Fuel battery cell

Abstract

To provide a fuel battery cell, in which a part of an internal seal part is constructed by a pressure-sensitive adhesive layer, capable of sufficiently guiding a fluid in a flow path.SOLUTION: A fuel battery cell includes a frame for holding a membrane electrode assembly and a separator stacked on the frame. The fuel battery cell includes: an internal seal part between the frame and the separator for sealing a fluid flow path to the outside; and an external seal part between the other separator and the separator for sealing the fluid flow path to the outside. The internal seal part is composed of a part of the separator and a pressure-sensitive adhesive layer. The separator includes a flow path wall that guides the fluid within the flow path between the frame and the separator. The fuel battery cell includes the pressure-sensitive adhesive layer between the flow path wall and the frame, and between the frame and the part of the separator constituting an overlapping part which is a portion disposed at a position overlapping with the external seal part when the frame and the separator are viewed along an overlapping direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to fuel cells. [Background technology]

[0002] Conventionally, there exist fuel cell stacks configured by stacking multiple fuel cells. In a fuel cell stack, fuel gas and oxidizing gas flow through multiple supply flow paths that extend independently in the stacking direction of the fuel cells. The fuel gas and oxidizing gas delivered to each fuel cell through these flow paths flow through independent flow paths within each fuel cell. The fuel gas and oxidizing gas used in the reaction within each fuel cell are then sent out of the fuel cell stack through multiple exhaust flow paths that extend independently in the stacking direction of the fuel cells.

[0003] In order to form independent flow paths for the fuel gas and the oxidizing gas and to prevent the fuel gas and the oxidizing gas from leaking outside the fuel cell stack, sealing members are arranged in the fuel cell stack between the frame that holds the membrane electrode assembly (MEA) and the separators, and between adjacent separators.

[0004] In the technology of Patent Document 1, a loop-shaped sealing member is provided around the MEA between each separator arranged on both sides of the MEA and a frame that holds the MEA. The sealing member consists of a sealing member main portion that is adhered to the separator and an adhesive layer that is disposed on the surface of the sealing member main portion. The sealing member main portion is made of a cross-linked foamed rubber material. The adhesive layer uses a UV-crosslinkable acrylic adhesive, particularly a hydrocarbon acrylate adhesive.

[0005] In the technology of Patent Document 1, during assembly of a fuel cell, the main part of the sealing member made of foam rubber flexibly deforms, and the adhesive layer made of hydrocarbon acrylate-based adhesive firmly adheres to the frame as the object to be sealed, ensuring initial sealing performance. Even if the reaction force of the foam rubber material decreases after long-term use, the adhesive layer made of hydrocarbon acrylate-based adhesive continues to adhere to the frame as the object to be sealed, maintaining reliable sealing performance. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-18703 Summary of the Invention [Problem to be solved by the invention]

[0007] Flow paths are provided within the fuel cell so that the fuel gas and oxidizing gas delivered along the stacking direction of the fuel cell are distributed and circulated in appropriate amounts to each position inside the fuel cell. These flow paths are defined and separated from each other by walls provided in the separators.

[0008] When the fuel cell stack is pressed in the stacking direction to ensure sealing between adjacent separators and between the separators and the frame holding the MEA, it is preferable that the upper ends of the wall sections defining the flow paths of each fluid within the fuel cell be in close contact with the frame holding the MEA. However, when an adhesive layer is provided in addition to the main part of the sealing member, as in the technology of Patent Document 1, there is a risk of gaps forming between the upper ends of the wall sections defining the flow paths of each fluid and the frame holding the MEA.

[0009] If a gap exists between the upper end of the wall defining the fluid flow paths within the fuel cell and the frame holding the MEA, the fuel gas and oxidant gas will flow over the wall, resulting in insufficient control of the amount of fuel gas and oxidant gas distributed to each location within the fuel cell. Furthermore, the water generated during power generation cannot be adequately drained. As a result, the power generation efficiency of the fuel cell stack decreases.

