Fuel cell and moving body provided with fuel cell

Abstract

The present invention provides a fuel cell in which a flat separator is used on one side and a separator with flow channels is used on the other side to improve power generation efficiency by creating parallel flow channels of gas and cooling water in a power generation area, while also considering the arrangement of manifolds for gas and cooling water. A fuel cell in one embodiment of the present disclosure has: a flat separator in which gas manifolds arranged side-by-side along a first direction and cooling water manifolds arranged along a second direction are formed; a separator with flow channels, disposed opposite the flat separator; and a membrane electrode assembly disposed between the flat separators and the separators with flow channels, wherein, out of an anode gas and a cathode gas, one gas is circulated between the flat separator and the membrane electrode assembly while the other gas is introduced between the membrane electrode assembly and the separator with flow channels via a through hole, and the cooling water, the anode gas, and the cathode gas are each circulated along the second direction in an area overlapping a power generation area.

Description

Fuel cell and mobile body equipped with the fuel cell

[0001] The present disclosure relates to a fuel cell and a mobile body, such as a fuel cell vehicle or a ship, that is equipped with the fuel cell.

[0002] In a system using a fuel cell, hydrogen gas is supplied to one electrode (a fuel electrode) and oxygen gas is supplied to the other electrode (a cathode), and electrical energy is obtained by the reaction between these. Such a system is typically mounted on a mobile object, such as a fuel cell vehicle.

[0003] Fuel cell vehicles are equipped with a fuel cell stack made up of several hundred unit cells (fuel cell units) that are separated and stacked by separators, for example. The separators in the fuel cell stack disclosed in Patent Document 1 have the functions of electrically connecting the cathodes and anodes of adjacent unit cells and supplying cathode gas (air) and anode gas (hydrogen) to the target electrodes from gas channels provided on their surfaces.

[0004] Japanese Patent Application Laid-Open No. 2015-195193

[0005] However, the current technology, not limited to the above-mentioned patent documents, has the following problem: In other words, as exemplified in Patent Document 1, for example, the specifications of separators in fuel cells may be such that one side sandwiching a membrane electrode assembly (MEA) is a flat type (also referred to as a flat separator) and the other side is an uneven type having grooves for forming flow channels (also referred to as a separator with flow channels or a grooved flow channel separator).

[0006] In this case, for example, gas may flow through the surface of the uneven separator facing the MEA, while coolant may flow through the surface opposite the MEA. In this case, as shown in Patent Document 1, it is preferable to make the flow paths of gas and coolant parallel in the power generation area where the MEA is located, from the perspective of improving the power generation efficiency of the fuel cell as much as possible. However, in conventional configurations including Patent Document 1, it is difficult to say that the arrangement of manifolds for gas and coolant flowing into the power generation area is efficient while ensuring the parallel configuration of the flow paths in the power generation area, and there is still significant room for improvement.

[0007] The present disclosure has been made in consideration of the above-mentioned problems as an example, and aims to provide a fuel cell cell in which the gas and cooling water flow paths in the power generation area are parallel, improving power generation efficiency, while also taking into consideration the placement of gas and cooling water manifolds, even in a fuel cell cell that uses a flat separator on one side and a separator with a flow path on the other, and a mobile body such as a fuel cell vehicle that is equipped with this fuel cell.

[0008] In order to solve the above problems, a fuel cell according to one embodiment of the present disclosure includes a flat separator on which an anode gas manifold and a cathode gas manifold are arranged side by side along a first direction relative to a power generation area, and a cooling water manifold is arranged along a second direction perpendicular to the first direction, and a separator with flow channels on which manifolds corresponding to the anode gas manifold, the cathode gas manifold, and the cooling water manifold are respectively formed, the separator being arranged opposite the flat separator, and through which cooling water can flow via a surface side of flow channel grooves on a surface opposite to the surface facing the flat separator. and a membrane electrode assembly disposed between the flat separator and the separator with channels and fixed within a frame of a subgasket having through holes through which gas can flow, wherein one of an anode gas and a cathode gas flows between the flat separator and the membrane electrode assembly, and the other of the anode gas and the cathode gas flows along a back surface side of the channel groove via the through holes and is introduced between the membrane electrode assembly and the separator with channels, and the cooling water, the anode gas, and the cathode gas each flow along the second direction within a region overlapping with the power generation area.

