JP2007026737A - Fuel cell and manufacturing method of fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for suppressing leakage of a liquid to be supplied to a fuel cell in the fuel cell in which a membrane electrode assembly having a separator and a seal line constituted of a plurality of welded metal plates are laminated. <P>SOLUTION: This is the fuel cell, in which separators constituted of a plurality of metal plates welded along a prescribed welding line and the membrane electrode assembly contacted with the separators are alternately laminated and which has a sealing part. The sealing part has the seal line that is constituted to suppress the leakage of the prescribed liquid to be supplied to the fuel cell by being contacted with the separator, while the seal line and the prescribed welding line are arranged to have a prescribed positional relationship, and the prescribed positional relationship is the one that is arranged so that a line obtained by the seal line projected to a projection surface orthogonal to the laminating direction of the separator and the membrane electrode assembly and a line obtained by projecting the prescribed welding line on the projection surface are not mutually overlapped. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel cell, and more particularly to a technique for suppressing leakage of fluid supplied to a fuel cell when a separator has a configuration in which a plurality of metal plates are welded.

  2. Description of the Related Art Conventionally, a substantially flat membrane electrode assembly (MEA) and a separator are used as main components, and these membrane electrode assemblies and separators are stacked and fastened in the stacking direction. Fuel cells are being developed. As such a separator, a separator having a configuration in which a plurality of metal plates are stacked has been proposed (see Patent Document 1 below).

Japanese Patent Laid-Open No. 2004-6104

  In such a separator having a stack structure, an adhesive may be used for joining between a plurality of metal plates. In this case, there has been a problem that the thickness of the separator is increased by the adhesive, and the thermal conductivity is reduced as compared with the case where the metal plates are brought into direct contact with each other.

  In order to solve such a problem, a method of joining a plurality of metal plates by welding is conceivable. However, when joining by welding, a portion irradiated with a laser beam, an electron beam or the like is distorted, so that the sealing performance is deteriorated and a fluid such as fuel gas or oxidant gas supplied to the fuel cell leaks. Can occur.

  The present invention has been made in order to solve at least a part of the above-described problems, and in a fuel cell including a separator configured by welding a plurality of metal plates, leakage of fluid supplied to the fuel cell is prevented. It aims at providing the technology which controls.

  In order to solve at least a part of the above-described problem, a fuel cell according to the present invention has separators and membrane electrode composites alternately stacked and abuts against a surface of the separator facing the membrane electrode composite. A fuel cell having a seal portion, wherein the separator is formed by welding a plurality of metal plates along a predetermined welding line, and the fuel cell by contacting the separator with the separator. A seal line configured to suppress leakage of a predetermined fluid supplied to the seal line, and the seal line and the predetermined weld line are arranged in a predetermined positional relationship, The positional relationship includes a line obtained by projecting the seal line to a projection plane orthogonal to the stacking direction of the separator and the membrane electrode assembly, and the projection plane. A line obtained by projecting the predetermined welding line and, and summarized in that but a positional relationship so as not to overlap each other.

  As described above, in the fuel cell of the present invention, the seal line and the predetermined welding line are obtained by projecting the seal line onto the projection plane orthogonal to the stacking direction of the separator and the membrane electrode assembly, and this projection. Since the line obtained by projecting the welding line to the surface is arranged so as not to overlap each other, the predetermined fluid supplied to the fuel cell due to such overlap Leakage can be suppressed.

  Leakage due to such overlapping occurs due to deformation of the separator due to welding. That is, since the separator is deformed by a line corresponding to a predetermined welding line by welding, the seal line does not come into contact with the separator in a line corresponding to the predetermined welding line corresponding to the overlapping portion. As a result, the hermeticity of the seal is lowered and a predetermined fluid leaks.

  In the fuel cell of the present invention, the plurality of metal plates may include a first electrode facing plate having a surface facing the first electrode of the membrane electrode assembly, and a second electrode of the membrane electrode assembly. And a second electrode facing plate having a facing surface, and an intermediate plate sandwiched between the first electrode facing plate and the second electrode facing plate.

  As described above, in the fuel cell of the present invention, the plurality of metal plates include the first electrode facing plate having a surface facing the first electrode of the membrane electrode assembly, the second electrode of the membrane electrode assembly, A second electrode facing plate having a facing surface, and an intermediate plate sandwiched between the first electrode facing plate and the second electrode facing plate. Thus, for example, a metal plate for supplying fuel gas to the anode of the membrane electrode assembly, a metal plate for supplying oxidant gas to the cathode, and cooling between these two metal plates and passing through the inside. The fuel cell of the present invention can be applied as a fuel cell comprising a three-layer separator comprising a metal plate for cooling the fuel cell with a medium.

In the fuel cell of the present invention, the fluid electrode, the membrane electrode composite, and the separator are communicated in the thickness direction. The fluid supply port communicates the membrane electrode complex and the separator in the thickness direction. The fluid discharge port, and the intermediate plate penetrates in the thickness direction and communicates with the supply port, and penetrates in the thickness direction and communicates with the discharge port. A discharge channel forming portion, wherein the first electrode facing plate and the second electrode facing plate are respectively a first supply port forming portion that forms part of the supply port, and the discharge A first discharge port forming part that forms a part of the outlet; a fluid supply hole that penetrates in the thickness direction and communicates with the supply flow path forming part; A fluid discharge hole in communication with the membrane electrode assembly. And a second supply port forming portion for forming a part, a second outlet forming portion which forms part of the discharge port, and
The predetermined welding line is disposed so as to surround at least one of the first supply port forming portion or the first discharge port forming portion, and the seal line is at least the second supply. The fluid supply having the first seal line arranged so as to surround the mouth forming portion and the second discharge port forming portion, and the first electrode plate or the second electrode plate in contact with each other. A second seal line disposed so as to surround both the hole and the fluid discharge hole,
The predetermined positional relationship is such that a line obtained by projecting the first seal line onto the projection surface is surrounded by a line obtained by projecting the predetermined weld line onto the projection surface. And a line obtained by projecting the predetermined welding line onto the projection surface is contained in a region surrounded by a line obtained by projecting the second seal line onto the projection surface. Such a positional relationship may be used.

