Fuel battery cell and fuel battery

Abstract

This fuel battery cell (10) comprises a core sheet (22) and a separator (20). The core sheet (22) is provided with: an MEA (24) that has an electrolyte membrane (24a) and an electrode layer (24b); and a frame-shaped sheet (23). The separator (20) is provided with a first inlet part (50a) into which a first gas is introduced, a first outlet part (60a) from which the first gas is discharged, a second inlet part (50b) into which a second gas is introduced, and a second outlet part (60b) from which the second gas is discharged. At least one among the first inlet part (50a), the second inlet part (50b), the first outlet part (60a), and the second outlet part (60b) has a plurality of protrusion parts (100) that protrude toward the frame-shaped sheet (23) and support the frame-shaped sheet (23). The protrusion parts (100) abut against the frame-shaped sheet (23) and restrict displacement of the frame-shaped sheet (23) in the planar direction.

Description

Fuel cell and fuel cell 【0001】 The present disclosure relates to a fuel cell and a fuel cell. 【0002】 In the fuel cell described in Patent Document 1, a fuel cell is disclosed in which a carbon porous body and a metal porous body are provided as an intermediate layer to relieve the stress applied to the electrolyte membrane. 【0003】 Japanese Patent Application Laid-Open No. 2013-196884 【0004】 By the way, in the above-described aspect, in the gas diffusion part, there is a problem that the frame-shaped sheet is deformed due to factors such as the generation of differential pressure between the anode and the cathode, and the flow path is blocked. Although the deformation can be suppressed by thickening the frame-shaped sheet or supporting the frame-shaped sheet with a metal plate, such a structure causes the fuel cell to thicken and the fuel cell to become larger. 【0005】 An object of the present disclosure is to provide a fuel cell capable of suppressing blockage of a flow path in a diffusion part while suppressing the thickness. 【0006】 A fuel cell according to an aspect of the present disclosure includes: a core sheet; a separator provided outside the core sheet; the core sheet includes a membrane electrode assembly (MEA) having an electrolyte membrane and an electrode layer provided outside the electrolyte membrane; a resin-made frame-shaped sheet that supports the MEA; the separator has an inlet part and an outlet part; the inlet part has a first inlet part into which a first gas is introduced and a second inlet part into which a second gas is introduced; the outlet part has a first outlet part from which the first gas is discharged and a second outlet part from which the second gas is discharged; at least one of the first inlet part and the second inlet part, and the first outlet part and the second outlet part protrudes toward the frame-shaped sheet and has a plurality of convex parts that support the frame-shaped sheet; the convex parts are abutted against the frame-shaped sheet to suppress displacement of the frame-shaped sheet in the plane direction. 【0007】 According to the above, it is possible to provide a fuel cell capable of suppressing blockage of a flow path in a diffusion part while suppressing the thickness. 【0008】 Figure 1 is a perspective view of a fuel cell using the fuel cell cell according to the present disclosure. Figure 2 is an exploded perspective view of the fuel cell cell according to this embodiment. Figure 3 is a front view of the separator according to this embodiment. Figure 4 is a front view showing the separator according to the present disclosure superimposed. Figure 5A is a diagram showing the gas flow in the fuel cell cell according to this embodiment. Figure 5B is a diagram showing the gas flow in the fuel cell cell according to this embodiment. Figure 6A is an enlarged view of region VI in Figure 5B. Figure 6B is a cross-sectional view taken along the B-B line in the diffusion section in Figure 6A. Figure 7 is a cross-sectional view of the portion in the fuel cell where the first inlet-side diffusion section of the anode-side separator and the second outlet-side collection section of the cathode-side separator overlap in a planar projection view. 【0009】 [Details of Embodiments of the Disclosure] Specific examples of fuel cell cells 10 according to embodiments of the Disclosure will be described below with reference to the drawings. However, the Disclosure is not limited to these examples and is intended to include all modifications within the meaning and scope of the Claims, as indicated by the Claims. 【0010】 In Figure 1, etc., U, D, F, B, R, and L indicate directions in the fuel cell cell 10, where U is upward, D is downward, F is forward, B is backward, R is to the right, and L is to the left. In the following explanation, when there is no distinction between right and left, the term "side" may be used. 【0011】 Figure 1 is a perspective view of a fuel cell 1 using the fuel cell cell 10 according to this disclosure. 