fuel cell

Abstract

This technology provides a way to suppress gas leaks by preventing the sub-gasket from peeling off the gasket in regions where the surface pressure from the flow-through separator is relatively low. [Solution] The fuel cell cell of the present disclosure is a fuel cell cell comprising at least a first separator, a first gasket, a sub-gasket, a membrane electrode assembly, a second separator, and a second gasket, which are stacked together, wherein at least one of the first separator and the second separator is a separator with a flow path, and the sub-gasket is further provided with a tension-applying portion located outward from the end of the first gasket for applying tension to the sub-gasket to press a region of the sub-gasket from which the surface pressure from the separator with a flow path is relatively low toward the first gasket.

Description

Technical Field

[0001] The present disclosure relates to fuel cell.

Background Art

[0002] Conventionally, technologies for suppressing gas leakage in fuel cells are known.

[0003] For example, in Patent Document 1, a fuel cell power generation body including a solid polymer electrolyte membrane and gas diffusion electrodes disposed on both sides of the solid polymer electrolyte membrane, and sheet-like gaskets disposed on both main surface sides of the fuel cell power generation body and having a size protruding from the edge of the fuel cell power generation body, and outer pressing means disposed outside the sheet-like gaskets and pressing the gaskets against the edge and end surfaces of the fuel cell power generation body from the outside are provided. A gas seal structure of a fuel cell is disclosed.

[0004] Further, in Patent Document 2, a fuel cell assembly including a membrane electrode assembly, a cathode separation plate, a gasket, and a metal shim, wherein the cathode separation plate has a series of undulations extending, an air flow path is provided between first and second end portions in an opposing relationship, the gasket is provided between the separation plate and the membrane electrode assembly to form a fluid seal at the peripheral end portion of the membrane electrode assembly, the metal shim is disposed between the gasket and the separation plate to cover the peripheral end portion of the membrane electrode assembly, and is integrated with the separation plate and has first and second elongated pieces, and the first and second elongated pieces extend in the long axis direction so as to cross the undulations of the separation plate and also extend along the first and second end portions of the separation plate respectively. A fuel cell assembly is disclosed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] Gaskets such as those disclosed in Patent Documents 1 and 2 are generally used together with sub-gaskets to enhance sealing performance and are typically bonded to the sub-gaskets via adhesive. Furthermore, on the side of the sub-gasket opposite the gasket, a separator with a flow channel, which has an uneven structure for forming gas flow channels and cooling water flow channels, is typically laminated.

[0007] Incidentally, sub-gaskets are generally difficult to bond and are thin, so they expand when gas pressure is applied. Also, due to the uneven structure of the flow-flow separator, the sub-gasket has difficulty receiving the surface pressure from the flow-flow separator evenly, resulting in areas where the surface pressure is relatively low. Therefore, in these areas where the surface pressure is relatively low, if the gas pressure increases, the sub-gasket can peel off from the gasket, causing a gas leak.

[0008] In view of these circumstances, the purpose of this disclosure is to provide a technology that suppresses gas leakage by preventing the sub-gasket from peeling off the gasket in regions of the sub-gasket where the surface pressure from the flow-through separator is relatively low. [Means for solving the problem]

[0009] A fuel cell according to one embodiment of the present disclosure is a fuel cell comprising at least a first separator, a first gasket, a sub-gasket, a membrane electrode assembly, a second separator, and a second gasket, which are stacked together, wherein at least one of the first separator and the second separator is a flow-channel separator, and the sub-gasket is further provided with a tension-applying portion located outward from the end of the first gasket for applying tension to the sub-gasket to press a region of the sub-gasket from which the surface pressure from the flow-channel separator is relatively low toward the first gasket. [Effects of the Invention]