[0010] Furthermore, the sealing member disposed between the frame and the separator is not disposed in the same location as the sealing member disposed between the separators. When an adhesive layer is disposed in addition to the main sealing member portion in the sealing member disposed between the frame and the separator, as in the technology of Patent Document 1, the following problems arise in the area where the sealing member disposed between the separators is located when viewed along the stacking direction of the fuel cell cells. Specifically, gaps may occur in the area where the frame holding the MEA and the separator are in close contact and should transmit force to each other in the stacking direction, preventing the sealing member disposed between the separators from fully exhibiting its sealing performance. As a result, fuel gas and oxidizing gas may leak out of the fuel cell stack from between adjacent separators. [Means for solving the problem]

[0011] The present disclosure can be realized in the following forms.

[0012] According to one aspect of the present disclosure, there is provided a fuel cell including a frame that holds a membrane electrode assembly and a separator that is stacked on the frame. The fuel cell includes an internal seal between the frame and the separator that seals a fluid flow path from the outside, and an external seal between the separator and another separator that is arranged on the opposite side of the separator from the frame and seals the fluid flow path from the outside. The internal seal includes at least a portion of the separator and an adhesive layer made of an adhesive that is arranged on the frame side of the portion of the separator. The separator includes flow path walls between the frame and the separator that guide the fluid in the flow path toward different portions of the surface of the membrane electrode assembly. The fuel cell has an adhesive layer made of the adhesive between the flow path wall and the frame, and between the frame and a part of the separator constituting the overlapping portion, which is the portion arranged in a position overlapping with the external seal portion when viewed along the overlapping direction of the frame and the separator. By adopting such an embodiment, the pressure-sensitive adhesive layer can ensure sufficient sealing performance between the internal seal portion and the frame for a long period of time, thereby preventing fluid from leaking out of the fuel cell from between the frame and the separator for a long period of time. Furthermore, the pressure-sensitive adhesive layer can ensure a sufficient seal between the flow path wall and the frame, thereby preventing the fluid from flowing beyond the flow path wall, and as a result, the fluid in the flow path can be sufficiently guided toward different portions of the surface of the membrane electrode assembly. Furthermore, in the above-described embodiment, a pressure-sensitive adhesive layer is disposed in the internal seal portion at a position that overlaps with the external seal portion when viewed along the overlapping direction of the frame and separator. This allows the force applied to the separator by the external seal portion to be transmitted between the frame and the separator via the pressure-sensitive adhesive layer. As a result, deformation of the frame and the separator can be reduced compared to when there is a gap between the frame and the separator at the position that overlaps with the external seal portion. This allows the external seal portion to ensure sufficient sealing between the separator and other separators. The present disclosure may be realized in various forms other than a centrifugal dehydrator, such as a fuel cell stack, a method for manufacturing a fuel cell stack or a fuel cell unit, or the like. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a plan view showing a frame 100 that constitutes a part of a fuel cell 1 of the present embodiment. [Figure 2] FIG. 2 is a plan view showing a separator 201 that constitutes the oxygen electrode of the fuel cell 1 of this embodiment. [Figure 3] FIG. 2 is a plan view showing a separator 202 that constitutes the hydrogen electrode of the fuel cell 1 of this embodiment. [Figure 4] FIG. 2 is a plan view showing a separator 700 that constitutes a part of the fuel cell 1 of this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] A. Implementation: The fuel cell 1 of this embodiment constitutes part of a fuel cell stack. The fuel cell 1 is supplied with fuel gas and oxidizing gas to generate electricity. The fuel cell 1 includes a frame 100, separators 201, 202, internal seal members 310, 320, an external seal member 400, and a separator 700. In the fuel cell 1, the frame 100, the separators 201, 202, and the separator 700 are arranged one on top of the other.

[0015] FIG. 1 is a plan view showing a frame 100 constituting a part of a fuel cell 1 of this embodiment. To facilitate understanding of the technology, FIG. 1 shows an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other. The X-axis, the Y-axis, and the Z-axis form a left-handed system. In describing the frame 100 using FIG. 1, the positive Y-axis direction is also referred to as "up." "Down" is the opposite direction of up. The positive X-axis direction is also referred to as "right." "Left" is the opposite direction of right. With respect to the illustrated configuration, the side of the positive Z-axis direction is also referred to as the "front side." With respect to the illustrated configuration, the side of the negative Z-axis direction is also referred to as the "back side." In the fuel cell 1, the frame 100, separators 201 and 202, and separator 700 are arranged overlapping in the Z-axis direction.