[0009] In order to solve the above-described problems, a moving body according to another embodiment of the present disclosure is equipped with the fuel cell of the present disclosure.

[0010] According to the present disclosure, a fuel cell is constructed using a flat separator on one side and a separator with a flow path on the other side, and the flow paths through which gas and cooling water flow in the power generation area are parallel, thereby suppressing pressure loss and improving power generation efficiency.

[0011] 6 is a functional block diagram of a fuel cell stack formed by stacking fuel cells according to an embodiment, and a fuel cell vehicle (an example of a mobile body) equipped with this fuel cell stack. A schematic diagram showing components of a fuel cell according to an embodiment. A schematic diagram showing a membrane electrode assembly included in a fuel cell according to an embodiment. A perspective view schematically showing a subgasket and a portion of a first gasket (cathode gasket) in a fuel cell according to an embodiment. A top view schematically showing a portion of a subgasket and a portion of a first gasket (cathode gasket) in a fuel cell according to an embodiment. A top view schematically showing the outer surface side (opposite the side facing the MEA) of a separator with channels in a fuel cell according to an embodiment. A cross-sectional view taken along line A-A of the α portion in FIG. 6. A cross-sectional view taken along line B-B of the β portion in FIG. 6. A schematic diagram showing a form in which cooling water flows on the outer surface side of a separator with channels according to an embodiment, and the channel structure. A schematic diagram showing a channel structure in which gas (anode gas) flows on the inner surface side (side facing the MEA) of a separator with channels according to an embodiment. A schematic diagram showing a channel structure in a stepped portion of a separator with channels according to an embodiment. 1A and 1B are schematic diagrams illustrating a gas (anode gas) flow pattern and a flow path structure on the inner surface side and at a step portion of a separator with flow channels according to an embodiment, and a cooling water flow pattern and a flow path structure on a step portion of a separator with flow channels according to an embodiment.

[0012] Next, preferred embodiments for carrying out the present disclosure will be described. Furthermore, configurations other than those described in detail can be implemented by appropriately supplementing elemental technologies and configurations related to known fuel cells, fuel cell stacks, and fuel cell systems, including the driving thereof, including those described in the above-mentioned patent documents.

[0013] <Fuel Cell Vehicle 300> First, the configuration of a fuel cell vehicle 300 as an example of a mobile body in this disclosure will be described with reference to Fig. 1. As shown in Fig. 1, the fuel cell vehicle 300 in this embodiment is configured to include a fuel cell stack 200, an inverter 210, a load (such as an electric motor) 220, and a control device 230. In the fuel cell vehicle 300, under the control of the control device 230, electric power generated in the fuel cell stack 200 is supplied to the load 220 via the well-known inverter 210. Note that the fuel cell vehicle 300 in this embodiment is configured to include various well-known devices (not shown) that are mounted on fuel cell vehicles, such as a hydrogen tank, a gas supply mechanism (anode gas supply device, cathode gas supply device), a refrigerant supply device, and a DC / DC converter.

[0014] The fuel cell stack 200 is constructed by stacking several tens to several hundreds of fuel cell units 100, which serve as unit cells (described later), in the stacking direction. Each fuel cell unit 100 has the function of generating electricity by reacting an anode gas (also called a fuel gas or hydrogen gas) with a cathode gas (oxygen in the air, also called an oxidant gas). The fuel cell stack 200 is equipped with a known voltage sensor SR that can measure the voltage applied to the fuel cell stack and the voltage of each individual fuel cell unit 100. １ and a known current sensor SR capable of measuring the current flowing through the fuel cell 100. ２ The fuel cell 100 is not particularly limited as long as it does not deviate from the spirit of the present disclosure, and a known PEFC (polymer electrolyte fuel cell) or the like is suitable, for example.

