fuel cell

Abstract

This technology provides a way to optimize pressure loss by maintaining the contact area with the membrane electrode assembly in a fuel cell at or below the same level as conventional methods, while simultaneously increasing the cross-sectional area of ​​the cooling water flow path. [Solution] The first separator in the fuel cell cell of the present disclosure has an uneven structure for forming a gas flow path on the membrane electrode assembly side and a cooling water flow path on the second separator side that is alternately arranged with the gas flow path, the uneven structure includes a plurality of corners, and the partition wall portion separating the gas flow path and the cooling water flow path includes a protruding portion that extends toward the gas flow path side and has a third corner vertex with respect to a reference line connecting the first corner vertex on the membrane electrode assembly side and the second corner vertex on the second separator side.

Description

Technical Field

[0006] , ,

[0001] This disclosure relates to fuel cell.

Background Art

[0002] Conventionally, fuel cells including separators with channels for forming gas flow channels and cooling water flow channels are known.

[0003] For example, in Patent Document 1, a plurality of groove-shaped reaction gas flow channels formed on the opposing surface to the membrane electrode assembly through which reaction gas flows, a communication path formed on the same opposing surface to the membrane electrode assembly and communicating adjacent reaction gas flow channels, and a plurality of groove-shaped cooling water flow channel forming paths formed in parallel with the reaction gas flow channels on the back surface of the opposing surface to the membrane electrode assembly and constituting a part of the cooling water flow channel are provided.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the conventional technology as disclosed in Patent Document 1, by overlapping these separators with channels so that the cooling water flow channels provided in two adjacent separators with channels face each other, the cross-sectional area of the cooling water flow channel is enlarged. Therefore, even for cooling water with a larger flow rate and higher viscosity than the reaction gas, the pressure loss can be suppressed to a certain extent.

[0006] In order to reduce the manufacturing cost of fuel cell cells, it is desirable to manufacture fuel cell cells in which one of the two channel-equipped separators is a flat plate separator and the other is a channel-equipped separator. However, in such fuel cell cells, it is difficult to increase the cross-sectional area of ​​the cooling water channel while maintaining the thickness of the fuel cell, as is done in conventional technology. Furthermore, when increasing the cross-sectional area of ​​the cooling water channel, there is a problem that the contact resistance increases if the contact area between the channel-equipped separator and the membrane electrode assembly is reduced.

[0007] In view of these circumstances, the purpose of this disclosure is to provide a technology that optimizes pressure loss by maintaining the contact area with the membrane electrode assembly in a fuel cell at or below the same level as conventional methods, while increasing the cross-sectional area of ​​the cooling water flow path. [Means for solving the problem]

[0008] A fuel cell according to one embodiment of the present disclosure is a fuel cell comprising at least a first separator, a second separator, and a membrane electrode assembly, wherein the first separator has an uneven structure for forming a gas flow path on the membrane electrode assembly side and a cooling water flow path on the second separator side that is alternately arranged with the gas flow path, the uneven structure includes a plurality of corners, and the partition wall separating the gas flow path and the cooling water flow path includes an overhang that protrudes toward the gas flow path and has a third corner vertex with respect to a reference line connecting the first corner vertex on the membrane electrode assembly side and the second corner vertex on the second separator side of the plurality of corners. [Effects of the Invention]

[0009] According to one embodiment of the present disclosure, the contact area with the membrane electrode assembly in the fuel cell can be maintained at or below the same level as in the conventional method, and the pressure loss can be optimized by increasing the cross-sectional area of ​​the cooling water flow path. [Brief explanation of the drawing]

[0010] [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 schematic cross-sectional view including a separator with a flow channel in a fuel cell cell according to one embodiment of the present disclosure. [Figure 4] This is a cross-sectional view including a flow channel separator in a fuel cell according to a first embodiment of the present disclosure. [Figure 5] This is a cross-sectional view including a flow channel separator in a fuel cell according to a second embodiment of the present disclosure. [Modes for carrying out the invention]

[0011] 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.

[0012] (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.

[0013] 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 the fuel cell cells 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 cells 100. The fuel cell cells 100 are not particularly limited and may be, for example, a known polymer electrolyte fuel cell (PEFC).

[0014] 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.