[0016] The frame 100 is a plate-like structure having a substantially rectangular outer shape. The frame 100 holds a membrane electrode assembly 110 in its central portion (see the center portion of the middle section in FIG. 1). The membrane electrode assembly 110 is exposed on the front and back sides of the frame 100.

[0017] An oxidizing gas supply manifold Moi is disposed at the lower right of the frame 100. The supply manifold Moi is a through-hole that penetrates the frame 100. The supply manifold Moi distributes the oxidizing gas that is supplied to the membrane electrode assembly 110. The oxidizing gas is air.

[0018] An exhaust manifold Moo for oxidizing gas is disposed at the upper left of the frame 100. The exhaust manifold Moo is a through-hole that penetrates the frame 100. The exhaust manifold Moo distributes the oxidizing gas used in the reaction in the membrane electrode assembly 110.

[0019] A fuel gas supply manifold Mhi is disposed at the lower left of the frame 100. The supply manifold Mhi is a through-hole that penetrates the frame 100. The supply manifold Mhi distributes the fuel gas to be supplied to the membrane electrode assembly 110. The fuel gas is hydrogen gas.

[0020] A fuel gas discharge manifold Mho is disposed on the upper right of the frame 100. The discharge manifold Mho is a through-hole that penetrates the frame 100. The discharge manifold Mho distributes the fuel gas used in the reaction in the membrane electrode assembly 110.

[0021] A coolant supply manifold Mwi is disposed in the middle left portion of the frame 100. The supply manifold Mwi is a through-hole that penetrates the frame 100. The supply manifold Mwi circulates a coolant for controlling the temperature of the membrane electrode assembly 110. The main component of the coolant is ethylene glycol.

[0022] A discharge manifold Mwo for the coolant is disposed in the middle right part of the frame 100. The discharge manifold Mwo is a through-hole that penetrates the frame 100. The discharge manifold Mwo circulates the coolant that has received heat from the membrane electrode assembly 110 via the separator 202.

[0023] FIG. 2 is a plan view showing a separator 201 constituting the oxygen electrode of a fuel cell 1 of this embodiment. To facilitate understanding of the technology, FIG. 2 shows an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other. In describing the separator 201 using FIG. 2, the negative Y-axis direction is also referred to as "up." "Down" is the opposite direction of up. The positive X-axis direction is also referred to as "right." "Left" is the opposite direction of right. With respect to the illustrated configuration, the side of the negative Z-axis direction is also referred to as the "front side." With respect to the illustrated configuration, the side of the positive Z-axis direction is also referred to as the "back side." The X-axis, Y-axis, and Z-axis shown in FIG. 2 correspond to the X-axis, Y-axis, and Z-axis shown in FIG. 1.

[0024] In the fuel cell 1, the separator 201 is rotated 180° vertically from the orientation shown in Fig. 2 and placed on the surface of the frame 100 shown in Fig. 1. Therefore, in the separator 201 shown in Fig. 2, the oxidizing gas supply manifold Moi is shown at the upper right, and the oxidizing gas discharge manifold Moo is shown at the lower left. In the separator 201 shown in Fig. 2, the fuel gas supply manifold Mhi is shown at the upper left, and the fuel gas discharge manifold Mho is shown at the lower right. In the separator 201 shown in Fig. 2, the coolant supply manifold Mwi is shown at the middle left, and the coolant discharge manifold Mwo is shown at the middle right.

[0025] The separator 201 has, in its center, a plurality of oxidizing gas channels for circulating the oxidizing gas along the membrane electrode assembly 110. The oxidizing gas channels are defined by a plurality of channel walls 231 that protrude in the negative direction of the Z axis from the surface of the separator 201 (see the center of the middle section of FIG. 2). The channel walls 231 extend along the X axis direction. The oxidizing gas flows through the plurality of oxidizing gas channels in the negative direction of the X axis. During this time, the oxidizing gas comes into contact with the membrane electrode assembly 110 that faces the separator 201, and is subjected to a reaction.

[0026] The separator 201 has a connecting flow path in the upper right part that connects the oxidizing gas supply manifold Moi to an oxidizing gas flow path formed by flow path walls 231. The connecting flow path is divided by a plurality of flow path walls 221 that protrude in the negative direction of the Z axis on the surface of the separator 201. The flow path walls 221 are ridges that protrude in the negative direction of the Z axis and are formed by press working.