【0012】 As shown in Figure 1, the fuel cell 1 is constructed by stacking one or more fuel cell cells 10. The fuel cell 1 has end plates provided at both ends of the stacked fuel cell cells 10, electrodes for extracting electricity generated by the fuel cell, and a case shown by the dashed line in Figure 1. In the following description, the fuel cell 10 may be simply referred to as "cell". 【0013】One end plate is provided with inlets and outlets for each fluid into the stack, designated as the first gas inlet 2, first gas outlet 3, second gas inlet 4, second gas outlet 5, cooling water inlet 6, and cooling water outlet 7. 【0014】 The configuration of the fuel cell 10 will be explained using Figures 2 to 4. Figure 2 is an exploded perspective view of the fuel cell 10 according to this embodiment. As shown in Figure 2, the fuel cell 10 has a separator 20 and a core sheet 22. Two separators 20 sandwich the core sheet 22 to constitute the fuel cell 10. The fuel cell 10 allows gas to flow between the separator 20 and the core sheet 22. Two types of gas, a first gas and a second gas, flow between the separator 20 and the core sheet 22, with different flow paths. 【0015】 As shown in Figure 2, the core sheet 22 is a substantially rectangular member in side view. The core sheet 22 has a frame-shaped sheet 23 and an MEA (Membrane Electrode Assembly) 24. The MEA 24 has a pair of electrode layers 24b (including a catalyst layer and a gas diffusion layer) and an electrolyte membrane 24a sandwiched between the pair of electrode layers 24b. The MEA 24 can generate electricity by reacting the first gas and second gas flowing between the separator 20 and the core sheet 22 with the electrolyte membrane 24a and the electrode layers 24b. 【0016】 The frame-shaped sheet 23 is a thin, frame-shaped sheet made of resin that supports the MEA 24. Two frame-shaped sheets 23 support the MEA 24 by sandwiching its outer edges. The MEA 24 is exposed through the central opening of the frame-shaped sheet 23. 【0017】 The separator 20 is a thin plate-shaped component made of carbon material, metal material, etc. The separator 20 has an anode-side separator 20a and a cathode-side separator 20b. In the following description, the anode-side separator 20a and the cathode-side separator 20b may be collectively referred to as "separator 20". 【0018】As shown in Figure 2, the separator 20 has a gas flow channel groove 21, an inlet portion 50, and an outlet portion 60. The separator 20 forms a gas flow channel between itself and the core sheet 22 through which gas can pass. The gas flow channel groove 21 is formed from the inlet portion 50 to the outlet portion 60. In this embodiment, the gas flow channel groove 21 is a wavy, uneven shape formed on the surface of the separator 20, extending from the inlet portion 50 to the outlet portion 60. The gas flow channel groove 21 forms a plurality of fine flow channels between itself and the core sheet 22. In Figure 2, the gas flow channel groove 21 is depicted as being only a part of the separator 20, but in reality, it is provided on the entire surface of the separator 20 facing the electrode layer 24b. 【0019】 The inlet 50 allows gas to be introduced between the separator 20 and the core sheet 22. The separator 20 forms a space between itself and the core sheet 22 that serves as the inlet 50. The outlet 60 allows the gas introduced between the separator 20 and the core sheet 22 to be discharged. The inlet 50 and the outlet 60 are provided at the ends of the separator 20 in the direction in which the gas flow channel groove 21 extends. 【0020】 In this embodiment, the anode-side separator 20a is provided with a first gas flow channel groove 21a as a gas flow channel groove 21. The anode-side separator 20a is also provided with an inlet 50 and an outlet 60, namely a first inlet 50a and a first outlet 60a. In this embodiment, the cathode-side separator 20b is provided with a second gas flow channel groove 21b as a gas flow channel groove 21. The cathode-side separator 20b is also provided with an inlet 50 and an outlet 60, namely a second inlet 50b and a second outlet 60b. 【0021】A first gas is introduced as a gas between the anode-side separator 20a and the core sheet 22. A second gas is introduced as a gas between the cathode-side separator 20b and the core sheet. Cooling water is introduced into the flow path formed between adjacent fuel cell cells 10. In this embodiment, a cross-flow method is adopted in which the first gas and the second gas flow into the fuel cell cell 10 from opposing directions. Therefore, please note that the positions of the inlet 50 and outlet 60 are different for the anode-side separator 20a and the cathode-side separator 20b. 【0022】 Figure 3 shows front views (viewed from the front) of the anode-side separator 20a and cathode-side separator 20b according to this embodiment. In this figure, the first gas flows between the back surface (opposite side of the paper) of the anode-side separator 20a and the core sheet 22 (see Figure 2). The second gas flows between the surface of the cathode-side separator 20b and the core sheet 22 (see Figure 2). 