Fuel cells and mobile devices

Abstract

To provide a fuel cell that uses a flat plate as one of separators and that increases a size of a gas inlet to achieve both pressure-loss reduction and thickness reduction, and to provide a mobile unit equipped with the fuel cell.SOLUTION: A fuel cell in one embodiment of the present disclosure comprises a plurality of metallic plate separators including a flat separator and a channel-equipped separator, and has an anode-gas channel, a cathode-gas channel, and a coolant channel formed therein. A peripheral edge of a manifold of the channel-equipped separator whose one surface has a channel serving as the coolant channel is provided with a step that surrounds the peripheral edge of the manifold to increase a height of a gas inlet disposed at the other surface of the channel-equipped separator. A shortened seal material having a thickness smaller than a thickness of a peripheral seal material provided in a region other than the peripheral edge of the manifold is disposed on the step to surround the peripheral edge of the manifold.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This disclosure relates to fuel cells and mobile devices such as fuel cell vehicles that are equipped with these fuel cells. [Background technology]

[0002] In general, fuel cell systems utilize fuel cells, where hydrogen gas is supplied to one electrode (fuel electrode) and oxygen gas is supplied to the other electrode (air electrode), electrical energy is obtained through the reaction between these two.

[0003] In fuel cell vehicles equipped with such fuel cells, several hundred single cells, separated by separators, are stacked and mounted as a fuel cell stack. Each separator has the function of providing electrical connections to the cathodes and anodes of adjacent single cells, and the function of supplying cathode gas (air) and anode gas (hydrogen) to the target electrodes from gas channels provided on its surface. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2007-123181 [Patent Document 2] Japanese Patent Publication No. 2013-54872 [Patent Document 3] International Publication No. 2015 / 072584 [Patent Document 4] Japanese Patent Publication No. 2017-16942 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, not only in the aforementioned patent documents, but also in current technology, the following challenges exist. For example, when stacking the fuel cells described above to use as a fuel cell stack, the number of stacks may reach several hundred, especially in automotive applications. In such cases, it is desirable to make the components constituting the fuel cell as thin as possible. In this respect, using a metal plate as a separator in a fuel cell can contribute to this thinning.

[0006] More specifically, Patent Document 3 proposes a configuration in which a flat plate (a metal plate with a generally flat main surface) with a flow path and a gas diffusion layer formed on its surface is used as a separator, and a membrane electrode assembly (MEA) is sandwiched between a pair of separators via a sealing material. However, when one separator is a flat plate, one gas (e.g., hydrogen) must flow between this plate and the MEA, while the other separator must allow cooling water and the other gas (e.g., air) to flow. In this case, the thickness of the air inlet formed between the MEA and the separator becomes small, equivalent to the thickness of the gas diffusion layer, which presents the problem of increased pressure loss of the air introduced from the manifold.

[0007] This disclosure has been made in view of the above-mentioned problems as an example, and aims to provide a fuel cell and a mobile device such as a fuel cell vehicle equipped with this fuel cell, which uses a flat plate as one of the separators, enlarges the gas inlet to reduce pressure loss, and achieves a thin profile at the same time. [Means for solving the problem]

[0008] To solve the above problems, a fuel cell in one embodiment of the present disclosure is configured to include a plurality of metal plate separators, each consisting of a planar separator and a separator with a flow path, and having an anode gas flow path, a cathode gas flow path, and a cooling water flow path formed therein, wherein a stepped portion is provided around the manifold periphery of a separator with a flow path, one of which has a flow path that forms the cooling water flow path, such that the height of the gas inlet located on the other side is increased, and a shortened sealing material, which is thinner in thickness than the peripheral sealing material provided in the area other than the manifold periphery, is arranged on the stepped portion so as to surround the manifold periphery.

[0009] Also, in order to solve the above problems, the moving body in another aspect of the present disclosure is equipped with the fuel cell of the present disclosure.