[0027] The separator 201 is provided with a connecting flow path in the lower left section that connects the oxidizing gas flow path formed by the flow path wall 231 with an exhaust manifold Moo for the oxidizing gas. The connecting flow path is divided by a plurality of flow path walls 222 that protrude in the negative direction of the Z axis on the surface of the separator 201. The flow path walls 222 are ridges that protrude in the negative direction of the Z axis and are formed by press working.

[0028] In the separator 201, the flow path walls 221 and 222 guide the oxidizing gas in the oxidizing gas flow path between the frame 100 and the separator 201 toward different portions of the surface of the membrane electrode assembly 110.

[0029] The separator 201 is provided with a support portion 261 (see the lower right part of FIG. 2) in a region surrounded by the oxidizing gas flow path defined by the plurality of flow path walls 231, the connecting flow paths separated by the plurality of flow path walls 221, the fuel gas supply manifold Mhi, and the coolant supply manifold Mwi. The support portion 261 is a ridge portion formed by press working and protruding in the negative direction of the Z axis. The support portion 261 receives a force in the Z-axis direction from the frame 100 on which the separator 201 is placed. The support portion 261 prevents the frame 100 from bending in the Z-axis direction at the portion where the support portion 261 is placed.

[0030] The separator 201 is provided with a support portion 262 in a region surrounded by the oxidizing gas flow path defined by the plurality of flow path walls 231, the connecting flow path separated by the plurality of flow path walls 222, the fuel gas discharge manifold Mho, and the coolant discharge manifold Mwo (see the upper left part of FIG. 2). The support portion 262 is a ridge portion that protrudes in the negative direction of the Z axis and is formed by press working. The support portion 262 receives a force in the Z axis direction from the frame 100 on which the separator 201 is placed. The support portion 262 prevents the frame 100 from bending in the Z axis direction at the region that overlaps the support portion 262.

[0031] FIG. 3 is a plan view showing a separator 202 constituting the hydrogen electrode of a fuel cell 1 of this embodiment. To facilitate understanding of the technology, FIG. 3 shows an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other. In describing the separator 201 using FIG. 3, the positive Y-axis direction is also referred to as "up." "Down" is the opposite direction of up. The positive X-axis direction is also referred to as "right." "Left" is the opposite direction of right. With respect to the illustrated configuration, the side of the positive Z-axis direction is also referred to as the "front side." With respect to the illustrated configuration, the side of the negative Z-axis direction is also referred to as the "back side." The X-axis, Y-axis, and Z-axis shown in FIG. 3 correspond to the X-axis, Y-axis, and Z-axis shown in FIG. 1.

[0032] In the fuel cell 1, the separator 202 is placed on the back surface of the frame 100 shown in Fig. 1 in the orientation shown in Fig. 3. Therefore, in the separator 202 shown in Fig. 3, an oxidizing gas supply manifold Moi is shown at the lower right and an oxidizing gas discharge manifold Moo is shown at the upper left, similar to the frame 100 shown in Fig. 1. In the separator 202 shown in Fig. 3, a fuel gas supply manifold Mhi is shown at the lower left and a fuel gas discharge manifold Mho is shown at the upper right. In the separator 202 shown in Fig. 3, a coolant supply manifold Mwi is shown at the middle left and a coolant discharge manifold Mwo is shown at the middle right.

[0033] The separator 202 has, in its center, a plurality of fuel gas flow channels for circulating fuel gas along the membrane electrode assemblies 110. The fuel gas flow channels are defined by a plurality of flow channel walls 236 that protrude in the positive direction of the Z axis from the surface of the separator 202 (see the center of the middle section of FIG. 3 ). The flow channel walls 236 extend along the X axis direction. The fuel gas flows through the plurality of fuel gas flow channels in the positive direction of the X axis. The fuel gas comes into contact with the membrane electrode assemblies 110 that are arranged opposite the separator 202, and is subjected to a reaction.

[0034] The separator 202 has, in its lower left section, a connecting flow path that connects the fuel gas supply manifold Mhi and a fuel gas flow path formed by flow path walls 236 (see the lower left section of FIG. 3). The connecting flow path is divided by a plurality of flow path walls 226 that protrude in the positive direction of the Z axis on the surface of the separator 202. The flow path walls 226 are ridges that protrude in the positive direction of the Z axis and are formed by press working.