  By adopting such a configuration, in the fuel cell of the present invention, the predetermined welding line is arranged so as to surround at least one of the first supply port forming portion and the first discharge port forming portion. Therefore, fluid leakage from the first supply port forming portion or the first discharge port forming portion surrounded by the predetermined welding line can be suppressed. In addition, the seal line has at least the first supply line and the second electrode plate that are in contact with the first seal line that surrounds the second supply port formation unit and the second discharge port formation unit, respectively. And a second seal line arranged so as to surround both the fluid supply hole and the fluid discharge hole. Therefore, the first seal line can suppress the leakage of fluid from the second supply port generation unit and the second discharge port formation unit, and the second seal line can prevent the fluid supply hole. The leakage of the fluid supplied and discharged from the fluid discharge hole to the outside of the fuel cell can be suppressed.

  Further, by adopting such a configuration, the predetermined positional relationship between the seal line and the predetermined welding line is such that a line obtained by projecting the first seal line onto the projection surface is predetermined with respect to the projection surface. A line obtained by projecting a predetermined weld line to the projection surface is included in a region surrounded by a line obtained by projecting the welding line of the second seal line to the projection surface. The positional relationship is included in the area surrounded by the line obtained by projecting. Therefore, the positional relationship between the seal line and the predetermined welding line is such that the line obtained by projecting the seal line on the projection surface and the line obtained by projecting the predetermined weld line on the projection surface overlap each other. It can be in a positional relationship that does not become necessary.

  In the fuel cell of the present invention, the second seal line may be disposed along the outer periphery of the membrane electrode assembly at a substantially edge portion of the membrane electrode assembly.

  With such a configuration, in the fuel cell of the present invention, the second seal line is disposed along the outer periphery of the membrane electrode assembly in a portion (substantially edge portion) near the edge of the membrane electrode assembly. Has been. Therefore, by arranging the predetermined welding line inside the substantially edge portion of the separator, the line obtained by projecting the predetermined welding line onto the projection surface projects the second seal line onto the projection surface. Thus, the positional relationship can be such that it is included in the area surrounded by the line.

  The membrane electrode composite of the present invention is a membrane electrode composite capable of constituting a fuel cell by alternately laminating a separator constituted by welding a plurality of metal plates along a predetermined welding line. A seal portion having a seal line configured to suppress leakage of a predetermined fluid supplied to the fuel cell by contacting the separator, and at least a part of the seal line includes: The gist is that the membrane electrode assembly is disposed along the outer periphery of the membrane electrode assembly at a substantially edge portion.

  With such a configuration, in the membrane electrode assembly of the present invention, at least a part of the seal line is on the outer periphery of the membrane electrode assembly in a portion (substantially edge portion) near the edge of the membrane electrode assembly. Are arranged along. Therefore, by disposing the predetermined welding lines of the separators that are alternately stacked when the fuel cell is configured inside the substantially edge portion of the separator, the positional relationship between the seal line and the predetermined welding lines can be changed. A position where a line obtained by projecting a seal line onto a projection surface orthogonal to the stacking direction of the membrane electrode assembly and a line obtained by projecting a predetermined welding line onto this projection surface do not overlap each other. Relationship can be. As a result, it is possible to suppress leakage of a predetermined fluid due to such overlapping.

  Leakage due to such overlapping occurs due to deformation of the separator due to welding. That is, since the separator is deformed by a line corresponding to a predetermined welding line by welding, the seal line does not come into contact with the separator in a line corresponding to the predetermined welding line corresponding to the overlapping portion. As a result, the hermeticity of the seal is lowered and a predetermined fluid leaks.

  Note that the present invention is not limited to the above-described aspects of the device invention such as the fuel cell and the membrane electrode assembly, and can also be realized as a method invention such as a fuel cell manufacturing method.

Hereinafter, the best mode for carrying out the present invention will be described in the following order based on examples.
A. Example:
A1. Fuel cell configuration:
A2. Fuel cell operation:
A3. Positional relationship between the seal line and the welding line in the comparative example:
A4. Positional relationship between seal line and welding line in this embodiment:
A5. Effects of the embodiment:
B. Variation:

A. Example:
A1. Fuel cell configuration:
FIG. 1 is an explanatory diagram showing a schematic configuration of a fuel cell as one embodiment of the present invention. A fuel cell 10 shown in FIG. 1 includes a plurality of fuel cell modules 20, an end plate 30, a tension plate 31, an insulator 33, and a terminal 34. The fuel cell 10 has a layered structure in which a plurality of fuel cell modules 20 are stacked in the stacking direction shown in FIG. The stacked fuel cell modules 20 are sandwiched between the two end plates 30 with the insulator 33 and the terminal 34 interposed therebetween. Then, these two end plates 30 are coupled to the tension plate 31 by bolts 32, whereby each fuel cell module 20 is fastened with a predetermined compressive force in the stacking direction.

  The fuel cell 10 is supplied with a reaction gas (fuel gas and oxidant gas) used for the cell reaction and a cooling medium for cooling the fuel cell 10. Briefly, hydrogen as fuel gas is supplied to the anode electrode side of the fuel cell 10 from a hydrogen tank 210 storing high-pressure hydrogen via a pipe 250. The piping 250 is provided with a shut valve 220 and a pressure regulating valve 230 for adjusting the supply of hydrogen. The hydrogen discharged from the anode electrode side of the fuel cell 10 is returned to the pipe 250 through the pipe 260 and is circulated again to the fuel cell 10. A circulation pump 240 for circulation is disposed on the pipe 260.

  Air as an oxidant gas is supplied from the air pump 310 to the cathode electrode side of the fuel cell 10 via the pipe 350. The air discharged from the cathode electrode side of the fuel cell 10 is released into the atmosphere through the pipe 360. The fuel cell 10 is further supplied with water as a cooling medium from the radiator 420 via the pipe 450. On the other hand, the water discharged from the fuel cell 10 is sent to the radiator 420 via the pipe 460 and circulated to the fuel cell 10 again. A circulation pump 410 for circulation is arranged on the pipe 460.

  Instead of the hydrogen tank 210 described above, hydrogen may be generated by a reforming reaction using alcohol, hydrocarbon or the like as a raw material. Further, as the cooling medium, non-freezing water such as ethylene glycol, air, or the like may be used instead of water.

  FIG. 2 is an exploded perspective view showing a detailed configuration of the fuel cell module 20 in FIG. The stacking direction shown in FIG. 2 is the same as the stacking direction shown in FIG. As shown in FIG. 1, the fuel cell module 20 includes a seal-integrated membrane electrode assembly (hereinafter referred to as a seal-integrated MEA) 21 and a separator 25. The fuel cell module 20 is configured by alternately laminating these seal-integrated MEAs 21 and separators 25. FIG. 2 shows one each.