[0015] The inverter 210 is configured to have the function of converting DC power obtained by boosting the voltage using, for example, a DC / DC converter (not shown) into AC power suitable for driving an electric motor, which is the downstream load 220. There are no particular limitations on the inverter 210 as long as it can perform the above function, and various known inverters including, for example, a three-phase bridge circuit can be used.

[0016] The load 220 is configured to include, for example, a known electric motor capable of outputting power for driving drive wheels (not shown) of the fuel cell vehicle 300. Note that in this embodiment, an electric motor that generates the power required for the drive wheels is used as an example of the load 220, but the load 220 may also be other electrical equipment mounted on the fuel cell vehicle 300. Furthermore, one example of the electric motor is a known three-phase AC electric motor.

[0017] The control device 230 is a known ECU (Electronic Control Unit) mounted on the electric vehicle, and is configured to include a known CPU which is an arithmetic processing device, a known ROM which is a memory element that stores programs used by the CPU, calculation parameters, etc., and a known RAM which is a memory element that temporarily stores various information. The control device 230 may also be configured to include a known BMU (Battery Management Unit) that monitors and controls the state of the battery. The control device 230 may be configured to be able to communicate with other known EUCs and various sensors (not shown) mounted on the fuel cell vehicle 300.

[0018] While the following description uses a fuel cell vehicle as an example of a moving body, the present disclosure can be applied to various known moving bodies that can move using a fuel cell system as a driving source, such as ships, aircraft, trains, etc. In other words, the fuel cell stack of the present disclosure can be applied not only to fuel cell vehicles but also to other moving bodies such as ships and aircraft.

[0019] <Fuel Cell 100> Next, the configuration of the fuel cell 100 in this embodiment will be described with reference to Figures 2 to 13 as appropriate. As shown in Figure 2 and other figures, the fuel cell 100 in this embodiment is configured to include a membrane electrode assembly (MEA 30) sandwiched between a flat separator 10 and a separator with flow channels 20. The MEA 30 in the fuel cell 100 is surrounded by a subgasket 40 provided around the MEA 30. As shown in Figure 2 and other figures, a first gasket 50 is provided between the flat separator 10 and the separator with flow channels 20 in the fuel cell 100. A second gasket 60 is provided on the side of the separator with flow channels 20 in the fuel cell 100 opposite the MEA 30.

[0020] The flat separator 10 is a rectangular flat plate type separator in which a cooling water manifold WM and a gas manifold GM are formed. Such a flat separator 10 can be, for example, a metal separator made of known aluminum or stainless steel, or a carbon separator made of known carbon-based material.

[0021] As can be seen from FIG. 2 , in the flat separator 10 of this embodiment, the cooling water manifold WM is provided at the end of the long side of the flat separator 10. As an example, the cooling water manifold WM is a cooling water inlet WM into which the cooling water flows into the fuel cell 100. ｉｎ and a cooling water outlet WM flowing out from the fuel cell 100 ｏｕｔ and are provided on opposite long sides of the flat separator 10 so as to be diagonally arranged.

[0022] As can be seen from FIG. 2, the gas manifold GM in the flat separator 10 of this embodiment is provided at the end of the short side of the flat separator 10. The gas manifold GM in this embodiment is a cathode gas manifold GM through which air flows as the cathode gas described above. １ and an anode gas manifold GM through which hydrogen flows as the anode gas. ２ and

[0023] As an example, the cathode gas manifold GM １ indicates the cathode gas manifold inlet GM through which the cathode gas flows into the fuel cell 100. １ｉｎ and a cathode gas manifold outlet GM through which the cathode off-gas flows out from the fuel cell 100. １ｏｕｔ and are provided on opposite short sides of the flat separator 10 so as to be diagonally arranged.

[0024] As an example, the anode gas manifold GM ２ indicates an anode gas manifold inlet GM through which anode gas flows into the fuel cell 100 ２ｉｎ and an anode gas manifold outlet GM through which anode off-gas flows out from the fuel cell 100. ２ｏｕｔ and are provided on opposite short sides of the flat separator 10 so as to be diagonally arranged.

