and the following modification examples can be implemented in combination with each other within a technically non - conflicting range.

[0100] · The shapes of the introduction holes 91, 93, 95 and the discharge holes 92, 94, 96 are not limited to the rectangular shape in plan view as exemplified in the above embodiment. For example, the shapes of the introduction holes 91, 93, 95 and the discharge holes 92, 94, 96 may be square or oval in plan view.

[0101] · The flow of the reaction gas and the cooling medium in the holes 91, 92, 93, 94, 95, 96 is not limited to that exemplified in the above embodiment. For example, the hole 96 may be used as the introduction hole for the oxidant gas, and the hole 95 may be used as the discharge hole for the oxidant gas. Further, accordingly, the hole 94 may be used as the introduction hole for the cooling medium, and the hole 93 may be used as the discharge hole for the cooling medium. That is, the oxidant gas flowing through the groove flow path 57 and the cooling medium flowing through the groove flow paths 38A, 58 may flow in the same direction as the fuel gas flowing through the groove flow path 37.

[0102] · The number of the groove flow paths 37 is not limited to six as exemplified in the above embodiment, and may be five or less, or seven or more. · Each groove width of the groove flow path 37, that is, the flow path cross-sectional area, does not have to be constant over the entire extending direction of the groove flow path 37 as long as the effects according to the present invention are achieved.

[0103] · The separator 30 is not limited to having a portion where the groove flow path 37 located most outward in the third direction Z among the plurality of groove flow paths 37 is located outside the outer edge of the inner opposing surface 30a as exemplified in the above embodiment. For example, the groove flow path 37 may be located at the same position as the outer edge of the inner opposing surface 30a in the third direction Z, or may be located inside the outer edge. Along with this, the corrugated portion 81 of the plurality of ribs 38 located most outward in the third direction Z may be located inside the outer edge of the inner opposing surface 30a.

[0104] · The recess 43 is not limited to being provided such that the inner surface 45b is continuous with the side surface 42b of the convex portion 40 as exemplified in the second embodiment. For example, the recess 43 may be provided at an interval from the convex portion 40 in the extending direction of the corrugated portion 81.

[0105] · The recess 43 is not limited to being provided on both sides of each convex portion 40 in the extending direction of the corrugated portion 81 as exemplified in the second embodiment. For example, the recess 43 may be provided only on either one of both sides of each convex portion 40 in the above extending direction.

[0106] · The recess 43 is not limited to being provided adjacent to the convex portion 40 in the extending direction of the corrugated portion 81 as exemplified in the second embodiment. That is, the separator 30 may have at least three recesses 43 arranged continuously in the extending direction of the rib 38.

[0107] · The separator 30 is not limited to the case where the recess 43 is provided only in the narrow portion 83 in the corrugated portion 81 of the rib 38 as exemplified in the second embodiment. That is, the arrangement of the recess 43 in the separator 30 can be changed as appropriate. For example, the recess 43 may be provided in both the narrow portion 83 and the general portion 82 in the corrugated portion 81, or may be provided only in the general portion 82. Further, the recess 43 is not limited to being provided only in the corrugated portion 81, and for example, it may be provided in both the corrugated portion 81 and the extending portion 84, or may be provided only in the extending portion 84.

[0108] · The recess 43 does not have to be provided in each of the ribs 38 as exemplified in the second embodiment, and it is sufficient if it is provided in at least one rib 38. · The recess 43 is not limited to being provided at a plurality of locations in the extending direction of the rib 38 as exemplified in the second embodiment. That is, the rib 38 may have the recess 43 provided at at least one location in the above-mentioned extending direction.

[0109] · The shape of the recess 43 is not limited to the shape exemplified in the second embodiment, and can be changed as follows. That is, the shape of the recess 43 is not limited to the case where the bottom surface 44 extends in the plane direction of the MEA 10 as exemplified in the same embodiment, and for example, the shape of the recess 43 may be U-shaped in cross section. Further, the inner surface 45a is not limited to being inclined with respect to the bottom surface 44 as exemplified in the same embodiment, and for example, it may rise perpendicular to the bottom surface 44.

[0110] · The recess 43 may be provided in the rib 38 in the third embodiment. In this case, the recess 43 may be provided at a position that does not overlap with the contact member 140 in the extending direction of the rib 38.