Effects of the Invention

[0010] According to the present disclosure, even if a flat plate is used for one of the separators, it is possible to increase the gas inlet and reduce the pressure loss while achieving a thinner profile.

Brief Description of the Drawings

[0011] [Figure 1] It is a schematic diagram of a fuel cell stack according to the first embodiment and a functional block diagram of a fuel cell vehicle equipped with this fuel cell stack. [Figure 2] It is a perspective view excerpting a part of the fuel cell constituting the fuel cell stack according to the first embodiment. [Figure 3] It is a top view showing a part of the separator with flow paths in the fuel cell of the first embodiment. [Figure 4] It is a perspective view showing a part of the separator with flow paths in the fuel cell of the first embodiment. [Figure 5] It is a top view excerpting and showing a part of the membrane electrode assembly (MEA) in the fuel cell of the first embodiment. [Figure 6] It is a perspective view excerpting and showing a part of the membrane electrode assembly (MEA) in the fuel cell of the first embodiment. [Figure 7] It is a top view excerpting and showing a part of the planar separator in the fuel cell of the first embodiment. [Figure 8] It is a perspective view excerpting and showing a part of the planar separator in the fuel cell of the first embodiment. [Figure 9] It is a cross-sectional view schematically showing the A-A cross-section in FIG. 3 and the like. [Figure 10] It is a cross-sectional view schematically showing the B-B cross-section in FIG. 3 and the like. [Figure 11] It is a cross-sectional view schematically showing the C-C cross-section in FIG. 3 and the like. [Figure 12]This is a schematic diagram showing a fuel cell stack according to the second embodiment. [Figure 13] This is a top view of a part of the fuel cell stack according to the second embodiment. [Figure 14] This is a schematic cross-sectional view of the DD section in Figure 13. [Modes for carrying out the invention]

[0012] Next, preferred embodiments for implementing this disclosure will be described. Furthermore, configurations other than those detailed can be implemented by appropriately supplementing known elemental technologies and configurations related to fuel cells, fuel cell stacks, and fuel cell systems including their drives, including those mentioned in the aforementioned patent documents.

[0013] [First Embodiment] <Fuel cell vehicle 300> First, the configuration of the fuel cell vehicle 300, which is an example of a mobile device in this disclosure, will be explained with reference to Figure 1(a). The fuel cell vehicle 300 in this embodiment is configured to include a fuel cell stack 200, a DC / DC converter 210, an inverter 220, a load (such as an electric motor) 230, and a control device 240. As an example, under the control of the control device 240, the power generated by the fuel cell stack 200 is supplied to the electric motor as the load 230 via the DC / DC converter 210 and the inverter 220. The fuel cell vehicle 300 in this embodiment may further include various known equipment mounted on a fuel cell vehicle, such as a hydrogen tank and a gas supply mechanism (anode gas supply device, cathode gas supply device, refrigerant supply device, etc.).

[0014] The fuel cell stack 200 is composed of several tens to several hundred fuel cell cells 100, which will be described later, stacked in the stacking direction. Each fuel cell cell 100 has the function of generating electricity by reacting a fuel gas (hydrogen gas) with an oxidizing gas (oxygen in the air).

[0015] The DC / DC converter 210 is a known transformer that boosts the power generated by the fuel cell stack 200 to a desired voltage and supplies it to the inverter 220. As an example, the DC / DC converter 210 performs the boosting process described above via a known chopper circuit.

[0016] The inverter 220 is configured to convert the DC power obtained by boosting the DC / DC converter 210 described above into AC power suitable for driving the electric motor, which is the subsequent load 230. There are no particular restrictions on the inverter 220 as long as it performs the above function, and various known inverters, including a three-phase bridge circuit, can be used.

[0017] The load 230 includes a known electric motor capable of outputting power to drive, for example, the drive wheels (not shown) of the fuel cell vehicle 300. In this embodiment, an electric motor that generates the power required for the drive wheels is given as an example of the load 230, but the load 230 may be other electrical equipment mounted on the fuel cell vehicle 300. As an example of the electric motor, a known three-phase AC electric motor can be given.