【0023】 As shown in Figure 3, the inlet section 50 has an inlet hole 51 and a diffusion section 52. The inlet hole 51 is a hole for taking in gas taken in from the first gas inlet 2 and the second gas inlet 4 shown in Figure 1 into the cell, and gas is introduced into the inside of the cell 10 from the inlet hole 51. The gas introduced from the inlet hole 51 is diffused in the diffusion section 52, and the gas pressure acting in the diffusion section 52 guides the gas to the gas flow channel groove 21. The outlet section 60 has an outlet hole 61 and a collection section 62. The outlet hole 61 is provided to discharge the gas introduced between the separator 20 and the core sheet 22. The gas that flows out from the gas flow channel groove 21 is collected in the collection section 62 toward the outlet hole 61 and discharged to the outside of the cell from the outlet hole 61. 【0024】 In this embodiment, the inlet hole 51 and the outlet hole 61 are located at diagonal corners of the separator 20. 【0025】 In the following explanation, the inlet hole 51 and the outlet hole 61 may be collectively referred to as the "hole section." Also, in the following explanation, the diffusion section 52 and the collection section 62 may be collectively referred to as the "diffusion collection section." 【0026】Although not shown in this embodiment, a seal structure is provided between the separator 20 and the core sheet 22, surrounding the gas inlet hole 51, diffusion section 52, gas flow channel groove 21, collection section 62, and outlet hole 61. This seal structure is also provided in the cooling water flow channel formed between the fuel cell cells 10. The seal structure allows each fluid to flow without mixing with each other. 【0027】 Figure 4 is a front view of the fuel cell cell 10 according to this disclosure. The anode-side separator 20a is located on the near side of the page in Figure 4, and the cathode-side separator 20b is located on the far side of the page in Figure 4. Figure 4 depicts the anode-side separator 20a and the cathode-side separator 20b as seen from the front in perspective. 【0028】 In this embodiment, the anode-side separator 20a has a first flow path consisting of a first gas inlet hole 51a, a first gas diffusion section 52a, a first gas flow path groove 21a, a first gas outlet hole 61a, and a first gas collection section 62a. The cathode-side separator 20b has a second flow path consisting of a second gas inlet hole 51b, a second gas diffusion section 52b, a second gas flow path groove 21b, a second gas outlet hole 61b, and a second gas collection section 62b. 【0029】 As shown in Figure 4, in the single fuel cell cell 10 according to this embodiment, the inlet portion 50 and outlet portion 60 do not overlap when viewed transparently from the side of the fuel cell cell 10. Furthermore, when the single fuel cell cell 10 according to this embodiment is viewed transparently from the side, the first gas diffusion portion 52a overlaps with the second gas collection portion 62b, and the first gas collection portion 62a overlaps with the second gas diffusion portion 52b. 【0030】Next, the manner in which gas flows between the separators 20 will be described using Figures 5A and 5B. Figures 5A and 5B are diagrams showing the gas flow in the fuel cell cell 10 according to this embodiment. Figure 5A is a diagram illustrating the first flow path formed between the anode-side separator 20a and the core sheet 22 when the fuel cell cell 10 is viewed from the front. Figure 5B is a diagram illustrating the second flow path formed between the cathode-side separator 20b and the core sheet 22 when the fuel cell cell 10 is viewed from the front. 【0031】 As shown in Figures 5A and 5B, in this embodiment, the first gas is introduced between the anode-side separator 20a and the core sheet 22 through the first gas inlet hole 51a. After being introduced through the first gas inlet hole 51a, the first gas diffuses in the vertical direction of the first gas flow channel groove 21a via the first gas diffusion section 52a and flows to the left, where the first gas outlet hole 61a is located. The second gas flows between the cathode-side separator 20b and the core sheet 22 (see Figure 2) in a different direction from the first gas, but similar to the first gas. In other words, when the first gas and the second gas are introduced into the fuel cell cell 10, the first gas and the second gas flow in directions that intersect with the core sheet 22 in between. In this embodiment, the first gas is hydrogen gas and the second gas is air. 【0032】 In this embodiment, a cross-flow type (counter-flow type) fuel cell cell 10 is described in which the direction in which the first gas flows and the direction in which the second gas flows are different, but the disclosure is not limited thereto. For example, a parallel-flow type fuel cell cell in which the first gas and the second gas flow in the same direction may also be used. 