[0035] The separator 202 has a connecting flow path in the upper right part that connects a fuel gas flow path formed by the flow path wall 236 with the fuel gas discharge manifold Mho. The connecting flow path is divided by a plurality of flow path walls 227 that protrude in the positive direction of the Z axis on the surface of the separator 202. The flow path walls 227 are ridges that protrude in the positive direction of the Z axis and are formed by press working.

[0036] In the separator 202, the flow path walls 226, 227 guide the oxidizing gas in the oxidizing gas flow path between the frame 100 and the separator 202 toward different portions of the surface of the membrane electrode assembly 110.

[0037] The separator 202 has a support portion 263 in a region surrounded by the oxidizing gas flow path defined by the plurality of flow path walls 236, the connecting flow path separated by the plurality of flow path walls 226, the oxidizing gas discharge manifold Moo, and the coolant supply manifold Mwi (see the upper left part of FIG. 3). The support portion 263 is a ridge portion that protrudes in the positive direction of the Z axis and is formed by press working. The support portion 263 receives a force in the Z axis direction from the frame 100 on which the separator 202 is placed. The support portion 263 prevents the frame 100 from bending in the Z axis direction at the region that overlaps the support portion 263.

[0038] The separator 202 has a support portion 264 at a location surrounded by the oxidizing gas flow path defined by the multiple flow path walls 236, the connecting flow path separated by the multiple flow path walls 227, the oxidizing gas supply manifold Moi, and the coolant discharge manifold Mwo (see the lower right part of FIG. 3 ). The support portion 264 is a ridge portion that protrudes in the positive direction of the Z axis and is formed by press working. The support portion 264 receives force in the Z axis direction from the frame 100 on which the separator 202 is placed. The support portion 264 prevents deflection of the frame 100 in the Z axis direction at the location that overlaps with the support portion 264.

[0039] FIG. 4 is a plan view showing a separator 700 constituting a part of the fuel cell 1 of this embodiment. To facilitate understanding of the technology, FIG. 4 shows an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other. In describing the separator 700 using FIG. 4, the positive Y-axis direction is also referred to as "up." "Down" is the opposite direction of up. The positive X-axis direction is also referred to as "right." "Left" is the opposite direction of right. With respect to the illustrated configuration, the side of the positive Z-axis direction is also referred to as the "front side." With respect to the illustrated configuration, the side of the negative Z-axis direction is also referred to as the "back side." The X-axis, Y-axis, and Z-axis shown in FIG. 4 correspond to the X-axis, Y-axis, and Z-axis shown in FIG. 1.

[0040] In the fuel cell 1, the separator 700 is placed on the back surface of the separator 202 shown in Fig. 3 in the orientation shown in Fig. 4. Therefore, in the separator 700 shown in Fig. 4, an oxidizing gas supply manifold Moi is shown at the lower right and an oxidizing gas discharge manifold Moo is shown at the upper left, similar to the frame 100 shown in Fig. 1 and the separator 202 shown in Fig. 3. In the separator 700 shown in Fig. 4, a fuel gas supply manifold Mhi is shown at the lower left and a fuel gas discharge manifold Mho is shown at the upper right. In the separator 700 shown in Fig. 4, a coolant supply manifold Mwi is shown at the middle left and a coolant discharge manifold Mwo is shown at the middle right.

[0041] The separator 700 has a plurality of coolant flow paths for circulating coolant in its central portion, which overlaps with the membrane electrode assembly 110. The coolant flow paths are defined by a plurality of flow path walls 430 that protrude in the positive direction of the Z axis from the surface of the separator 700 (see the central portion of the middle section in FIG. 4). The flow path walls 430 extend along the X axis direction. The coolant flows through the plurality of coolant flow paths in the positive direction of the X axis. The coolant comes into contact with the separator 202, which is disposed opposite the separator 700, and receives heat from the membrane electrode assembly 110 via the separator 202.

[0042] Separator 700 has a connecting flow path in the upper left section that connects coolant supply manifold Mwi and a coolant flow path formed by flow path walls 430. The connecting flow path is divided by a plurality of flow path walls 421 that protrude in the positive direction of the Z axis on the surface of separator 700. Flow path walls 421 are ridges that protrude in the positive direction of the Z axis and are formed by press working.

