JP6268362B2 - Manufacturing method of fuel cell member - Google Patents

Description

  The present invention relates to a method for producing a member for a fuel cell used for a solid polymer electrolyte fuel cell or the like.

  A solid polymer electrolyte fuel cell is configured by stacking one or more layers of cells each including a membrane electrode assembly (MEA) and a separator to form a module.

  The MEA includes an electrolyte membrane made of an ion exchange membrane, an anode electrode made of a catalyst layer arranged on one surface of the electrolyte membrane, and a cathode electrode made of a catalyst layer arranged on the other surface of the electrolyte membrane.

  A diffusion layer is usually provided between the MEA and the separator. This diffusion layer is for improving the diffusion of the reaction gas to the catalyst layer, and constitutes the electrode in cooperation with the catalyst layer, so it may be considered as a part of the electrode.

  The separator is formed with a fuel gas flow path for supplying fuel gas (hydrogen) to the anode and an oxidation gas flow path for supplying oxidizing gas (oxygen, usually air) to the cathode, and electrons between adjacent cells. This constitutes the passage.

  Current collector plates and end plates are arranged at both ends of the cell stack in the cell stacking direction, the cell stack is clamped in the cell stacking direction, and fixed with fastening members and bolts extending in the cell stacking direction outside the cell stack. A stack is formed.

  On the anode side of the solid polymer electrolyte fuel cell, a reaction for converting hydrogen into hydrogen ions and electrons is performed, and the hydrogen ions move through the electrolyte membrane to the cathode side. On the other hand, on the cathode side, oxygen, hydrogen ions, and electrons (electrons generated at the anode of the adjacent MEA and passing through the separator, or generated at the anode of the cell at one end of the cell stack and cell stacking through the external circuit) The reaction of generating water from the electrons coming into the cathode of the cell at the other end of the body is performed.

Anode side: H ₂ → 2H ⁺ + 2e ⁻
Cathode side: 2H ⁺ + 2e ⁻ + (1/2) O ₂ → H ₂ O
In order to perform the above reaction, fuel gas and oxidizing gas are supplied to and discharged from the stack. At this time, Joule heat is generated in the separator, and heat is generated in the cathode by the water generation reaction. Therefore, a flow path through which a cooling medium (usually cooling water) flows between the cells for each cell or for each of a plurality of cells. The fuel cell is cooled by circulating a cooling medium in the flow path.

  In order to prevent leakage and mixing of fuel gas, oxidant gas, and cooling medium from the respective flow paths in the stack, a gasket is provided between fuel cell components (separator, electrolyte membrane, etc.). The elements are sealed. As this gasket, there are a gasket between the separators when the MEA is sandwiched and a gasket between the separators when the cooling water flow path is mainly formed.

The gasket between the modules seals the cooling medium (usually cooling water) and adheres the positive and negative electrodes as electrodes. In manufacturing the gasket, a known O-ring or rim molded product is arranged. It can be used (Patent Document 1 or Patent Document 2).

Japanese Patent Application Laid-Open No. 2010-244689 JP 2010-244690 A

  A polymer electrolyte membrane, a membrane-electrode assembly having a pair of electrodes sandwiching the polymer electrolyte membrane between each other, and a pair of sandwiching the membrane-electrode assembly between each other in contact with the electrodes The cell stack, which is a laminate composed of a plurality of single cells with a plate-like separator, has a tight design tolerance due to expansion and contraction due to heating, and is still improved from the viewpoint of long-term durability of the cell stack There was room for.

  Patent Document 1 discloses a lamination diagram of a manufacturing method in which an electrode member and a separator are integrally molded, and an uncrosslinked solid rubber is disposed on both the electrode member and the separator to be bonded, and is integrated in the laminating direction. It is configured to let you.

  The uncrosslinked solid rubber is a frame-like gasket member having adhesiveness, and is molded in advance at both the bonding points, and the electrode member and separator of the power generation unit are put into the mold and the mold is clamped. At the same time, pressurization and heating are performed to crosslink the uncrosslinked product of the solid rubber, seal the peripheral edge of the electrode member, and integrate the electrode member and the separator.

  In order to integrally mold a module, which is a single power generation electrode, together with an electrode portion and a separator, it is necessary to laminate rubber used as a gasket in a state of an uncrosslinked solid rubber in advance and to crosslink the rubber when integrally molded. .

  This cross-linking reaction requires heating and pressurization with a substrate having heat conduction using a mold. In particular, the electrolyte membrane, which is a constituent material of the power generation unit, has a large shrinkage rate, and there is a risk that the dimensional stability in the integration process is significantly deteriorated.