[0010] According to one embodiment of the present disclosure, gas leakage can be suppressed by preventing the sub-gasket from peeling off the gasket in a region of the sub-gasket where the surface pressure from the flow-through separator is relatively low. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram of a vehicle equipped with a fuel cell cell according to one embodiment of the present disclosure. [Figure 2] This is an exploded perspective view showing a schematic configuration of a fuel cell cell according to one embodiment of the present disclosure. [Figure 3] This is a plan view showing a part of a fuel cell according to the first embodiment of the present disclosure. [Figure 4] This is a portion of the A-A' cross-sectional view shown in Figure 3. [Figure 5] This diagram illustrates a portion of the B-B' cross-section shown in Figure 3, specifically the case where there is no tension from the support material. [Figure 6] This is a plan view showing a part of a fuel cell according to the first embodiment of the present disclosure. [Figure 7] This is a plan view showing a part of a fuel cell according to the first embodiment of the present disclosure. [Figure 8] This is a plan view showing a part of a fuel cell according to a second embodiment of the present disclosure. [Figure 9]This is a partial perspective cross-sectional view taken along the line C-C' shown in Figure 8. [Modes for carrying out the invention]

[0012] Preferred embodiments of this disclosure will be described in detail below with reference to the attached drawings. In this specification and the drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant descriptions will be omitted.

[0013] (1. Overall configuration of the vehicle) Referring to Figure 1, the vehicle 1 according to this embodiment comprises at least a fuel cell stack 2, an inverter 3, a load 4, and a control device 5. In the vehicle 1, under the control of the control device 5, the electricity generated by the fuel cell stack 2 is supplied to the load 4 via the inverter 3. The vehicle 1 also includes known equipment (not shown) that is installed in fuel cell vehicles, such as a hydrogen tank, an anode gas supply device, a cathode gas supply device, a refrigerant supply device, and a DC / DC converter.

[0014] The fuel cell stack 2 is constructed by stacking several tens to several hundred fuel cell cells 100, which will be described later, in the stacking direction. Each fuel cell cell 100 has the function of generating electricity by reacting an anode gas with a cathode gas. The fuel cell stack 2 may be equipped with a known voltage sensor 6 capable of measuring the voltage applied to each fuel cell cell 100. The fuel cell stack 2 may also be equipped with a known current sensor 7 capable of measuring the current flowing through the fuel cell cell 100. The fuel cell cell 100 is not particularly limited and may be, for example, a known polymer electrolyte fuel cell (PEFC).

[0015] The inverter 3 has the function of converting DC power obtained by boosting it, for example, by a DC / DC converter, into AC power suitable for driving the load 4. The inverter 3 is not particularly limited as long as it performs the above-described function, and known inverters including, for example, a three-phase bridge circuit can be used.

[0016] The load 4 includes, for example, a known electric motor capable of outputting power for driving the drive wheels of the vehicle 1. The electric motor is, for example, a known three-phase alternating current type electric motor. Note that the load 4 may be other electrical equipment mounted on the vehicle 1.

[0017] The control device 5 is a known ECU (Electronic Control Unit) mounted on a fuel cell vehicle, and includes one or more processors such as one or more CPUs (Central Processing Unit), and one or more memories such as semiconductor memories, magnetic memories, or optical memories that are communicably connected to the processor. Further, the control device 5 may further include a known BMU (Battery Management Unit) that monitors and controls the state of the battery. Note that the control device 5 may be communicably configured with other known EUCs and various sensors (not shown) mounted on the vehicle 1.

[0018] (2. Overall Configuration of Fuel Cell) Referring to FIG. 2, the overall configuration of the fuel cell 100 applicable to the fuel cell stack 2 provided in the vehicle 1 will be briefly described. The fuel cell 100 is configured by laminating, for example, a flat separator 10, a first gasket 20, a sub-gasket 30, a separator 40 with flow paths, and a second gasket 50 in this order. Further, the fuel cell 100 further includes a membrane electrode assembly 60 sandwiched between the flat separator 10 and the separator 40 with flow paths. Note that the flat separator 10 is an example of the "first separator" of the present disclosure, and the separator 40 with flow paths is an example of the "second separator" of the present disclosure. Also, the first gasket 20 and the second gasket 50 may each be a combination of a cathode gasket and a cooling water gasket, or a combination of an anode gasket and a cooling water gasket.