[0018] The control device 240 is a known Electronic Control Unit (EUC) mounted on an electric vehicle, and is configured to include a known CPU, which is an arithmetic processing unit; a known ROM, which is a memory element that stores programs and calculation parameters used by the CPU; and a known RAM, which is a memory element that temporarily stores various information. The control device 240 may also further include a known Battery Management Unit (BMU) that monitors and controls the battery status. The control device 240 may also be configured to communicate with other known EUCs and various sensors (not shown) mounted on the fuel cell vehicle 300.

[0019] In the following explanation, a fuel cell vehicle will be used as an example of a mobile device, but this disclosure is applicable to various known mobile devices that can be moved by being equipped with a fuel cell system as a power source, such as ships, aircraft, or trains. In other words, the fuel cell stack of this disclosure is not limited to fuel cell vehicles, but can also be applied to other mobile devices such as ships and aircraft.

[0020] <Fuel cell stack 200> Next, the configuration of the fuel cell stack 200 in this embodiment will be described with reference to Figure 1(b). As can be seen from the figure, the fuel cell stack 200 in this embodiment is constructed by sandwiching a plurality of fuel cell cells 100 stacked in the stacking direction between a pair of end plates 201. In addition, a current collector plate 202 is placed inside each end plate 201, so that the power generated by the fuel cell cells 100 can be extracted via the extraction electrode 202e of the current collector plate 202.

[0021] As can be seen from the figure, on one side of the end plate 201a in the stacking direction of the cells, an oxidizing gas supply port 203a, a refrigerant supply port 204a, and a fuel gas supply port 205a are provided, respectively. Oxidizing gas, refrigerant, and fuel gas are supplied to the fuel cell cell 100 through these supply ports. Similarly, on the other side of the end plate 201a in the longitudinal direction, an oxidizing gas discharge port 203b, a refrigerant discharge port 204b, and a fuel gas discharge port 205b are provided, respectively.

[0022] As a result, for example, oxidizing gas is supplied to multiple fuel cell cells 100 from the oxidizing gas supply port 203a and then discharged from the oxidizing gas discharge port 203b. Similarly, fuel gas is supplied to multiple fuel cell cells 100 from the fuel gas supply port 205a and then discharged from the fuel gas discharge port 205b. In addition, refrigerant (for example, known cooling water) is circulated within the fuel cell stack 200 from the refrigerant supply port 204a and then discharged from the refrigerant discharge port 204b.

[0023] In this embodiment, an oxidizing gas supply port 203a, a refrigerant supply port 204a, and a fuel gas supply port 205a are provided on one end plate 201a side, but the embodiment is not limited to this configuration. That is, the above-mentioned supply ports may be provided on the end plate 201b side instead of the end plate 201a side.

[0024] <Fuel cell cell 100> Next, the configuration of the fuel cell cell 100 in this embodiment will be described with reference to Figures 2 to 11 as appropriate. As shown in Figure 2 and other figures, the fuel cell cell 100 in this embodiment is composed of a plurality of metal plate separators 30, each consisting of a planar separator 10 and a flow channel separator 20, which will be described later. The following describes the structure around the inlet ports into which gases and liquids flow into each fuel cell cell 100, but it goes without saying that the same principles can be applied to the structures around the outlet ports from which these gases and liquids are discharged.

[0025] These planar separators 10 and flow channel separators 20, along with the sealing material 40 described later, form the anode gas flow channel 11, the cooling water flow channel 22, and the cathode gas flow channel 23, respectively. In this embodiment, the cooling water flow channel 22, the cathode gas flow channel 23, and the anode gas flow channel 11 are stacked in that order from one side 20a (the side of the flow channel separator 20 that corresponds to the outside of the fuel cell cell 100), but the configuration of this disclosure is not limited to this form.

