JP2006216491A - Separator of fuel cell and manufacturing method of separator of fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make processing of a separator easy, with respect to the separator of a fuel cell. <P>SOLUTION: The separator 25 is composed of a cathode facing plate 22, an anode facing plate 23, and an intermediate plate 24. Each of constituent elements (anode system, cathode system, cooling system) forming the separator 25 is composed of a penetrating part which penetrates these three plates in thickness direction, and a projection-recess shape part formed by a plastic work (for example, press work). As a result, the separator 25 can be worked using a process method (punching work and press work) easy and with high productivity. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a separator for a fuel cell, and more particularly to a technique for facilitating the processing of the separator.

  A fuel cell, for example, a polymer electrolyte fuel cell, supplies a fuel gas containing hydrogen and an oxidizing gas containing oxygen to two electrodes (cathode electrode and anode electrode) facing each other with an electrolyte membrane interposed therebetween. Thus, the reactions shown in the following formulas (1) and (2) are performed, and the chemical energy of the substance is directly converted into electric energy.

Cathode reaction (oxygen electrode): 2H ⁺ + 2e ⁻ + (1/2) O ₂ → H ₂ O (1)
Anode reaction (fuel electrode): H ₂ → 2H ⁺ + 2e ⁻ (2)

  As a main structure of such a fuel cell, a so-called stack structure has been developed in which a substantially flat membrane electrode assembly (MEA) and a separator are stacked and fastened in the stacking direction.

  Here, as a separator of a fuel cell, a separator having a three-layer structure including an anode side plate, a cathode side plate, and an intermediate plate sandwiched between both plates is known (for example, Patent Documents). 1). This separator having a three-layer structure includes reaction gas passages formed by half-etching on the surfaces of the anode-side and cathode-side plates. Then, the reaction gas is distributed to the reaction gas passage through the delivery passage provided in the intermediate plate and the long hole-shaped gas supply hole provided at the end of the reaction gas passage described above.

JP 2004-6104 A

  However, in the above conventional technique, since the reaction gas flow paths of the anode side and cathode side plates are processed by half etching, there is a problem that the number of processing steps for manufacturing increases. In addition, since it is necessary to select materials for the anode side and cathode side plates in consideration of the workability of half-etching, the material selection is limited, and corrosion resistance may be sacrificed.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to facilitate the processing of a fuel cell separator in a fuel cell separator.

  In order to solve the above problems, a first aspect of the present invention includes a cathode facing plate having a facing surface with a cathode electrode, an anode facing plate having a facing surface with an anode electrode, the cathode facing plate and the anode facing. Provided is a fuel cell separator including an intermediate plate sandwiched between plates. The separator according to the first aspect of the present invention includes an oxidizing gas supply manifold, an oxidizing gas discharge manifold, a fuel gas supply manifold, and a fuel gas that penetrate the cathode facing plate, the anode facing plate, and the intermediate plate in the thickness direction. A discharge manifold, and the intermediate plate penetrates in the thickness direction and an oxidizing gas supply flow path forming portion that forms an oxidizing gas supply flow path communicating with the oxidizing gas supply manifold. And an oxidizing gas discharge channel forming portion that forms an oxidizing gas discharge channel that communicates with the oxidizing gas discharge manifold, and a fuel gas supply channel that penetrates in the thickness direction and communicates with the fuel gas supply manifold. A fuel gas supply flow path forming portion that penetrates in the thickness direction and communicates with the fuel gas discharge manifold. A fuel gas discharge flow path forming portion that forms a fuel gas discharge flow path, and the cathode facing plate is formed by plastic working and has an uneven shape that forms an oxidizing gas flow path with the cathode electrode A first concavo-convex shape portion having a thickness direction, an oxidant gas supply hole communicating with the oxidant gas supply channel and the oxidant gas channel, and a thickness direction, and the oxidation An oxidant gas discharge hole communicating with the oxidant gas channel, and the anode facing plate is formed by plastic working and forms a fuel gas channel between the anode electrode and the anode electrode plate While passing in the thickness direction, the second concavo-convex shape portion having an uneven shape, and the fuel gas supply hole that communicates the fuel gas supply channel and the fuel gas channel, and through the thickness direction, The fuel And oxidizing gas discharge hole communicating scan discharge passage and with said fuel gas flow channel, characterized in that it comprises a.

  In the separator according to the first aspect of the present invention, all of the path (hereinafter referred to as the cathode system) from when the oxidizing gas is supplied to when it is discharged (hereinafter referred to as a cathode system) (oxidizing gas supply manifold-oxidizing gas supply flow path-oxidizing gas supply). (Hole-oxidizing gas flow path-oxidizing gas discharge hole-oxidizing gas discharge flow path-oxidizing gas discharge manifold) and all the paths (hereinafter referred to as anode system) from when the fuel gas is supplied to the exhaust gas (hereinafter referred to as anode system) Supply manifold-fuel gas supply flow path-fuel gas supply hole-fuel gas flow path-fuel gas discharge hole-fuel gas discharge flow path-fuel gas discharge manifold) penetrates the three plates in the thickness direction, respectively. It is formed only by the part and the uneven part formed by plastic working. As a result, the cathode system and the anode system can be processed using only an easy and highly productive processing method.