[0019] (2-1. Flat Separator) The flat plate separator 10 is a rectangular flat separator. One of the gases, anode gas or cathode gas, flows through the surface of the flat plate separator 10 facing the membrane electrode assembly 60. The flat plate separator 10 has through holes MF1 for the cooling water manifold and through holes MF2 and MF3 for the gas manifold. Specifically, the through hole MF1 for the cooling water manifold in the flat plate separator 10 is formed in a part of the long side of the flat plate separator 10. The through holes MF2 and MF3 for the gas manifold in the flat plate separator 10 are each formed in a part of the short side of the flat plate separator 10.

[0020] The flat plate separator 10 may be a metal separator made of, for example, known aluminum or stainless steel, or a carbon separator made of known carbon-based material, but is not particularly limited.

[0021] (2-2. First gasket) The first gasket 20 has an outer shape corresponding to the flat plate separator 10. The first gasket 20 has through holes MF1 for the cooling water manifold and through holes MF2 and MF3 for the gas manifold, which correspond to the flat plate separator 10. Specifically, the through hole MF1 for the cooling water manifold in the first gasket 20 is formed in a part of the long side of the first gasket 20 so as to correspond to the flat plate separator 10. The through holes MF2 and MF3 for the gas manifold in the first gasket 20 are each formed in a part of the short side of the first gasket 20 so as to correspond to the flat plate separator 10.

[0022] The first gasket 20 may be made of a sealing material such as polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), silicone rubber, ethylene propylene rubber, or fluororubber, but is not particularly limited.

[0023] (2-3. Sub-gasket) The sub-gasket 30 has an outer shape corresponding to the flat plate separator 10 and the first gasket 20. The sub-gasket 30 has through-holes MF1 for the cooling water manifold and through-holes MF2 and MF3 for the gas manifold, which correspond to the flat plate separator 10 and the first gasket 20. Specifically, the through-hole MF1 for the cooling water manifold in the sub-gasket 30 is formed in a part of the long side of the sub-gasket 30 so as to correspond to the flat plate separator 10 and the first gasket 20. The through-holes MF2 and MF3 for the gas manifold in the sub-gasket 30 are formed in a part of the short side of the sub-gasket 30 so as to correspond to the flat plate separator 10 and the first gasket 20, respectively. In the example shown in Figure 2, the through-holes MF2 and MF3 for the gas manifold are arranged side by side along the short side of the sub-gasket 30. The sub-gasket 30 also has a housing space in the center where the membrane electrode assembly 60 is arranged.

[0024] The sub-gasket 30 may be made of a sealing material such as polyethylene naphthalate (PEN), polyethylene terephthalate (PET), or polyphenylene sulfide (PPS), but is not particularly limited to that material.

[0025] (2-4. Separator with flow path) The flow channel separator 40 has at least an uneven structure for forming a gas flow channel and a cooling water flow channel. On the side of the flow channel separator 40 facing the membrane electrode assembly 60, the other of the anode gas and cathode gas flows, while on the side of the flow channel separator 40 opposite the membrane electrode assembly 60, cooling water flows.

[0026] The flow-through separator 40 has through-holes MF1 for the cooling water manifold and MF2 and MF3 for the gas manifold, corresponding to the flat plate separator 10, the first gasket 20, and the sub-gasket 30. Specifically, the cooling water manifold through-hole MF1 in the flow-through separator 40 is formed in a part of the long side of the flow-through separator 40 so as to correspond to the flat plate separator 10, the first gasket 20, and the sub-gasket 30. The gas manifold through-holes MF2 and MF3 in the flow-through separator 40 are formed in a part of the short side of the flow-through separator 40 so as to correspond to the flat plate separator 10, the first gasket 20, and the sub-gasket 30, respectively.

[0027] The flow channel separator 40 may be a metal separator made of, for example, known aluminum or stainless steel, or a carbon separator made of known carbon-based material, but is not particularly limited.

