Fuel cell

Abstract

To provide a fuel cell separator capable of improving performance, and a fuel cell capable of improving the performance of power generation.SOLUTION: Fuel cell separators 30, and 40 have central portions 35 and 45 constituting central portions in a plan view seen from a thickness direction Z, and peripheral portions 36 and 46 that are shaped to surround the central portions 35 and 45 in a plan view. The central portions 35 and 45 are made of metal material and the peripheral portions 36, 46 are made of synthetic resin material. Stepped portions 37, 47 forming the outer edges of the central portions 35, 45 and inner edges 36B, 46B of the peripheral portions 36, 46 overlap in the thickness direction Z, and are joined via elastic bodies 38 and 48.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention , burn This concerns battery charging. [Background technology]

[0002] Patent Document 1 discloses a fuel cell. This fuel cell includes a membrane electrode assembly, a pair of gas diffusion layers, and a pair of fuel cell separators. The membrane electrode assembly includes an electrolyte membrane, and an anode and a cathode, which are catalytic electrode layers formed on each side of the electrolyte membrane. The fuel cell has a structure in which the membrane electrode assembly is sandwiched between a pair of gas diffusion layers, and the membrane electrode assembly and the pair of gas diffusion layers are sandwiched between a pair of fuel cell separators from both sides in the thickness direction.

[0003] Patent Document 1 also discloses a fuel cell separator structure in which the central portion in a plan view, which faces the membrane electrode assembly, is made of a metal plate, and the peripheral portion surrounding the central portion is made of a synthetic resin material. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2006-210060 A Summary of the Invention [Problem to be solved by the invention]

[0005] In general, the thermal expansion coefficient of synthetic resin materials is higher than that of metallic materials, and for this reason, the fuel cell separator has a structure in which the thermal expansion coefficient of the central portion made of metallic material is higher than that of the peripheral portion made of synthetic resin material, resulting in a difference in the thermal expansion coefficient between the central portion and the peripheral portion.

[0006] In the above fuel cell separator, the difference in thermal expansion coefficient may cause thermal stress or deformation in the central or peripheral portion, which may lead to a decrease in the durability of the fuel cell separator and a decrease in the power generation performance of a fuel cell that uses the fuel cell separator. [Means for solving the problem]

[0007] The fuel cell separator for solving the above problem is a plate-shaped fuel cell separator having a central portion made of a first material and constituting a central part in a planar view from the thickness direction, and a peripheral portion made of a second material having a different thermal expansion coefficient than the first material and forming a shape that surrounds the central portion in the planar view, wherein the outer edge of the central portion and the inner edge of the peripheral portion overlap in the thickness direction and are joined via an elastic body.

[0008] In the above configuration, when the temperature of the fuel cell separator changes, a force acts to shift the outer edge of the central portion and the inner edge of the peripheral portion in a direction intersecting the thickness direction of the fuel cell separator, due to the difference in the amount of thermal expansion between the central portion and the peripheral portion.

[0009] According to the above configuration, the outer edge of the central portion and the inner edge of the peripheral portion are joined via an elastic body, and the elastic body is elastically deformed to allow relative movement between the outer edge of the central portion and the inner edge of the peripheral portion. This makes it possible to suppress the occurrence of thermal stress in the central portion and the peripheral portion of the fuel cell separator, and to suppress thermal deformation of the central portion and the peripheral portion. This makes it possible to improve the performance (durability, etc.) of the fuel cell separator.

[0010] In the above fuel cell separator, the elastic body is adhered to the outer edge of the central portion and the inner edge of the peripheral portion by an adhesive. According to the above-mentioned configuration, an elastic body having a suitable degree of elasticity can be attached between the outer edge of the central portion and the inner edge of the peripheral portion by using a suitable adhesive.

[0011] A fuel cell for solving the above problem includes a membrane electrode assembly, a pair of gas diffusion layers sandwiching the membrane electrode assembly therebetween, and a pair of fuel cell separators sandwiching the membrane electrode assembly and the pair of gas diffusion layers from both sides in a thickness direction, the fuel cell separator having a plate shape and including a central portion made of a first material and constituting a central portion in a planar view from the thickness direction, and a peripheral portion made of a second material having a different thermal expansion coefficient from the first material and having a shape that surrounds the periphery of the central portion in the planar view, and the outer edge of the central portion and the inner edge of the peripheral portion overlap in the thickness direction and are joined via an elastic body.