  In the separator according to the first aspect of the present invention, the intermediate plate has an annular shape that surrounds outer peripheries of the first uneven portion and the second uneven portion in plan view, and the oxidizing gas flow The passage is formed by a recess of the first uneven shape portion, and the fuel gas flow path is formed by a recess of the second uneven shape portion, and the intermediate plate side of the anode facing plate and the anode facing plate These surfaces may be in contact with each other in the concave portions in the first concavo-convex shape portion and the second concavo-convex shape portion. By so doing, the conductivity of the separator is ensured by the direct contact between the anode facing plate and the cathode facing plate.

  In the separator according to the first aspect of the present invention, a cooling medium flow is caused between the cathode plate and the anode plate by the convex portions of the first concave-convex shape portion and the convex portions of the second concave-convex shape portion. The separator further includes a cooling medium supply manifold penetrating the cathode facing plate, the anode facing plate, and the intermediate plate in a thickness direction, and a cooling medium discharge manifold, and the intermediate plate Further penetrates in the thickness direction and a cooling medium supply flow path forming portion that forms a cooling medium supply flow path that communicates the cooling medium supply manifold and the cooling medium flow path. And a cooling medium discharge flow path forming section that forms a cooling medium discharge flow path that communicates the cooling medium discharge manifold and the cooling medium flow path. And it may be. In this way, all of the path (hereinafter referred to as a cooling system) from when the cooling medium for cooling the fuel cell is supplied to when it is discharged (hereinafter referred to as a cooling system) (cooling medium supply manifold-cooling medium supply flow path-cooling medium). (Flow path-cooling medium discharge flow path-cooling medium discharge manifold) is formed by only through portions that penetrate the three plates in the thickness direction and uneven portions formed by plastic working. Thus, the processing can be performed using only a processing method that is easy in cooling system and high in productivity.

  The separator which concerns on the 1st aspect of this invention WHEREIN: When the outer peripheral part of the said 1st uneven | corrugated shaped part and the said 2nd uneven | corrugated shaped part comprises a fuel cell, when comprised between the said separator and adjacent components. It is an outer periphery seal part which the sealing material to seal contact | abuts, each manifold may be located in the outer side of the said outer periphery seal part, and each supply hole and each discharge hole may be located inside the said electric power generation part outer periphery seal part. . In this way, each supply channel and each discharge channel tunnels the seal portion from the inside of the separator, so that the contact portion with the seal material can be flat, and the sealing performance is improved.

  In the separator according to the first aspect of the present invention, a plurality of the supply flow path forming portions and the respective discharge flow path forming portions may be arranged side by side in the sealing direction of the outer peripheral seal portion. In this way, inside the separator in the seal portion, a space portion in which various supply flow channels or discharge flow channels are formed, a dense portion in which no flow channel is formed, and a plurality of them are alternately arranged in the seal direction. Thus, deformation of the anode facing plate and the cathode facing plate can be suppressed.

  According to a second aspect of the present invention, there is provided a cathode facing plate having a surface facing the cathode electrode, an anode facing plate having a surface facing the anode electrode, and an intermediate sandwiched between the cathode facing plate and the anode facing plate. A plate, an oxidant gas supply manifold, an oxidant gas discharge manifold, a fuel gas supply manifold, and a fuel gas discharge manifold that penetrate the cathode facing plate, the anode facing plate, and the intermediate plate in a thickness direction, Passes through in the thickness direction and forms an oxidizing gas supply flow path forming portion that forms an oxidizing gas supply flow path that communicates with the oxidizing gas supply manifold, and penetrates in the thickness direction and communicates with the oxidizing gas discharge manifold. Oxidizing gas discharge channel forming part for forming oxidizing gas discharging channel and thickness direction A fuel gas supply flow path forming portion that forms a fuel gas supply flow path that communicates with the fuel gas supply manifold, and a fuel gas discharge flow that penetrates in the thickness direction and communicates with the fuel gas discharge manifold A fuel gas discharge flow path forming portion that forms a path, and the cathode facing plate has a first concavo-convex shape portion having a convex and concave shape that forms an oxidizing gas flow path between the cathode electrode and the cathode electrode, and a thickness An oxidant gas supply hole that penetrates in the direction and communicates with the oxidant gas supply channel and the oxidant gas channel, and penetrates in the thickness direction and includes the oxidant gas discharge channel and the oxidant gas channel. An oxidant gas discharge hole communicating therewith, and the anode facing plate penetrates in the thickness direction with a second concavo-convex shape part having a concavo-convex shape forming a fuel gas flow channel between the anode counter plate and the anode electrode. In addition, a fuel gas supply hole that communicates the fuel gas supply channel and the fuel gas channel, and an oxidizing gas that penetrates in the thickness direction and communicates the fuel gas discharge channel and the fuel gas channel. A method for manufacturing a separator for a fuel cell comprising a discharge hole is provided. In the separator manufacturing method according to the second aspect of the present invention, the first uneven shape portion in the cathode facing plate and the second uneven shape portion in the anode facing plate are formed by plastic working. It is characterized by.

  By so doing, the oxidizing gas flow path and the fuel gas flow path are processed by easy and highly productive plastic working, so that the productivity of the separator can be improved.

  Hereinafter, a separator according to the present invention will be described based on examples with reference to the drawings.

A. Example / Configuration of Fuel Cell and Separator:
With reference to FIGS. 1-4, the schematic structure of the fuel cell comprised using the separator concerning an Example and the separator concerning an Example is demonstrated. FIG. 1 is an explanatory diagram illustrating an external configuration of a fuel cell configured using a separator according to an embodiment. FIG. 2 is an explanatory diagram showing a schematic configuration of modules constituting the fuel cell in the embodiment. FIG. 3 is a plan view of a cathode facing plate and an anode facing plate constituting the separator according to the embodiment. FIG. 4 is a plan view of an intermediate plate constituting the separator and a seal-integrated membrane electrode assembly (hereinafter, the membrane electrode assembly is also referred to as MEA (Membrane-Electrode Assembly)).