[0028] (2-5. Second gasket) The second gasket 50 has an outer shape corresponding to the flat plate separator 10, the first gasket 20, the sub-gasket 30, and the separator with a flow path 40. The second gasket 50 has through holes MF1 for the cooling water manifold and through holes MF2 and MF3 for the gas manifold, corresponding to the flat plate separator 10, the first gasket 20, the sub-gasket 30, and the separator with a flow path 40. Specifically, the through hole MF1 for the cooling water manifold in the second gasket 50 is formed in a part of the long side of the second gasket 50 so as to correspond to the flat plate separator 10, the first gasket 20, the sub-gasket 30, and the separator with a flow path 40. Furthermore, the through-holes MF2 and MF3 for the gas manifold in the second gasket 50 are formed in a portion of the short side of the second gasket 50 so as to correspond to the flat plate separator 10, the first gasket 20, the sub-gasket 30, and the separator with flow path 40, respectively.

[0029] The second gasket 50 may be made of a sealing material such as polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), silicone rubber, ethylene propylene rubber, or fluororubber, but is not particularly limited.

[0030] (2-6. Membrane electrode assembly) As described above, the membrane electrode assembly 60 is attached to the housing space formed in the sub-gasket 30. The membrane electrode assembly 60 may be a known or any membrane electrode assembly comprising an electrolyte layer (not shown) sandwiched between a pair of catalyst layers (not shown) and a pair of gas diffusion layers (not shown).

[0031] The overall configuration of a fuel cell cell 100 that can be mounted on a vehicle 1 according to one embodiment of this disclosure has been briefly described above. However, the fuel cell cell 100 in this disclosure is not limited thereto, and may further include known or arbitrary gaskets other than the first gasket 20 and the second gasket 50, for example.

[0032] (3. First Embodiment) In this disclosure, it is important to provide a tension-applying section, located outward from the end of the first gasket 20, that applies tension to the sub-gasket 30 in a region of the sub-gasket 30 shown in Figure 2 where the surface pressure from the flow-channel separator 40 is relatively low, in order to press it toward the first gasket 20. Hereinafter, with reference to Figures 3 to 7, the tension-applying section according to the first embodiment will be described in detail using a flat plate separator 110, a first gasket 120, a sub-gasket 130, and a flow-channel separator 140, which can be applied as the flat plate separator 10, first gasket 20, sub-gasket 30, and flow-channel separator 40 shown in Figure 2, as examples.

[0033] (3-1. Overhang) Referring to Figures 3 and 4, the sub-gasket 130 further includes an overhang 131 that extends outward from the end 121 of the first gasket 120. "Outward" means the side of the first gasket 120, and in the example shown in Figure 3, it means the side of the first gasket 120 that is away from the center of the cell.

[0034] Specifically, the protruding portion 131 may include a flat portion 131a that abuts against the main surface 111 of the flat plate separator 110 by a support material 170, which will be described later, and an inclined portion 131b that is continuous with the flat portion 131a and connects to the main body portion 132 of the sub-gasket 130. That is, in the cross-sectional view A-A' of Figure 4, the sub-gasket 130 may have a step corresponding to the thickness of the first gasket 120 formed by the flat portion 131a, the inclined portion 131b, and the main body portion 132.

[0035] The shapes of the flat portion 131a, the inclined portion 131b, and the main body portion 132 are not particularly limited, as long as tension can be applied by the support material 170 described later, and can be appropriately determined according to the shape of the first gasket 120, etc. The protruding portion 131 may be integrally molded with the sub-gasket 130 when the sub-gasket 130 is formed by a known or arbitrary method.

[0036] (3-2. Support material) Referring to Figure 4, the support material 170 corresponding to the tension-applying portion in the first embodiment is positioned on the main surface 133 of the protruding portion 131 that is opposite to the first gasket 120. The technical significance of positioning the support material 170 will be explained below.