[0012] According to the above configuration, the outer edge of the center portion of the fuel cell separator and the inner edge of the peripheral portion are joined via an elastic body, and the elastic body is elastically deformed to allow relative movement between the outer edge of the center portion and the inner edge of the peripheral portion. This makes it possible to suppress the occurrence of thermal stress in the center portion and the peripheral portion of the fuel cell separator, and to suppress thermal deformation of the center portion and the peripheral portion. This makes it possible to improve the performance (durability, etc.) of the fuel cell separator, and ultimately to improve the power generation performance of the fuel cell.

[0013] In the above fuel cell, the elastic body is adhered to the outer edge of the central portion and the inner edge of the peripheral portion by an adhesive. According to the above-mentioned configuration, an elastic body having a suitable degree of elasticity can be attached between the outer edge of the central portion and the inner edge of the peripheral portion by using a suitable adhesive.

[0014] In the above fuel cell, a sheet-shaped spacer member is sandwiched between the peripheral portions of the pair of fuel cell separators, and the membrane electrode assembly and the pair of gas diffusion layers are sandwiched between the central portions of the pair of fuel cell separators, and it is preferable that the elastic modulus of the material forming the elastic body is smaller than the elastic modulus of the material forming the gas diffusion layers.

[0015] The gas diffusion layer, which constitutes part of the fuel cell, is structurally prone to greater dimensional variation than other components. For this reason, in the above-mentioned configuration, the spacing between the pair of fuel cell separators, more specifically, the spacing between the central portions that sandwich the gas diffusion layers, is prone to variation. Therefore, when assembling the fuel cell separators, the variation in the spacing between the central portions may cause variation in the relative positions in the thickness direction between the central portions and the peripheral portions.

[0016] According to the above configuration, since an elastic body is provided between the central portion and the peripheral portion, the deviation due to the variation in the relative position between the central portion and the peripheral portion is tolerated through the elastic deformation of the elastic body. Moreover, since the elastic body has a smaller elastic modulus than the gas diffusion layer, when the fuel cell separator is assembled, the elastic body can be elastically deformed while suppressing the deformation of the gas diffusion layer. Therefore, according to the above configuration, the fuel cell separator, whose central portion and peripheral portion are made of different materials, can be suitably assembled in a manner according to the dimensional variation of the gas diffusion layer sandwiched by the central portion, while suppressing the shape change of the gas diffusion layer. Effect of the Invention

[0017] According to the present invention, the performance of a fuel cell separator can be improved. [Brief description of the drawings]

[0018] [Figure 1] 1 is a cross-sectional side view of a fuel cell according to one embodiment; [Diagram 2] FIG. 2 is a plan view showing a schematic configuration of a fuel cell as viewed from the first separator side. [Diagram 3] FIG. 4 is an exploded perspective view showing a schematic configuration of a first separator as viewed obliquely from above. [Figure 4] 4 is an enlarged cross-sectional side view of the elastic body of the first separator and its periphery. FIG. [Diagram 5] FIG. 2 is a plan view showing a schematic configuration of a fuel cell as viewed from the second separator side. [Figure 6] FIG. 4 is an exploded perspective view showing a schematic configuration of a second separator as viewed obliquely from below. [Figure 7] 4 is a side cross-sectional view showing an enlarged view of the elastic body of the second separator and its periphery. FIG. [Figure 8] 4 is a side cross-sectional view showing an elastic body and its periphery in a state where the elastic body is elastically deformed in a planar direction. FIG. [Figure 9] 5 is an explanatory diagram for explaining an elastic deformation mode in a thickness direction of an elastic body. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] An embodiment of a fuel cell separator and a fuel cell will be described below. As shown in Figs. 1 and 2, the fuel cell 10 of this embodiment has a rectangular shape in a plan view. The fuel cell 10 of this embodiment is a polymer electrolyte fuel cell. The fuel cell 10 includes a membrane electrode gas diffusion layer assembly (hereinafter, MEGA20). The fuel cell 10 includes a pair of separators (first separator 30, second separator 40) that sandwich both sides of the MEGA20 and form a flow path for a reactant gas. In the following description, the long side direction of the fuel cell 10 is defined as the length direction X, the short side direction of the fuel cell 10 is defined as the width direction Y, and the stacking direction of the fuel cell 10 is defined as the thickness direction Z.