  Among these, the separator 25 includes an anode facing plate 22, an intermediate plate 23, and a cathode facing plate 24. The anode facing plate 22 faces the anode electrode side of the seal-integrated MEA 21 and the cathode facing plate 24 faces the cathode electrode of the adjacent seal-integrated MEA (not shown) in the lower part of the drawing. The intermediate plate 23 is sandwiched between the anode facing plate 22 and the cathode facing plate 24.

  Of these plates 22, 23, and 24, the anode facing plate 22 includes a fuel gas supply manifold forming portion 221 a, a fuel gas discharge manifold forming portion 221 b, an oxidant gas supply manifold forming portion 222 a, and an oxidant gas discharge manifold forming portion. 222b, a cooling medium supply manifold forming portion 223a, and a cooling medium discharge manifold forming portion 223b. Each of these manifold forming portions 221a, 221b, 222a, 222b, 223a, and 223b is formed as a through portion that penetrates the anode facing plate 22 in the thickness direction.

  Further, the anode facing plate 22 has a plurality of fuel gas supply holes 225 and a plurality of fuels in a portion DA (hereinafter referred to as “power generation unit”) DA of the seal-integrated MEA 21 described later. A gas exhaust hole 226. The fuel gas supply hole 225 and the fuel gas discharge hole 226 are formed as through portions that penetrate the anode facing plate 22 in the thickness direction.

  The cathode facing plate 24 is disposed at the same position as the anode facing plate 22 at a fuel gas supply manifold forming portion 241a, a fuel gas discharge manifold forming portion 241b, an oxidant gas supply manifold forming portion 242a, an oxidant gas discharge manifold forming portion 242b, and a cooling device. It has a medium supply forming part manifold 243a and a cooling medium discharge manifold forming part 243b. Each of these manifold forming portions 241a, 241b, 242a, 242b, 243a, 243b is formed as a through portion that penetrates the cathode facing plate 24 in the thickness direction.

  Further, the cathode facing plate 24 has a plurality of oxidant gas supply holes 245 and a plurality of oxidant gas discharge holes 246. The oxidant gas supply hole 245 and the plurality of oxidant gas discharge holes 246 are formed as through portions that penetrate the cathode facing plate 24 in the thickness direction.

  The intermediate plate 23 is formed at the same position as the anode facing plate 22 and the cathode facing plate 24 at a fuel gas supply manifold formation portion 231a, a fuel gas discharge manifold formation portion 231b, an oxidant gas supply manifold formation portion 232a, and an oxidant gas discharge manifold. Part 232b. Each of these manifold forming portions 231a, 231b, 232a, 232b is formed as a through portion that penetrates the intermediate plate 23 in the thickness direction.

  Further, the intermediate plate 23 has a plurality of long holes, which are a fuel gas supply flow path forming part 235, a fuel gas discharge flow path forming part 236, an oxidant gas supply flow path forming part 237, and an oxidant gas discharge flow path forming part. 238. One end of each of these flow path forming portions 235 to 238 communicates with each of the manifold forming portions 231a, 231b, 232a, and 232b. Further, the other ends of the fuel gas supply flow path forming part 235 and the fuel gas discharge flow path forming part 236 communicate with the fuel gas supply hole 225 and the fuel gas discharge hole 226 formed in the anode facing plate 22, respectively. . Similarly, the other ends of the oxidant gas supply channel forming part 237 and the oxidant gas discharge channel forming part 238 are respectively connected to the oxidant gas supply hole 245 and the oxidant gas discharge hole formed in the cathode facing plate 24. 246.

  In addition, the intermediate plate 23 has a plurality of long hole cooling medium flow path forming portions 239 that vertically cut the intermediate plate. And each flow path formation part 235-239 in the intermediate | middle plate 23 mentioned above is formed as a penetration part which penetrates the intermediate | middle plate 23 in thickness direction.

  Each of the plates 22, 23, and 24 described above is manufactured by forming the above-described through portions in a titanium thin plate. Accordingly, each of the plates 22, 23, and 24 has a symmetrical structure. The plates 22, 23, and 24 are welded and joined together along a predetermined welding line. As each of the plates 22, 23, and 24, instead of a titanium thin plate, for example, a metal thin plate such as a titanium alloy or a stainless steel thin plate surface plated to prevent corrosion is used. Also good.

  On the other hand, the seal-integrated MEA 21 includes an MEA portion 50 and a seal portion 51 that surrounds the MEA portion 50. Of these, the seal portion 51 is made of silicon rubber. Further, the seal portion 51 is disposed at the same position as the anode facing plate 22 and the cathode facing plate 24 described above, at a fuel gas supply manifold forming portion 211a, a fuel gas discharge manifold forming portion 211b, an oxidant gas supply manifold forming portion 212a, and an oxidant. A gas discharge manifold forming portion 212b, a cooling medium supply manifold forming portion 213a, and a cooling medium discharge manifold forming portion 213b are provided. The seal-integrated MEA 21 has a symmetrical structure except for the electrode direction (the anode electrode side or the cathode electrode side) in the MEA portion 50 described later. Further, the sealing portion 51 described above may be configured using other resin materials such as butyl rubber and fluoro rubber instead of silicon rubber.

  Each of these manifold forming portions 211a, 211b, 212a, 212b, 213a, and 213b is formed as a through portion that penetrates the seal-integrated MEA 21 (seal portion 51) in the thickness direction. Furthermore, the seal part 51 has a seal line (not shown) to be described later. This seal line will be described later.

  FIG. 3 is a cross-sectional view showing the AA cross section shown in FIG. 2 in a state where the seal-integrated MEA 21 and the separator 25 shown in FIG. 2 are stacked. As shown in FIG. 3, in the seal-integrated MEA 21, the MEA unit 50 includes an electrolyte membrane 21c, an anode electrode side diffusion layer 21a, and a cathode electrode side diffusion layer 21b. The MEA unit 50 is further provided with an anode electrode and a cathode electrode made of a catalyst layer, but is omitted for convenience of explanation.

  The anode electrode side diffusion layer 21a is disposed on the surface facing the separator 25, and the cathode electrode side diffusion layer 21b is disposed on the surface facing the adjacent separator (not shown) above the seal-integrated MEA 21.

  On the other hand, in the seal-integrated MEA 21, the seal portion 51 includes a portion formed so as to have a thickness as compared with other portions, and has a seal line as a ridgeline of this portion. The seal line is in contact with the separator 25 as shown in FIG.

  As shown in FIG. 3, a fuel supply manifold is formed by the fuel gas supply manifold forming portions 211a, 221a, 231a, and 241a, and an oxidant gas supply manifold is formed by the oxidant gas supply manifolds 212a, 222a, 232a, and 242a. Has been.

