JP5332399B2 - Fuel cell separator and fuel cell using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide technology using a separator having simple construction for improving the fluid distributing performance of a fuel cell, while improving the fluid sealing performance. <P>SOLUTION: The fuel cell separator 200 includes two plates 210, 220, and an intermediate plate 230. The intermediate plate 230 has a flow path for oxygen and a flow path for the refrigerant. On the outer surface of the anode plate 220, a flow path for hydrogen is formed by two linear flow path grooves 221a, 221b formed by pressing work, and a dimple 226. The linear flow path grooves 221a, 221b are provided on the upstream and downstream sides of a power generating region EA, respectively. In the power generating region EA, they extend linearly, along a direction which intersects the flowing direction of the hydrogen. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a fuel cell.

  A fuel cell generally includes a membrane electrode assembly that is a power generator in which electrodes are arranged on both surfaces of an electrolyte membrane, and the membrane electrode assembly is sandwiched between separators. A separator is comprised with the plate-shaped member which has electroconductivity, and has a fluid flow path for reaction gas or a refrigerant | coolant (patent document 1 etc.).

Japanese Patent Laid-Open No. 7-263003 JP 2006-318863 A JP 2006-236597 A

  In the separator, it is desired that the flow characteristics of the reaction gas and the refrigerant in the power generation region used for power generation be improved by the fluid flow path, and that the fluid sealability in the fluid flow path be ensured. ing. On the other hand, since the fuel cell is required to be reduced in size and weight in order to be installed in a limited space such as a vehicle, the configuration of the separator is further simplified and reduced in size and weight. It is preferable. However, the reality is that until now there has not been enough ingenuity to meet these requirements.

  An object of the present invention is to provide a technique capable of improving the fluid distribution of a fuel cell by a separator and improving the fluid sealing performance with a simple configuration.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
A fuel cell separator for sandwiching a power generator of a fuel cell, comprising: two plates; and an intermediate layer forming member sandwiched between the two plates, wherein the intermediate layer forming member includes at least An intermediate layer flow path for the refrigerant is provided, and a plate surface flow path for the reactive gas formed as a recess is provided on the outer surface of at least one of the two plates, and the plate surface The flow path is connected to a power generation section gas flow path that is a flow path for the reaction gas in the power generation section of the power generation body, and is straight along a direction that intersects the flow direction of the reaction gas in the power generation section gas flow path. A fuel cell separator including a linear channel groove extending in a shape.
According to the fuel cell separator, the straight flow channel improves the flow characteristics of the reaction gas in the direction in which the straight flow channel extends, and also improves the sealing performance between the intermediate layer flow channel and the plate surface flow channel. it can.

[Application Example 2]
The fuel cell separator according to Application Example 1, wherein the straight channel groove is formed by protruding the plate toward the intermediate layer forming member by pressing the plate.
According to this fuel cell separator, it is possible to easily form the straight flow channel by press working.

[Application Example 3]
The separator for a fuel cell according to Application Example 1 or Application Example 2, wherein the reaction gas includes a fuel gas, and the linear flow path groove includes a fuel gas straight flow path groove for the fuel gas. Fuel cell separator.
According to this fuel cell separator, it is possible to easily improve the flowability and sealing performance of the fuel gas in the fuel cell.

[Application Example 4]
4. The fuel cell separator according to any one of Application Examples 1 to 3, wherein the straight channel groove is a supply for supplying the reaction gas provided on the upstream side of the power generation unit gas channel. A straight flow channel groove for discharge and a straight flow channel groove for discharging the reaction gas provided on the downstream side of the power generation unit gas flow channel, and the plate surface flow channel includes the straight flow channel for supply A fuel cell separator including a power generation plate surface flow path provided so as to protrude toward the intermediate layer flow path between the road groove and the discharge straight flow path groove.
According to this fuel cell separator, the supply and discharge straight flow channel grooves can improve the flow characteristics of the reaction gas in the flow channel direction of the straight flow channel. Moreover, the flow distribution property of the reaction gas in the power generation section is improved by the power generation section plate surface flow path. Furthermore, the flow distribution property of the fluid in the intermediate layer flow path can be improved by projecting the power generation unit plate surface flow path to the intermediate layer flow path side to constitute a part of the intermediate layer flow path.