[0020] <Manifold holes 11~16> As shown in FIG. 2, the fuel cell 10 has a plurality of through holes (hereinafter, manifold holes 11-16) penetrating in the thickness direction Z. The manifold holes 11 and 16 form a manifold through which an oxidant gas flows. The manifold holes 12 and 15 form a manifold through which cooling water flows. The manifold holes 13 and 14 form a manifold through which a fuel gas flows. The oxidant gas is, for example, air containing oxygen. The fuel gas is, for example, hydrogen. The manifold holes 11-16 are, for example, rectangular in a plan view.

[0021] The manifold holes 11-13 are provided adjacent to one end edge of the fuel cell 10 in the longitudinal direction X (the left side in FIG. 2) and spaced apart from one another in the width direction Y. In this embodiment, the manifold holes 11, 12, 13 are provided in order from one side in the width direction Y (the upper side in FIG. 2).

[0022] The manifold holes 14 to 16 are provided adjacent to the other end edge (right side in FIG. 2) of the fuel cell 10 in the longitudinal direction X and spaced apart from one another in the width direction Y. In this embodiment, the manifold holes 14, 15, and 16 are provided in order from one side in the width direction Y (upper side in FIG. 2).

[0023] <mega20> As shown in Fig. 1, the MEGA 20 includes a plate-shaped membrane electrode assembly 21 and a pair of gas diffusion layers 25, 26 sandwiching the membrane electrode assembly 21. The membrane electrode assembly 21 is composed of an electrolyte membrane and a pair of catalyst layers (anode and cathode) sandwiching the electrolyte membrane. The gas diffusion layers 25, 26 are formed in a porous sheet shape from carbon fibers and a binder that binds the carbon fibers. The MEGA 20 is disposed in the center of the fuel cell 10 in the planar direction.

[0024] <Frame member 27> A sheet-like frame member 27 is provided inside the fuel cell 10. The frame member 27 is made of a synthetic resin material (for example, polypropylene). The frame member 27 has a rectangular frame shape. In the fuel cell 10, the MEGA 20 is housed in a central through-hole (hereinafter, central hole 27A) of the frame member 27. The manifold holes 11 to 16 are formed in the frame member 27. The frame member 27 is sandwiched between the first separator 30 and the second separator 40. In the fuel cell 10, the first separator 30 and the second separator 40 are joined via the frame member 27. In this embodiment, the frame member 27 corresponds to a spacer member.

[0025] <First separator 30> As shown in FIGS. 1 to 6, the first separator 30 and the second separator 40 have the same size and a rectangular shape in a plan view.

[0026] As shown in FIGS. 2 and 3, the first separator 30 is in the form of a plate and has manifold holes 11-16. 1 and 2, a fuel gas flow field section 31, an upstream distribution section 32, and a downstream distribution section 33 are defined in the portion of the first separator 30 facing the MEGA 20. As indicated by the two-dot chain line in FIG. 2, the fuel gas flow field section 31 is provided in the center portion in the surface direction of the first separator 30, more specifically, in the portion facing the MEGA 20. The upstream distribution section 32 connects the manifold hole 13 and the fuel gas flow field section 31. The downstream distribution section 33 connects the manifold hole 14 and the fuel gas flow field section 31.

[0027] 1, the first separator 30 is provided with a plurality of ridges 34 that protrude away from the MEGA 20 in the thickness direction Z. A space defined by the ridges 34 and the MEGA 20 constitutes a fuel gas flow path 31A.

[0028] As shown in Figures 1 to 3, the first separator 30 has a structure divided into a central portion 35 that constitutes the central part when viewed in a plan view from the thickness direction Z, and a peripheral portion 36 that has a shape that surrounds the periphery of the central portion 35 when viewed in a plan view.

[0029] <Central part 35> The central portion 35 is formed in a rectangular shape in a plan view from a metal material (e.g., a stainless steel plate) as a first material. In this embodiment, the metal material constituting the central portion 35 corresponds to the first material. The central portion 35 mainly constitutes a portion of the first separator 30 facing the MEGA 20, more specifically, a portion in contact with the MEGA 20. The protrusion 34 is formed in the central portion 35. A step portion 37 is provided on the outer edge portion of the central portion 35. The step portion 37 has a step shape in which the outer edge side portion of the central portion 35 is located farther away from the MEGA 20 (upward in FIG. 1) than the central side portion. The step portion 37 extends around the entire outer edge of the central portion 35.