【0033】 Next, the diffusion collection section will be described in detail using Figures 6A and 6B. Figure 6A is an enlarged view of the circularly enclosed region VI in Figure 5B. Figure 6B is a view along the arrow showing the B-B cross-section of the collection section in Figure 6A. In the following description, the second gas collection section 62b of the cathode-side separator 20b will be described in detail, but other diffusion collection sections besides the second gas collection section 62b may have a similar configuration. 【0034】As shown in Figure 6A, the diffusion collection unit has a protrusion 100 and a base portion 101. The base portion 101 is, for example, the part that constitutes the main body of the cathode-side separator 20b. The protrusion 100 is processed to protrude convexly from the base portion 101 so as to abut against the frame-shaped sheet 23. More specifically, the protrusion 100 protrudes toward the frame-shaped sheet 23 sandwiched between the anode-side separator 20a and the cathode-side separator 20b. 【0035】 As shown in Figure 6B, the protrusion 100 has a flat portion 102 at its tip. The flat portion 102 is configured to be able to make surface contact with the frame-shaped sheet 23. The adjacent protrusions 100, the frame-shaped sheet 23, and the base portion 101 form a gas passage R. 【0036】 As shown in Figure 6A, the distance between the protrusions 100 on the second gas collection section 62b is set to correspond to the distance from the first gas inlet hole 51a. As shown in Figure 6A, the distance S1 between protrusion 100a and protrusion 100b is smaller than the distance S2 between protrusion 100c and protrusion 100d, which are located further from the first gas inlet hole 51a than protrusion 100a and protrusion 100b. 【0037】 The configuration of the protrusion 100 of the fuel cell cell 10 according to this embodiment will be described in detail with reference to Figure 7. Figure 7 is a cross-sectional view showing the portion where the first gas diffusion portion 52a of the anode-side separator 20a and the second gas collection portion 62b of the cathode-side separator 20b sandwich the frame-shaped sheet 23. In Figure 7, the anode-side separator 20a is located above the frame-shaped sheet 23, and the cathode-side separator 20b is located below the frame-shaped sheet 23. 【0038】As shown in Figure 7, the separator 20 and the frame-shaped sheet 23 are in contact at the contact portion 200. The contact portion 200 refers to the portion of the separator 20 and the frame-shaped sheet 23 that is in contact. The contact between the frame-shaped sheet 23 and the anode-side separator 20a at the contact portion 200 forms a gas passage R (gas passage R1 in Figure 7). The contact between the frame-shaped sheet 23 and the cathode-side separator 20b at the contact portion 200 forms a gas passage R (gas passage R2 in Figure 7). In this embodiment, hydrogen gas flows through gas passage R1 as the first gas. Air flows through gas passage R2 as the second gas. 【0039】 When gas is introduced into gas conduits R1 and R2, the frame-shaped sheet 23 is subjected to pressure from both the first gas and the second gas. 【0040】 More specifically, the pressure of the gas flowing through the gas conduit R is highest near the inlet hole 51 and lowest near the outlet hole 61 due to pressure loss within the flow path. For this reason, the pressure in the gas conduit R1 of the first gas diffusion section 52a tends to be higher than the pressure in the gas conduit R2 of the second gas collection section 62b. In particular, in this embodiment, where the first gas is hydrogen gas and the second gas is air, the pressure loss of air is higher than that of hydrogen gas, so the pressure in the gas conduit R1 of the first gas diffusion section 52a will be higher than the pressure in the gas conduit R2 of the second gas collection section 62b. 【0041】 Gas passages R1 and R2 are separated by a deformable resin frame-shaped sheet 23. Due to the pressure difference between the gas passages R1 and R2, the frame-shaped sheet 23 separating gas passages R1 and R2 may deform. Specifically, the frame-shaped sheet 23 may bulge outwards in a convex shape toward the base portion 101 of the cathode-side separator 20b, blocking gas passage R2. If the frame-shaped sheet 23 deforms, it may block gas passages R1 and R2. 【0042】The amount of deformation of the frame-shaped sheet 23 due to the differential pressure is determined by the magnitude of the differential pressure, the bending rigidity of the frame-shaped sheet 23, the distance between the convex portions 100 that support the frame-shaped sheet 23, and the like. According to the fuel cell 10 according to the present disclosure, even when the plate thickness of the frame-shaped sheet 23 is thin and the bending rigidity is low, by reducing the distance between the convex portions 100 that support the frame-shaped sheet 23 in accordance with the rigidity of the frame-shaped sheet 23, while suppressing the thickness of the frame-shaped sheet 23, the deformation of the frame-shaped sheet 23 due to the differential pressure can be suppressed to such an extent that the gas conduction path R is not blocked. 