[0037] Referring to Figure 5, the separator with a flow path 140 has an uneven structure in which convex portions 141 and concave portions 142 are alternately repeated, and a gas flow path FP is formed in the area surrounded by the convex portions 141 and the sub-gasket 130. Here, in the region 136 of the sub-gasket 130 that is in contact with the gas flow path FP, the surface pressure from the separator with a flow path 140 is relatively lower than in the region of the sub-gasket 130 that is in contact with the concave portions 142. Therefore, if the support material 170 is not placed, when the gas pressure increases, the region 136 of the sub-gasket 130 in which the surface pressure from the separator with a flow path 140 is relatively low (hereinafter sometimes abbreviated as the "low surface pressure region") will peel off from the first gasket 120.

[0038] In contrast, by positioning the support material 170, tension is applied to the sub-gasket 130 from the main body portion 132 toward the protruding portion 131. This tension creates a pressing force that pushes the low-pressure region 136 of the sub-gasket 130 toward the first gasket 120, thereby assisting the bonding force between the first gasket 120 and the sub-gasket 130. Consequently, the sub-gasket 130 can be prevented from peeling away from the first gasket 120, thereby suppressing gas leakage.

[0039] Furthermore, according to the first embodiment, the member for directly pressing down the low-pressure region 136 of the sub-gasket 130 from the gas flow path FP side is not placed within the gas flow path FP. Therefore, the gas flow within the gas flow path FP can be kept smooth.

[0040] Specifically, the support material 170 may extend outward from the end 121 of the first gasket 120, along the direction in which the end 121 extends. In the example shown in Figure 3, the end 121 of the first gasket 120 is a sealing wall separating the gas flowing from the gas manifold through-hole MF2 from the gas flowing from the gas manifold through-hole MF3, and is inclined with respect to the long and short sides of the first gasket 120, connecting the long and short sides. Furthermore, the support material 170 may have a rectangular cross-section that can abut against the flat portion 131a of the protruding portion 131 in the A-A' cross-sectional view in Figure 4. However, the cross-section of the support material 170 is not necessarily limited to a rectangular shape, as long as the tension described above can be applied. Furthermore, it is preferable that the height position of the main surface 171 of the support material 170 opposite to the flat portion 131a of the sub-gasket 130 coincides with or substantially coincides with the height position of the main surface 134 of the main body portion 132 of the sub-gasket 130 opposite to the first gasket 120.

[0041] The material of the support material 170 may be a sealing material similar to that of the first gasket 120, but is not particularly limited as long as it can provide the tension described above. The support material 170 may also be fixed to the main surface 133 of the protruding portion 131 with a known or any adhesive.

[0042] (3-3. Gasket material) Referring to Figure 4, it is preferable that gasket material be filled in the region R surrounded by the flat separator 110, the first gasket 120, and the sub-gasket 130. By filling with gasket material, even if the sub-gasket 130 peels off from the first gasket 120 in the low surface pressure region 136 of the sub-gasket 130 as shown in Figure 5, gas leakage can be suppressed. However, when gasket material is filled, the pressing force described above also acts on the gasket material, so the effect on the sub-gasket 130 may be lower than when gasket material is not filled, but this does not pose a particular problem in achieving the effects of this disclosure.

[0043] Specifically, the gasket material is preferably filled into the region R enclosed by the main surface 111 of the flat separator 110 on the side of the first gasket 120, the end surface 122 of the first gasket 120, and the main surface 135 of the inclined portion 131b of the sub-gasket 130 that is opposite to the support material 170. The filling of the gasket material can be carried out appropriately by known or arbitrary methods when laminating the first gasket 120 and the sub-gasket 130 onto the flat separator 110.

[0044] The gasket material can be any known or arbitrary liquid gasket, but as long as it can suppress the gas leak described above, it may also be a rubber material that has been pre-formed into a shape that fits into the shape of region R.

[0045] (3-4. Release Department) Referring to Figure 3, the arrangement of the support material 170 may cause excessive stress in the in-plane direction of the sub-gasket 130, in which case the sub-gasket 130 may be unintentionally damaged. Therefore, it is preferable that the sub-gasket 130 further has a relief portion 137 outside the support material 170, which corresponds to the tension-applying portion, to release the stress acting in the in-plane direction of the sub-gasket 130.