[0111] · The same changes as those of the recess 43 listed so far can also be made to the recess 243 in the fourth embodiment. · The recess 243 in the fourth embodiment can be omitted.

[0112] · As illustrated in the first and second embodiments, the separator 30 is not limited to having the convex portion 40 provided only at the narrow portion 83 in the corrugated portion 81 of the rib 38. That is, the arrangement of the convex portion 40 in the separator 30 can be changed as appropriate. For example, the convex portion 40 may be provided at both the narrow portion 83 and the general portion 82 in the corrugated portion 81, or may be provided only at the general portion 82. In this case, as shown in FIG. 23, the separator 30 in the first embodiment may be such that the first rib 381 having the convex portion 40 provided only at the general portion 82 and the second rib 382 having the convex portion 40 provided only at the narrow portion 83 are alternately arranged in the third direction Z.

[0113] · The arrangement of the contact member 140 in the third embodiment can also be changed as appropriate in the same manner as the arrangement of the convex portion 40 in the separator 30 described above. · The arrangement of the convex portion 240 in the fourth embodiment can also be changed as appropriate in the same manner as the arrangement of the convex portion 40 in the separator 30 described above.

[0114] · The convex portion 40 does not have to be provided on each of the ribs 38 as illustrated in the first and second embodiments, and it is sufficient if it is provided on at least one rib 38. · The separator 30 is not limited to having the contact members 140, 30B provided on each of the ribs 38 as illustrated in the third and fourth embodiments, and it is sufficient if the contact members 140, 30B are provided for at least one rib 38.

[0115] · As illustrated in the first embodiment, the convex portion 40 is not limited to being provided at a plurality of locations in the extending direction of the rib 38 on the inner opposing surface 30a. That is, as shown in FIG. 24, the convex portion 40 may be provided over the entire extending direction of the corrugated portion 81. In this case, the convex portion 40 provided on the extending portion 84 may extend from the convex portion 40 provided on the corrugated portion 81, or may be provided independently. Also, the convex portion 40 can be omitted from the extending portion 84.

[0116] · The contact member 140 is not limited to being provided at a plurality of locations in the extending direction of the rib 38 on the inner facing surface 30a as exemplified in the third embodiment, and the same changes as those made to the convex portion 40 described above can be made.

[0117] · The convex portion 240 of the contact member 30B is not limited to being provided at a plurality of locations in the extending direction of the rib 38 on the inner facing surface 30a as exemplified in the fourth embodiment, and the same changes as those made to the convex portion 40 described above can be made.

[0118] · The base portion 246 of the contact member 30B does not necessarily have to be provided over the entire extending direction of the rib 38 as exemplified in the fourth embodiment. That is, the separator 30 may be such that a plurality of contact members 30B are provided at intervals in the extending direction of the rib 38. Further, the separator 30 is not limited to being such that the contact member 30B is adhered to both the corrugated portion 81 and the extending portion 84 of the rib 38, and the contact member 30B may be adhered to only one of the corrugated portion 81 and the extending portion 84. In any case, the protruding height of the portion of the rib 38 where the contact member 30B is not provided may be made larger by the height of the base portion 246 of the contact member 30B. Also, at this time, at least one of the convex portion 40 and the concave portion 43 may be provided for the same portion.

[0119] · The shape of the convex portion 40 can be changed as follows. That is, the shape of the convex portion 40 is not limited to having the top surface 41 extending in the plane direction of the MEA 10, and for example, the shape of the convex portion 40 may be an inverted U-shaped cross section. Further, the side surface 42a is not limited to being inclined with respect to the top surface 41, and for example, it may extend perpendicular to the top surface 41.

[0120] · The shape of the contact member 140 is not limited to the shape exemplified in the third embodiment, and the same changes as those made to the convex portion 40 described above can be made. · The shape of the convex portion 240 of the contact member 30B is not limited to the shape exemplified in the fourth embodiment, and the same changes as those made to the convex portion 40 described above can be made.

[0121] · The plurality of groove channels 37 is not limited to being composed of a plurality of first groove channels 71 and a plurality of second groove channels 72. For example, the plurality of groove channels 37 may have at least one first groove channel 71 and one second groove channel 72 adjacent to each other, and may additionally have groove channels different from the first groove channel 71 and the second groove channel 72.