[0015] Load 4 includes, for example, a known electric motor capable of outputting power to drive the drive wheels of vehicle 1. The electric motor is, for example, a known three-phase AC electric motor. Load 4 may also be other electrical equipment mounted on vehicle 1.

[0016] The control device 5 is a known ECU (Electronic Control Unit) mounted on a fuel cell vehicle, and comprises one or more processors such as CPUs (Central Processing Units) and one or more memories such as semiconductor memories, magnetic memories, or optical memories that are communicatively connected to the processors. The control device 5 may also further comprise a known BMU (Battery Management Unit) for monitoring and controlling the battery status. The control device 5 may be configured to communicate with other known EUCs and various sensors (not shown) mounted on the vehicle 1.

[0017] (2. Overall configuration of the 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 repeatedly laminating, for example, a flat separator 10, a first gasket 20, a sub gasket 30, a separator 40 with flow channels, 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 channels. Note that the separator 40 with flow channels is an example of the "first separator" in the present disclosure, and the flat separator 10 is an example of the "second separator" in the present disclosure.

[0018] (2-1. Flat Separator) Unlike the separator 40 with flow channels, the flat separator 10 is a rectangular flat separator in which no flow channels are formed. However, the flat separator 10 does not need to be flat over its entire area, and it only needs to be flat at least in the reaction area that contacts the membrane electrode assembly 60. On the side of the flat separator 10 facing the membrane electrode assembly 60, one of the anode gas and the cathode gas (for example, the cathode gas) flows. In the flat separator 10, through holes for the cooling water manifold and through holes for the gas manifold are appropriately formed.

[0019] Note that the flat separator 10 may be a metal separator made of, for example, known aluminum, stainless steel, or titanium, or may be a carbon separator or the like made of a known carbon-based material.

[0020] (2-2. First Gasket) The first gasket 20 has an outer shape corresponding to the flat separator 10. In the first gasket 20, through holes for the cooling water manifold and through holes for the gas manifold corresponding to the flat separator 10 are appropriately formed.

[0021] The first gasket 20 may be made of a sealing material such as polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), or a synthetic resin material such as silicone resin.

[0022] (2-3. Sub-gasket) The sub-gasket 30 has an outer shape corresponding to the flat plate separator 10 and the first gasket 20. Through holes for the cooling water manifold and gas manifold are appropriately formed in the sub-gasket 30, corresponding to the flat plate separator 10 and the first gasket 20. In addition, the sub-gasket 30 has a housing space formed in the center where the membrane electrode assembly 60 is arranged.

[0023] The sub-gasket 30 may be made of a sealing material such as a synthetic resin material such as polyethylene naphthalate (PEN), polyethylene terephthalate (PET), or polyphenylene sulfide (PPS).

[0024] (2-4. Separator with flow path) The flow channel separator 40 has an uneven structure that forms gas flow channels and cooling water flow channels. Specifically, the flow channel separator 40 has an uneven structure that forms gas flow channels on the membrane electrode assembly 60 side and cooling water flow channels on the flat plate separator 10 side that are alternately arranged with the gas flow channels. On the side of the flow channel separator 40 facing the membrane electrode assembly 60, the other gas of the anode gas and cathode gas (for example, anode gas) flows, while on the side of the flow channel separator 40 opposite the membrane electrode assembly 60, cooling water flows.

[0025] The flow-through separator 40 is appropriately formed with through-holes for the cooling water manifold and gas manifold, corresponding to the flat plate separator 10, the first gasket 20, and the sub-gasket 30.

[0026] The separator 40 with a flow path may be a metal separator made of, for example, known materials such as aluminum, stainless steel, or titanium.

[0027] (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 flow path 40. The second gasket 50 is appropriately formed with through holes for the cooling water manifold and through holes for the gas manifold, corresponding to the flat plate separator 10, the first gasket 20, the sub-gasket 30, and the separator with flow path 40.

[0028] The second gasket 50 may be made of a sealing material such as polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), or a synthetic resin material such as silicone resin.

[0029] (2-6. Membrane electrode assembly) 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 arbitrary membrane electrode assembly in which an electrolyte layer (not shown) is sandwiched between a pair of catalyst layers (not shown) and a pair of gas diffusion layers (not shown).

[0030] 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.