[0046] Specifically, the relief portion 137 may be a notch formed by intermittently or continuously cutting into a portion of the surface of the subgasket 130 in a known or arbitrary manner at any location on the subgasket 130 that does not contribute to gas sealing. In the example shown in Figure 3, the subgasket 130 has an outer shape similar to that of the flat plate separator 110, and the notch corresponding to the relief portion 137 extends along the long side of the subgasket 130 near the boundary with the long side of the first gasket 120. However, the shape of the notch corresponding to the relief portion 137 is not particularly limited as long as it can relieve the stress acting in the in-plane direction of the subgasket 130.

[0047] (3-5. Reinforcement Sections) Referring to Figure 6, the tension-applying section may further include, in addition to the support material 170 described above, a reinforcing section 172 extending from the support material 170 toward the short side of the first gasket 120 along the short side of the first gasket 120. Note that the separator with flow path 140 is not shown in Figure 6. Specifically, the reinforcing section 172 may include a plurality of ribs 172a, 172b, 172c, 172d, 172e, 172f, and 172g. Each of the plurality of ribs 172a to g is spaced apart at predetermined intervals along the short side of the first gasket 120 and may extend from the support material 170 toward the short side of the first gasket 120 along the long side of the first gasket 120 (more specifically, in front of or inside the gas manifold through hole MF2). The thickness of the multiple ribs 172a to g is determined such that the height position of the main surface of the multiple ribs 172a to g opposite to the flat separator 110 coincides with or substantially coincides with the height position of the main surface 134 of the main body portion 132 of the sub-gasket 130 opposite to the first gasket 120.

[0048] Such a reinforcing portion 172 allows for uniform or substantially uniform surface pressure to be applied to the second gasket 50 shown in Figure 2. Furthermore, because the support material 170 and the reinforcing portion 172 are integrated, the tension-applying area is enlarged, making handling easier.

[0049] (3-6. Others) Referring to Figure 7, the support material 170 and the first gasket 120 described above may be integrally molded. Note that, as in Figure 6, the separator 140 with a flow path is omitted from Figure 7. Specifically, at least one rib (for example, rib 172a) among the plurality of ribs 172a to g extends along the long side of the first gasket 120 and beyond the through hole MF2 for the gas manifold, thereby integrally molding the support material 170 and the first gasket 120. This facilitates the transport of parts and the positioning of the support material 170.

[0050] (3-7. Summary) As described above, the fuel cell cell 100 according to the first embodiment further includes a support material 170 corresponding to a tension-applying portion, located outward from the end 121 of the first gasket 120. Specifically, the sub-gasket 130 further includes an overhang portion 131 extending outward from the end 121 of the first gasket 120. The support material 170 is positioned on the main surface 133 of the overhang portion 131 that is opposite to the first gasket 120.

[0051] With this configuration, tension is applied to the sub-gasket 130 to press the low-pressure region 136 of the sub-gasket 130 toward the first gasket 120. That is, tension is applied to the sub-gasket 130 from the main body portion 132 toward the protruding portion 131. This tension creates a pressing force that pushes the low-pressure region 136 of the sub-gasket 130 toward the first gasket 120, thereby assisting the bonding force between the first gasket 120 and the sub-gasket 130. Consequently, it is possible to prevent the sub-gasket 130 from peeling away from the first gasket 120 in the low-pressure region 136 of the sub-gasket 130, and thereby suppress gas leakage.

[0052] (4. Second Embodiment) Hereinafter, with reference to Figures 8 and 9, the tension-applying unit according to the second embodiment will be described in detail, using as an example the flat plate separator 210, first gasket 220, sub-gasket 230, and flow-channel separator 240 that can be applied as the flat plate separator 10, first gasket 20, sub-gasket 30, and flow-channel separator 40 shown in Figure 2.