[0025] As can be seen from FIG. 2 and other figures, the anode gas manifold GM of this embodiment ２ is the cooling water manifold WM and the cathode gas manifold GM １ The present embodiment is not limited to the above-described arrangement, and the cathode gas manifold GM １ However, the above-mentioned configuration includes a cooling water manifold WM and an anode gas manifold GM. ２ In this way, the flat separator 10 may be arranged between the anode gas manifold GM arranged in the first direction (X direction) with respect to the power generation area. ２ and cathode gas manifold GM １ and a cooling water manifold WM arranged along a second direction (Y direction) perpendicular to the first direction.

[0026] The separator with channels 20 is disposed opposite the flat separator 10. The MEA 30, which will be described later, is disposed between the flat separator 10 and the separator with channels 20. In this embodiment, anode gas flows through the side of the separator with channels 20 facing the MEA 30, and cooling water flows through the side of the separator with channels 20 opposite the MEA 30. For ease of explanation, part (near the center) of the channels of the separator with channels 20, through which the cooling water and anode gas flow, is not shown in FIG. 2 .

[0027] One of the anode gas and cathode gas (cathode gas in this embodiment, as an example) can flow through the surface of the flat separator 10 facing the MEA 30. Furthermore, the other of the anode gas and cathode gas (anode gas in this embodiment) can flow through the surface of the separator 20 with channels facing the MEA 30 in parallel with the one gas on the front and back of the MEA 30.

[0028] The MEA 30 is a known membrane electrode assembly in which an electrolyte layer is sandwiched between a pair of catalyst layers and a pair of gas diffusion layers. The MEA 30 of this embodiment is disposed between the flat separator 10 and the separator 20 with flow channels, and is fixed within the frame of a subgasket 40 having through-holes 41 through which gas can flow. As shown in Fig. 3, the MEA 30 of this embodiment has a structure in which a known pair of anode catalyst layer 32 and cathode catalyst layer 34 sandwiches a known electrolyte layer 33.

[0029] An anode gas diffusion layer (anode GDL) 31 is provided on the side of the anode catalyst layer 32 opposite the electrolyte layer 33. A cathode gas diffusion layer (cathode GDL) 35 is provided on the side of the cathode catalyst layer 34 opposite the electrolyte layer 33. The cathode gas diffusion layer 35 may be, for example, a known porous flat plate, also known as a metal porous body, through which cathode gas can flow; a structure in which a mesh-like metal plate, also known as a three-dimensional fine mesh, is layered on carbon paper or carbon cloth; or a structure in which flow channels are formed in carbon paper. The cathode gas diffusion layer 35 is not limited to the embodiment exemplified here, as long as it has the function of transporting cathode gas to the cathode catalyst layer 34, even if the opposing separator does not have a flow channel formed therein. In this embodiment, cathode gas flows through the surface of the planar separator 10 facing the MEA 30. However, when anode gas flows through the surface, the anode GDL will have the embodiment exemplified above.

[0030] That is, the cathode gas diffusion layer 35 of this embodiment may be a gas diffusion layer in which a mesh-like metal plate and carbon paper are laminated opposite the planar separator 10. In this way, the cathode gas diffusion layer 35 of this embodiment may appropriately include a known three-dimensional fine mesh as needed. Note that by arranging the anode flow paths provided by the separator 20 and the macro gas flow direction of the cathode gas diffusion layer 35 (the direction of the large gas flow within the cathode gas diffusion layer 35) parallel to each other, the anode gas and cathode gas can flow parallel to each other on the front and back sides of the electrolyte layer 33 in the power generation region.

[0031] The subgasket 40 described below may have a thickness roughly the same as that of the electrolyte layer or the combined thickness of the electrolyte layer and the catalyst layer. Therefore, the end faces of the anode gas diffusion layer 31 and the cathode gas diffusion layer 35 may be exposed on the surface of the subgasket 40 or the CCM (Catalyst Coated Membrane).