  Further, in the construction method disclosed in Patent Document 2 in which a plurality of cell stacks are pressurized and heated over the entire laminate to crosslink the entire gasket line, the design tolerances of individual modules become extremely strict. The production efficiency may be deteriorated due to the time required for adjusting the pressure. In addition, it is necessary to use a gasket material that can be crosslinked at a relatively low temperature without affecting the electrode part.

  In the gasket seal line in which the gaskets are linearly arranged, particularly in the gasket seal line on the surface of the cooling medium between the modules, resistance to hot water is required to cool the entire heated cell stack.

  In this environment, water resistance that does not cause volume expansion due to water absorption is required, oxygen radicals are relatively large, and radical resistance is required. However, the low-temperature crosslinked gasket material has a relatively low crosslinking density and low radical resistance. For this reason, at the time of long-term power generation, there is a possibility that cooling water leaks due to deterioration of the gasket seal line.

  According to the present invention, in a fuel cell member in which a flow path of a cooling medium for cooling an electrode portion is formed between two separators, a seal member can be easily and accurately arranged between the two separators, and the reliability of the seal is improved. For the purpose.

The method for producing a member for a fuel cell according to the present invention provides a fuel cell comprising a power generation unit in which an electrolyte membrane is sandwiched between catalyst layers of an anode and a cathode, and a non-power generation unit disposed for cooling the electrode unit of the power generation unit. In the fuel cell member to be used, the non-power generation unit includes a first separator and a second separator, and the first separator and the second separator are stacked in close contact with each other. A method for producing a member, wherein an unvulcanized seal is formed at a predetermined position on a surface constituting a cooling medium flow path in which a cooling medium for cooling the electrode portion flows between the first separator and the second separator. A seal portion forming step for forming a portion, a placing step for placing the second separator on the seal forming surface of the first separator, and pressurization in the stacking direction of the first separator and the second separator And it has heated by crosslinking the unvulcanized sealing portion, and the sealing crosslinking step.

  According to the present invention, since the unvulcanized rubber is directly formed on the first separator, the mold can be molded at a lower cost than sealing all surfaces of the separator requiring a gasket. Can be processed. In addition, since the first separator can be directly seal-molded without using a release agent, there is no deterioration in battery performance due to contamination, and there is no vulcanization by sandwiching the electrode member. It is easy to make it possible to impart high durability.

  Therefore, in the fuel cell member in which the flow path of the cooling medium for cooling the electrode portion is configured between the two separators, the seal member can be easily and accurately arranged between the two separators, and the reliability of the seal can be improved. it can.

1 is a perspective view of a polymer electrolyte fuel cell according to Embodiment 1 of the present invention. The fragmentary sectional view which shows a part of cross section of the polymer electrolyte fuel cell of FIG. Schematic sectional view showing a gasket direct molding process to the separator in Embodiment 1 of the present invention Schematic sectional view showing a molding process to a gasket transfer mold in the first embodiment of the present invention Schematic sectional view showing a part of the gasket-integrated lamination vulcanization molding process on the cooling medium surface in Embodiment 1 of the present invention FIG. 5 is a schematic cross-sectional view showing an integrally molded product of a cooling medium surface gasket formed through the process of FIG. Schematic sectional view showing a gasket direct molding process to the separator in Embodiment 2 of the present invention Schematic sectional view showing a molding process to a gasket transfer mold in Embodiment 2 of the present invention FIG. 8 is a schematic cross-sectional view showing a laminated state of the molded cooling medium surface gasket integrated product and the power generation unit through the process of FIG. The fragmentary sectional view which shows a part of separator integral gasket molding in this invention The fragmentary sectional view which shows a part of separator integrated gasket molding of another form in this invention The fragmentary sectional view which shows a part of separator integrated gasket molding of another form in this invention Schematic diagram of the gasket line of the separator integrated gasket molding of the present invention Schematic view of another form of gasket line of separator-integrated gasket molding of the present invention

  The inventor of the present application, in a method for manufacturing a gasket seal line for a non-power generation part that does not heat and pressurize the power generation part, includes a seal part forming step for forming an unvulcanized seal part, a second separator, and a seal for the first separator. A placing step for placing on the forming surface, and a crosslinking step for pressurizing and heating in the laminating direction of the first separator and the second separator to crosslink and seal the unvulcanized seal portion. In this case, the inventors have found that the position of the sealing member can be formed accurately and simply, and is firmly sealed by the gasket sandwiched between the separators, so that a highly reliable fuel cell member can be obtained. The present invention has been made based on this finding.