  The fuel cell 10 is a polymer electrolyte fuel cell that is relatively small and excellent in power generation efficiency. The fuel cell 10 includes a module 20, an end plate 30, a tension plate 31, an insulator 33, and a terminal 34. The module 20 is sandwiched between two end plates 30 with the insulator 33 and the terminal 34 interposed therebetween. That is, the fuel cell 10 has a layered structure in which a plurality of modules 20 are stacked. Further, the tension plate 31 is coupled to the end plates 30 by bolts 32, whereby the modules 20 are fastened with a predetermined compressive force in the stacking direction.

  The fuel cell 10 is supplied with a reaction gas (fuel gas and oxidizing gas) used for a cell reaction and a cooling medium for cooling the fuel cell 10. Briefly, hydrogen as fuel gas is supplied to the anode of the fuel cell 10 from a hydrogen tank 210 storing high-pressure hydrogen via a pipe 250. Instead of the hydrogen tank 210, hydrogen may be generated by a reforming reaction using alcohol, hydrocarbon, or the like as a raw material. The pipe 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 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 oxidizing gas is supplied from the air pump 310 to the cathode of the fuel cell 10 through the pipe 350. The air discharged from the cathode of the fuel cell 10 is released into the atmosphere via the pipe 360. Further, a cooling medium is supplied to the fuel cell 10 from the radiator 420 via the pipe 450. As the cooling medium, water, antifreeze water such as ethylene glycol, air, or the like can be used. The cooling medium discharged from the fuel cell 10 is sent to the radiator 420 via the pipe 460 and is circulated to the fuel cell 10 again. A circulation pump 410 for circulation is arranged on the pipe 460.

  As shown in FIG. 2, the module 20 is configured by alternately laminating separators 25 and seal-integrated MEAs 21.

  As shown in FIG. 2, the separator 25 includes a cathode facing plate 22 having a surface facing the cathode electrode of the seal-integrated MEA 21, an anode facing plate 23 having a surface facing the anode electrode, a cathode facing plate 22 and an anode. An intermediate plate 24 sandwiched between the opposing plate 23 is provided. These three plates are overlapped and joined by hot pressing.

  The cathode facing plate 22 is a substantially rectangular metal thin plate. In this embodiment, a SUS (stainless steel) plate is used as the metal thin plate. As shown in FIG. 3A, the cathode facing plate 22 includes a fuel gas supply manifold forming portion 221a and a fuel gas discharge manifold forming portion 221b that form various manifolds at the left and right ends when the separator 25 is formed. And an oxidizing gas supply manifold forming portion 222a, an oxidizing gas discharge manifold forming portion 222b, a cooling medium supply manifold forming portion 223a, and a cooling medium discharge manifold forming portion 223b. Further, the cathode facing plate 22 is further arranged in the center side from the oxidizing gas supply manifold forming portion 222a and a plurality of the oxidizing gas supply holes 225 formed in the center side from the oxidizing gas discharge manifold forming portion 222b. And an oxidizing gas discharge hole 226 formed. These various manifold forming portions, the oxidizing gas supply hole 225, and the oxidizing gas discharge hole 226 are all formed as through portions that penetrate the cathode facing plate 22 in the thickness direction, and can be formed by punching.

  The cathode facing plate 22 has a shape in which a convex portion and a concave portion are continuous as shown in FIG. 2 (hereinafter referred to as a concave-convex shape), as shown in FIG. 2, in the power generation portion facing the MEA (cathode electrode) when configuring the fuel cell. ing. A portion (power generation unit) having the uneven shape of the cathode facing plate 22 is referred to as a first uneven shape portion. As shown in FIG. 2 and FIG. 3A, the first uneven shape portion causes the cathode facing plate 22 to have the oxidizing gas flow path forming portion 229a on the surface facing the MEA and the cooling medium flow on the opposite surface. The path forming portions 229b are alternately formed in the vertical direction. Here, in the present specification, a portion of the first uneven portion that forms the oxidizing gas flow path forming portion 229a (a portion that protrudes to the surface facing the intermediate plate 24) is defined as a recess, and the cooling medium flow A portion where the path forming portion 229b is formed (a portion protruding toward the surface facing the cathode electrode) is referred to as a convex portion. The convex portion of the first concave-convex shape portion forms a groove having a substantially rectangular cross-sectional shape on the surface facing the intermediate plate 24, and the concave portion of the first concave-convex shape portion on the surface facing the cathode electrode. A groove having a substantially rectangular cross-sectional shape is formed. The first uneven portion is formed by plastic working represented by press working.

  The anode facing plate 23 is a substantially square metal thin plate having the same size as the cathode facing plate 22. The same material as the cathode facing plate 22 can be used. As shown in FIG. 3B, the anode facing plate 23 is located at the same position as the cathode facing plate 22, at the fuel gas supply manifold forming portion 231a, the fuel gas discharge manifold forming portion 231b, and the oxidizing gas supply manifold forming portion 232a. And an oxidizing gas discharge manifold forming portion 232b, a cooling medium supply manifold forming portion 233a, and a cooling medium discharge manifold forming portion 233b. The anode facing plate 23 is further arranged in a plurality of fuel gas supply holes 237 formed side by side on the center side from the fuel gas supply manifold forming portion 231a and a plurality in the center side from the fuel gas discharge manifold forming portion 231b. It has a fuel gas discharge hole 238 formed. These various manifold forming portions, fuel gas supply holes 237, and fuel gas discharge holes 238 are all formed as through portions that penetrate the anode facing plate 23 in the thickness direction, and can be formed by punching.