[Application Example 5]
The fuel cell separator according to application example 4, wherein the power generation plate surface flow path has a dimple shape.
According to this fuel cell separator, the fluid distribution can be more easily improved by the arrangement of the dimples.

[Application Example 6]
A fuel cell, comprising the fuel cell separator according to any one of Application Examples 1 to 5.

A. First embodiment:
FIG. 1 is a schematic diagram showing the configuration of a fuel cell as an embodiment of the present invention. The fuel cell 1000 is a polymer electrolyte fuel cell that generates power by receiving supply of hydrogen and oxygen as reaction gases. The fuel cell 1000 may not be a polymer electrolyte fuel cell, and the present invention can be applied to any of various types of fuel cells.

  The fuel cell 1000 has a stack structure in which a plurality of membrane electrode assemblies 100 and separators 200 are alternately stacked. The separator 200 includes a cathode plate 210, an anode plate 220, and an intermediate plate 230 that is sandwiched between the two plates 210 and 220. The laminated body of the membrane electrode assembly 100 and the separator 200 is sandwiched by two end plates 401 and 402 from the stacking direction, and receives a load in the stacking direction via the two end plates 401 and 402 by the fastening member 403. And concluded.

  FIG. 2A is a schematic view showing the configuration of the membrane electrode assembly 100, and shows the surface on the cathode side. The configuration of the surface on the anode side of the membrane electrode assembly 100 is the same as the surface on the cathode side, and therefore illustration and description thereof are omitted. The membrane electrode assembly 100 is a substantially long deformation member, and includes a power generation unit 110 used for power generation and a seal gasket 120 for preventing leakage of fluid formed on the outer periphery of the power generation unit 110.

  The seal gasket 120 is provided with eight manifold holes M1, M2, M3a, M3b, M4a, M4b, M5, and M6 as through holes for the reaction gas and the refrigerant. Specifically, the configuration is as follows. The hydrogen supply manifold hole M1 and the hydrogen discharge manifold hole M2 are respectively provided at diagonal positions of the membrane electrode assembly 100 with the power generation unit 110 interposed therebetween. The refrigerant supply manifold hole M5 and the refrigerant discharge manifold hole M6 are provided along respective short sides facing each other with the power generation unit 110 interposed therebetween. Further, two oxygen supply manifold holes M3a and M3b and two oxygen discharge manifold holes M4a and M4b are provided in parallel along each long side facing each other with the power generation unit 110 interposed therebetween. . The hydrogen supply manifold hole M1 and the oxygen discharge manifold holes M4a and M4b are provided on the same long side, and the hydrogen discharge manifold hole M2 and the oxygen supply manifold holes M3a and M3b Are provided on the same long side.

  Further, a seal line SL (illustrated by two lines in the figure) for preventing fluid leakage is provided on the outer surface of the seal gasket 120. Specifically, the seal line SL is provided so as to surround each of the manifold holes M1, M2, M3a, M3b, M4a, M4b, M5, M6 and the power generation unit 110. The manifold holes M1, M2, M3a, M3b, M4a, M4b, M5, M6 and the seal line SL may have other configurations.

  FIG. 2B is a cross-sectional view of the membrane electrode assembly 100 taken along the line BB shown in FIG. The power generation unit 110 includes an electrolyte membrane 10 that is a thin film of a solid polymer that exhibits good proton conductivity in a wet state. Electrodes 21 and 22 (a cathode 21 and an anode 22) are disposed on the outer surface of the electrolyte membrane 10, respectively. A catalyst layer (not shown) carrying a catalyst (for example, platinum) for promoting a fuel cell reaction is formed on the surface side of each electrode 21, 22 that is in contact with the electrolyte membrane 10. On the other hand, a gas diffusion layer (not shown) for spreading the reaction gas over the entire electrode surface is formed on the surface of each electrode 21, 22 that is not in contact with the electrolyte membrane 10. The two electrodes 21 and 22 can be made of carbon paper, for example.

  The outer peripheral end portion 10e of the electrolyte membrane 10 protrudes from the outer peripheral end portions 21e and 22e of the two electrodes 21 and 22, and the seal gasket 120 is molded so as to cover the outer peripheral end portions 10e, 21e, and 22e. Yes. With this configuration, the occurrence of cross leak that moves without being subjected to the fuel cell reaction to the electrode opposite to the electrode to which the reaction gas is supplied is suppressed at the electrode end portions 21e and 22e. The seal line SL provided on the outer surface of the seal gasket 120 is formed as a protrusion 121 (lip 121) on the outer surface of the seal gasket 120.