【0043】 Specifically, the maximum deflection amount δ when a differential pressure P is applied to the frame-shaped sheet 23 that deflects between any adjacent pair of convex portions 100 can be approximately calculated as the maximum displacement when a distributed load is applied to a simply supported beam with both ends restrained. That is, assuming that the differential pressure between the first gas and the second gas is P, the thickness of the frame-shaped sheet 23 is h, the elastic modulus of the frame-shaped sheet 23 is E, the height of the convex portion 100 is D, and the distance between the contact portions 200 of the frame-shaped sheet 23 with the adjacent convex portions 100 is L, the maximum deflection amount δ is expressed by the following formula. From the above formula, it can be seen that even when the thickness h of the frame-shaped sheet 23 is thin, by reducing the distance L between the contact portions 200 of the convex portion 100 and the frame-shaped sheet 23, the value of the deflection amount δ can be suppressed to be small. As a criterion for the maximum deflection amount δ not to block the flow path, it can be mentioned that the deflection amount δ of the frame-shaped sheet 23 does not exceed 1 / 3 of the convex portion height D, that is, the flow path height. Expressed by a mathematical formula, it is as follows. By configuring the fuel cell 10 so as to satisfy the above formula, it is possible to suppress the blockage of the gas conduction path R due to the deformation of the frame-shaped sheet 23. For example, it can be used as an index for the height of the convex portion 100 to prevent the gas conduction path R from being blocked, corresponding to the thickness h and the elastic modulus E of the frame-shaped sheet 23. Also, it can be used as an index for determining the thickness h and the elastic modulus E of the frame-shaped sheet 23, corresponding to the height D of the convex portion 100. 【0044】 In the embodiment shown in FIG. 7, the height D of the convex portion 100f is the distance from the base portion 101e to the contact portion 200 where the flat portion 102e and the frame-shaped sheet 23 contact. Also, the distance L between the adjacent convex portions 100 is the distance between the contact portions 200 of the adjacent convex portions 100. 【0045】 In the embodiment shown in FIG. 7, the convex portions 100e and 100f provided in the diffusion portion abut against the frame-shaped sheet 23, suppressing the displacement of the frame-shaped sheet 23 in the plane direction. Further, the convex portion 100e has a flat portion 102e, and the convex portion 100f has a flat portion 102f. The flat portion 102e and the flat portion 102f can be in surface contact with the frame-shaped sheet 23, and since the contact area can be increased, the pressure applied to the frame-shaped sheet 23 can be dispersed. 【0046】 The pressure applied to the frame-shaped sheet 23 from the gas flowing through the gas conduction path R is the highest near the inlet hole 51 and the lowest near the outlet hole 61. Therefore, in the vicinity of the diffusion portion where the inlet hole 51 and the outlet hole 61 are provided, the difference (differential pressure) between the pressure applied to the frame-shaped sheet 23 by the gas conduction path R on the anode side and the pressure applied to the frame-shaped sheet 23 by the gas conduction path R on the cathode side is large. Thus, the vicinity of the inlet hole 51 and the outlet hole 61 is an environment where the frame-shaped sheet 23 is particularly likely to deform. 【0047】 In the present embodiment, when the separators are overlapped and viewed transparently, the convex portions 100a and 100b provided in the second gas collection portion 62b of the cathode-side separator 20b are located near the first gas inlet hole 51a of the anode-side separator 20a. The pressure due to the first gas is the maximum near the first gas inlet hole 51a, while the second gas collection portion 62b is located downstream in the gas flow path of the second gas, so the pressure due to the gas is small. As a result, the vicinity of the first gas inlet hole 51a is a place where the differential pressure between the first gas and the second gas becomes the largest. 【0048】 According to the fuel cell of the present disclosure, the separation distance between the convex portions 100 at the inlet portion 50 is smaller the closer it is to the inlet hole 51, and the separation distance at the outlet portion 60 is smaller the closer it is to the outlet hole 61. Thereby, the convex portion 100 can effectively support the portion where the differential pressure in the frame-shaped sheet 23 is high, and it is possible to provide the fuel cell 10 that can suppress the deformation of the frame-shaped sheet 23. 【0049】For example, in the fuel cell cell 10 according to this embodiment, the distance between the protrusions 100 is reduced in areas where the gas differential pressure is large, such as near the first gas inlet hole 51a. As a result, the support spacing of the frame-shaped sheet 23 by the protrusions 100 is reduced, which increases the support rigidity of the separator and prevents deformation of the frame-shaped sheet 23 due to the differential pressure. 