  Similar to the cathode facing plate 22, the anode facing plate 23 has an uneven shape in the power generation portion facing the MEA when the fuel cell is configured (see FIG. 2). A portion (power generation unit) having an uneven shape of the anode facing plate 23 is referred to as a second uneven shape portion. As shown in FIG. 2 and FIG. 3 (b), the second uneven portion causes the anode facing plate 23 to have the fuel gas flow path forming portion 239a on the surface facing the MEA and the coolant flow on the opposite surface. The path forming portions 239b are alternately formed in the vertical direction. Here, in the present specification, a portion of the second concavo-convex shape portion that forms the fuel gas flow path forming portion 239a (a portion that protrudes on the side facing the intermediate plate 24) is defined as a concave portion, and the cooling medium flow A portion where the path forming portion 239b is formed (a portion protruding toward the surface facing the anode electrode) is referred to as a convex portion. The convex portion of the second concave-convex shape portion forms a groove having a substantially rectangular cross section on the surface facing the intermediate plate 24, and the concave portion of the second concave-convex shape portion is on the surface facing the anode electrode. A groove having a substantially rectangular cross-sectional shape is formed. The second uneven portion is formed by plastic working represented by press working.

  The intermediate plate 24 is a substantially rectangular metal thin plate having the same size as the cathode facing plate 22 and the anode facing plate 23. The same material as the cathode facing plate 22 and the anode facing plate 23 can be used. As shown in FIG. 3C, the intermediate plate 24 is provided at the same position as the cathode facing plate 22 and the anode facing plate 23 at the fuel gas supply manifold forming portion 241a, the fuel gas supply manifold forming portion 241a, and the oxidizing gas supply. A manifold forming part 242a and an oxidizing gas discharge manifold forming part 242b are provided.

  As shown in FIG. 4A, the intermediate plate 24 has one end communicating with the oxidizing gas supply manifold forming portion 242a and is an oxidation hole that is a long hole formed toward the center from the oxidizing gas supply manifold forming portion 242a. A plurality of gas supply flow path forming portions 245 are formed side by side. Further, the intermediate plate 24 is a long hole having a shape similar to that of the oxidizing gas supply flow path forming portion 245, and an oxidizing gas discharge flow path forming portion 246 having one end communicating with the oxidizing gas discharge manifold forming portion 242b, and a fuel gas supply It has a fuel gas supply channel forming part 247 whose one end communicates with the manifold forming part 241a, and a fuel gas discharge channel forming part 248 whose one end communicates with the fuel gas discharge manifold forming part 241b.

  As shown in FIG. 4A, the intermediate plate 24 has a power generation unit through-portion 249 in which a power generation unit facing the MEA is cut out when the fuel cell is configured. Thereby, when the intermediate plate 24 constitutes the separator 25, the first uneven shape portion (power generation portion) in the cathode facing plate 22 and the second uneven shape portion (power generation portion) in the anode facing plate 23 in plan view. It will have an annular shape that surrounds the outer periphery. The separator 25 is configured by the power generation unit penetrating portion 249 so that the first uneven portion of the cathode facing plate 22 and the second uneven portion of the anode facing plate 23 can come into contact with each other. More specifically, as shown in FIG. 2, the recess in the first uneven shape portion and the recess in the second uneven shape portion are in contact with each other. In other words, the back surface of the oxidizing gas flow path forming portion 229a and the back surface of the cooling medium flow path forming portion 239b are in contact with each other.

  The intermediate plate 24 further has one end communicating with the above-described power generation unit penetrating portion 249 and the other end forming a cooling medium supply flow path that is a long hole located near the left end of the intermediate plate 24 in FIG. Part 244a. The intermediate plate 24 further has one end communicating with the above-described power generation unit penetrating portion 249 and the other end forming a cooling medium discharge flow path that is a long hole located near the right end of the intermediate plate 24 in FIG. Part 244b. A plurality of cooling medium supply flow path forming portions 244a and cooling medium discharge flow path forming portions 244b are formed side by side in the vertical direction in FIG.

  The above-described various manifold forming portions and various flow path forming portions in the intermediate plate 24 are all formed as through portions that penetrate the anode facing plate 23 in the thickness direction. The intermediate plate 24 is a flat plate having no particular structure other than these through portions. Therefore, the intermediate plate 24 can be produced simply by punching a substantially rectangular metal thin plate.

  As shown in FIG. 4B, the seal-integrated MEA 21 includes an MEA and a seal portion 50 joined to the outer peripheral edge of the MEA. As shown in FIG. 2, the MEA includes an electrolyte membrane 211 made of an ion exchange membrane, an electrode (for example, an anode electrode, not shown) made of a catalyst layer disposed on one surface of the electrolyte membrane 211, and an electrolyte membrane 211. Electrode (for example, cathode electrode, not shown) made of a catalyst layer disposed on the other surface of the catalyst, and a diffusion layer 212 disposed on the separator facing surface of each catalyst layer. The diffusion layer 212 can be configured using, for example, a metal (for example, titanium) porous body or a carbon porous body.