  3A and 3B are schematic views illustrating the configuration of the cathode plate 210 of the separator 200. FIG. 3A shows a surface in contact with the anode plate 220 (hereinafter referred to as “anode surface”), and FIG. 3B shows a surface (hereinafter referred to as the cathode 21) of the membrane electrode assembly 100. (Referred to as “cathode surface”). 3A and 3B, a region that overlaps the power generation unit 110 (FIG. 2A) of the membrane electrode assembly 100 when the fuel cell 1000 is viewed in the stacking direction is indicated by a one-dot broken line. It is shown in the figure. Hereinafter, this region is referred to as “power generation region EA”. In FIG. 3B, the seal line SL formed on the cathode surface when assembled as the fuel cell 1000 is indicated by a broken line.

  The cathode plate 210 is a plate-like member having a substantially long side conductivity that is substantially the same size as the membrane electrode assembly 100. The cathode plate 210 can be constituted by a thin metal plate, for example. As with the membrane electrode assembly 100, manifold holes M1, M2, M3a, M3b, M4a, M4b, M5, and M6 are formed in the cathode plate 210.

  In the vicinity of each of the oxygen manifold holes M3a, M3b, M4a, and M4b of the cathode plate 210, two through-hole rows P1 and P2 in which a plurality of through-holes are arranged in a row are provided. The first through-hole row P1 is provided between the oxygen supply manifold holes M3a and M3b and the power generation area EA, and the second through-hole row P2 includes oxygen discharge manifold holes M4a and M4b. It is provided between the power generation area EA. Each through-hole row P1, P2 is a region surrounded by the seal line SL provided in the seal gasket 120 of the membrane electrode assembly 100 when assembled as the fuel cell 1000, and the power generation unit 110 is disposed. It is arranged in the same area as the area to be processed.

  FIG. 4 is a schematic diagram showing the configuration of the anode plate 220 of the separator 200. 4A shows a surface (hereinafter referred to as “anode surface”) facing the anode 22 of the membrane electrode assembly 100, and FIG. 4B shows a surface in contact with the cathode plate 210 (hereinafter referred to as “anode surface”). (Referred to as “cathode surface”). 4A and 4B show that two straight flow path grooves 221a and 221b are provided instead of the through-hole rows P1 and P2, and a dimple 226 is provided in the power generation area EA. Other than this, it is almost the same as FIGS. 3 (A) and 3 (B). 4 (A) and 4 (B), the regions overlapping the through-hole rows P1, P2 of the cathode plate 210 when the fuel cell 1000 is viewed in the stacking direction (hereinafter referred to as “through-hole rows P1, P2”). The region is referred to as a “formation region”) by a broken line. In FIG. 4B, a seal line SL formed on the anode surface when assembled as the fuel cell 1000 is indicated by a broken line.

  The two straight channel grooves 221a and 221b are linear grooves provided by projecting the anode plate 220 to the cathode surface side by pressing. The first straight channel groove 221a extends from the first through hole row P1 in the plate center side in the long side direction of the power generation region EA, and one end thereof is connected to the hydrogen supply manifold hole M1. . On the other hand, the second straight channel groove 221b extends from the second through hole row P2 in the long side direction of the power generation area EA on the center side of the plate, and one end thereof is connected to the hydrogen discharge manifold hole M2. ing.

  A dimple 226 is provided between the two straight flow channel grooves 221a and 221b by projecting the anode plate 220 to the cathode surface side by pressing, as with the two straight flow channel grooves 221a and 221b. . Here, in the present specification, a plurality of convex portions or concave portions arranged continuously on a reference plane is referred to as “dimple”. In particular, a dimple composed of convex portions is called a “convex dimple”, and a dimple composed of concave portions is called a “concave dimple”. That is, the dimple 226 constitutes a concave dimple when viewed from the anode surface side (FIG. 4A), and constitutes a convex dimple when viewed from the cathode surface side (FIG. 4B). 4A and 4B, the dimple 226 includes a plurality of convex portions (concave portions) having a substantially circular shape when viewed from a direction perpendicular to the surface of the anode plate 220 in the power generation region EA. In FIG. 4, the four sides are arranged at substantially equal intervals.