[0122] · The second groove channel 72 is not limited to having the same waveform as the corrugated portion 73 of the first groove channel 71 as exemplified in the above embodiment, and the wavelength λ, amplitude A, and wave number of the corrugated portion 74 may be appropriately changed to be different from those of the corrugated portion 73. In this case, the narrow portion 83 of the rib 38 does not have to be located between the vertices V1 and V2 and between the vertices V2 and V3 of the corrugated portion 81 as exemplified in the above embodiment.

[0123] · The shape of the first groove channel 71 is not limited to the shape exemplified in the above embodiment. That is, the first groove channel 71 is not limited to having a constant wavelength λ and amplitude A of the corrugated portion 73 over the entire extending direction of the corrugated portion 73. For example, the wavelengths λ and amplitudes A of the three waves of the corrugated portion 73 may be different from each other.

[0124] · The wave number of the corrugated portion 73 is not limited to the three exemplified in the above embodiment, and may be two or less, or four or more. · The shape of the plurality of groove channels 37 is not limited to the shape exemplified in the above embodiment, and can be appropriately changed as follows. That is, the plurality of groove channels 37 is not limited to including the first groove channel 71 and the second groove channel 72 that each extend in a wavy shape in the plane direction of the inner opposing surface 30a. For example, each of the groove channels 37 may be changed to extend linearly in the plane direction of the inner opposing surface 30a.

[0125] · The contact members 140 and 30B are not limited to being adhered to the rib 38 with an adhesive as exemplified in the third and fourth embodiments. For example, the contact member 140 (30B) may be joined to the rib 38 by thermally pressing the contact member 140 (30B) and the base material 30A.

[0126] · The binder contained in the conductive material forming the contact members 140 and 30B is not limited to the epoxy resin exemplified in the third and fourth embodiments, and for example, a phenolic resin can also be used. Further, the binder is not limited to a thermosetting resin, and thermoplastic resins such as polypropylene, polyamide, and polyphenylene sulfide can also be used.

[0127] · The contact member 140 (contact member 30B) may be integrally formed with respect to the rib 38 by inserting the base material 30A into a mold and performing injection molding. · The base material 30A of the separator 30 is not limited to being formed by press-molding a metal member, and for example, it can also be formed by cutting or etching. Similarly, the separator 30 in the first and second embodiments can also be formed.

[0128] · The material used for the base material 30A of the separator 30 is not limited to titanium or stainless steel, and for example, aluminum or carbon can also be used. Similarly, the same materials can be used for the separator 30 in the first and second embodiments.

[0129] · The separator for a fuel cell according to the present invention is not limited to the separator 30 joined to the anode electrode 11B side of the MEA 10 as exemplified in the above embodiment, and can also be applied to the separator 50 joined to the cathode electrode 11A side.

Explanation of Reference Numerals

[0130] λ... Wavelength A... Amplitude θ1, θ2, θ3, θ4, θ5... Inclination angles H1, H2, H3, H4, H5… Height V1, V2, V3… Vertices W… Width X… First direction Y… Second direction Z… Third direction 10… Membrane electrode assembly, MEA 11A… Cathode electrode 11B… Anode electrode 12… Gas diffusion layer, GDL 20… Frame member 21… Through-hole 22… Through-hole 23… Through-hole 24… Through-hole 25… Through-hole 26… Through-hole 27… Opening 30… Separator 30A… Substrate 30B, 140… Contact member 30a… Inner opposing surface 30b… Outer opposing surface 30c… Surface 31… Through-hole 32… Through-hole 33… Through-hole 34… Through-hole 35… Through-hole 36… Through-hole 37… Grooved flow path 37A… Rib 38… Rib 38A… Grooved flow path 38a… General surface 38b… Tip surface 40, 240… Protrusion 41, 141, 241… Top surface 42a, 42b, 142a, 242a, 242b… Side surface 43, 243… Recess 44, 244… Bottom surface 45a, 45b, 245a, 245b… Inner surface 50… Separator 50a… First surface 50b… Second surface 51… Through-hole 52… Through-hole 53... Through-hole 54... Through-hole 55... Through-hole 56... Through-hole 57... Groove flow path 58... Groove flow path 71... First groove flow path 72... Second groove flow path 73... Wavy portion 74... Wavy portion 75... Extended portion 76... Extended portion 81... Wavy portion 82... General portion 83... Narrow-width portion 84... Extended portion 90... Single cell 91... Introduction hole 92... Introduction hole 93... Introduction hole 94... Outlet hole 95... Outlet hole 96... Outlet hole 146a... Joint surface 246... Base portion 246a... Joint surface 246b... General surface 381... First rib 382... Second rib