【0050】 Furthermore, in the above embodiment, the distance between the protrusions 100 was changed according to the distance from the inlet hole 51 and the outlet hole 61, but instead of changing the distance between the protrusions 100, the bending rigidity of the frame-shaped sheet 23 may be changed. That is, by increasing the bending rigidity of the frame-shaped sheet 23 closer to the inlet hole and outlet hole (for example, by increasing the plate thickness), deformation of the frame-shaped sheet in areas with larger differential pressure can be suppressed. 【0051】 Furthermore, in the fuel cell cell 10 according to this disclosure, the protrusions 100 may be dimples that protrude toward the frame-shaped sheet 23. This configuration makes it easier to increase the flow area of ​​the gas passage R. 【0052】 While embodiments of this disclosure have been described above, it goes without saying that the technical scope of this disclosure should not be interpreted restrictively by the description of these embodiments. These embodiments are merely examples, and it will be understood by those skilled in the art that various modifications to the embodiments are possible within the scope of the invention described in the claims. The technical scope of this disclosure should be determined based on the scope of the invention described in the claims and the scope of its equivalents. 【0053】 Although preferred embodiments of the present invention have been described above, these embodiments are merely examples of the present invention, and it is possible to combine them based on the knowledge of those skilled in the art, and such forms are also included within the scope of the present invention. 【0054】As described above, the following is disclosed in this specification: (1) A fuel cell cell comprising: a core sheet; a separator provided on the outside of the core sheet, wherein the core sheet comprises an electrolyte membrane and an electrode layer provided on the outside of the electrolyte membrane; and a resin frame-shaped sheet supporting the MEA; the separator comprises an inlet portion and an outlet portion; the inlet portion comprises a first inlet portion into which a first gas is introduced and a second inlet portion into which a second gas is introduced; the outlet portion comprises a first outlet portion into which the first gas is discharged and a second outlet portion into which the second gas is discharged; and at least one of the first inlet portion and the second inlet portion, and the first outlet portion and the second outlet portion, has a plurality of protrusions that project toward the frame-shaped sheet and support the frame-shaped sheet; the protrusions abut against the frame-shaped sheet to suppress the displacement of the frame-shaped sheet in the planar direction. (2) The fuel cell cell according to (1), wherein the protrusions are dimples that project toward the frame-shaped sheet. (3) The fuel cell cell according to (1) or (2), wherein the protrusion has a flat portion that abuts against the frame-shaped sheet, and the flat portion and the frame-shaped sheet are in surface contact. (4) The fuel cell cell according to any one of (1) to (3), wherein the first gas is hydrogen gas and the second gas is air. (5) The fuel cell cell according to any one of (1) to (4), wherein the first gas and the second gas are configured to flow in opposite directions, and the protrusion is provided at least at the outlet portion. (6) The fuel cell cell according to any one of (1) to (5), wherein the inlet portion has an inlet hole, the outlet portion has an outlet hole, and the distance between the multiple protrusions in the inlet portion or the outlet portion changes according to the distance from the inlet hole and the outlet hole. (7) The fuel cell cell according to (6), wherein the distance between the protrusions in the inlet portion becomes smaller as it approaches the inlet hole, and the distance between the protrusions in the outlet portion becomes smaller as it approaches the outlet hole. (8) The fuel cell cell according to any one of (1) to (7), wherein the inlet portion has an inlet hole, the outlet portion has an outlet hole, the bending rigidity of the frame-shaped sheet increases closer to the inlet hole, and the bending rigidity of the frame-shaped sheet at the outlet portion increases closer to the outlet hole.(9) A fuel cell cell according to any one of (1) to (9), wherein the following equation holds true for the maximum amount of deflection δ of the frame-shaped sheet that deflects between any adjacent pair of the protrusions, where P is the differential pressure between the first gas and the second gas, h is the thickness of the frame-shaped sheet, E is the modulus of elasticity of the frame-shaped sheet, D is the height of the protrusions, and L is the distance between the contact portions of adjacent protrusions with the frame-shaped sheet. (10) A fuel cell using any one of the fuel cell cells described in (1) through (9).