  FIG. 4C is a schematic diagram showing a cross section of the anode plate 220 taken along the line CC shown in FIG. In FIG. 4C, the cathode plate 210 disposed when the separator 200 is configured is illustrated by broken lines. Thus, the bottom surface of each recess of the dimple 226 and the bottom surfaces of the two flow channel grooves 221 a and 221 b are in direct contact with the anode surface of the cathode plate 210.

  FIG. 5 is a schematic view showing the configuration of the intermediate plate 230. FIG. 5 shows a surface that contacts the anode plate 220 (hereinafter referred to as “anode surface”). In FIG. 5, when the separator 200 is configured, regions where the through-hole rows P1 and P2 of the cathode plate 210 and the dimples 226 of the anode plate 220 are arranged are indicated by broken lines. The configuration of the surface of the intermediate plate 230 that contacts the cathode plate 210 (hereinafter referred to as “cathode surface”) is the same as that of the anode surface, and therefore illustration and description thereof are omitted.

  The intermediate plate 230 is a substantially long side-shaped resin member having substantially the same size as the two plates 210 and 220 described above, and the manifold holes M1, M2, M3a, M3b, and M4a are the same as the two plates 210 and 220. , M4b, M5, M6. The intermediate plate 230 can be constituted by, for example, a laminate film. The intermediate plate 230 can also be configured by a member other than a resin member, for example, a metal thin plate.

  The intermediate plate 230 is provided with oxygen connecting passages 231a and 231b which are a plurality of parallel comb-shaped through grooves extending from the manifold holes M3a, M3b, M4a and M4b for oxygen toward the power generation region EA. ing. When the separator 200 is configured, the oxygen connection channel 231a is connected to each through hole of the through hole row P1 provided in the cathode plate 210 to configure an oxygen supply channel. When the separator 200 is configured, the oxygen connection channel 231b is connected to each through hole of the through hole row P2 provided in the cathode plate 210 to configure an oxygen discharge channel.

  In addition, the intermediate plate 230 is provided with through grooves 233a and 233b for accommodating the two straight flow path grooves 221a and 221b of the anode plate 220 when the separator 200 is configured. Hereinafter, the through grooves 233a and 233b are referred to as “hydrogen channel through grooves 233a and 233b”. Further, the intermediate plate 230 is formed with a through window portion 235 that connects the manifold hole M5 for supplying refrigerant and the manifold hole M6 for discharging refrigerant. The through window 235 accommodates the dimple 226 of the anode plate 220 when the separator 200 is configured.

  FIG. 6 is a schematic diagram showing an assembly process of the fuel cell 1000. FIG. 6 shows a schematic cross-sectional view of each of the plates 210, 220, 230, the membrane electrode assembly 100, and the gas flow path member 500 at a cut surface corresponding to the AA cut shown in FIG. ing.

  The intermediate plate 230 is sandwiched between the cathode plate 210 and the anode plate 220 to form the separator 200. At this time, the two straight flow path grooves 221 a and 221 b of the anode plate 220 are fitted into the hydrogen flow path through grooves 233 a and 233 b of the intermediate plate 230, and the convex dimple 226 of the anode plate 220 is the through window of the intermediate plate 230. Part 235 is accommodated.

  Further, the membrane electrode assembly 100 is sandwiched between the separators 200, and at this time, the gas flow path members 500 are disposed between the electrodes 21 and 22 and the separators 200. The gas flow path member 500 is a member that functions as a gas flow path for spreading the reaction gas supplied to the power generation area EA over the entire surfaces of the electrodes 21 and 22. The gas flow path member 500 has conductivity, and also functions as a conductive path between the cathode 21 and the cathode plate 210. The gas flow path member 500 can be formed of a conductive porous member such as a sintered metal, or can be formed of a metal processing member such as a so-called mesh, expanded metal, or punching metal.