  For the seal portion 50, for example, a resin material such as silicon rubber, butyl rubber, or fluororubber is used. The seal part 50 is produced by injection molding a resin material with the outer peripheral end of the MEA facing the cavity of the mold. By doing so, the MEA and the seal portion 50 are joined without a gap, and the oxidizing gas and the fuel gas can be prevented from leaking from the joined portion. Similar to the cathode facing plate 22 and the anode facing plate 23, the seal portion 50 includes an oxidizing gas supply manifold forming portion 501 a, an oxidizing gas discharge manifold forming portion 501 b, a fuel gas supply manifold forming portion 502 a, a cooling medium supply manifold forming portion 503 a, A cooling medium discharge manifold forming portion 503b is provided. As shown in FIG. 2, when the fuel cell 10 is configured, the seal portion 50 seals between the separator 25 that contacts one surface and the separator 25 that contacts the other surface. As shown in FIG. 4B, the seal portion 50 is sealed so as to surround the outer periphery of the MEA (when viewed from the separator 25, the outer periphery of the first and second uneven portions) and the outer periphery of each manifold. Yes. In FIG. 3D, only the seal line SL connecting the separator 25 and the abutting portion of the seal portion 50 is shown for easy viewing of the drawing.

  With reference to FIGS. 5-7, the structure of the various flow paths formed in the separator 25 is demonstrated. FIGS. 5A and 5B are a plan view and a cross-sectional view showing a state where the separator and the seal-integrated MEA according to the embodiment are stacked. FIG. 6 is a cross-sectional view showing a BB cross section, a CC cross section, a DD cross section, and an EE cross section in FIG. 7 is a cross-sectional view showing the FF cross section and the GG cross section in FIG. 5. Moreover, FIG. 2 has shown the AA cross section in FIG.

  The separator 25 is formed with various manifolds penetrating in the thickness direction as indicated by hatching in FIG. That is, the fuel gas supply manifold forming portion 221a, the fuel gas supply manifold forming portion 231a, and the fuel gas supply manifold forming portion 241a formed on the cathode facing plate 22, the anode facing plate 23, and the intermediate plate 24, respectively, A gas supply manifold is formed. Similarly, a fuel gas discharge manifold, an oxidizing gas supply manifold, an oxidizing gas discharge manifold, a cooling medium supply manifold, and a cooling medium discharge manifold are formed in the separator 25, respectively.

  As shown in FIG. 2, the separator 25 includes a first uneven portion of the cathode facing plate 22 and a second uneven portion of the anode facing plate 23 in the power generation portion DA shown in FIG. The cooling medium flow path forming portion 229b (the convex portion in the first uneven shape portion) of the cathode facing plate 22 and the cooling medium flow path forming portion 239b (the convex shape in the second uneven shape portion) of the anode facing plate 23 are in contact with each other. Part) forms a cooling medium flow path 73. Further, when the fuel cell is configured, the oxidizing gas flow path is formed between the diffusion layer 212 on the cathode side of the MEA and the oxidizing gas flow path forming part 229a (the recessed part in the first uneven shape part) of the cathode facing plate 22 described above. 72 is formed. Similarly, a fuel gas flow path 71 is formed between the diffusion layer 212 on the anode side of the MEA and the fuel gas flow path forming portion 239a (the concave portion in the second concave-convex shape portion) of the anode facing plate 23 described above. .

  As shown in FIGS. 5 and 6A, the separator 25 includes an oxidizing gas supply flow path forming portion 245 formed in the intermediate plate 24, and a contact surface 23a of the anode facing plate 23 with the intermediate plate 24. The oxidizing gas supply channel 63 is formed by the contact surface 22a of the cathode facing plate 22 with the intermediate plate 24. One end of the oxidizing gas supply channel 63 communicates with the oxidizing gas supply manifold. The oxidizing gas supply hole 225 communicates the oxidizing gas supply channel 63 with the above-described oxidizing gas channel 72.

  As shown in FIGS. 5 and 6B, the separator 25 includes an oxidizing gas discharge flow path forming portion 246 formed in the intermediate plate 24, and a contact surface 23 a of the anode facing plate 23 with the intermediate plate 24. The oxidizing gas discharge flow path 64 is formed by the contact surface 22a of the cathode facing plate 22 with the intermediate plate 24. One end of the oxidizing gas discharge channel 64 communicates with the oxidizing gas discharge manifold. The oxidizing gas discharge hole 226 communicates the oxidizing gas discharge channel 64 with the above-described oxidizing gas channel 72.

  Further, as shown in FIGS. 5 and 6C and 6D, the separator 25 has the same structure as that of the oxidizing gas system described above, and the fuel gas supply channel 61 and the fuel gas are also used for the fuel gas system. A discharge channel 62 is formed. As with the oxidizing gas system, the fuel gas supply channel 61 has one end communicating with the fuel gas supply manifold and the other end communicating with the fuel gas channel 71 via the fuel gas supply hole 237. The fuel gas discharge passage 62 has one end communicating with the fuel gas discharge manifold and the other end communicating with the fuel gas passage 71 via the fuel gas discharge hole 238.

  As shown in FIGS. 5 and 7B, the separator 25 includes a cooling medium supply flow path forming portion 244a formed in the intermediate plate 24, and a contact surface 23a of the anode facing plate 23 with the intermediate plate 24. The cooling medium supply channel 66 is formed by the contact surface 22 a of the cathode facing plate 22 with the intermediate plate 24. One end of the cooling medium supply flow channel 66 communicates with the cooling medium supply manifold, and the other end communicates with the cooling medium flow channel 73 formed by the first and second irregularities described above.