[0032] The subgasket 40 is disposed between the flat separator 10 and the separator with channels 20 and around the membrane electrode assembly (MEA 30). There are no particular limitations on the material of the subgasket 40, and known sealing materials such as resin materials applicable to fuel cells can be used. As can be seen from Figures 2 and 4, the subgasket 40 has a central storage space (MEA storage frame 42) in which the MEA 30 is disposed, and has the same outer shape and manifolds as the flat separator 10 and the separator with channels 20.

[0033] More specifically, in the subgasket 40 of this embodiment, the cooling water manifold WM is provided at the end of the long side of the subgasket 40 so as to correspond to the flat separator 10, etc. Also, in the subgasket 40 of this embodiment, the gas manifold (cathode gas manifold GM １ , anode gas manifold GM ２ ) are provided at the end of the short side of the subgasket 40 so as to correspond to the flat separator 10, the separator with flow channels 20, etc. In addition to the above-mentioned manifolds, the subgasket 40 is also formed with through-holes 41 that connect the cathode side and the anode side and allow gas to flow therethrough.

[0034] The first gasket 50 is disposed between the flat separator 10 and the separator with flow channels 20. The first gasket 50 faces the subgasket 40 between the flat separator 10 and the separator with flow channels 20. The first gasket 50 includes the manifold, sealing wall 51, and relay flow channels 52 described above.

[0035] As shown in FIG. 2 and other figures, the first gasket 50 has the same outer shape and manifolds as the subgasket 40 and the flat separator 10. That is, in the first gasket 50, the cooling water manifold WM is provided at the end of the long side of the first gasket 50 so as to correspond to the flat separator 10 and the subgasket 40. In addition, in the first gasket 50 of this embodiment, the gas manifold (cathode gas manifold GM １, anode gas manifold GM ２ ) are provided at the end of the short side of the first gasket 50 so as to correspond to the planar separator 10, the subgasket 40, etc.

[0036] The first gasket 50 is connected to the anode gas manifold GM described above. ２ The first gasket 50 is provided with a sealing wall 51 adjacent to the through-hole 41, which corresponds to the through-hole 41 and ensures the sealing of the gas flowing through the through-hole 41. There are no particular restrictions on the material of the first gasket 50, and known sealing materials such as resin materials that are applicable to fuel cells can be used. The first gasket 50 maintains the sealing property in the planar direction and is used to seal the cathode gas manifold GM １ The cathode gas flowing through the cathode manifold GM is guided to the cathode gas diffusion layer 35 of the MEA 30, and the sealing wall 51 maintains the sealing property in the stacking direction. ２ The anode gas flowing through the subgasket 40 is guided to the through-holes 41 of the subgasket 40 .

[0037] The second gasket 60 is provided on the side of the channeled separator 20 opposite the MEA 30. As shown in Figure 2 and other figures, the outer shape of the second gasket 60 is the same as the outer shapes of the subgasket 40, the flat separator 10, and the channeled separator 20. There are no particular restrictions on the material of the second gasket 60, and any known sealing material, such as a resin material, that is applicable to fuel cells can be used.

[0038] In this embodiment, cooling water flows through the separator 20 with channels on the side opposite to the MEA 30, and therefore the second gasket 60 is provided with a cooling water inlet hole 61 and a cooling water outlet 62 through which the cooling water flows. In this way, in the fuel cell 100 of this embodiment, cooling water flows through the other surface side of the separator 20 with channels opposite to one surface thereof via the cooling water manifold WM.

[0039] A flat separator 10 of a different fuel cell 100 is stacked on the side of the second gasket 60 opposite the separator 20 with channels. The subgasket 40, first gasket 50, and second gasket 60 described above ensure sealing between the manifolds of the flat separator 10 and the separator 20 with channels within the stacked fuel cell 100.