  FIG. 7A shows a partial schematic cross-sectional view of the fuel cell 1000 at a cut surface corresponding to the AA cut shown in FIG. 5, and the flow of oxygen is indicated by arrows. Part of the oxygen supplied from the oxygen supply manifold holes M3a and M3b flows into the oxygen connection channel 231a of the intermediate plate 230. Oxygen that has flowed into the oxygen connecting flow channel 231 a flows into the gas flow channel member 500 disposed on the cathode side of the membrane electrode assembly 100 through each through hole of the through hole row P 1 of the cathode plate 210. Oxygen spreads over the entire surface of the cathode 21 by the gas flow path member 500 and the gas diffusion layer (not shown) of the cathode 21 and is supplied to the fuel cell reaction. The cathode exhaust gas containing oxygen that has not been subjected to the fuel cell reaction and moisture generated by the fuel cell reaction passes through the through holes of the through hole row P2 of the cathode plate 210 from the gas flow path member 500 to the intermediate plate. 230 flows to the oxygen connecting channel 231b. Thereafter, the cathode exhaust gas flows out into the oxygen discharge manifold holes M4a and M4b and is discharged to the outside of the fuel cell 1000.

  FIG. 7B shows a partial schematic cross-sectional view of the fuel cell 1000 at a cut surface corresponding to the BB cut shown in FIG. In FIG. 7B, the flow of the refrigerant is indicated by arrows. A part of the refrigerant supplied from the refrigerant supply manifold hole M5 flows into the through window 235 of the intermediate plate 230 and flows into the power generation area EA. In the power generation area EA, the refrigerant passes between the convex portions constituting the dimple 226, flows out into the refrigerant discharge manifold hole M6 with heat generated by the fuel cell reaction, and goes outside the fuel cell 1000. And discharged. That is, the dimple 226 of the anode plate 220 functions as a spacer between the cathode plate 210 and the anode plate 220 and also functions as a refrigerant flow path in the power generation area EA. The dimple 226 also functions as a conductive path for generated electricity.

  8A and 8B are schematic diagrams for explaining the flow of hydrogen in the fuel cell 1000. FIG. FIG. 8A is a schematic view similar to FIG. 2A showing the anode surface side of the membrane electrode assembly 100. In FIG. 8A, the region overlapping with the straight flow channel grooves 221a and 221b of the separator 200 when viewed along the stacking direction of the fuel cell 1000 is indicated by a broken line, and hydrogen in the direction along the electrode surface is shown. The flow is shown by arrows. FIG. 8B is a schematic cross-sectional view of the fuel cell 1000 taken along the line BB shown in FIG. 8A, in which an arrow indicating the flow of hydrogen is shown instead of an arrow indicating the flow of oxygen. Except for this, it is almost the same as FIG.

  Part of the hydrogen supplied from the manifold hole M1 for supplying hydrogen flows into the power generation area EA (power generation unit 110) across the seal line SL via the straight flow path groove 221a of the anode plate 220. In the straight flow channel 221a, hydrogen spreads over the long side direction of the power generation area EA (FIG. 8A). Hydrogen in the straight channel groove 221a flows into the gas channel member 500 disposed on the anode side of the membrane electrode assembly 100, and the gas diffusion layer (not shown) of the gas channel member 500, the dimple 226, and the anode 22 is shown. ) Is spread over the entire surface of the anode 22 and used for the fuel cell reaction (FIG. 8B). The anode exhaust gas containing hydrogen that has not been subjected to the fuel cell reaction reaches the hydrogen discharge manifold hole M2 from the gas flow path member 500 via the discharge-side straight flow path groove 221b, and is external to the fuel cell 1000. Is discharged.

  Here, normally, the amount of reactant gas supplied in the power generation region tends to increase as the region is closer to the supply manifold hole. However, in this fuel cell 1000, two straight flow path grooves 221a and 221b connected to the gas flow path member 500 disposed in the power generation section 110 on the anode side are provided on the upstream side and the downstream side of the power generation area EA, respectively. ing. Each of the two straight flow channel grooves 221a and 221b extends in the long side direction of the power generation region (that is, the direction from each of the manifold holes M1 and M2 toward the opposite side across the power generation region EA). The channel resistance is smaller than that of the gas channel member 500. Therefore, hydrogen spreads in the long side direction of the power generation area EA through the straight flow path grooves 221a and 221b and flows into the gas flow path member 500 and the gas diffusion layer of the anode 22. In the gas diffusion layer of the gas flow path member 500 and the anode 22, hydrogen flows in the direction along the short side direction of the power generation area EA as a whole. That is, the straight flow grooves 221a and 221b suppress the non-uniform hydrogen flow distribution in the long side direction of the power generation area EA, thereby improving the hydrogen distribution. In addition, the flow direction of hydrogen in the straight flow path grooves 221a and 221b is a direction intersecting with the entire flow direction of hydrogen in the power generation region EA.