[0031] (3-1. First Embodiment) Referring to Figures 3 and 4, the "first separator" in the fuel cell cell 100 according to the first embodiment will be described in detail, using as an example the flow channel separator 140 applicable as the flow channel separator 40 shown in Figure 2.

[0032] As shown in Figure 3, the fuel cell cell 100 has a stacked structure in which at least a membrane electrode assembly 160, a channel separator 140, and a flat plate separator 110 are repeated in this order. That is, in the cross-sectional view of Figure 3, another membrane electrode assembly 160 is stacked on the side of the flat plate separator 110 opposite to the channel separator 140.

[0033] The flow-channel separator 140 has a grooved structure 141 for forming a gas flow channel FP1 on the membrane electrode assembly 160 side, which can be used as the membrane electrode assembly 60 shown in Figure 2, and a cooling water flow channel FP2 on the flat plate separator 110 side, which can be used as the flat plate separator 10 shown in Figure 2. The gas flow channel FP1 and the cooling water flow channel FP2 are arranged alternately by the grooved structure 141.

[0034] Specifically, the separator with a flow path 140 has a recessed portion 142 on the side not in contact with the cooling water flow path FP2 that contacts the membrane electrode assembly 160, a protrusion 143 on the side not in contact with the gas flow path FP1 that contacts the flat plate separator 110, and a partition wall portion 144 connecting the recessed portion 142 and the protrusion 143, which are repeated in a direction intersecting the direction in which the gas flow path FP1 and the cooling water flow path FP2 extend.Therefore, the gas flow path FP1 is formed in a compartment surrounded by the protrusion 143, the partition wall portion 144 and the membrane electrode assembly 160.The cooling water flow path FP2 is formed in a compartment surrounded by the recessed portion 142, the partition wall portion 144 and the flat plate separator 110.The partition wall portion 144 separates the gas flow path FP1 and the cooling water flow path FP2. Note that Figure 3 is intended to illustrate a schematic cross-section of the flow channel separator 140, and therefore the partition wall portion 144 is shown in a simplified manner.

[0035] The gas flow path FP1 may be an anode gas flow path or a cathode gas flow path, but it is preferable that it be an anode gas flow path from the viewpoint that the effects of the first embodiment are more pronounced.

[0036] Referring also to Figure 4, the uneven structure 141, composed of the recessed portion 142 and the convex portion 143, further includes a plurality of corners. These corners may be portions composed of curved surfaces having a predetermined radius of curvature, which are formed when the uneven structure 141 is formed by, for example, press working such as bending. The number of circles of curvature constituting these curved surfaces is not necessarily limited to one, but may be multiple. However, the corners in this disclosure are not limited to this, and may not have the radius of curvature described above, and may be portions composed of, for example, two planar portions.

[0037] The partition wall portion 144 may include an inclined portion 144a connected to the recess 142 and a vertical wall portion 144b that is continuous with the inclined portion 144a and connected to the convex portion 143. In this case, a first corner vertex P1 on the membrane electrode assembly 160 side is formed at the boundary between the inclined portion 144a and the recess 142. A second corner vertex P2 on the flat plate separator 110 side is formed at the boundary between the vertical wall portion 144b and the convex portion 143. A third corner vertex P3 is formed at the boundary between the inclined portion 144a and the vertical wall portion 144b.

[0038] The first corner vertex P1, the second corner vertex P2, and the third corner vertex P3 may, in the case where the aforementioned corner has a radius of curvature, be the intersection points in the cross-sectional view of Figure 4 of the tangent line at one end of the circle of curvature containing one end of the curved surface constituting the corner and the tangent line at the other end of the circle of curvature containing the other end of the curved surface. In the example shown in Figure 4, - The tangent line at one end of the curved surface portion constituting the corner portion, and the circle of curvature passing through the center of the thickness of the flow-through separator 140 at that end, - The tangent line at the other end of the curved surface portion constituting the corner, and the circle of curvature that includes the other end and passes through the center of the thickness at the other end, The intersection points are defined as the vertices of each corner. Note that, depending on the radius of curvature of the circle of curvature, each corner vertex may be located either inside or outside the wall thickness of the flow-type separator 140.