[0043] Separator 700 has a connecting flow path in the lower right section that connects a coolant flow path formed by flow path wall 430 with a coolant discharge manifold Mwo. The connecting flow path is divided by a plurality of flow path walls 422 that protrude in the positive direction of the Z axis on the surface of separator 700. Flow path walls 422 are ridges that protrude in the positive direction of the Z axis and are formed by press working.

[0044] In the separator 700, the flow path walls 421 and 422 guide the coolant in the coolant flow path between the separator 202 and the separator 700 toward different portions of the separator 202.

[0045] The internal seal portion 310 seals the flow paths of the fluids, oxidizing gas, fuel gas, and coolant, from the outside between the frame 100 and the separator 201 (see FIG. 2). In FIG. 2, the internal seal portion 310 is shown as a black configuration. The internal seal portion 310 is arranged so as to independently surround the fuel gas supply manifold Mhi, the fuel gas discharge manifold Mho, the coolant supply manifold Mwi, and the coolant discharge manifold Mwo.

[0046] The internal seal portion 310 is arranged to surround the oxidizing gas supply manifold Moi, the connecting flow path separated by the flow path wall 221, the oxidizing gas flow path defined by the flow path wall 231, the connecting flow path separated by the flow path wall 222, and the oxidizing gas discharge manifold Moo.

[0047] When viewed along the Z-axis direction, the internal seal portion 310 is disposed in a portion that overlaps with the external seal portion 400. However, when viewed along the Z-axis direction, there is a portion where the external seal portion 400 is located but where the internal seal portion 310 is not disposed.

[0048] The internal seal portion 310 is composed of a part of the separator 201 and an adhesive layer. The part of the separator 201 that constitutes part of the internal seal portion 310 is a ridge that protrudes in the negative direction of the Z axis. The adhesive layer is arranged on the frame 100 side of the part of the separator 201 that constitutes part of the internal seal portion 310. In the manufacturing process of the fuel cell 1, first, the adhesive layer is arranged on the frame 100, and then the separator 201 is overlaid on the frame 100. The adhesive layer is composed of an adhesive. More specifically, the adhesive is an acrylic adhesive.

[0049] The internal seal portion 320 seals the flow paths of the oxidizing gas, fuel gas, and coolant fluids from the outside between the frame 100 and the separator 202 (see FIG. 3). In FIG. 3, the internal seal portion 320 is shown as a black configuration. The internal seal portion 320 is arranged to independently surround the oxidizing gas supply manifold Moi, the oxidizing gas discharge manifold Moo, the coolant supply manifold Mwi, and the coolant discharge manifold Mwo.

[0050] The internal seal portion 320 is arranged to surround the fuel gas supply manifold Mhi, the connecting flow path separated by the flow path wall 226, the oxidizing gas flow path defined by the flow path wall 236, the connecting flow path separated by the flow path wall 227, and the fuel gas discharge manifold Mho.

[0051] When viewed along the Z-axis direction, the internal seal portion 320 is disposed in a portion that overlaps with the external seal portion 400. However, when viewed along the Z-axis direction, there is a portion where the external seal portion 400 is located but where the internal seal portion 320 is not disposed.

[0052] The internal seal portion 320 has the same configuration as the internal seal portion 310. That is, the internal seal portion 320 is composed of a portion of the separator 202 and an adhesive layer. The portion of the separator 202 that constitutes part of the internal seal portion 320 is a ridge that protrudes in the positive direction of the Z axis. The adhesive layer is arranged on the frame 100 side of the portion of the separator 202 that constitutes part of the internal seal portion 320. In the manufacturing process of the fuel cell 1, first, the adhesive layer is arranged on the frame 100, and then the separator 202 is overlapped with the frame 100.

[0053] With this configuration, the adhesive layer can ensure sufficient sealing performance over a long period of time between the inner seal portions 310, 320 and the frame 100. This makes it possible to prevent fluid from leaking out of the fuel cell 1 from between the frame 100 and the separators 201, 202 over a long period of time.

[0054] The external seal unit 400 seals the flow paths of the fluids, oxidizing gas, fuel gas, and coolant, from the outside between the separator 202 and a separator 700, which is arranged on the opposite side of the separator 202 from the frame 100 (see FIG. 4). In FIG. 4, the external seal unit 400 is shown as a black configuration. The external seal unit 400 is arranged so as to independently surround the oxidizing gas supply manifold Moi, the oxidizing gas discharge manifold Moo, the fuel gas supply manifold Mhi, and the fuel gas discharge manifold Mho.