  FIG. 9A is an enlarged schematic cross-sectional view showing the vicinity of the oxygen discharge manifold holes M4a and M4b in FIG. 8B. FIG. 9 (B) shows a fuel cell 1000a as a comparative example of the present invention, and is a partial schematic cross section showing a cutting site of the fuel cell 1000a of the comparative example corresponding to the cutting site shown in FIG. 9 (A). FIG. The fuel cell 1000a of this comparative example is the same as the fuel cell 1000 of this example except that the configuration of the anode plate 220a is different.

  The anode plate 220a of the comparative example is provided with through holes 222a and 222b in place of the two straight flow channel grooves 221a and 221b (FIG. 8B) (the illustration of the through hole 222b is omitted). ing). Even in such a configuration, the manifold holes M1 and M2 for hydrogen are formed in the power generation area EA via the through holes 233a and 233b for the hydrogen flow path of the intermediate plate 230 and the through holes 222a and 222b of the anode plate 220a, respectively. It communicates with the anode 22. Accordingly, a hydrogen path similar to that of the fuel cell 1000 of the present embodiment is configured.

  By the way, in the separator in which the fluid flow path is formed, it is generally preferable that the sealing performance against the fluid is ensured. However, in the fuel cell 1000a of the comparative example, each fluid is sealed around the hydrogen flow path through grooves 233a and 233b by the contact surface CS between the cathode plate 210 and the anode plate 220 and the intermediate plate 230. Only (FIG. 9B). On the other hand, in the fuel cell 1000 of the present embodiment, the flow path walls of the straight flow path grooves 221 a and 221 b are configured by the plate surface of the anode plate 220. That is, the separator 200 of the present example has improved sealing performance between the fluids compared to the separator 200a of the comparative example.

  Moreover, in general, a separator having a fluid flow path preferably suppresses deformation of the fluid flow path due to a manufacturing error or the like in order to suppress a decrease in fluid flowability. Furthermore, it is preferable that the separator be reduced in size and weight with a simpler configuration in order to reduce the size and weight of the fuel cell.

  Here, in the fuel cell 1000a of the comparative example, the groove wall surface constituting the hydrogen flow path through grooves 233a and 233b is a resin member constituting the intermediate plate 230 (FIG. 9B). Therefore, in the separator 200a of the comparative example, in order to suppress the deformation of the hydrogen passage through grooves 233a and 233b, by increasing the thickness T1 and T2 of the groove wall surface of the hydrogen passage through grooves 233a and 233b, It is preferable to increase its rigidity. However, if the thicknesses T1 and T2 of the groove wall surfaces of the hydrogen channel through grooves 233a and 233b are increased, the separator 200a itself may be increased in size. In addition, when the intermediate plate 230 is formed of a member having high rigidity such as metal, the weight of the separator may increase.

  On the other hand, in the fuel cell 1000 of the present embodiment, the flow passage wall surfaces of the straight flow passage grooves 221 a and 221 b are constituted by the plate surface of the anode plate 220. Accordingly, the flow passage wall surfaces of the straight flow passage grooves 221a and 221b are higher in rigidity than the groove wall surfaces of the hydrogen flow passage through grooves 233a and 233b of the comparative example, and deformation of the fluid flow passage is further suppressed. Further, according to the configuration of the separator 200 of the present embodiment, the thickness T1 of the groove wall surface of the through holes 233a, 233b for the hydrogen flow channel is compared with that of the comparative example while maintaining the rigidity of the flow wall surface of the straight flow channel 221a, 221b. , T2 can be reduced. Therefore, the separator 200 can be made smaller than the separator 200a of the comparative example, and a fuel cell using the separator 200 can be made smaller.

  As described above, according to the separator 200 of the present embodiment, the flow distribution of the fluid in the fuel cell by the separator can be improved with a simpler configuration, and the sealing performance against the fluid can be improved.

B. Second embodiment:
FIGS. 10A to 10C are schematic views showing the configuration of an anode plate 220B constituting the separator 200B as the second embodiment of the present invention. FIGS. 10A to 10C are the same as FIGS. 4A to 4C except that the outer peripheral convex portion 228 is added and the outer periphery is enlarged with the addition of the outer peripheral convex portion 228. Is almost the same. The other configuration of the fuel cell using the separator 200B of this embodiment is the same as that of the first embodiment (FIG. 1).