[0040] <Flow Pattern of Gas and Coolant in Separator with Flow Channels> Next, the structure of the separator with flow channels 20 in the fuel cell 100 of this embodiment will be described in detail with reference to Figs. 6 to 10. As described above, the separator with flow channels 20 of this embodiment has an anode gas manifold GM ２ , cathode gas manifold GM １ and cooling water manifold WM are formed and arranged opposite to the flat separator 10. In addition, the separator 20 with flow channels of this embodiment is configured so that cooling water can flow through the surface side of the flow channel grooves (concave and convex) on the side opposite to the side facing the flat separator 10.

[0041] More specifically, the flow channel grooves provided in the separator 20 with channels include anode gas flow channel grooves provided on the back surface facing the power generation area corresponding to the MEA 30, and coolant flow channel grooves provided on the surface opposite the side facing the MEA 30 (front surface side). As shown in the figure, the separator 20 with channels has a concave-convex structure for forming the channels, and when coolant flows through a groove forming a recess, for example, gas (anode gas in this example) flows inside the adjacent protrusion. In other words, the separator 20 with channels of this embodiment is configured such that, when viewed in a planar direction, channels through which coolant flows are interposed between channels through which anode gas flows.

[0042] As can be understood by mutually referring to FIGS. 7 to 9 and 13, the cooling water flow groove is provided opposite the power generation area and has a first depth dp １The cooling water main channel 21 on the surface side having the cooling water manifold WM, the cooling water inlet channel 22 on the surface side connected to the cooling water manifold WM, and the cooling water main channel 21 and the cooling water inlet channel 22 are connected to each other to form the fourth depth dp ４ and the fourth depth dp ４ a second depth dp shallower than ２ and a cooling water connection channel 25 having a cooling water passage area 26 in the intermediate step portion MS through which the cooling water flows. ４ may have

[0043] On the other hand, as can be understood by mutually referring to Figures 7, 8, 10, and 12, the anode gas flow channel groove is disposed adjacent to the cooling water main channel 21 and facing the power generation area, and has the first depth dp １ anode main channel 23 on the rear side having a cooling water inlet channel 22 and an anode gas manifold GM ２ The anode introduction channel 24 on the rear side connected to the anode main channel 23 and the anode introduction channel 24 is connected to a fourth depth dp ４ and the fourth depth dp ４ a third depth dp shallower than ３ and an anode connection channel 27 having a region (a gas passage region 28 in the intermediate step portion MS through which the anode gas flows). ４ may have

[0044] As described above, the flow channels of the separator 20 with flow channels are formed by providing a concave-convex structure to a flat plate. Therefore, the second depth dp of the cooling water passage area 26 in the cooling water connection channel 25 in the intermediate step portion MS is ２ and the third depth dp of the gas passage region 28 in the anode connection channel 27. ３ are desirably adjusted taking into consideration the pressure loss of each fluid, and do not necessarily need to be equal to each other.

[0045] One of the features of the fuel cell 100 in this embodiment is the anode gas manifold GM ２ The anode gas supplied to the power generation area from the subgasket 40 is first supplied between the MEA 30 and the flat separator 10, which are surrounded by the subgasket 40, and then supplied to the anode side through the through-holes 41 in the subgasket 40.

[0046] More specifically, in the fuel cell 100 of this embodiment, by providing the above-mentioned through hole 41 of the subgasket 40 and the sealing wall 51 and relay flow path 52 of the first gasket 50, a structure is formed in the first gasket 50 on the cathode side that guides cathode gas and anode gas from their respective manifolds (see Figures 4 to 10).

[0047] In the fuel cell 100 of this embodiment, the area where the anode gas is guided from the cathode side to the anode side is surrounded by the sealing wall 51 described above, maintaining hermeticity. Furthermore, above the through-holes 41, flow paths (anode introduction channels 24) that transport the anode gas in orthogonal directions (X direction and Y direction) are formed by the flow-path separators 20 (see FIG. 12 ). This allows the anode gas supplied from the manifold to pass from the cathode side to the anode side via the through-holes 41 and the like.