[0026] 1-1. Flow channel structure for cooling water Next, the flow path structure for the cooling water in the fuel cell cell 100 will be described with reference to Figures 2 to 4 and Figure 9. As is clear from these figures, the cooling water flow path 22 in the fuel cell cell 100 is provided on one of the aforementioned surfaces 20a of the flow path separator 20. Since multiple fuel cell cells 100 are stacked in the fuel cell stack 200, the planar separators of adjacent fuel cell cells 100 will be positioned above the aforementioned surface 20a of this flow path separator 20.

[0027] As shown in FIGS. 3 and 4, the separator 20 with flow paths is surrounded by a first sealing material 41 at its periphery. Further, at the longitudinal ends of the separator 20 with flow paths, there are hydrogen discharge holes 11 out (H2 manifold) through which anode gas flows in, refrigerant introduction holes 22 in (refrigerant manifold) through which refrigerant (such as cooling water) flows in, and air introduction holes 23 in (air manifold) through which cathode gas flows in are provided. In this embodiment, the refrigerant manifold is located between the H2 manifold and the air manifold, but the arrangement form of these introduction holes is not limited to the above and may be appropriately interchanged. As shown in the figure, in this embodiment, the air introduction hole 23 in and the hydrogen discharge hole 11 out are arranged such that the refrigerant introduction hole 22 in is located between them. However, for example, the refrigerant introduction hole 22 in may be arranged between the air introduction hole 23 in and the hydrogen introduction hole 11 in .

[0028] Further, the hydrogen discharge holes 11 out , the refrigerant introduction holes 22 in and the air introduction holes 23 in are separated by the above-mentioned first sealing material 41. Also, as described above, since the cooling water flow path 22 is formed on one surface 20a of the separator 20 with flow paths, a first reinforcing member 61 that allows cooling water to flow is arranged on the side of the cooling water flow path 22 among the peripheries of the refrigerant introduction holes 22 in . The first reinforcing member 61 is configured to have a strength that allows the refrigerant (cooling water in this example) flowing in from the refrigerant introduction hole 22 in to flow through, and to ensure the sealing performance between the separator 20 with flow paths and the third sealing material 43 and the other sealing surfaces arranged continuously in the stacking direction with the first reinforcing member 61. Specific examples of such a first reinforcing member 61 include known porous members formed of resin materials, metal materials, etc., and metal press members.

[0029] Furthermore, since a cooling water channel 22 is formed on one of the surfaces 20a of the separator 20 with a flow path, the hydrogen discharge hole 11 is formed on this one surface 20a side. out It is surrounded by the first sealing material 41 described above. Similarly, to prevent cathode gas from flowing onto one side 20a, an air inlet 23 is provided on this side 20a. in It is surrounded by a second seal material 42, which is different from the first seal material 41.

[0030] In other words, as can be understood by comparing Figures 3 and 4, a stepped portion 25 is formed on the periphery of the gas (air) manifold of the separator 20 with a flow channel, where one side 20a is a cooling water flow channel. This stepped portion 25 is a stepped portion that rises from the main surface of the separator so that one side 20a of the separator 20 with a flow channel bulges out (becomes a convex portion, protrudes).

[0031] In other words, in the fuel cell cell 100 of this embodiment, a gas inlet 24 is formed on the other side 22b, which is the back side of the stepped portion 25, with its height (opening) increased by the amount of the bulge. Thus, in the fuel cell cell 100 of this embodiment, a stepped portion 25 is provided around the manifold periphery of a separator with a flow path, on one side of which a flow path that serves as a cooling water flow path 22 is formed, so as to increase the height of the gas inlet 24 located on the other side.