Claims

1. A fuel cell comprising: a core sheet; a separator provided on the outside of the core sheet; the core sheet having an electrolyte membrane and an electrode layer provided on the outside of the electrolyte membrane; a resin frame-shaped sheet supporting the MEA; the separator having an inlet and an outlet; the inlet having a first inlet through which a first gas is introduced and a second inlet through which a second gas is introduced; the outlet having a first outlet through which the first gas is discharged and a second outlet through which the second gas is discharged; at least one of the first inlet and the second inlet, and the first outlet and the second outlet, having a plurality of protrusions that project toward the frame-shaped sheet and support the frame-shaped sheet; and the protrusions abutting against the frame-shaped sheet to suppress the displacement of the frame-shaped sheet in the planar direction.

2. The fuel cell cell according to claim 1, wherein the protrusions are dimples that protrude toward the frame-shaped sheet.

3. The fuel cell cell according to claim 1 or 2, wherein the convex portion has a flat portion that abuts against the frame-shaped sheet, and the flat portion and the frame-shaped sheet are in surface contact.

4. The fuel cell cell according to claim 1 or 2, wherein the first gas is hydrogen gas and the second gas is air.

5. The fuel cell cell according to claim 1 or 2, wherein the first gas and the second gas are configured to flow in opposite directions, and the protrusion is provided at least at the outlet portion.

6. The fuel cell cell according to claim 1 or 2, wherein the inlet portion has an inlet hole, the outlet portion has an outlet hole, and the distance between the plurality of protrusions in the inlet portion or the outlet portion varies according to the distance from the inlet hole and the outlet hole.

7. The fuel cell cell according to claim 6, wherein the separation distance at the inlet portion decreases as it approaches the inlet hole, and the separation distance at the outlet portion decreases as it approaches the outlet hole.

8. The fuel cell cell according to claim 1 or 2, wherein the inlet portion has an inlet hole, the outlet portion has an outlet hole, the bending rigidity of the frame-shaped sheet increases closer to the inlet hole, and the bending rigidity of the frame-shaped sheet at the outlet portion increases closer to the outlet hole.

9. The fuel cell cell according to claim 1 or 2, wherein the following equation holds true for the maximum deflection amount δ of the frame-shaped sheet that deflects between any adjacent pair of the protrusions, where P is the differential pressure between the first gas and the second gas, h is the thickness of the frame-shaped sheet, E is the modulus of elasticity of the frame-shaped sheet, D is the height of the protrusions, and L is the distance between the contact portions of adjacent protrusions with the frame-shaped sheet.

10. A fuel cell using the fuel cell cell described in claim 1 or 2.

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