[0053] (4-1. Overhang) The sub-gasket 230 further includes an overhang 231 that extends outward from the end 221 of the first gasket 220. The overhang 231 may include a flat portion 231a and an inclined portion 231b, which can be configured similarly to the overhang 131 in the first embodiment, and further details will be referred to in the description of the first embodiment.

[0054] (4-2.Protrusion) The separator with a flow path 240 further includes a protruding portion 241 that extends toward the protruding portion 231 and abuts against the protruding portion 231, as a tension-applying portion. The technical significance of the separator with a flow path 240 including the protruding portion 241 will be explained below.

[0055] If the flow-channel separator 240 does not include the protrusion 241, for the same reasons as in the first embodiment, the low-pressure region of the sub-gasket 230, where the surface pressure from the flow-channel separator 240 is relatively low, will peel off from the first gasket 220 when the gas pressure increases. In contrast, by including the protrusion 241 in the flow-channel separator 240, tension is applied to the sub-gasket 230 from the main body 232 toward the protruding portion 231. This tension creates a pressing force that pushes the low-pressure region of the sub-gasket 230 toward the first gasket 220, thus assisting the bonding force between the first gasket 220 and the sub-gasket 230. Therefore, it is possible to prevent the sub-gasket 230 from peeling off from the first gasket 220, and thus suppress gas leakage.

[0056] Specifically, in the plan view of Figure 8, the protruding portion 241 may be formed in multiple locations spaced apart from each other along the direction in which the end portion 221 extends (specifically, the C-C' direction) beyond the end portion 221 of the first gasket 220. In the example shown in Figure 8, the end portion 221 of the first gasket 220 is a sealing wall that separates the gas flowing from the gas manifold through-hole MF2 from the gas flowing from the gas manifold through-hole MF3, and is inclined with respect to the long and short sides of the first gasket 220 and connects the long and short sides.

[0057] More specifically, referring to Figure 9, the separator with a flow path 240 has an uneven structure in which recesses 242 that contact the sub-gasket 230 and protrusions 243 that contact a flat plate separator 210 (not shown) are arranged alternately. Here, a gas flow path FP is formed in the region surrounded by the protrusions 243 and the sub-gasket 230, and a cooling water flow path is formed on the side of the recess 242 opposite to the sub-gasket 230. Furthermore, a projection 241 is formed in the recess 242, outside the end 221 of the first gasket 220, where a part of the recess 242 protrudes toward the overhang 231 and abuts against the flat portion 231a. In the example shown in Figure 9, the protruding portion 241 includes a first side wall portion 241a extending in the C-C' direction, a contact portion 241b that is continuous with the first side wall portion 241a and abuts against the flat portion 231a, and a second side wall portion 241c that is continuous with the contact portion 241b and extends in the C-C' direction, with a rectangular cross-section intersecting in the C-C' direction.

[0058] The protruding portion 241 can be appropriately formed by known or arbitrary press working or the like when forming the separator 240 with a flow path. In the example shown in Figure 9, the protruding portion 241 is configured as a hollow structure partially surrounded by a first side wall portion 241a, a contact portion 241b, and a second side wall portion 241c. However, the disclosure is not limited thereto, and the protruding portion 241 may be configured as a solid structure insofar as it abuts against the overhang portion 231, or it may be configured so that the recess 242 is flush with the surface.

[0059] (4-3. Gasket material) It is preferable that gasket material be filled in the region R surrounded by the flat separator 210, the first gasket 220, and the sub-gasket 230. Specifically, it is preferable that gasket material be filled in the region R surrounded by the main surface 211 of the flat separator 210 on the side of the first gasket 220, the end surface 222 of the first gasket 220, and the main surface 235 of the inclined portion 231b of the sub-gasket 230 that is opposite to the protruding portion 241. The material of the gasket material is the same as in the first embodiment, so the explanation in the first embodiment will be used with reference.

[0060] (4-4. Release Department) Preferably, the sub-gasket 230 has a stress relief portion (not shown) acting in the in-plane direction of the sub-gasket 230, which can be configured similarly to the stress relief portion 137 in the first embodiment, outside the protruding portion 241 corresponding to the tension-applying portion.