[0030] <Surrounding area 36> The peripheral portion 36 is made of a synthetic resin material (e.g., polypropylene) and has a rectangular frame shape in plan view. In this embodiment, the synthetic resin material constituting the peripheral portion 36 corresponds to a second material having a thermal expansion coefficient different from that of the first material. The peripheral portion 36 mainly constitutes a portion of the first separator 30 facing the frame member 27, i.e., a portion in contact with the frame member 27. The manifold holes 11 to 16 are formed in the peripheral portion 36. In this embodiment, the central portion 35 is attached to the peripheral portion 36 in such a manner that the central through-hole (central hole 36A) in the peripheral portion 36 is blocked. The peripheral portion 36 and the central portion 35 constitute the first separator 30.

[0031] As shown in Figures 3 and 4, the first separator 30 has a structure in which the outer edge of the central portion 35 (specifically, the step portion 37) and the inner edge 36B of the peripheral portion 36 overlap in the thickness direction Z of the first separator 30.

[0032] <Elastic body 38> In addition, in a portion where the step portion 37 forming the outer edge of the central portion 35 and the inner edge 36B of the peripheral portion 36 overlap, the central portion 35 and the peripheral portion 36 are joined via an elastic body 38. The elastic body 38 is formed of an elastic synthetic resin material (e.g., urethane). As a result, in this embodiment, the elastic modulus of the material forming the elastic body 38 is smaller than the elastic modulus of the material forming the gas diffusion layers 25, 26. The elastic body 38 has a rectangular cross section and forms a quadrangular ring extending around the entire periphery of the central portion 35. In this embodiment, the surface of the elastic body 38 on the step portion 37 side of the central portion 35 is bonded to the step portion 37, and the surface of the elastic body 38 on the inner edge 36B side of the peripheral portion 36 is bonded to the inner edge 36B via an adhesive layer 39 (FIG. 4). In this embodiment, the elastic body 38 is adhered to the step portion 37 of the central portion 35 and the inner edge 36B of the peripheral portion 36 by an adhesive.

[0033] <Second separator 40> As shown in FIGS. 5 and 6, the second separator 40 is in the form of a plate and has manifold holes 11-16.

[0034] 1 and 5, an oxidant gas flow section 41, an upstream distribution section 42, and a downstream distribution section 43 are provided in the portion of the second separator 40 on the MEGA 20 side. As indicated by the two-dot chain line in Fig. 5, the oxidant gas flow section 41 is provided in the center portion in the surface direction of the second separator 40, more specifically, in the portion facing the MEGA 20. The upstream distribution section 42 connects the manifold hole 16 and the oxidant gas flow section 41. The downstream distribution section 43 connects the manifold hole 11 and the oxidant gas flow section 41.

[0035] 1, the second separator 40 is provided with a plurality of ridges 44 that protrude away from the MEGA 20 in the thickness direction Z. A space defined by the ridges 44 and the MEGA 20 constitutes an oxidizing gas flow field 41A.

[0036] As shown in Figures 1, 5 and 6, the second separator 40 has a structure divided into a central portion 45 that constitutes the central part when viewed in a planar view from the thickness direction Z, and a peripheral portion 46 that has a shape that surrounds the periphery of the central portion 45 when viewed in a planar view.

[0037] <Surrounding area 46> The peripheral portion 46 is formed of a synthetic resin material (e.g., polypropylene) as the second material in the shape of a rectangular frame in plan view. The peripheral portion 46 mainly constitutes a portion of the second separator 40 that faces the frame member 27, i.e., a portion that contacts the frame member 27. The manifold holes 11 to 16 are formed in the peripheral portion 46. In this embodiment, the central portion 45 is attached to the peripheral portion 46 in such a manner that the central through-hole (hereinafter, central hole 46A) in the peripheral portion 46 is blocked. The peripheral portion 46 and the central portion 45 constitute the second separator 40.

[0038] As shown in FIGS. 6 and 7, the second separator 40 has a structure in which the outer edge of the central portion 45 (specifically, the step portion 47) and the inner edge 46B of the peripheral portion 46 overlap in the thickness direction Z of the second separator 40.