[0039] On the other hand, if the corners described above do not have a radius of curvature, in the cross-sectional view of Figure 4, the first corner vertex P1 may be the intersection of a line passing through the thickness center of the recess 142 and a line passing through the thickness center of the inclined portion 144a. The second corner vertex P2 may be the intersection of a line passing through the thickness center of the convex portion 143 and a line passing through the thickness center of the wall-up portion 144b. The third corner vertex P3 may be the intersection of a line passing through the thickness center of the inclined portion 144a and a line passing through the thickness center of the wall-up portion 144b.

[0040] However, as will be described later, the definition of each corner vertex in this disclosure is not necessarily limited to these, as long as it is possible to realize the technical concept of this disclosure, which is to enlarge the flow path cross-sectional area of ​​the cooling water flow path FP2 by having the protruding portion 145 extend from the cooling water flow path FP2 side to the gas flow path FP1 side.

[0041] The height h of the inclined portion 144a along the stacking direction of the fuel cell cell 100 is preferably greater than the compression thickness of the gas diffusion layer of the membrane electrode assembly 160. For example, the height h can be 60 μm or more, but this disclosure is not limited thereto and can be appropriately determined according to the characteristics of the gas diffusion layer. The compression thickness is defined as the original thickness of the gas diffusion layer minus the thickness when the gas diffusion layer is compressed by the recess 142.

[0042] Although the wall portion 144b is shown in Figure 4 as being perpendicular or substantially perpendicular to the flat plate separator 110, this disclosure is not necessarily limited thereto, and it may be inclined as appropriate towards the gas flow path FP1 side.

[0043] The partition wall 144 includes an overhang 145 that extends toward the gas flow path FP1 side with respect to a reference line L connecting the first corner vertex P1 and the second corner vertex P2, and has a third corner vertex P3. This overhang 145 allows the contact area with the membrane electrode assembly 160 to be maintained at or below the same level as conventional designs, while also increasing the flow path cross-sectional area of ​​the cooling water flow path FP2 to be larger than that of the gas flow path FP1. Furthermore, since the flow path cross-sectional area of ​​the cooling water flow path FP2 can be increased while maintaining the height along the stacking direction of the fuel cell cell 100 at the same level as conventional designs, a compact fuel cell cell 100 can be realized.

[0044] For example, by setting the width W1 on the membrane electrode assembly 160 side of the cooling water channel FP2 to 0.8 mm, the width W2 on the flat plate separator 110 side to 1.09 mm, and the height H along the stacking direction of the channel-equipped separator 140 to 0.35 mm (including the base plate thickness of 0.1 mm), the cross-sectional area of ​​the cooling water channel FP2 can be increased compared to conventional designs. However, the various dimensions of the channel-equipped separator 140 are not necessarily limited to these.

[0045] As described above, the separator 140 with a flow path in the fuel cell cell 100 according to the first embodiment has an uneven structure 141 for forming a gas flow path FP1 on the membrane electrode assembly 160 side and a cooling water flow path FP2 on the flat plate separator 110 side, which is alternately arranged with the gas flow path FP1. In particular, the uneven structure 141 includes a plurality of corners. Furthermore, the partition wall portion 144 separating the gas flow path FP1 and the cooling water flow path FP2 includes an overhang portion 145 that protrudes toward the gas flow path FP1 side and has a third corner vertex P3 with respect to a reference line L connecting the first corner vertex P1 on the membrane electrode assembly 160 side and the second corner vertex P2 on the flat plate separator 110 side.

[0046] According to the first embodiment, in order to reduce the manufacturing cost of the fuel cell cell 100, for example, a flat plate separator 110 is used as the "first separator" and a flow-channel separator 140 is used as the "second separator". Specifically, the partition wall portion 144 of the flow-channel separator 140 that separates the gas flow channel FP1 and the cooling water flow channel FP2 includes an overhang portion 145 that extends toward the gas flow channel FP1 side. As a result, the contact area with the membrane electrode assembly 160 can be maintained at or below the same level as conventional designs, and the pressure loss can be optimized by increasing the flow channel cross-sectional area of ​​the cooling water flow channel FP2.

[0047] Furthermore, the partition wall portion 144 in the first embodiment has a less complex structure than the partition wall portion 244 in the second embodiment described later, making it easier to process and further reducing the manufacturing cost of the flow-flow separator 140 and, consequently, the fuel cell cell 100.