[0061] (4-5. Summary) As described above, the fuel cell cell 100 according to the second embodiment further includes a protruding portion 241 corresponding to a tension-applying portion located outward from the end portion 221 of the first gasket 220. Specifically, the sub-gasket 230 further includes an overhanging portion 231 extending outward from the end portion 221 of the first gasket 220. The separator with a flow path 240 further includes a protruding portion 241 as a tension-applying portion that protrudes toward the overhanging portion 231 and abuts against the overhanging portion 231.

[0062] With this configuration, tension is applied to the sub-gasket 230 to press the low-pressure region of the sub-gasket 230, where the surface pressure from the flow-flow separator 240 is relatively low, toward the first gasket 220. In other words, tension is applied to the sub-gasket 230 from the main body portion 232 toward the protruding portion 231. This tension creates a pressing force that pushes the low-pressure region of the sub-gasket 230 toward the first gasket 220, thereby assisting the bonding force between the first gasket 220 and the sub-gasket 230. Consequently, it is possible to prevent the sub-gasket 230 from peeling away from the first gasket 220 in the low-pressure region of the sub-gasket 230, and thereby suppress gas leakage.

[0063] Furthermore, according to the second embodiment, the protrusion 241, which functions as a tension-applying portion, is integrally molded with the flow-flow separator 240. As a result, positioning of the tension-applying portion relative to the sub-gasket 230 becomes easier than in the first embodiment, improving the yield of the fuel cell 100 and reducing the number of parts in the fuel cell 100.

[0064] While preferred embodiments of the present disclosure have been described in detail above with reference to the attached drawings, the present disclosure is not limited to such examples. It is clear to any person with ordinary skill in the art to which the present disclosure belongs that various modifications or alterations can be conceived within the scope of the technical idea described in the claims, and these will naturally also be understood to fall within the technical scope of the present disclosure. For example, the functions, etc., included in each component or step can be rearranged in a logically consistent manner, and multiple components or steps can be combined into one or divided into separate components.

[0065] Furthermore, the technology disclosed herein can also be realized as a vehicle 1 equipped with the fuel cell cell 100 according to the embodiment described above. [Explanation of symbols]

[0066] 1: Vehicle, 2: Fuel cell stack, 3: Inverter, 4: Load, 5: Control device, 6: Voltage sensor, 7: Current sensor, 100: Fuel cell cell, 10, 110, 220: Flat plate separator, 20, 120, 220: First gasket, 30, 130, 230: Sub-gasket, 40, 140, 240: Separator with flow path, 50, 150, 250: Second gasket, 60, 160, 260: Membrane electrode assembly, 131, 231: Overhang, 137: Relief part, 170: Support material (tension applying part), 241: Protrusion (tension applying part)

Claims

1. A fuel cell comprising at least a first separator, a first gasket, a sub-gasket, a membrane electrode assembly, a second separator, and a second gasket, stacked together, At least one of the first separator and the second separator is a separator with a flow path, A tension-applying portion is further provided outside the end of the first gasket to apply tension to the sub-gasket, which presses the region of the sub-gasket where the surface pressure from the flow-flow separator is relatively low toward the first gasket. Fuel cell.

2. The sub-gasket further includes an overhang that extends outward from the end of the first gasket, The tension-applying portion is positioned on the side of the main surface of the protruding portion opposite to the first gasket. The fuel cell cell according to claim 1.

3. The sub-gasket further includes an overhang that extends outward from the end of the first gasket, The separator with a flow path further includes, as the tension-applying portion, a protruding portion that protrudes toward the protruding portion and abuts against the protruding portion. The fuel cell cell according to claim 1.

4. In the region surrounded by the first separator, the first gasket, and the sub-gasket, gasket material is filled. A fuel cell cell according to any one of claims 1 to 3.

5. The sub-gasket has a relief portion outside the tension-applying portion for releasing stress acting in the in-plane direction of the sub-gasket. A fuel cell cell according to any one of claims 1 to 3.

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