[0039] <Elastic body 38> In addition, the central portion 45 and the peripheral portion 46 are joined via an elastic body 48 at a portion where the step portion 47 forming the outer edge of the central portion 45 and the inner edge 46B of the peripheral portion 46 overlap. The elastic body 48 is formed of an elastic synthetic resin material (e.g., urethane). As a result, in this embodiment, the elastic modulus of the material forming the elastic body 48 is smaller than the elastic modulus of the material forming the gas diffusion layers 25, 26. The elastic body 48 has a rectangular cross section and forms a quadrangular ring extending around the entire periphery of the central portion 45. In this embodiment, the surface of the elastic body 48 on the step portion 47 side of the central portion 45 is bonded to the step portion 47 via an adhesive layer 49 (FIG. 7) made of an adhesive, and the surface of the elastic body 48 on the inner edge 46B side of the peripheral portion 46 is bonded to the inner edge 46B.

[0040] <Action and effect> The effects of this embodiment will be described. (1) The separator 30, 40 has a central portion 35, 45 made of a metal material and a peripheral portion 36, 46 made of a synthetic resin material. A step portion 37, 47 constituting the outer edge of the central portion 35, 45 and an inner edge 36B, 46B of the peripheral portion 36, 46 overlap each other in the thickness direction Z and are joined together via an elastic body 38, 48.

[0041] In this embodiment, the amount of thermal expansion of the central portions 35, 45 of the separators 30, 40 differs from the amount of thermal expansion of the peripheral portions 36, 46. Therefore, when the temperature of the separators 30, 40 changes, a force is generated that displaces the step portions 37, 47 of the central portions 35, 45 and the inner edges 36B, 46B of the peripheral portions 36, 46 in a direction intersecting the thickness direction Z (more specifically, in a planar direction) due to the difference in the amount of thermal expansion.

[0042] In the separators 30 and 40 of this embodiment, the step portions 37 and 47 forming the outer edges of the central portions 35 and 45 and the inner edges 36B and 46B of the peripheral portions 36 and 46 are joined via the elastic bodies 38 and 48. Therefore, as shown in FIG. 8, the elastic body 38 is elastically deformed to allow relative movement in the planar direction between the step portion 37 of the central portion 35 and the inner edge 36B of the peripheral portion 36. Similarly, the elastic body 48 (see FIG. 7) is elastically deformed to allow relative movement in the planar direction between the step portion 47 of the central portion 45 and the inner edge 46B of the peripheral portion 46. This makes it possible to suppress the occurrence of thermal stress in the central portions 35 and 45 and the peripheral portions 36 and 46 of the separators 30 and 40, and to suppress thermal deformation of the central portions 35 and 45 and the peripheral portions 36 and 46. Therefore, the performance (durability, etc.) of the separators 30, 40 can be improved, and the power generation performance of the fuel cell 10 can be improved.

[0043] (2) The elastic bodies 38, 48 are bonded by an adhesive to the step portions 37, 47 of the central portions 35, 45 and the inner edges 36B, 46B of the peripheral portions 36, 46. This allows the elastic bodies 38, 48, which have appropriate elasticity, to be attached between the step portions 37, 47 of the central portions 35, 45 and the inner edges 36B, 46B of the peripheral portions 36, 46 using an appropriate adhesive.

[0044] (3) A sheet-like frame member 27 is sandwiched between a pair of peripheral portions 36, 46. The MEGA 20 is sandwiched between a pair of central portions 35, 45. The elastic modulus of the material forming the elastic bodies 38, 48 is smaller than the elastic modulus of the material forming the gas diffusion layers 25, 26.

[0045] The gas diffusion layers 25, 26 constituting a part of the fuel cell 10 are likely to have greater dimensional variation compared to other components due to their structure. For this reason, it can be said that the fuel cell 10 is likely to have variation in the spacing between the pair of separators 30, 40, more specifically, the spacing between the central portions 35, 45 which sandwich the gas diffusion layers 25, 26. Therefore, when assembling the separators 30, 40, the variation in the spacing of the central portion 35 may cause variation in the relative positions of the central portion 35 and the peripheral portion 36 in the thickness direction Z.