  In addition, a space (hereinafter referred to as “cooling medium flow path”) surrounded by the cooling medium flow path forming portion 239 that is a through portion in the intermediate plate 23, the anode facing plate 22, and the cathode facing plate 24. A plurality are formed.

  Further, a space surrounded by the fuel gas supply flow path forming part 235, which is a through-hole in the intermediate plate 23, the anode facing plate 22 and the cathode facing plate 24 (hereinafter referred to as “fuel gas supply flow path”). ) Is formed. One end of the fuel gas supply channel communicates with the fuel gas supply hole 225, and the other end communicates with the fuel gas supply manifold.

  Similarly, a space (hereinafter referred to as “oxidant gas supply flow path”) surrounded by the oxidant gas supply flow path forming portion 237, the anode facing plate 22 and the cathode facing plate 24 is formed. ing. One end of the oxidant gas supply channel communicates with the oxidant gas supply hole 245 and the other end communicates with the oxidant gas supply manifold.

  4 is a cross-sectional view showing a cross section taken along the line B-B shown in FIG. 2 in a state where the seal-integrated MEA 21 and the separator 25 shown in FIG. 2 are stacked. As shown in FIG. 4, the fuel gas discharge manifold forming portions 211b, 221b, 231b, and 241b provide the fuel gas discharge manifold, and the oxidant gas discharge manifold forming portions 212b, 222b, 232b, and 242b provide the oxidant gas discharge manifold. , Each is formed.

  Further, a space surrounded by the fuel gas discharge flow path forming portion 236 that is a through portion in the intermediate plate 23, the anode facing plate 22, and the cathode facing plate 24 (hereinafter referred to as “fuel gas discharge flow path”). ) Is formed. One end of the fuel gas discharge channel communicates with the fuel gas discharge hole 226, and the other end communicates with the fuel gas discharge manifold.

  Similarly, a space (hereinafter referred to as “oxidant gas discharge flow path”) surrounded by the oxidant gas discharge flow path forming portion 238, the anode facing plate 22 and the cathode facing plate 24 is formed. ing. One end of the oxidant gas discharge channel communicates with the oxidant gas discharge hole 246, and the other end communicates with the oxidant gas discharge manifold.

A2. Fuel cell operation:
Hydrogen as a fuel gas supplied to the fuel cell 10 flows from the upper side to the lower side of the fuel supply manifold shown in FIG. On the other hand, the hydrogen discharged from the fuel cell 10 flows from the lower side to the upper side of the fuel gas discharge manifold shown in FIG.

  Here, in the intermediate plate 23 shown in FIG. 3, part of the hydrogen that passes through the fuel gas supply manifold forming portion 231 a flows into the fuel gas supply flow path and passes through the fuel gas supply hole 225 to the anode facing plate 22. It is supplied to the anode electrode side diffusion layer 21a (not shown) of the opposed seal-integrated MEA 21. The supplied hydrogen diffuses throughout the power generation unit DA and is subjected to an electrochemical reaction at the anode electrode.

  After the electrochemical reaction, hydrogen flows into the fuel gas discharge passage through the fuel gas discharge hole 226 of the anode facing plate 22 shown in FIG. 4 and is discharged from the fuel cell 10 through the fuel gas discharge manifold.

  Contrary to the hydrogen described above, the air as the oxidant gas supplied to the fuel cell 10 flows through the oxidant gas supply manifold shown in FIG. On the other hand, the air discharged from the fuel cell 10 flows from the upper side to the lower side of the oxidant gas discharge manifold shown in FIG.

  Here, in the intermediate plate 23 shown in FIG. 3, a part of the air passing through the oxidant gas supply manifold forming portion 232a flows into the oxidant gas supply flow path, passes through the oxidant gas supply hole 245, and faces the cathode. It is supplied to the diffusion layer on the cathode electrode side of the seal-integrated MEA (not shown) facing the plate 24. The supplied air diffuses over the entire power generation unit and is subjected to an electrochemical reaction at the anode electrode.

  After the electrochemical reaction, the air flows through the oxidant gas discharge hole 246 of the cathode facing plate 24 shown in FIG. 4 and flows into the oxidant discharge passage, and is discharged from the fuel cell 10 through the oxidant gas discharge manifold. The

  The water as the cooling medium supplied to the fuel cell 10 flows from the upper side to the lower side of the drawing while passing through the cooling medium supply manifold forming portions 213a, 223a, and 243a shown in FIG. In the intermediate plate 23, part of the water flows into the cooling medium flow path shown in FIGS. 3 and 4 from one end side (the back side of the drawing) of the cooling medium flow path forming portion 239. The inflowing water passes through the cooling medium flow path and passes through the intermediate plate 23, and from the other end side (front side of the drawing) of the cooling medium flow path forming portion 239, the cooling medium discharge manifold forming portion 243 b of the cathode facing plate 24. And discharged from the fuel cell 10.

A3. Positional relationship between the seal line and the welding line in the comparative example:
Next, before describing the positional relationship between the seal line and the welding line, which is a characteristic part of the present invention, the positional relationship between the seal line and the welding line in the comparative example of the prior art will be described for comparison with the present embodiment. .

  In addition, the configuration of the fuel cell in the following comparative example is different from the configuration of the fuel cell 10 in the above-described embodiment in that a predetermined line (hereinafter referred to as an “adhesion line”) is used between the plates 22, 23, and 24 using an adhesive. The point of joining is different. Note that the operation of the fuel cell in the comparative example is the same as the operation in the above-described embodiment, and thus the description thereof is omitted. Further, in the fuel cell of the comparative example, the same portions as those of the fuel cell 10 of the above-described embodiment will be described with the same reference numerals for convenience of explanation.

  FIG. 5 is an explanatory view showing an adhesive line in a comparative example. A two-dot chain line shown in FIG. 4 indicates an adhesion line on the surface of the intermediate plate 23 facing the anode facing plate 22. An adhesive line is also arranged at the same position on the back surface of the intermediate plate 23 (the surface facing the cathode facing plate 24).

  As shown in FIG. 5, the adhesion line in the comparative example is composed of adhesion lines A1, A2, B1, B2, C1, and C2. Among these, the bonding line A1 surrounds the fuel gas supply manifold forming portion 231a and the fuel gas supply flow path forming portion 235. Similarly, the bonding line A2 includes the fuel gas discharge manifold formation portion 231b and the fuel gas discharge flow path formation portion 236, and the bonding line B1 includes the oxidant gas supply manifold formation portion 232a and the oxidant gas supply flow passage formation portion 237. The adhesive line B2 surrounds the oxidant gas discharge manifold forming part 232b and the oxidant gas discharge flow path forming part 238, respectively.