  Further, as shown in FIG. 5 and FIG. 7B, a cooling medium discharge channel 67 is formed in the separator 25 with the same configuration as the cooling medium supply channel 66 described above. One end of the cooling medium discharge channel 67 communicates with the cooling medium discharge manifold, and the other end communicates with the cooling medium channel 73 described above.

  Here, as shown in FIG. 5A, the fuel gas supply channel 61, the fuel gas discharge channel 62, the oxidizing gas supply channel 63, the oxidizing gas discharge channel 64, and the cooling medium supply channel 66 in the separator 25. Each of the cooling medium discharge channels 67 is formed so as to tunnel a seal portion (hereinafter referred to as an outer periphery seal portion) on the outer periphery of the uneven portion from the inside of the separator 25. That is, various manifolds communicating with one end of these flow paths are located outside the outer peripheral seal portion. Each supply hole (oxidation gas supply hole 225, fuel gas supply hole 237), each discharge hole (oxidation gas discharge hole 226, fuel gas discharge hole 238), and cooling medium flow path communicating with the other end of these flow paths are provided. 73 is located inside the outer peripheral seal portion.

  FIG. 5B shows a cut surface (sl1-sl1 cross section in FIG. 5A) of the separator 25 and the seal-integrated MEA 21 on the outer peripheral seal portion. As shown in FIG. 5A, a plurality of fuel gas supply channels 61, oxidizing gas supply channels 63, and cooling medium channels 65 are arranged side by side in the seal line direction. Accordingly, as shown in FIG. 5B, the cross section on the outer peripheral seal portion is a portion (space portion) where the fuel gas supply channel 61, the oxidizing gas supply channel 63, and the cooling medium channel 65 are formed. And dense portions S are alternately arranged. As a result, the dense portion S becomes a support, and the deformation of the cathode facing plate 22 and the anode facing plate 23 due to the sealing pressure is suppressed. In addition, the sl2-sl2 cross section in Fig.5 (a) is also the same structure. About this, the code | symbol is attached | subjected in parentheses in FIG.5 (b), and detailed description is abbreviate | omitted.

・ Fuel cell operation:
Similarly, with reference to FIGS. 5 to 7, the operation of the fuel cell configured using the separator according to the embodiment will be briefly described.

  The oxidant gas supplied to the fuel cell 10 passes through the oxidant gas supply manifold, the oxidant gas supply channel 63, the oxidant gas supply hole 225, and the oxidant gas channel 72 as shown by arrows in FIG. It is supplied to the diffusion layer 212 on the cathode side. The oxidizing gas supplied to the oxidizing gas channel 72 is distributed over the entire power generation unit DA and is subjected to an electrochemical reaction at the cathode electrode. Thereafter, the oxidizing gas is discharged to the outside through the oxidizing gas flow path 72 -the oxidizing gas discharge hole 226 -the oxidizing gas discharge flow path 64 -the oxidizing gas discharge manifold, as indicated by an arrow in FIG. 6B.

  Similarly, the fuel gas supplied to the fuel cell 10 is, as indicated by arrows in FIG. 6C, a fuel gas supply manifold-fuel gas supply channel 61-fuel gas supply hole 237-fuel gas channel 71. And supplied to the diffusion layer 212 on the anode side. The fuel gas supplied to the diffusion layer 212 diffuses throughout the power generation unit DA (not shown) and is subjected to an electrochemical reaction at the anode electrode. Thereafter, as shown by an arrow in FIG. 6D, the fuel gas is discharged to the outside through the fuel gas passage 71-fuel gas discharge hole 238-fuel gas discharge passage 62-fuel gas discharge manifold.

  The cooling medium supplied to the fuel cell 10 is, as indicated by arrows in FIG. 7B, a cooling medium supply manifold-cooling medium supply channel 66-cooling medium channel 73-cooling medium discharge channel 67-cooling medium. It is discharged outside through the discharge manifold. The cooling medium absorbs heat energy of the fuel cell 10 while cooling mainly in the cooling medium flow path 73 to cool the fuel cell 10.

  As the fuel gas, for example, high-purity hydrogen gas can be used, and as the oxidizing gas, for example, air can be used. As the cooling medium, water, antifreeze water such as ethylene glycol, air, or the like can be used.

  In the separator 25 according to the embodiment configured as described above, the fuel gas flow channel 71, the oxidizing gas flow channel 72, and the cooling medium flow channel 73 are formed by an uneven shape formed by plastic working (press work). Yes. Further, the other fuel gas supply flow path 61, fuel gas discharge flow path 62, oxidizing gas supply flow path 63, oxidizing gas discharge flow path 64, cooling medium supply flow path 66, and cooling medium discharge flow path 67 are easy. Therefore, it is possible to perform processing using only a highly productive processing method (punching). Further, all of the intermediate plate 24 can be processed using only an easy and highly productive processing method (punching). And the separator 25 can be easily produced only by joining three plates. Therefore, the productivity of the fuel cell 10 can be improved.

  Further, the fuel gas passage 71, the oxidizing gas passage 72, and the cooling medium passage 73 are alternately formed by the uneven shape of the cathode facing plate 22 and the anode facing plate 23, so that the thickness of the separator 25 is reduced. However, supply and discharge of the reaction gas and the cooling medium can be realized. As a result, a fuel cell with a high current density can be configured.

  In addition, the reaction gas (the reaction gas (60) is formed by the fuel gas supply channel 61, the fuel gas discharge channel 62, the oxidizing gas supply channel 63, and the oxidizing gas discharge channel 64 that tunnel the seal portion on the outer periphery of the uneven portion from the inside of the separator 25. (Oxidizing gas and fuel gas) are supplied and discharged, so that the contact portion with the seal portion is flat and the sealing property between the separator and the separator is excellent.