[0046] As shown in Fig. 9, in the fuel cell 10 of this embodiment, elastic bodies 38, 48 are provided between the step portions 37, 47 of the central portions 35, 45 and the inner edges 36B, 46B of the peripheral portions 36, 46. Therefore, the deviation due to the variation in the relative positions of the central portions 35, 45 and the peripheral portions 36, 46 in the thickness direction Z (the vertical direction in Fig. 9) is tolerated through the elastic deformation of the elastic bodies 38, 48 in the thickness direction Z. Moreover, since the elastic bodies 38, 48 have a smaller elastic modulus than the gas diffusion layers 25, 26, when the separators 30, 40 are assembled, the elastic bodies 38, 48 can be elastically deformed while suppressing the deformation of the gas diffusion layers 25, 26.

[0047] In the separators 30, 40 of this embodiment, the central portions 35, 45 and the peripheral portions 36, 46 are made of different materials. According to this embodiment, the assembly work of the separators 30, 40 can be suitably performed in accordance with the dimensional variation of the gas diffusion layers 25, 26 sandwiched by the central portions 35, 45 while suppressing deformation of the gas diffusion layers 25, 26.

[0048] <Modification> The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other to the extent that no technical contradiction occurs.

[0049] The structure of the portion of the separator 30, 40 where the elastic body 38, 48 is provided, specifically, the structure of the outer edge of the central portion 35, 45 and the structure of the inner edge 36B of the peripheral portion 36, 46, can be changed arbitrarily. For example, a step portion may be formed on the inner edge of the peripheral portion 36, 46. As the step portion, a step shape in which the inner edge side portion of the peripheral portion 36, 46 is located farther from the MEGA 20 than the outer edge side portion can be adopted, or a step shape in which the inner edge side portion is located closer to the MEGA 20 than the outer edge side portion can be adopted. In addition, it is also possible to not form the step portion 37 on the outer edge of the central portion 35, and to form the outer edge flat.

[0050] The gas diffusion layers 25, 26 may have a structure in which a base layer formed into a porous sheet shape from carbon fibers and a binder that bonds the carbon fibers is laminated with a porous thin film (so-called microporous layer) whose main components are a synthetic resin material and a conductive material.

[0051] In the above embodiment, the elastic body 38, 48 is bonded to the step portion 37, 47 of the central portion 35, 45 and the inner edge 36B, 46B of the peripheral portion 36, 46 by the adhesive layer 39, 49 made of an adhesive. Alternatively, an adhesive having a suitable elasticity after curing may be used, and the step portion 37, 47 of the central portion 35, 45 and the inner edge 36B, 46B of the peripheral portion 36, 46 may be bonded only via the adhesive layer made of this adhesive. In this configuration, the adhesive layer corresponds to the elastic body.

[0052] The fuel cell separator according to the above embodiment may be used as only one of the first separator 30 and the second separator 40. The fuel cell separator according to the above embodiment can be applied to any fuel cell separator having a central portion and a peripheral portion made of different materials, such as a separator having a central portion made of a carbon-based material (carbon or a mixture of carbon and a synthetic resin material) and a peripheral portion made of a synthetic resin material. [Explanation of symbols]

[0053] 10…fuel cell 20...Membrane electrode gas diffusion layer assembly (MEGA) 21...Membrane electrode assembly 25...Gas diffusion layer 26...Gas diffusion layer 27...Frame member 30…First separator 35,45…Central part 36,46…periphery 36B, 46B...Common-law marriage 37,47…Step section 38, 48…Elastic body 39,49...adhesive layer 40…Second separator

Claims

1. A fuel cell comprising: a membrane electrode assembly; a pair of gas diffusion layers sandwiching the membrane electrode assembly therebetween; and a pair of fuel cell separators sandwiching the membrane electrode assembly and the pair of gas diffusion layers from both sides in a thickness direction, the fuel cell separator has a plate shape, and includes a central portion made of a first material and constituting a central portion in a plan view seen from the thickness direction, and a peripheral portion made of a second material having a thermal expansion coefficient different from that of the first material and having a shape surrounding the periphery of the central portion in the plan view, a sheet-shaped spacer member is sandwiched between the peripheral portions of the pair of fuel cell separators; The outer edge of the central portion and the inner edge of the peripheral portion overlap each other in the thickness direction and are joined together via an elastic body. fuel cell.

2. The elastic body is bonded to the outer edge of the central portion and the inner edge of the peripheral portion by an adhesive. The fuel cell according to claim 1 .

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