Claims

1. A separator for a fuel cell, having a facing surface facing the power generation part of the fuel cell, wherein a plurality of groove channels through which a reaction gas flows are provided side by side on the facing surface, wherein a plurality of ribs are provided on the facing surface, which are located between the groove channels and protrude toward the power generation part, wherein a convex part protruding toward the power generation part is provided on the rib, wherein the convex part has a top surface extending in the plane direction of the power generation part and a pair of side surfaces extending by bending from both ends of the top surface in the arrangement direction of the plurality of groove channels, wherein the pair of side surfaces are inclined so as to be separated from the top surface in the arrangement direction as they are separated from the power generation part in the facing direction between the power generation part and the separator, wherein the protruding height of the convex part is 10 μm or more and 30 μm or less, wherein the inclination angle of the pair of side surfaces with respect to the top surface is 1 degree or more and 5 degrees or less, A separator for a fuel cell.

2. A separator for a fuel cell, having a facing surface facing the power generation part of the fuel cell, wherein a plurality of groove channels through which a reaction gas flows are provided side by side on the facing surface, wherein a plurality of ribs are provided on the facing surface, which are located between the groove channels and protrude toward the power generation part, wherein a convex part protruding toward the power generation part is provided on the rib, wherein the power generation part is held by a frame member located on the outer periphery of the power generation part, when the facing surface is an inner facing surface, the separator has an outer facing surface facing the frame member, the plurality of groove channels and the plurality of ribs each have an extension part extending to the outer facing surface, the convex part is also provided on the extension part of the rib, A separator for a fuel cell.

3. A separator for a fuel cell, having a facing surface facing the power generation part of the fuel cell, wherein a plurality of groove channels through which a reaction gas flows are provided side by side on the facing surface, wherein a plurality of ribs are provided on the facing surface, which are located between the groove channels and protrude toward the power generation part, wherein a convex part protruding toward the power generation part is provided on the rib, the separator includes a base material having the plurality of groove channels and the plurality of ribs, and a contact member joined to the base material and contacting the power generation part, wherein the convex part is constituted by the contact member, the contact member includes a base part joined to the rib, The convex portion protrudes from the base portion. The base portion is provided with a concave portion located at the center of the base portion in the arrangement direction of the plurality of groove channels. The concave portion has a bottom surface that extends in the surface direction of the power generation portion and faces the power generation portion, and a pair of inner surfaces that rise from both ends of the bottom surface in the arrangement direction. The pair of inner surfaces are inclined so as to be farther from the bottom surface in the arrangement direction as they approach the power generation portion in the facing direction between the power generation portion and the separator. The concave portion is provided at a position that does not overlap with the convex portion in the extending direction of the rib. Separator for a fuel cell.

4. A separator for a fuel cell having a facing surface facing the power generation portion of the fuel cell, wherein a plurality of groove channels through which a reaction gas flows are provided side by side on the facing surface. The facing surface is provided with a plurality of ribs that are located between the groove channels and protrude toward the power generation portion. The rib is provided with a convex portion that protrudes toward the power generation portion and a concave portion that is located at the center of the rib in the arrangement direction of the plurality of groove channels. The concave portion has a bottom surface that extends in the surface direction of the power generation portion and faces the power generation portion, and a pair of inner surfaces that rise from both ends of the bottom surface in the arrangement direction. The pair of inner surfaces are inclined so as to be farther from the bottom surface in the arrangement direction as they approach the power generation portion in the facing direction between the power generation portion and the separator. The concave portion is provided at a position that does not overlap with the convex portion in the extending direction of the rib. Separator for a fuel cell.

5. A pair of separators, A power generation portion having a pair of gas diffusion layers that are sandwiched between the pair of separators and contact each of the pair of separators. At least one of the pair of separators is the separator according to claim 1 or claim 2. The power generation portion is compressed in the facing direction between the power generation portion and the separator by the convex portion. Single cell of a fuel cell.

6. A pair of separators, A power generation portion having a pair of gas diffusion layers that are sandwiched between the pair of separators and contact each of the pair of separators. At least one of the pair of separators is the separator according to claim 3 or claim 4. The power generation unit is compressed in the facing direction by the convex portion and sinks into the concave portion. A single cell of a fuel cell.

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