  Further, as described with reference to FIG. 5B, the fuel gas supply channel 61, the fuel gas are arranged so that the space portions and the dense portions are alternately arranged in the cross section on the outer peripheral seal portion of the power generation unit. A plurality of discharge flow paths 62, oxidizing gas supply flow paths 63, oxidizing gas discharge flow paths 64, cooling medium supply flow paths 66, and cooling medium discharge flow paths 67 are arranged side by side in the sealing direction. As a result, similarly to the first embodiment, the deformation of the cathode facing plate 22 and the anode facing plate 23 due to the sealing pressure is suppressed.

  In addition, the conventional so-called press separator requires four or more parts in order to realize the functions of the separator 25 according to the embodiment (reaction gas supply and discharge, cooling medium supply and discharge) ( For example, the separator 25 is an anode side separator, a cathode side separator, a sealing part between two separators, a part for supplying and discharging reaction gas, and the separator 25 is only three parts as in the first embodiment. The number of parts is reduced.

  Furthermore, since the fuel cell 10 according to this embodiment uses the seal-integrated MEA 21 in which the MEA and the seal portion 50 are integrated, the module 20 is a simple configuration in which the separator 25 and the seal-integrated MEA 21 are alternately stacked. Structure. Therefore, the productivity of the fuel cell is improved.

B. Variations:
In the above embodiment, the metal thin plates constituting the cathode facing plate 22 and the anode facing plate 23 may use other materials. For example, a material having high corrosion resistance such as titanium or a titanium alloy may be used. Further, after press molding, corrosion-resistant plating may be applied (Pt plating, Pd plating, etc.).

  In the above embodiment, the three plates are joined by hot pressing, but other joining methods such as diffusion joining, brazing, welding, etc. can be used.

  As mentioned above, although the Example and modification of this invention were demonstrated, this invention is not limited to these Example and modification at all, and implementation in a various aspect is possible within the range which does not deviate from the summary. It is.

Explanatory drawing which shows the external appearance structure of the fuel cell comprised using the separator which concerns on an Example. Explanatory drawing which shows schematic structure of the module which comprises the fuel cell in an Example. The top view of the cathode opposing plate and anode opposing plate which comprise the separator which concerns on an Example. The intermediate plate which comprises the separator which concerns on an Example, and the top view of seal | sticker integrated MEA. The top view and sectional drawing which show a mode that the separator which concerns on an Example, and seal integrated MEA were piled up. FIG. 6 is a first cross-sectional view showing various cross sections in FIG. 5. FIG. 6 is a second cross-sectional view showing various cross sections in FIG. 5.

Explanation of symbols

10 ... Fuel cell 20 ... Module 21 ... MEA with integrated seal
211 ... Electrolyte membrane 212 ... Diffusion layer 22 ... Cathode facing plate 221a ... Fuel gas supply manifold formation part 221b ... Fuel gas discharge manifold formation part 222a ... Oxidation gas supply manifold formation part 222b ... oxidizing gas discharge manifold forming part 223a ... cooling medium supply manifold forming part 223b ... cooling medium discharge manifold forming part 225 ... oxidizing gas supply hole 226 ... oxidizing gas discharge hole 229a ... oxidation Gas channel forming part 229b ... Cooling medium channel forming part 23 ... Anode facing plate 231a ... Fuel gas supply manifold forming part 231b ... Fuel gas discharge manifold forming part 232a ... Oxidizing gas supply manifold Forming part 232b ... Oxidizing gas discharge manifold forming part 233a ... Cooling medium supply manifold forming part 233b ... Cooling medium discharge manifold Forming part 237 ... Fuel gas supply hole 238 ... Fuel gas discharge hole 239a ... Fuel gas flow path forming part 239b ... Cooling medium flow path forming part 24 ... Intermediate plate 241a ... Fuel Gas supply manifold formation part 241b ... Fuel gas discharge manifold formation part 242a ... Oxidation gas supply manifold formation part 242b ... Oxidation gas discharge manifold formation part 244a ... Cooling medium supply flow path formation part 244b ... Cooling medium discharge flow path forming section 245 ... Oxidizing gas supply flow path forming section 246 ... Oxidizing gas discharge flow path forming section 247 ... Fuel gas supply flow path forming section 248 ... Fuel gas discharge flow path forming Section 249 ... Power generation section through section 25 ... Separator 30 ... End plate 31 ... Tension plate 32 ... Bolt 33 ... Insulator 34 ... Terminal 50 ... Seal section 501a .. .Oxidizing gas supply manifold formation 501b ... oxidizing gas discharge manifold forming portion 502a ... fuel gas supply manifold forming portion 502b ... fuel gas discharge manifold forming portion 503a ... cooling medium supply manifold forming portion 503b ... cooling medium discharge manifold forming portion 61 ... Fuel gas supply flow path 62 ... Fuel gas discharge flow path 63 ... Oxidation gas supply flow path 64 ... Oxidation gas discharge flow path 66 ... Cooling medium supply flow path 67 ... Cooling Medium discharge channel 71 ... Fuel gas channel 72 ... Oxidation gas channel 73 ... Cooling medium channel DA ... Power generation unit

Claims (6)