  The outer periphery convex part 228 is a convex part provided by making it protrude to the cathode surface side by press work. The outer peripheral convex portion 228 is provided on the outer peripheral edge portion of the anode plate 220B, and is formed in a circumferential shape so as to surround each manifold hole M1, M2, M3a, M3b, M4a, M4b, M5, M6. The outer peripheral convex portion 228 protrudes to the same extent as the straight flow path grooves 221a and 221b and the dimple 226 that protrude to the other cathode surface side.

  FIG. 11 is a schematic view showing a fuel cell 1000B using the separator 200B of the second embodiment, and is a partial schematic cross-sectional view similar to FIG. 9 (A). The cathode plate 210B of the separator 200B is the same as the cathode plate 210 (FIG. 3) of the first embodiment except that the outer periphery is enlarged like the anode plate 220B. Further, the intermediate plate 230B of the separator 200B is the intermediate plate 230 of the first embodiment (FIG. 5) except that the outer periphery thereof is reduced so as to be accommodated in the inner periphery of the outer peripheral convex portion 228 of the anode plate 220B. ). The cathode plate 210B and the anode plate 220B are preferably integrated by brazing and joining at the outer peripheral convex portion 228.

  As described above, according to the fuel cell 1000B of the second embodiment, the leakage of fluid from the separator 200B to the outside of the fuel cell 1000B can be suppressed by the outer peripheral convex portion 228 provided on the outer peripheral edge of the separator 200B. Further, the outer peripheral convex portion 228 can improve the rigidity of the anode plate 220B, and can suppress the distortion. Therefore, it is possible to suppress a decrease in the sealing performance against the fluid in the fuel cell 1000B due to the deformation of the anode plate 220B.

C. Variations:
The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

C1. Modification 1:
In the above embodiment, the straight flow path grooves 221a and 221b extend in the long side direction of the separator, that is, in a direction substantially perpendicular to the flow direction of the reaction gas in the power generation region EA. However, the flow path directions of the straight flow path grooves 221a and 221b may be other directions as long as they intersect with the flow direction of the reaction gas in the power generation region EA.

  Further, the two straight flow path grooves 221a and 221b are provided on the upstream side and the downstream side of the power generation area EA, respectively. However, it is sufficient that at least one of the two linear flow channel grooves 221a and 221b is provided. However, it is possible to further improve the fluid distribution by providing both of the two straight flow path grooves 221a and 221b for supply and discharge.

C2. Modification 2:
In the above embodiment, the hydrogen flow paths formed on the outer surface of the anode plate 220 formed by the straight flow path grooves 221 a and 221 b and the dimples 226 are provided by pressing the anode plate 220. However, the hydrogen flow path may be formed as a thin groove on the outer surface of the anode plate 220 by performing etching or the like on the outer surface of the anode plate 220 without pressing the anode plate 220.

C3. Modification 3:
In the above embodiment, the dimples 226 are provided on the anode plates 220 and 220B, but the dimples 226 may be omitted. In this case, it is preferable that a refrigerant flow path member for constituting a refrigerant flow path and a conductive path is disposed in the through window portion 235 of the intermediate plates 230 and 230B. If the dimples 226 are formed on the anode plates 220 and 220B as in the above-described embodiment, it is possible to improve the flow distribution of the refrigerant and improve the cooling efficiency of the fuel cell. Further, since the generated electricity can be directly conducted between the cathode plates 210 and 210B and the anode plates 220 and 220B, the current collection efficiency by the separator can be improved. Furthermore, since the refrigerant flow path member can be omitted, it is possible to reduce the weight of the separator and to suppress an increase in its manufacturing cost.

  The dimple 226 may be formed by a convex portion having another arrangement configuration or a convex portion having another shape. For example, a plurality of convex portions may be arranged in a staggered manner, or the convex portions may be formed as flow channel walls (flow channel grooves) provided in parallel in the fluid flow direction. According to the separators 200 and 200B of the above-described embodiment, it is possible to easily improve the flowability of hydrogen and refrigerant by changing the shape and arrangement of the dimples 226.

C4. Modification 4:
In the above embodiment, the straight flow channel grooves 221a and 221b and the dimple 226 are provided on the anode plates 220 and 220B, but may be provided on the cathode plate.