  The bonding line C1 is in contact with the bonding line A1 and the bonding line B1 so as to surround one end of the plurality of cooling medium flow path forming portions 239, and the bonding line C2 surrounds the other end of the plurality of cooling medium flow path forming portions 239. In this way, it is in contact with the bonding line A2 and the bonding line B2.

  As an effect of these bonding lines, for example, the bonding line A <b> 1 suppresses hydrogen leakage from the fuel gas supply manifold forming portion 231 a and the fuel gas supply flow path forming portion 235 in the intermediate plate 23. Further, the adhesion line A1 is formed so that the hydrogen gas from the fuel gas supply manifold formation portion 221a and the fuel gas supply hole 225 in the anode facing plate 22 faces the fuel gas supply manifold formation portion 231a and the fuel gas supply flow path formation portion 235. Control leaks.

  Similarly, the bonding lines A2, B1, and B2 suppress leakage of hydrogen or air from the manifold forming portions 231b, 232a, and 232b and the flow path forming portions 236 to 238 that are surrounded by the intermediate plate 23, respectively. . Further, these adhesive lines A2, B1, B2 are respectively connected to the manifold forming portions 221b, 222a, 222b and the supply in the anode facing plate 22 facing the manifold forming portions 231b, 232a, 232b and the flow path forming portions 236 to 238 that are surrounded by them. The leakage of hydrogen or air from the hole 226 is suppressed.

  In addition, the bonding lines C1 and C2, together with the bonding lines A1, A2, B1, and B2, suppress water leakage from the above-described cooling medium flow path surrounded by the bonding lines.

  In addition, since the adhesion line is arrange | positioned in the same position also on the back surface of the intermediate | middle plate 23 shown in FIG. 5, leaking of hydrogen, air, and water is suppressed similarly also in the cathode opposing plate 24. FIG.

  On the other hand, also in the seal-integrated MEA 21, fluid flows through the manifold forming portions 211a, 211b, 212a, 212b, 213a, 213b and the MEA portion 50, so that these manifold forming portions 211a, 211b, 212a, 212b, 213a. , 213b and the MEA section 50 need not be leaked. Therefore, the seal-integrated MEA 21 is configured to suppress fluid leakage by bringing the seal line into contact with the separator 25 in the seal portion 51.

  FIG. 6 is an explanatory view showing a seal line of the seal-integrated MEA 21 in the comparative example. The broken line shown in FIG. 6 shows the seal line in the surface facing the anode facing plate 22 of the seal-integrated MEA 21. A seal line is also arranged at the same position on the back surface of the seal-integrated MEA 21 (the surface facing a cathode facing plate (not shown)).

  As shown in FIG. 6, the seal line in the comparative example is composed of seal lines M, X1, X2, Y1, Y2, Z1, and Z2. Among these, the seal line M surrounds the MEA unit 50. Similarly, the seal line X1 is the fuel gas supply manifold forming portion 211a, the seal line X2 is the fuel gas discharge manifold forming portion 211b, the seal run Y1 is the oxidant gas supply manifold forming portion 212a, and the seal line Y2 is the oxidant. The gas discharge manifold forming portion 212b, the seal line Z1 surrounds the cooling medium supply manifold forming portion 213a, and the seal line Z2 surrounds the cooling medium discharge manifold forming portion 213b.

  As an effect of these seal lines, for example, the seal line X1 suppresses the leakage of hydrogen from the fuel gas supply manifold forming portion 211a in the seal-integrated MEA 21. Further, the seal line X1 suppresses leakage of hydrogen from the fuel gas supply manifold forming portion 221a in the anode facing plate 22 facing the fuel gas supply manifold forming portion 211a.

  Similarly, the seal lines X2, Y1, Y2, Z1, and Z2 suppress leakage of hydrogen, air, or water from the manifold forming portions 211b, 212a, 212b, 213a, and 213b that are respectively surrounded by the seal-integrated MEA 21. To do. Further, these seal lines X2, Y1, Y2, Z1, and Z2 are respectively opposed to the manifold forming portions 211b, 212a, 212b, 213a, and 213b that are surrounded by the manifold forming portions 221b, 222a, 222b, and 223a in the anode facing plate 22. , 223b to suppress leakage of hydrogen, air or water.

  Further, the seal line M prevents hydrogen from leaking from the MEA portion 50 surrounded by the seal line M. Further, since both the fuel gas supply hole 225 and the fuel gas discharge hole 226 in the anode facing plate 22 facing each other are surrounded, the hydrogen diffused in the power generation unit DA is prevented from leaking outside the fuel cell 10.

  Since the seal line is arranged at the same position on the back surface of the seal-integrated MEA 21 shown in FIG. 6, hydrogen is supplied from portions corresponding to the portions of the anode facing plate 22 described above in the cathode facing plate (not shown). , Suppresses leakage of air and water.

  As described above, in the fuel cell 10 in the comparative example, the plates 22, 23, and 24 are joined with the adhesive in the above-described adhesion line, and the seal-integrated MEA 21 and the separator 25 in the above-described seal line. , The leakage of hydrogen, air and water flowing through the fuel cell 10 is suppressed.

  Here, in the comparative example described above, in order to reduce the thickness of the separator or improve the thermal conductivity, a case where the plates 22, 23 and 24 are joined by welding instead of the adhesive will be described below. . In addition, the welding line between each plate 22,23,24 is the same as the adhesion line shown in FIG. 5, and the seal line in seal-integrated MEA 21 is the same as the seal line shown in FIG.

  When joining between each plate 22,23,24 by welding, after overlapping each plate 22,23,24, on the opposite side to the welding surface (surface facing the intermediate plate 23) of the anode facing plate 22, That is, laser light is irradiated on a surface (hereinafter referred to as “MEA facing surface”) that faces the seal-integrated MEA 21.

  At this time, the laser light is irradiated along a line obtained by projecting a welding line onto the MEA facing surface (hereinafter referred to as “corresponding line”). As a result, the metal is melted / solidified in the welding line on the welding surface, and the anode facing plate 22 and the intermediate plate 23 are joined. Similarly, on the MEA-corresponding surface of the cathode facing plate 24, laser light is irradiated along the corresponding line, and the cathode facing plate 24 and the intermediate plate 23 are joined by the welding line.

  FIG. 7 is an explanatory diagram showing corresponding lines in the comparative example when the plates 22, 23, 24 are joined by welding. In addition, the dashed-two dotted line shown in FIG. 7 shows the corresponding line in the MEA opposing surface of the anode opposing plate 22 after overlapping and welding each plate.