A fuel cell separator comprising: a cathode facing plate having a surface facing the cathode electrode; an anode facing plate having a surface facing the anode electrode; and an intermediate plate sandwiched between the cathode facing plate and the anode facing plate. There,
An oxidizing gas supply manifold, an oxidizing gas discharge manifold, a fuel gas supply manifold, and a fuel gas discharge manifold that penetrate the cathode facing plate, the anode facing plate, and the intermediate plate in the thickness direction;
The intermediate plate is
An oxidant gas supply channel forming part that penetrates in the thickness direction and forms an oxidant gas supply channel that communicates with the oxidant gas supply manifold;
An oxidant gas discharge channel forming part that penetrates in the thickness direction and forms an oxidant gas discharge channel that communicates with the oxidant gas discharge manifold;
A fuel gas supply flow path forming portion that penetrates in the thickness direction and forms a fuel gas supply flow path communicating with the fuel gas supply manifold;
A fuel gas discharge passage forming portion that penetrates in the thickness direction and forms a fuel gas discharge passage communicating with the fuel gas discharge manifold;
With
The cathode facing plate is
A first concavo-convex shape portion having a concavo-convex shape which is formed by plastic working and forms an oxidizing gas flow path between the cathode electrode,
An oxidant gas supply hole penetrating in the thickness direction and communicating the oxidant gas supply channel and the oxidant gas channel;
An oxidant gas discharge hole penetrating in the thickness direction and communicating the oxidant gas discharge channel and the oxidant gas channel;
With
The anode facing plate is
A second concavo-convex shape portion formed by plastic working and having a concavo-convex shape that forms a fuel gas flow path between the anode and the anode,
A fuel gas supply hole penetrating in the thickness direction and communicating the fuel gas supply channel and the fuel gas channel;
An oxidizing gas discharge hole penetrating in the thickness direction and communicating the fuel gas discharge channel and the fuel gas channel;
A separator comprising: The separator according to claim 1,
The intermediate plate is
In a plan view, it has an annular shape that surrounds the outer periphery of the first uneven shape portion and the second uneven shape portion,
The oxidizing gas flow path is formed by a recess of the first uneven shape portion,
The fuel gas flow path is formed by a recessed portion of the second uneven shape portion,
The anode facing plate and the surface on the intermediate plate side of the anode facing plate are separators that come into contact with each other in the recesses in the first uneven shape portion and the second uneven shape portion. The separator according to claim 2,
A cooling medium flow path is formed between the cathode plate and the anode plate by the convex portion of the first concave-convex shape portion and the convex portion of the second concave-convex shape portion,
The separator further includes
A cooling medium supply manifold that penetrates the cathode facing plate, the anode facing plate, and the intermediate plate in a thickness direction; a cooling medium discharge manifold;
With
The intermediate plate further includes
A cooling medium supply flow path forming section that penetrates in the thickness direction and forms a cooling medium supply flow path that communicates the cooling medium supply manifold and the cooling medium flow path;
A cooling medium discharge flow path forming unit that penetrates in the thickness direction and forms a cooling medium discharge flow path that communicates the cooling medium discharge manifold and the cooling medium flow path;
A separator comprising: The separator according to any one of claims 1 to 3,
The outer peripheral portions of the first concavo-convex shape portion and the second concavo-convex shape portion are outer peripheral seal portions with which a sealing material that seals between the separator and an adjacent component contacts when the fuel cell is formed. ,
Each manifold is located outside the outer peripheral seal portion,
Each supply hole and each discharge hole is a separator located inside the said power generation part outer periphery seal part. The separator according to claim 4,
Each supply flow path forming section and each discharge flow path forming section are
The separator arrange | positioned along with the sealing direction of the said outer periphery seal part along with two or more. A cathode facing plate having a surface facing the cathode electrode, an anode facing plate having a surface facing the anode electrode, an intermediate plate sandwiched between the cathode facing plate and the anode facing plate,
An oxidizing gas supply manifold, an oxidizing gas discharge manifold, a fuel gas supply manifold, and a fuel gas discharge manifold that penetrate the cathode facing plate, the anode facing plate, and the intermediate plate in the thickness direction;
The intermediate plate is
An oxidant gas supply channel forming part that penetrates in the thickness direction and forms an oxidant gas supply channel that communicates with the oxidant gas supply manifold;
An oxidant gas discharge channel forming part that penetrates in the thickness direction and forms an oxidant gas discharge channel that communicates with the oxidant gas discharge manifold;
A fuel gas supply flow path forming portion that penetrates in the thickness direction and forms a fuel gas supply flow path communicating with the fuel gas supply manifold;
A fuel gas discharge passage forming portion that penetrates in the thickness direction and forms a fuel gas discharge passage communicating with the fuel gas discharge manifold;
With
The cathode facing plate is
A first concavo-convex shape portion having a concavo-convex shape forming an oxidizing gas flow path with the cathode electrode;
An oxidant gas supply hole penetrating in the thickness direction and communicating the oxidant gas supply channel and the oxidant gas channel;
An oxidant gas discharge hole penetrating in the thickness direction and communicating the oxidant gas discharge channel and the oxidant gas channel;
With
The anode facing plate is
A second concavo-convex shape portion having a concavo-convex shape forming a fuel gas flow path between the anode electrode and the anode electrode;
A fuel gas supply hole penetrating in the thickness direction and communicating the fuel gas supply channel and the fuel gas channel;
An oxidant gas discharge hole penetrating in the thickness direction and communicating the fuel gas discharge channel and the fuel gas channel;
A method for producing a separator for a fuel cell comprising:
The method for producing a separator, wherein the first uneven shape portion in the cathode facing plate and the second uneven shape portion in the anode facing plate are formed by plastic working.

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