[0032] Furthermore, in the fuel cell cell 100 of this embodiment, a shortened seal material (second seal material 42), which is thinner in thickness (height in the stacking direction) than the peripheral seal material (first seal material 41) provided in areas other than the periphery of the gas (air) manifold, is arranged on the stepped portion 25 described above, surrounding the periphery of the gas (air) manifold. More specifically, as shown in Figure 9, the thickness (height h2) of the second seal material 42 in this embodiment may be set to be smaller than the thickness (height h1) of the first seal material 41 described above by the height of the stepped portion 25. As a result, as shown in Figure 9 and other figures, when stacked as a fuel cell cell 100, the top of the flow channel groove 22a in the flow channel separator 20, the top of the second seal material 42 arranged on the stepped portion 25, and the top of the first seal material 41 surrounding the cooling water flow channel 22 are flush with each other.

[0033] Regarding the materials of the first sealant 41, the second sealant 42, and the third to sixth sealants 43 to 46 described later, examples include various known resin materials with appropriate additives added to a silicone rubber base, various resin materials that can be bonded by various methods such as heat bonding or pressure bonding, and composite members coated with such resin materials, as long as they perform the functions described in this embodiment. In this embodiment, the first sealant 41 and the second sealant 42 are formed using the same material, but these sealants may be formed from different materials as long as the thicknesses described above can be made different, and they may also be integrated. Furthermore, considering ease of assembly, the first sealant 41, the second sealant 42, and the third to sixth sealants 43 to 46 described later are preferably formed from known materials that can self-maintain their shape to some extent, such as silicone rubber. Furthermore, although the second sealing material 42 described above is used in this embodiment, the second sealing material 42 may be replaced with a known welding method such as laser welding.

[0034] Furthermore, the inner seal materials (second seal material 42, fourth seal material 44, sixth seal material 46) located inside the outer seal material (first seal material 41, third seal material 43, or fifth seal material 45) and arranged around a specific flow path may be made of a material with higher fluidity than the outer seal material, for example, by using a known liquid-type seal material such as a two-component seal material.

[0035] 1-2. Flow path structure for cathode gas (air) Next, the flow path structure for the cathode gas (air) in the fuel cell cell 100 will be described with reference to Figures 2, 5-6, and 9. As is clear from these figures, the cathode gas flow path 23 in the fuel cell cell 100 is provided on the other side 22b of the separator with flow path 20. In other words, the cathode gas flow path 23 is provided between the MEA 50 and the separator with flow path 20.

[0036] MEA50 is a known membrane electrode assembly comprising a pair of catalyst layers arranged on both sides of an electrolyte membrane. As can be seen from Figures 2 and 6, in this embodiment, a known gas diffusion layer, GDL1, is arranged on one side 50a of MEA50, and a known gas diffusion layer, GDL2, is arranged on the other side 50b. In this embodiment, GDL1 and GDL2 have been described as separate from MEA50, but these GDLs may also be included in the definition of the membrane electrode assembly.

[0037] As shown in Figures 5 and 6, on one side 50a of the MEA 50, the third sealing material 43 surrounds the periphery so as to seal the cathode gas flow path 23. And the hydrogen discharge hole 11 out and refrigerant inlet port 22 in These are separated from each other by the third sealing material 43 described above, preventing the anode gas and refrigerant from flowing into the cathode gas flow path 23. Furthermore, since a cathode gas flow path 23 is formed between one surface 50a of the MEA50 and the other surface 22b of the separator with flow path 20, the air inlet hole 23 inThe gas inlet 24 described above is formed on the side of the surrounding area that is the cathode gas flow path 23.

[0038] At this time, a second reinforcing member 62 through which cathode gas (air) can flow is placed in the gas inlet 24 described above. The second reinforcing member 62 is located in the air inlet 23 in The second reinforcing member 62 is configured to allow cathode gas flowing in from the opening and to have sufficient strength to ensure the sealing performance between the flow-through separator 20 and the second sealing material 42, as well as other sealing surfaces arranged in a continuous direction with the second reinforcing member 62 in the stacking direction. Specific examples of such a second reinforcing member 62 include a known porous member made of resin or metal, or a metal pressed member.