[0055] The external seal portion 400 is arranged to surround the coolant supply manifold Mwi, the connecting flow passages separated by flow passage walls 421, the coolant flow passages defined by flow passage walls 430, the connecting flow passages separated by flow passage walls 422, and the coolant discharge manifold Mwo.

[0056] In the fuel cell 1, adhesive layers Aad1 and Aad2 made of an adhesive are arranged on the front and back surfaces of the frame 100 in regions including the following portions. (i) Between the flow channel walls 221, 222, 226, 227 and the frame 100. (ii) Between the frame 100 and a part of the separators 201, 202 that constitute the overlapping portion, which is the portion that is arranged in a position that overlaps with the external seal portion 400 when the fuel cell 1 is viewed along the Z-axis direction.

[0057] In Fig. 1, the areas where the adhesive layers Aad1 and Aad2 are arranged are shown hatched. As shown in Fig. 1, the adhesive layers are provided not only between the flow path walls 221, 222, 226, and 227 and the frame 100, but also between adjacent flow path walls. In this embodiment, the adhesive layers Aad1 and Aad2 are formed on the frame 100. Similarly, adhesive layers are formed on the back surface of the frame 100 in areas corresponding to the above areas.

[0058] With this configuration, the adhesive layers Aad1 and Aad2 can ensure sufficient sealing between the flow path walls 221, 222, 226, and 227 and the frame 100. This reduces the possibility that the oxidizing gas and the fuel gas will flow beyond the flow path walls 221, 222, 226, and 227, and allows the fluids in the flow paths to be sufficiently guided toward different portions of the surface of the membrane electrode assembly 110.

[0059] Furthermore, in the above embodiment, the pressure-sensitive adhesive layers Aad1 and Aad2 are disposed in the internal seal portions 310 and 320 at positions that overlap the external seal portion 400 when viewed along the overlapping direction of the frame 100 and the separators 201 and 202. Therefore, the force applied to the separators 201 and 202 by the external seal portion 400 can be transmitted between the frame 100 and the separators 201 and 202 via the pressure-sensitive adhesive layers Aad1 and Aad2. As a result, deformation of the frame 100 and the separators 201 and 202 can be reduced compared to when there is a gap between the frame 100 and the separators 201 and 202. Therefore, the external seal portion 400 can ensure sufficient sealing between the separators 201 and 202 and another frame or another separator 700.

[0060] The present disclosure is not limited to the above-described embodiments and can be realized in various configurations without departing from the spirit thereof. For example, the technical features of the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention section can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0061] 1...fuel cell, 100...frame, 110...membrane electrode assembly, 201...separator, 202...separator, 221...flow path wall, 222...flow path wall, 226...flow path wall, 227...flow path wall, 231...flow path wall, 236...flow path wall, 261...support portion, 262...support portion, 263...support portion, 264...support portion, 310...internal seal portion, 320...internal seal portion, 400...external seal portion, 421...flow path wall, 422...flow path wall, 430...flow path wall, 700...separator, Aad1...adhesive layer, Aad2...adhesive layer, Mhi...supply manifold, Mho...discharge manifold, Moi...supply manifold, Moo...discharge manifold, Mwi...supply manifold, Mwo...discharge manifold

Claims

[Claim 1] A fuel cell comprising a frame that holds a membrane electrode assembly and a separator that is stacked on the frame, an internal seal portion between the frame and the separator that seals a fluid flow path from the outside; another separator disposed on the opposite side of the separator from the frame; and an external seal portion configured to seal a fluid flow path from the outside between the separator and the external seal portion, the internal seal portion is composed of at least a part of the separator and an adhesive layer made of an adhesive and disposed on the frame side of the part of the separator, The separator is a flow path wall is provided between the frame and the separator to guide the fluid in the flow path toward different portions of the surface of the membrane electrode assembly; The fuel cell is Between the flow path wall and the frame, and When the frame and the separator are viewed in the overlapping direction, a part of the separator constituting an overlapping portion, which is a portion arranged at a position overlapping with the external seal portion, is disposed between the frame and the separator. A fuel cell comprising an adhesive layer made of the adhesive.

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