[0048] (3-2. Second Embodiment) Referring to Figure 5, the "first separator" in the fuel cell cell 100 according to the second embodiment will be described in detail, using as an example the flow channel separator 240 applicable as the flow channel separator 40 shown in Figure 2.

[0049] The flow-channel separator 240 has an uneven structure including recesses 242 and protrusions 243 for forming a gas flow channel FP1 on the membrane electrode assembly 260 side, which can be applied as the membrane electrode assembly 60 shown in Figure 2, and a cooling water flow channel FP2 on the flat plate separator 210 side, which can be applied as the flat plate separator 10 shown in Figure 2, which is arranged alternately with the gas flow channel FP1.

[0050] The details of the uneven structure are the same as those of the uneven structure 141 in the first embodiment, so the explanation in the first embodiment will be used with reference. Also, as in the first embodiment, the gas flow path FP1 may be an anode gas flow path or a cathode gas flow path, but it is preferable that it be an anode gas flow path from the viewpoint that the effects of the second embodiment are more pronounced.

[0051] The uneven structure, including the recessed portion 242 and the convex portion 243, includes multiple corners. Furthermore, the partition wall portion 244 separating the gas flow path FP1 and the cooling water flow path FP2 includes a protruding portion 245 that extends toward the gas flow path FP1 side and has a third corner vertex P3, with respect to a reference line L1 connecting the first corner vertex P1 on the membrane electrode assembly 260 side and the second corner vertex P2 on the flat plate separator 210 side. In addition, the separator with a flow path 240 includes a diffusion portion 246 for diffusing the gas passing through the gas flow path FP1 toward the membrane electrode assembly 260 side between the protruding portion 245 and the membrane electrode assembly 260. Here, it is preferable that the diffusion portion 246 further includes a corner having a fourth corner vertex P4 on the cooling water flow path FP2 side with respect to a reference line L2 connecting the first corner vertex P1 and the third corner vertex P3. The definition of each corner vertex is the same as in the first embodiment, and the explanation in the first embodiment will be used accordingly.

[0052] The partition wall 244 may include a first vertical wall portion 244a, a flat portion 244b, and a second vertical wall portion 244c. In this case, the first vertical wall portion 244a connects to the recess 242. The flat portion 244b is continuous with the first vertical wall portion 244a and runs along the cooling water flow path FP2, extending from the cooling water flow path FP2 side to the gas flow path FP1 side. The second vertical wall portion 244c is continuous with the flat portion 244b and connects to the convex portion 243.

[0053] A first corner vertex P1 on the film electrode assembly 260 side is formed at the boundary between the recess 242 and the first wall portion 244a. A second corner vertex P2 on the flat plate separator 210 side is formed at the boundary between the second wall portion 244c and the convex portion 243. A third corner vertex P3 is formed at the boundary between the flat portion 244b and the second wall portion 244c. A fourth corner vertex P4 is formed at the boundary between the first wall portion 244a and the flat portion 244b.

[0054] In Figure 5, the first vertical section 244a and the second vertical section 244c are shown to be perpendicular or substantially perpendicular to the membrane electrode assembly 260 and the flat plate separator 210. However, this disclosure is not limited to these, and the first vertical section 244a and the second vertical section 244c may be inclined as appropriate from the cooling water flow path FP2 side to the gas flow path FP1 side. Similarly, in Figure 5, the flat section 244b is shown to be perpendicular or substantially perpendicular to the first vertical section 244a and the second vertical section 244c. However, this disclosure is not limited to these, and the flat section 244b may be inclined as appropriate towards the membrane electrode assembly 160 side or the flat plate separator 10 side.

[0055] When the partition wall 244 includes a first vertical section 244a, a flat section 244b, and a second vertical section 244c, the protruding section 245 may include, in the cross-sectional view of Figure 5, at least the reference line L1 described above and the region enclosed by the second vertical section 244c and the flat section 244b. Such a protruding section 245 allows the contact area with the membrane electrode assembly 260 to be maintained at or below the same level as conventional designs, while also allowing the cross-sectional area of ​​the cooling water flow path FP2 to be expanded to some extent compared to conventional designs, making it larger than the cross-sectional area of ​​the gas flow path FP1.