  As shown in FIG. 7, the corresponding line in the comparative example when the plates 22, 23, 24 are joined by welding is at the same position as the bonding line (welding line) shown in FIG. 5. Hereinafter, the corresponding lines respectively corresponding to the welding lines A1, A2, B1, B2, C1, and C2 shown in FIG. 5 are referred to as corresponding lines A11, A21, B11, B21, C11, and C21. The corresponding line on the cathode facing plate 24 side is also at the same position.

  In these corresponding lines, the MEA facing surface of the anode facing plate 22 is deformed due to distortion or warpage caused by the heat of the laser light. As described above, when the anode facing plate 22 deformed in the corresponding line and the seal-integrated MEA 21 are overlapped, hydrogen may leak due to the positional relationship between the seal line and the welding line.

  FIG. 8 is an explanatory diagram showing the positional relationship between the seal line and the welding line in the comparative example when the plates 22, 23, 24 are joined together by welding. In FIG. 8, a broken line indicates a line obtained by projecting a seal line to the MEA facing surface of the anode facing plate 22 (that is, a line on which the seal line comes into contact when stacked). A two-dot chain line indicates a line obtained by projecting a welding line to the MEA facing surface of the anode facing plate 22 (that is, a corresponding line).

  As shown in FIG. 8, the positional relationship between the seal line and the welding line is obtained by projecting the seal line onto the MEA facing surface of the anode facing plate 22 and the MEA facing surface of the anode facing plate 22. When the positional relationship is such that there is a portion where the line obtained by projecting the welding line overlaps, a portion where the seal line and the corresponding line overlap (hereinafter referred to as “overlap portion”) occurs. Become.

  Specifically, as shown in FIG. 8, the seal line M and the corresponding line A11 are in the overlapping portions q1 and q5, and the seal line M and the corresponding line B11 are in the overlapping portions q2 and q6. In the overlapping portions q3 and q5, the seal line M and the corresponding line A21 overlap in the overlapping portions q4 and q6, respectively.

  And when a seal line and a welding line are in the above positional relationship, hydrogen will leak from the overlapping parts q1-q6. Such hydrogen leakage will be described with reference to FIG. 9, taking the overlapping portion q5 as an example.

  9 is a cross-sectional view showing a part of the LL cross section in FIG. In FIG. 9, points P1 and P2 and overlapping portion q5 are the same as points P1 and P2 and overlapping portion q5 shown in FIG. 8, respectively. The LL cross section does not include the fuel gas supply manifold, the fuel gas supply hole 225 in the anode facing plate 22, and the fuel gas supply flow path forming portion 235 in the intermediate plate 23, but is illustrated for convenience of explanation. Yes.

  As shown in FIG. 8, the region (line) of the points P1 and P2 is a part of the corresponding line A11 and the corresponding line B21. Therefore, as shown in FIG. The counter plate 22 is deformed. As a result, the seal line M does not contact the anode facing plate 22 in the overlapping portion q5.

  Here, as shown by a thick solid line in FIG. 9, a part of the hydrogen supplied to the fuel cell 10 flows into the fuel gas supply flow path from the fuel gas supply manifold forming portion 231 a in the intermediate plate 23, and the fuel gas It is supplied to the anode electrode side diffusion layer 21 a of the seal-integrated MEA 21 through the supply hole 225. At this time, since the seal line M does not come into contact with the anode facing plate 22 in the overlapping portion q5, a part of the hydrogen supplied to the anode electrode side diffusion layer 21a leaks out of the seal line M from this portion. It will leak out of the battery 10.

  Such hydrogen leakage occurs not only in the overlapping portion q5 shown in FIG. 9 but also in the overlapping portions q1 to q4 and q6. Furthermore, since the corresponding lines of the cathode facing plate 24 also overlap with the corresponding lines in the same portions as the overlapping portions q1 to q6, air leaks from these overlapping portions in the same manner as the hydrogen leakage described above.

  Compared to the fuel cell of the comparative example described above, the fuel cell 10 of the present embodiment has a configuration in which the plates are joined by welding while suppressing the leakage of hydrogen and air described above. Hereinafter, the positional relationship between the seal line and the welding line, which is a characteristic part of the present invention, will be described.

A4. Positional relationship between seal line and welding line in this embodiment:
FIG. 10 is an explanatory view showing a seal line in the seal-integrated MEA 21 as an embodiment of the present invention. The broken line shown in FIG. 10 shows the seal line in the surface facing the anode facing plate 22 of the seal-integrated MEA 21. A seal line is also arranged at the same position on the back surface of the seal-integrated MEA 21 (the surface facing a cathode facing plate (not shown)).

  As shown in FIG. 10, the seal line in the present embodiment is composed of seal lines N, X1, X2, Y1, Y2, Z1, and Z2.

  As shown in FIG. 10, the seal line in the seal-integrated MEA 21 does not include the seal line M in the comparative example shown in FIG. However, since the seal line N is disposed along the outer periphery in a portion near the edge of the seal-integrated MEA 21, the seal line N passes through the fuel gas supply hole 225 and the fuel gas discharge hole 226 in the anode facing plate 22. Both will be enclosed. As a result, hydrogen supplied to the MEA unit 50 and diffused over the power generation unit DA of the anode facing plate 22 can be prevented from leaking outside the fuel cell.

  Similarly, also on the back surface, both the oxidant gas supply hole and the oxidant gas discharge hole of the cathode facing plate (not shown) are surrounded, supplied to the MEA unit 50, and diffused across the power generation unit of the cathode facing plate. It is possible to suppress the leaked air from leaking outside the fuel cell.

  On the other hand, the welding line in a present Example shall be the same as the welding line (adhesion line) in the comparative example shown in FIG. Therefore, the corresponding line in the present embodiment is the same as the corresponding line in the comparative example shown in FIG.

  FIG. 11 is an explanatory diagram showing the positional relationship between the seal line and the welding line in the present embodiment. In FIG. 11, a broken line indicates a line obtained by projecting a seal line to the MEA facing surface of the anode facing plate 22 (that is, a line where the seal line abuts when stacked). A two-dot chain line indicates a line obtained by projecting a welding line to the MEA facing surface of the anode facing plate 22 (that is, a corresponding line).

  The MEA facing surface of the anode facing plate 22 corresponds to a projection surface in the claims.