C5. Modification 5:
In the above embodiment, the gas diffusion layer in the gas flow path member 500 and the electrodes 21 and 22 may be omitted. In this case, the part of the separator 200 where the dimple 226 is formed protrudes toward the electrode side, and the electrode and the part where the dimple 226 is formed are brought into direct contact with each other. It is good also as what forms.

C6. Modification 6:
In the second embodiment, the outer circumferential convex portion 228 is formed as a circumferential convex portion, but may be formed as a dimple. Further, the outer peripheral convex portion 228 may be provided on the cathode plate 210.

Schematic which shows the structure of the fuel cell of 1st Example. Schematic which shows the structure of the membrane electrode assembly of 1st Example. Schematic which shows the structure of the cathode plate of 1st Example. Schematic which shows the structure of the anode plate of 1st Example. Schematic which shows the structure of the intermediate | middle plate of 1st Example. The schematic diagram which shows the assembly | attachment process of the fuel cell in 1st Example. Explanatory drawing for demonstrating the flow of oxygen and the refrigerant | coolant inside the fuel cell of 1st Example. Explanatory drawing for demonstrating the flow of hydrogen inside the fuel cell of 1st Example. The schematic sectional drawing which shows the structure of the fuel cell of 1st Example, and the schematic sectional drawing which shows the structure of the fuel cell of a comparative example. Schematic which shows the structure of the anode plate of 2nd Example. The partial schematic sectional drawing which shows the structure of the fuel cell of 2nd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Electrolyte membrane 10e ... Outer peripheral edge 21, 22 ... Electrode 21e, 22e ... Electrode edge 100 ... Membrane electrode assembly 110 ... Power generation part 120 ... Seal gasket 121 ... Lip 200, 200a, 200B ... Separator 210, 210B ... Cathode Plates 220, 220a, 220B ... Anode plates 221a, 221b ... Linear flow channel grooves 222a, 222b ... Through holes 226 ... Dimples 228 ... Outer peripheral projections 230,230B ... Intermediate plates 231a, 231b ... Oxygen connection channels 233a, 233b ... Hydrogen passage through groove 235 ... through window 401, 402 ... end plate 403 ... fastening member 500 ... gas passage member 1000, 1000a, 1000B ... fuel cell CS ... contact surface EA ... power generation region M1, M2, M3a, M3b , M4a, M4b, M5, M 6 ... Manifold hole P1, P2 ... Through hole row SL ... Seal line

Claims (6)

A fuel cell separator for sandwiching a power generator of a fuel cell,
Two plates,
An intermediate layer forming member constituted by a resin member and sandwiched between the two plates ;
With
The intermediate layer forming member is provided with an intermediate layer flow path for at least a refrigerant,
On the outer surface of at least one of the two plates, a plate surface flow path for the reaction gas formed as a recess is provided,
The plate surface flow path is connected to a power generation section gas flow path that is a flow path for the reaction gas in the power generation section of the power generation body, and intersects with the flow direction of the reaction gas in the power generation section gas flow path. along we saw including a straight flow grooves extending linearly,
The straight channel groove is formed as a bottomed recess that protrudes the plate to the intermediate layer forming member side,
A separator for a fuel cell , wherein the intermediate layer forming member is formed with a penetrating portion that accommodates the straight channel groove . The fuel cell separator according to claim 1,
The straight channel groove is a fuel cell separator formed by pressing the plate so as to protrude toward the intermediate layer forming member. The fuel cell separator according to claim 1 or 2,
The reaction gas includes a fuel gas,
The fuel cell separator, wherein the straight channel groove includes a fuel gas straight channel for the fuel gas. A fuel cell separator according to any one of claims 1 to 3,
The linear flow channel groove is provided on the upstream side of the power generation unit gas flow channel for supply of the reaction gas, and the linear flow channel groove is provided on the downstream side of the power generation unit gas flow channel. A straight flow channel for discharge for discharge of the reaction gas,
The plate surface flow path includes a power generation plate surface flow path provided so as to protrude toward the intermediate layer flow path between the supply straight flow path groove and the discharge straight flow path groove. Battery separator.   5. The fuel cell separator according to claim 4, wherein the power generation unit plate surface channel has a dimple shape. 6. A fuel cell,
A fuel cell comprising the fuel cell separator according to any one of claims 1 to 5.

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