[0056] Furthermore, if the partition wall portion 244 includes the first wall portion 244a, the flat portion 244b, and the second wall portion 244c, the diffusion portion 246 may include, in the cross-sectional view of Figure 5, at least the reference line L2 described above and the region enclosed by the first wall portion 244a and the flat portion 244b.

[0057] Here, the gas diffusion layer (not shown) included in the membrane electrode assembly 260 is typically made of a sponge-like material and may deform due to the surface pressure of the separator with a flow channel 240. However, according to the second embodiment, even if the gas diffusion layer (not shown) included in the membrane electrode assembly 260 deforms, a region can be secured between the protruding portion 245 of the gas flow channel FP1 and the membrane electrode assembly 260 (more specifically, near the contact point between the first wall portion 244a and the membrane electrode assembly 260) to diffuse the gas passing through the gas flow channel FP1 towards the membrane electrode assembly 260.

[0058] The height h' of the first wall portion 244a along the stacking direction of the fuel cell cell 100 is preferably greater than the compression thickness of the gas diffusion layer of the membrane electrode assembly 260. For example, the height h' can be 60 μm or more, but this disclosure is not limited thereto and can be appropriately determined according to the characteristics of the gas diffusion layer. The compression thickness is defined as the original thickness of the gas diffusion layer minus the thickness when the gas diffusion layer is compressed by the recess 242.

[0059] Similar to the first embodiment, in the cross-sectional view of Figure 5, the width W1 on the membrane electrode assembly 260 side of the cooling water channel FP2 can be set to 0.8 mm, the width W2 on the flat plate separator 210 side can be set to 1.09 mm, and the height H along the stacking direction can be set to 0.35 mm (including the base plate thickness of 0.1 mm). However, the various dimensions of the channel-equipped separator 240 are not necessarily limited to these.

[0060] As described above, the separator 240 with a flow path in the fuel cell cell 100 according to the second embodiment further includes, in addition to the first embodiment, a diffusion portion 246 between the protruding portion 245 of the gas flow path FP1 and the membrane electrode assembly 260 for diffusing the gas passing through the gas flow path FP1 toward the membrane electrode assembly 260.

[0061] According to the second embodiment, the diffusion portion 246 forms a region where gas can diffuse between the membrane electrode assembly 260 and the partition wall portion 244, thereby suppressing a decrease in gas pressure loss. In addition, in the second embodiment as well, the protruding portion 245 maintains the contact area with the membrane electrode assembly 260 at or below the same level as in the conventional design, and allows the flow path cross-sectional area of ​​the cooling water flow path FP2 to be expanded to some extent compared to the conventional design, making it larger than the flow path cross-sectional area of ​​the gas flow path FP1.

[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 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.

[0063] 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]

[0064] 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, 210: Flat plate separator (second separator), 20: First gasket, 30: Sub-gasket, 40, 140, 240: Separator with flow path (first separator), 50: Second gasket, 60, 160, 260: Membrane electrode assembly, 141: Uneven structure, 144, 244: Partition wall section, 145, 245: Protruding section, 246: Diffusion section

Claims

1. A fuel cell comprising at least a first separator, a second separator, and a membrane electrode assembly, The first separator has an uneven structure for forming a gas flow path on the membrane electrode assembly side and a cooling water flow path on the second separator side, which is arranged alternately with the gas flow path. The aforementioned uneven structure includes a plurality of corners, The partition wall separating the gas flow path and the cooling water flow path includes a protruding portion that extends toward the gas flow path and has a third corner vertex, with respect to a reference line connecting the first corner vertex on the membrane electrode assembly side and the second corner vertex on the second separator side among the plurality of corners. Fuel cell.

2. The cross-sectional area of ​​the cooling water channel is larger than the cross-sectional area of ​​the gas channel. The fuel cell cell according to claim 1.

3. The first separator further includes a diffusion portion between the protruding portion and the membrane electrode assembly in the gas flow path for diffusing the gas passing through the gas flow path toward the membrane electrode assembly. A fuel cell cell according to claim 1 or 2.

4. The diffusion portion further includes a corner having a fourth corner vertex on the cooling water flow path side with respect to a further reference line connecting the first corner vertex and the third corner vertex. The fuel cell cell according to claim 3.

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