[0048] In this way, in the fuel cell 100 of this embodiment, one of the anode gas and the cathode gas flows between the flat separator 10 and the MEA 30, and the other of the anode gas and the cathode gas flows through the through holes 41 on the back side of the flow channel groove and is introduced between the MEA 30 and the separator 20 with flow channels.

[0049] 6 to 8, the cooling water, anode gas, and cathode gas in this embodiment are configured to flow in the second direction (Y direction) along their respective flow paths in the region that overlaps with the power generation area. Here, when manifolds are arranged as shown in Fig. 2 to allow the cooling water to flow on the front side of separator 20 with flow paths and the anode gas to flow on the back side, an intermediate stage MS is required where the cooling water and the anode gas overlap and intersect in the thickness direction (Z direction).

[0050] 6, 7, 9, and 11 show the detailed structure of the intermediate stage portion MS in the separator 20 with channels of this embodiment. The intermediate stage portion MS is configured to include a coolant passing region 26 that is disposed on the front side of the separator 20 with channels and through which coolant flows, and a gas passing region 28 that is disposed on the back side of the separator 20 with channels and directly below the coolant passing region 26 and through which anode gas flows. As described above, the depth of the coolant passing region 26 and the depth of the gas passing region 28 may be the same, or one of them may be set to be deeper.

[0051] 11 and the like, in the separator 20 with flow channels of this embodiment, the cooling water introduction channel 22 is separated from the cooling water manifold WM and divided into a plurality of branches. In this way, a plurality of cooling water introduction channels 22 are provided side by side along the first direction (X direction), and a plurality of cooling water main channels 21 are connected to each branch in groups separated from other branches. In this case, the boundaries of each group are defined by the fourth depth dp ４ The anode is separated by an anode connecting channel 27 having a

[0052] In this embodiment, the first flow path groups FPG1 to FPG8 are divided into eight groups along the first direction as shown in Fig. 9, but the number of groups and the number of tributaries belonging to each group may be adjusted as appropriate. By disposing the intermediate stage portions MS intermittently as shown in Fig. 11, when the fuel cell stack 200 is configured, it is possible to minimize the area to which surface pressure is not applied while maintaining resistance to the surface pressure in the stack direction (Z direction in this example).

[0053] Furthermore, in each group of flow paths, the end EP in the flow direction (see FIGS. 11 and 13) has a fourth depth dp ４ By dividing the area by the anode connecting channel 27 having the anode connecting channel 27, it is possible to equalize the flow rate distribution of the cooling water in the first direction (X direction), and the cooling water can be supplied to the power generation area while suppressing unevenness, as illustrated in FIG. 13.

[0054] 2 and 6, in the separator 20 with flow channels of this embodiment, it can be said that the gas diffusion layer (GDL) and the like are reduced in size by the amount of the coolant connection channel 25 and the anode connection channel 27. By reducing the GDL in this way and bringing the recessed portion of the separator (metal) into contact with the underlying member (e.g., the subgasket 40) in the region where there is no GDL, it is possible to reduce the cost required for the GDL while also contributing to ensuring sufficient surface pressure in the planar direction.

[0055] As described above, the fuel cell 100 of this embodiment ensures a sufficient flow path area while suppressing pressure loss through efficient flow path arrangement, and furthermore, it is possible to supply fluid (coolant water or gas) to the power generation area corresponding to the MEA 30 without uneven flow via the intermediate stage MS or the like. Furthermore, the fuel cell 100 of this embodiment employs a structure in which manifolds for the gas and coolant supplied to the MEA 30 are arranged as described above and gas flows from one side (e.g., the cathode side) to the other side (the anode side) via the through-holes 41 or the like, thereby suppressing an increase in the area not used for power generation and improving the power generation efficiency of the fuel cell. The fuel cell stack 200 and mobile body (fuel cell vehicle 300) of this embodiment are configured to include the fuel cell 100 described above, thereby achieving the same effects as those described above.

[0056] Although the preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings, the present disclosure is not limited to such examples. It is clear that a person skilled in the art of the present disclosure may attempt further modifications to these embodiments and variations within the scope of the technical ideas set forth in the claims, and it is understood that these modifications also fall within the technical scope of the present disclosure.