[0039] In addition, in this embodiment, the air inlet hole 23 in A fourth sealing material 44 is arranged in the area surrounding the second reinforcing member 62 described above, excluding the area surrounding the second reinforcing member 62. As shown in Figure 9, the thickness of the fourth sealing material 44 may be set to be higher than the third sealing material 43 described above by the height of the stepped portion 25, and to be approximately the same height as the second reinforcing member 62 described above. In this way, on one side 50a of the MEA 50, the fourth sealing material 44 and the second reinforcing member 62 are arranged such that their tops are approximately the same height and covered by the stepped portion 25, and the air introduction hole 23 in It may also surround it.

[0040] Furthermore, as shown in Figure 9, in the fuel cell cell 100 of this embodiment, the thickness (height) of the second sealing material 42 located on the stepped portion 25 (the bulging side) may be set to a value obtained by subtracting the thickness of the stepped portion 25 from the thickness (height) of the first sealing material 41 (i.e., a value obtained by subtracting only the difference in the step). Similarly, as can be understood from Figure 11, the thickness (height) of the fourth sealing material 44 located below the stepped portion 25 may be set to a value obtained by adding the thickness of the stepped portion 25 to the thickness (height) of the third sealing material 43.

[0041] 1-3. Flow channel structure for anode gas (hydrogen) Next, the flow path structure for the anode gas (hydrogen) in the fuel cell cell 100 will be explained with reference to Figures 2, 7 to 9, etc. As is clear from the figures, the anode gas flow path 11 in the fuel cell cell 100 is provided on one side 10A of the planar separator 10. In other words, the anode gas flow path 11 is provided between the MEA 50 and the planar separator 10.

[0042] As shown in Figures 7 and 8, on one side 10A of the planar separator 10 (the other side 50b of the MEA 50), the fifth sealing material 45 surrounds the periphery so as to seal the anode gas flow path 11. And the refrigerant inlet hole 22 in The hydrogen discharge hole 11 is sealed by the fifth sealing material 45 described above. out This is how it is separated, preventing the refrigerant from flowing into the anode gas flow path 11. Similarly, the air inlet 23 in The hydrogen discharge hole 11 is sealed with a sixth seal material 46 having approximately the same thickness as the fifth seal material 45 described above. out This separation prevents air from flowing into the anode gas flow path 11.

[0043] Thus, in this embodiment, the air inlet hole 23 is made of a sixth seal material 46, which is different from the fifth seal material 45 described above. in Although the seal is surrounded and sealed, the sixth seal material 46 may be connected to the fifth seal material 45 so that the fifth seal material 45 and the sixth seal material 46 are formed as a single unit.

[0044] Furthermore, since an anode gas flow path 11 is formed on one of the surfaces 10A of the planar separator 10, the hydrogen discharge hole 11 out A third reinforcing member 63, through which hydrogen can flow, is positioned on the side of the anode gas flow path 11 within the surrounding area. The third reinforcing member 63 is connected to the hydrogen discharge hole 11 outThe third reinforcing member 63 is configured to allow hydrogen to flow through it, while also having sufficient strength to ensure the sealing performance between the MEA 50 and the third sealing material 43, and between the third reinforcing member 63 and other sealing surfaces arranged in a continuous lamination direction. Specific examples of such a third reinforcing member 63 include a known porous member made of resin or metal, or a metal pressed member.

[0045] 1-4. Comparison of Thickness (Height) of Sealing Materials and Reinforcement Members Next, referring to Figures 9 to 11, we will compare the thicknesses of each sealing material and each reinforcing member used in the fuel cell cell 100 of this embodiment. As described above, the fuel cell cell 100 of this embodiment is composed of sealing materials 40 (first sealing material 41 to sixth sealing material 46) having at least a plurality of different thicknesses. Of the plurality of sealing materials 40 described above, the fourth sealing material 44 does not necessarily need to have strict sealing properties, but only needs to have sufficient strength to ensure sealing properties of the sealing surfaces that are connected in the stacking direction. Furthermore, the fuel cell cell 100 of this embodiment is configured to include at least a plurality of reinforcing members 60 (first reinforcing member 61 to third reinforcing member 63) having different thicknesses from each other.