  As shown in FIG. 11, the line obtained by projecting the seal line X1 onto the MEA facing surface of the anode facing plate 22 is included in a region surrounded by the corresponding line A11. Similarly, the lines obtained by projecting the seal lines X2, Y1, and Y2 onto the MEA facing surface of the anode facing plate 22 are included in the regions surrounded by the corresponding lines A21, B11, and B21, respectively. Yes. Further, the lines obtained by projecting the seal lines Z1 and Z2 to the MEA facing surface of the anode facing plate 22 are included in a region surrounded by the corresponding lines C11 and C21 and A11, A21, B11 and B21. Yes.

  Further, all the corresponding lines are included in a region surrounded by a line obtained by projecting the seal line M onto the MEA facing surface of the anode facing plate 22.

  Therefore, there is no overlap between the line obtained by projecting the seal line on the MEA facing surface of the anode facing plate 22 and the corresponding line.

  Thus, the positional relationship between the seal line and the welding line in the present embodiment is such that the line obtained by projecting the seal line onto the MEA facing surface of the anode facing plate 22 and the facing line (the MEA facing of the anode facing plate 22). And a line obtained by projecting the welding line to the surface) so that they do not overlap each other.

  When the seal line and the welding line are in such a positional relationship, the seal line contacts the anode facing plate 22 at a portion other than the corresponding line that is a deformed portion, so that the supplied hydrogen is supplied to the fuel cell. Leakage to the outside can be suppressed.

  Similarly, for the cathode facing plate (not shown), the corresponding line on the MEA facing surface of the cathode facing plate and the seal line of the seal-integrated MEA do not overlap. Therefore, the seal line can suppress leakage of supplied air to the outside of the fuel cell.

  Thus, in the fuel cell 10 of the present embodiment, leakage of hydrogen, air, and water can be suppressed while the plates 22, 23, and 24 are joined by welding.

A5. Effects of the embodiment:
As described above, in the fuel cell of the present embodiment, the positional relationship between the seal line in the seal-integrated MEA 21 and the weld line in the anode facing plate 22 is projected onto the MEA facing surface of the anode facing plate. The obtained line and the line obtained by projecting the welding line to the MEA facing surface of the anode facing plate are in a positional relationship such that they do not overlap each other.

  Therefore, the seal line does not overlap with the corresponding line deformed by welding, and comes into contact with the opposing plate at a portion other than the corresponding line. As a result, hydrogen leakage due to the overlap between the corresponding line and the seal line can be suppressed. Similarly, with respect to the cathode facing plate 24, the positional relationship between the welding line and the seal line is similar, and air leakage due to the overlap between the corresponding line and the seal line can be suppressed.

  In addition, the seal-integrated MEA includes a seal line N disposed on both sides as a seal line along the outer periphery in a portion near the edge of the seal-integrated MEA. Therefore, the seal line N on the surface facing the anode facing plate 22 surrounds both the fuel gas supply hole 225 and the fuel gas discharge hole 226 in the anode facing plate 22.

  As a result, hydrogen supplied to the MEA unit and diffused over the power generation unit DA of the anode facing plate 22 can be prevented from leaking outside the fuel cell. Similarly, since the seal line N on the surface facing the cathode facing plate surrounds both the oxidant gas supply hole and the oxidant gas discharge hole in the cathode facing plate, air leaks to the outside of the fuel cell. Can be suppressed.

B. Variation:
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. .

B1. Modification 1:
In the embodiment described above, the separator 25 is composed of a total of three metal plates including the anode facing plate 22, the intermediate plate 23, and the cathode facing plate 24. However, the present invention is not limited to this. It may be composed of two metal plates, or may be composed of four or more metal plates. If the separator includes a plurality of metal plates, and each metal plate is welded by a welding line, by applying the present invention, in a fuel cell including the separator, a fuel gas, an oxidant gas, It is possible to suppress leakage of the cooling medium.

B2. Modification 2:
In the seal-integrated MEA 21 in the embodiment described above, the seal line is arranged at the position shown in FIG. 10, but in addition to these portions, a portion surrounding the MEA portion 50 as in the conventional seal line. You may make it arrange | position to. Further, in addition to the portion surrounding the MEA portion 50, it may be arranged in addition to the portion overlapping the corresponding line of the opposing plate.

  Even when the seal lines are added to these portions, as shown in FIG. 10, the portions near the edge of the seal-integrated MEA and the manifold forming portions 211a, 211b, 212a, 212b, 213a, and 213b are surrounded. Since the seal line is arranged in the part, it is possible to prevent the fuel gas, the oxidant gas, and the cooling medium from leaking.

B3. Modification 3:
In the separator 25 in the embodiment described above, the welding line is configured to be disposed in the portion illustrated in FIG. 4. However, in addition to the portion illustrated in FIG. 4, the welding line is configured to be disposed in another portion. It doesn't matter. Even in such a configuration, the positional relationship between the welding line and the seal line is obtained by projecting the seal line onto the MEA facing surface of the anode facing plate and the welding line onto this surface. If the positional relationship is such that the obtained line does not overlap with each other, the seal line and the corresponding line can be prevented from overlapping each other. As a result, fuel gas leakage can be suppressed.

  Similarly, leakage of the oxidant gas can be suppressed on the MEA facing surface of the cathode facing plate. In addition, by adding a welding line to other portions in this way, the sealing performance in the separator can be increased and the coupling between the plates can be strengthened.

B4. Modification 4:
The fuel cell in the above-described embodiment is configured to use the seal-integrated MEA as the membrane electrode assembly. However, instead of the seal-integrated MEA, the fuel cell may be configured to use a separate MEA from the seal portion. Good. For example, like the fuel cell described in Patent Document 1, the MEA and the seal member are integrated by laminating the separator and the MEA so as to interpose the seal member. And it is sufficient. In this case, the seal line in the seal member may be arranged at the same position as the seal line of the seal portion in the above-described embodiment.

  Even in such a configuration, the positional relationship between the seal line and the weld line in the seal member is obtained by projecting the seal line to the MEA facing surface of the anode facing plate, and the weld line with respect to this surface. And the line obtained by projecting can be positioned so as not to overlap each other. As a result, fuel gas leakage can be suppressed. Similarly, leakage of the oxidant gas can be suppressed on the MEA facing surface of the cathode facing plate.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which shows schematic structure of the fuel cell as one Example of this invention. FIG. 2 is an exploded perspective view showing a detailed configuration of the fuel cell module 20 in FIG. 1. Sectional drawing which shows the AA cross section shown in FIG. 2 in the state which laminated | stacked the seal integrated MEA21 and separator 25 of FIG. Sectional drawing which shows the BB cross section shown in FIG. 2 in the state which laminated | stacked the seal integrated MEA21 and separator 25 of FIG. Explanatory drawing which shows the adhesion line in a comparative example. Explanatory drawing which shows the seal line of seal integrated MEA21 in a comparative example. Explanatory drawing which shows the corresponding line in a comparative example in the case of joining between each plate 22,23,24 by welding. Explanatory drawing which shows the positional relationship of the seal line and welding line in a comparative example when joining between each plate 22,23,24 by welding. Sectional drawing which shows a part of LL cross section in FIG. Explanatory drawing which shows the seal line in the seal integrated MEA21 as one Example of this invention. Explanatory drawing which shows the positional relationship of the seal line and welding line in a present Example.