[0057] For example, the fuel cell 100 of the above-described embodiment may be configured such that the anode gas is supplied between the flat separator 10 and the MEA 30, and the cathode gas is supplied between the MEA 30 and the separator 20 with flow channels.

[0058] Furthermore, although the subgasket 40 and the cathode gasket (first gasket 50) in the above-described embodiments were configured separately, the subgasket and the cathode gasket may be molded as a single unit. Furthermore, the subgasket 40 in the above-described embodiments may be configured as two identically shaped subgaskets sandwiching a CCM, or as a single subgasket bonded to one side of the CCM via a known adhesive or the like. Furthermore, in the fuel cell 100 of the above-described embodiment, the flat separator 10 to the channeled separator 20 form a single cell unit, but the flat separator 10 and the channeled separator 20 may be joined together to sandwich a CCM or the like to form a stack.

[0059] Furthermore, in the fuel cell 100 of the above-described embodiment, a gasket is provided on the outer periphery of the cooling water, and the outer periphery of the anode is sealed by direct contact between the separator 20 with flow channels and the subgasket 40, but a gasket may be provided on the outer periphery of the anode, and the outer periphery of the cooling water may be sealed by contact between the separator 20 with flow channels and the flat separator 10, or welding may be performed, or an additional gasket may be provided.

[0060] REFERENCE SIGNS LIST 100 Fuel cell 10 Planar separator 20 Separator with flow passage 30 MEA (membrane electrode assembly) 40 Subgasket 50 First gasket (cathode side gasket) 60 Second gasket (coolant side gasket) 200 Fuel cell stack 210 Inverter 220 Load 230 Control device 300 Fuel cell vehicle (mobile body)

Claims

1. A fuel cell comprising: a flat separator having an anode gas manifold and a cathode gas manifold arranged side by side along a first direction with respect to a power generation area, and a cooling water manifold arranged along a second direction perpendicular to the first direction; a channeled separator having manifolds respectively formed thereon corresponding to the anode gas manifold, the cathode gas manifold, and the cooling water manifold, arranged opposite the flat separator, and through which cooling water can flow via the front side of the flow channel on the side opposite to the side facing the flat separator; and a membrane electrode assembly arranged between the flat separator and the channeled separator, and fixed within the frame of a subgasket having through holes through which gas can flow; wherein one of the anode gas and the cathode gas flows between the flat separator and the membrane electrode assembly, and the other of the anode gas and the cathode gas flows along the back side of the flow channel via the through holes to be introduced between the membrane electrode assembly and the channeled separator, The cooling water, the anode gas, and the cathode gas each flow along the second direction within an area overlapping with the power generation area.

2. The fuel cell according to claim 1, wherein said one gas is a cathode gas and said other gas is an anode gas.

3. The fuel cell according to claim 2, wherein the flow channel grooves provided in the separator with flow channels comprise: a cooling water main channel on the front surface side, disposed opposite the power generation area and having a first depth; a cooling water inlet channel on the front surface side, connected to the cooling water manifold; an anode main channel on the back surface side, disposed adjacent to the cooling water main channel and facing the power generation area, and having the first depth; an anode inlet channel on the back surface, disposed adjacent to the cooling water inlet channel and connected to the anode gas manifold; a cooling water connection channel, connecting the cooling water main channel and the cooling water inlet channel, each having a region of the first depth and a region of a second depth shallower than the first depth; and an anode connection channel, disposed directly below the cooling water connection channel, connecting the anode main channel and the anode inlet channel, each having a region of the first depth and a region of a third depth shallower than the first depth.

4. A fuel cell as described in claim 3, wherein the cooling water inlet channel is separated from the cooling water manifold and divided into a plurality of branches, a plurality of the cooling water main channels are provided lined up along the first direction, and a plurality of the cooling water main channels are connected in groups for each branch while being separated from other branches, and the boundaries of the groups are divided by the anode connection channel having the first depth.

5. A mobile object equipped with the fuel cell according to claim 1.

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