[0046] These first sealing materials 41 to sixth sealing materials 46 and first reinforcing members 61 to third reinforcing members 63 preferably have at least one of the relationships shown below, as an example.

[0047] (Relationship 1) Thickness of the first sealant 41 (height h1) > Thickness of the second sealant 42 (height h2)

[0048] (Relationship 2) Thickness of the fourth sealant 44 (height h4) > Thickness of the third sealant 43 (height h3)

[0049] (Relationship 3) Thickness of the 5th sealant 45 (height h5) ≈ Thickness of the 6th sealant 46 (height h5)

[0050] (Relationship 4) Thickness of the first sealing material 41 (height h1) ≈ Thickness of the first reinforcing member 61 (height h6)

[0051] (Relationship 5) Thickness of the second reinforcing member 62 (height h7) > Thickness of the third sealing material 43 (height h3)

[0052] (Relationship 6) Thickness of the third reinforcing member 63 (height h8) ≈ Thickness of the fifth sealing material 45 (height h5)

[0053] (Relationship 7) Thickness (height) of the stepped portion 25 ≈ Thickness (height h1) of the first sealant 41 - Thickness (height h2) of the second sealant 42

[0054] In this embodiment, multiple reinforcing members 60 (first reinforcing member 61 to third reinforcing member 63) are used, but the physical structure of these reinforcing members may be different depending on the object flowing through them. For example, the first reinforcing member 61, through which cooling water can flow, can be made of a metal plate with a wavy surface. On the other hand, the second and third reinforcing members 62 and 63, through which gas (air, oxygen) can flow, can be made of a metal plate with pressure-resistant ribs arranged at predetermined intervals to form a gas passage area.

[0055] As described above, if one of the separators that sandwich the MEA, which is the core of the fuel cell cell, is a flat plate and the other is a separator with a flow path, then if the stepped portion described above does not exist, the thickness (height) of the gas (air in this embodiment) inlet formed between the MEA and the separator with a flow path will be about the same as the thickness of the gas diffusion layer (GDL1). Therefore, the pressure loss of the air introduced from the manifold will be large due to the narrowness of the gas inlet.

[0056] On the other hand, in this embodiment, the fuel cell cell 100 has a stepped portion surrounding the manifold periphery of a separator with a flow path, one side of which has a flow path that serves as a cooling water flow path, so as to widen the height of the gas inlet located on the other side. Furthermore, a shortened sealing material (second sealing material 42), which is thinner than the peripheral sealing material (first sealing material 41) provided in the area other than the manifold periphery, is arranged on top of this stepped portion so as to surround the manifold periphery. As a result, in the fuel cell cell 100, even if a flat plate is used for one of the separators, the stepped portion allows for a wider opening of the gas inlet, reducing pressure loss while simultaneously achieving an overall thinner design.

[0057] [Second Embodiment] Next, the fuel cell cell 110 according to the second embodiment of this disclosure will be described with reference to Figures 12 to 14. In the fuel cell cell 100 of the first embodiment described above, the cooling water channel 22, the cathode gas (air) channel 23, and the anode gas (hydrogen) channel 21 were stacked in that order from one side 20a of the separator with a channel 20. In contrast, the fuel cell cell 110 of the second embodiment is mainly characterized in that the cathode gas (air) channel 23, the cooling water channel 22, and the anode gas (hydrogen) channel 21 are stacked in that order from the other side 22b of the separator with a channel 20. Therefore, in the following second embodiment, configurations similar to those described in the first embodiment will be given the same reference numerals, and their descriptions will be omitted as appropriate.

[0058] As shown in Figure 12, the fuel cell cell 110 is composed of a first unit 110A in which GDL1 and GDL2 sandwich the MEA50, and a second unit 110B in which a planar separator 10 and a separator with a flow path 20 are bonded together. The fuel cell stack of this embodiment is formed by alternately stacking these first unit 110A and second unit 110B.