Explanation of symbols

10 ... Fuel cell 20 ... Fuel cell module 30 ... End plate 31 ... Tension plate 32 ... Bolt 33 ... Insulator 34 ... Terminal 210 ... Hydrogen tank 220 ... Shut valve 230 ... Pressure control valve 240 ... Circulating pump 250 ... Piping 260 ... Piping 310 ... Air pump 350 ... Piping 360 ... Piping 410 ... Circulating pump 420 ... Radiator 450 ... Piping 460 ... Piping 21 ... Seal integrated MEA
21a ... Anode electrode side diffusion layer 21b ... Cathode electrode side diffusion layer 21c ... Electrolyte membrane 22 ... Anode facing plate 23 ... Intermediate plate 24 ... Cathode facing plate 25 ... Separator 211a , 221a, 231a, 241a, ... Fuel gas supply manifold formation part 211b, 221b, 231b, 241b, ... Fuel gas discharge manifold formation part 212a, 222a, 232a, 242a, ... Oxidant gas supply manifold formation Portions 212b, 222b, 232b, 242b,... Oxidant gas discharge manifold forming portions 213a, 223a, 243a ... Cooling medium supply manifold 213b, 223b, 243b ... Cooling medium discharge manifold 225 ... Fuel gas supply Hole 226 ... Fuel gas discharge hole DA ... Power generation part 239 ... Cooling medium flow path forming part 235 ... Fuel gas Supply channel formation unit 236 ... Fuel gas discharge channel formation unit 237 ... Oxidant gas supply channel formation unit 238 ... Oxidant gas discharge channel formation unit 245 ... Oxidant gas supply hole 246 ... Oxidant gas discharge holes A1, A2, B1, B2, C1, C2 ... Adhesion lines X1, X2, Y1, Y2, Z1, Z2, M, N ... Seal lines A11, A21, B11, B21, C11, C21 ... corresponding line P1, P2 ... point q1-q6 ... overlapping part

Claims (6)

A separator and a membrane electrode assembly are alternately stacked, and a fuel cell having a seal portion in contact with a surface of the separator facing the membrane electrode assembly,
The separator is configured by welding a plurality of metal plates along a predetermined welding line,
The seal portion has a seal line configured to suppress leakage of a predetermined fluid supplied to the fuel cell by contacting the separator.
The seal line and the predetermined welding line are arranged to have a predetermined positional relationship,
The predetermined positional relationship is obtained by projecting the seal line to a projection surface orthogonal to the stacking direction of the separator and the membrane electrode assembly, and projecting the predetermined welding line to the projection surface. The fuel cell is characterized in that it is in a positional relationship such that the lines obtained in this way do not overlap each other. The fuel cell according to claim 1, wherein
The plurality of metal plates are:
A first electrode facing plate having a surface facing the first electrode of the membrane electrode assembly;
A second electrode facing plate having a surface facing the second electrode of the membrane electrode assembly;
An intermediate plate sandwiched between the first electrode facing plate and the second electrode facing plate;
A fuel cell characterized by being. The fuel cell according to claim 2, further comprising:
A fluid supply port for communicating the membrane electrode assembly and the separator in a thickness direction;
A fluid discharge port that communicates the membrane electrode assembly and the separator in a thickness direction; and
With
The intermediate plate has a supply flow passage forming portion that penetrates in the thickness direction and communicates with the supply port, and a discharge flow passage formation portion that penetrates in the thickness direction and communicates with the discharge port,
The first electrode facing plate and the second electrode facing plate include a first supply port forming portion that forms part of the supply port and a first exhaust that forms part of the discharge port, respectively. An outlet forming portion, a fluid supply hole penetrating in the thickness direction and communicating with the supply flow path forming portion, and a fluid discharge hole penetrating in the thickness direction and communicating with the discharge flow path forming portion. ,
The membrane electrode assembly includes a second supply port forming part that forms a part of the supply port, and a second discharge port forming part that forms a part of the discharge port,
The predetermined welding line is disposed so as to surround at least one of the first supply port forming portion or the first discharge port forming portion,
The seal line is at least
A first seal line disposed so as to surround the second supply port forming part and the second discharge port forming part,
A second seal line disposed so as to surround both the fluid supply hole and the fluid discharge hole of the first electrode plate or the second electrode plate that is in contact with each other;
Have
The predetermined positional relationship is such that a line obtained by projecting the first seal line onto the projection surface is surrounded by a line obtained by projecting the predetermined weld line onto the projection surface. And a line obtained by projecting the predetermined welding line onto the projection surface is contained in a region surrounded by a line obtained by projecting the second seal line onto the projection surface. A fuel cell having a positional relationship as described above. The fuel cell according to claim 3, wherein
The fuel cell according to claim 1, wherein the second seal line is disposed along an outer periphery of the membrane electrode assembly at a substantially edge portion of the membrane electrode assembly. A membrane electrode assembly capable of constituting a fuel cell by alternately laminating with a separator constituted by welding a plurality of metal plates along a predetermined welding line,
A seal portion having a seal line configured to suppress leakage of a predetermined fluid supplied to the fuel cell by contacting the separator;
At least a part of the seal line is disposed along the outer periphery of the membrane electrode assembly at a substantially edge portion of the membrane electrode assembly. A separator configured by welding a plurality of metal plates along a predetermined welding line, and a seal line configured to suppress leakage of a predetermined fluid supplied to the fuel cell by contacting the separator. A membrane electrode assembly having a seal portion disposed, and a manufacturing method for manufacturing the fuel cell,
A step of alternately laminating the membrane electrode assembly and the separator so that the seal line and the welding line have a predetermined positional relationship;
The predetermined positional relationship is obtained by projecting the seal line to a projection surface orthogonal to the stacking direction of the separator and the membrane electrode assembly, and projecting the predetermined welding line to the projection surface. The fuel cell manufacturing method is characterized by being in a positional relationship such that the obtained line does not overlap with each other.

Images