[0059] Therefore, as can be understood by comparing Figures 13 and 14, in the fuel cell cell 110, the cathode gas (air) channel 23, the cooling water channel 22, and the anode gas (hydrogen) channel 21 are stacked in that order from the other side 22b of the separator 20 with a flow path. In other words, when viewing the second unit 110B from the MEA 50 side, the anode gas (hydrogen) channel 21, the cooling water channel 22, and the cathode gas (air) channel 23 are stacked in that order from one side 10A of the planar separator 10.

[0060] Furthermore, anode gas will flow into GDL2 of the MEA50 shown in Figure 12. Therefore, cathode gas that has flowed through the cathode gas (air) flow path 23 of the other fuel cell cell 110 adjacent to this fuel cell cell 110 will flow into the GDL1 side of the MEA50.

[0061] Thus, in the fuel cell cell described herein, the MEA 50 does not necessarily need to be sandwiched between the planar separator 10 and the separator with a flow path 20. For example, as in this embodiment, the planar separator 10 may be sandwiched between the MEA 50 and the separator with a flow path 20.

[0062] 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 obvious to any person with ordinary skill in the art to which the present disclosure pertains to attempt further modifications to these embodiments and variations within the scope of the technical idea set forth in the claims, and these modifications will naturally also fall within the technical scope of the present disclosure.

[0063] For example, in each of the embodiments described above, multiple sealing materials with different thicknesses (heights) were used, but sealing materials located in the same layer (for example, a combination of the first sealing material 41 and the second sealing material 42, or a combination of the third sealing material 43 and the fourth sealing material 44) may be molded as a continuous, integrated sealing material.

[0064] Furthermore, the reinforcing member 60 described above may be made of a porous metal material, such as aluminum or titanium. In addition, ribs or supports may be placed adjacent to the reinforcing member 60 to improve pressure resistance. Moreover, the reinforcing member 60 may be made of a highly dense porous material, as long as the reduction in pressure loss can be maintained.

[0065] Furthermore, in the first embodiment described above, a space is formed between the inside of the third seal material 43 and the outside of the fourth seal material 44. However, for example, at least one of the third seal material 43 and the fourth seal material 44 may be extended to fill this gap. Filling this gap can suppress the accumulation of moisture and other substances near the gas inlet hole. In this case, the gap between the third seal material 43 and the fourth seal material 44 may be filled with a material other than the material of the third seal material 43 and the fourth seal material 44. [Explanation of symbols]

[0066] 100, 110 fuel cell cells 30 Separators 10 Planar separators 20 Separator with flow path 40 sealing material 50 MEA (membrane electrode assembly) 60 Reinforcement members 200 fuel cell stacks 210 DC / DC Converter 220 Inverter 230 load 240 Control devices 300 Fuel cell vehicle (mobile)

Claims

1. In a fuel cell comprising a plurality of metal plate separators consisting of a planar separator and a separator with a flow path, in which an anode gas flow path, a cathode gas flow path, and a cooling water flow path are formed, A stepped portion is provided around the manifold periphery of a separator with a flow path, where one side of the manifold has a flow path that serves as the cooling water flow path, such that the height of the gas inlet located on the other side is increased. On the stepped portion, a shortened sealing material, which is thinner than the peripheral sealing material provided in areas other than the manifold periphery, is arranged to surround the manifold periphery. fuel cell.

2. The cooling water channel, the cathode gas channel, and the anode gas channel are stacked in that order, starting from one side of the aforementioned surface. The fuel cell according to claim 1.

3. The cathode gas channel, the cooling water channel, and the anode gas channel are stacked in that order, starting from the other side. The fuel cell according to claim 1.

4. The thickness of the shortened sealing material placed on the stepped portion is set to be the value obtained by subtracting the thickness of the stepped portion from the thickness of the sealing material placed around the shortened sealing material. The fuel cell according to claim 1.

5. A mobile body equipped with a fuel cell according to any one of claims 1 to 3.