A method for manufacturing a member for a fuel cell according to a first aspect of the present invention includes an electrolyte membrane including a first separator and a second separator, wherein the first separator and the second separator are closely stacked. A method for producing a fuel cell member used in a fuel cell, comprising: a power generation unit sandwiched between a catalyst layer of an anode and a cathode; and a non-power generation unit arranged for cooling an electrode unit of the power generation unit, A seal part forming step of forming an unvulcanized seal part at a predetermined position of a surface constituting a cooling medium flow path in which a cooling medium for cooling the electrode part flows between the second separator and the second separator ; Placing the second separator on the seal forming surface of the first separator, pressurizing in the stacking direction of the first separator and the second separator, and heating to apply the unapplied Sulfur seal part By crosslinking and has a crosslinking step of sealing.

  According to the fuel cell member manufacturing method of the first aspect of the present invention, since the unvulcanized rubber is directly formed on the first separator, the mold is formed by sealing all the surfaces of the separator that require gaskets. Can be molded at low cost, and the process can be saved. In addition, since the first separator can be directly seal-molded without using a release agent, there is no deterioration in battery performance due to contamination, and there is no vulcanization by sandwiching the electrode member. It is easy to make it possible to impart high durability.

  Further, a cell stack using a member that is easily thermally deformed, such as an electrolyte membrane used in the power generation unit, can be sealed without applying heat by using the fuel cell member obtained in the above step. Further, since the positional accuracy of the seal in the integration is determined by the mold size, if the accuracy of the mold is increased, the seal molding can be performed relatively easily and with high accuracy.

  Therefore, in the fuel cell member in which the flow path of the cooling medium for cooling the electrode portion is configured between the two separators, the seal member can be easily and accurately arranged between the two separators, and the reliability of the seal can be improved. it can.

  According to a second aspect of the present invention, there is provided a method of manufacturing a member for a fuel cell, wherein a cooling medium flow path through which a cooling medium that cools an electrode portion of a power generation unit formed by sandwiching an electrolyte membrane between an anode and a cathode catalyst layer flows and A method for manufacturing a member for a fuel cell configured between the second separator and a predetermined position on a surface of the first separator that forms the cooling medium flow path between the second separator and the second separator. The cooling medium flow path between a seal portion forming step for forming an unvulcanized seal portion and the second separator in the first separator in which the unvulcanized seal portion is formed in the seal portion forming step. A mounting step of overlapping the surface constituting the cooling medium flow path with the first separator of the second separator on the surface constituting the first separator, and the first separator overlaid in the previous placing step And before A cross-linking step of pressurizing the second separator in the stacking direction so that the unvulcanized seal portion is in close contact with the second separator, and heating to cross-link the unvulcanized seal portion. is there.

According to the fuel cell member manufacturing method of the second aspect of the invention, since the unvulcanized rubber is directly formed on the first separator, the mold is formed by sealing all surfaces of the separator requiring a gasket. Can be molded at low cost, and the process can be saved. In addition, since the first separator can be directly seal-molded without using a release agent, there is no deterioration in battery performance due to contamination, and there is no vulcanization by sandwiching the electrode member. It is easy to make it possible to impart high durability.

  Further, high durability can be ensured by using a gasket that is crosslinked at a relatively high temperature without using a member that is easily deformed by heat.

  Further, since the positional accuracy of the seal in the close integration of the first separator and the second separator is determined by the mold size, if the accuracy of the mold is increased, the seal molding is relatively easily performed with high accuracy. be able to.

  Therefore, in the fuel cell member in which the flow path of the cooling medium for cooling the electrode portion is configured between the two separators, the seal member can be easily and accurately arranged between the two separators, and the reliability of the seal can be improved. it can.

  In the method for producing a member for a fuel cell according to a third aspect of the invention, in the second aspect of the invention, the seal part forming step for forming the unvulcanized seal part on the surface of the first separator is performed by extrusion molding. .

  In the fuel cell member manufacturing method according to a fourth aspect of the present invention, in the first aspect, the second separator has a seal groove corresponding to the shape of the unvulcanized seal portion. The second separator is placed on the coolant flow path surface of the first separator so that the unvulcanized seal portion is accommodated in the seal groove.

  According to this, since the second separator has a seal groove, the first separator is placed, pressurized in the stacking direction of the first separator and the second separator, and heated. It is possible to effectively disperse the expansion force of the gasket when the unvulcanized seal part is cross-linked, and at the same time improve the durability of the seal by increasing the adhesion between the separator and the gasket. Can do.

  According to a fifth aspect of the present invention, there is provided a method for manufacturing a member for a fuel cell according to the fourth aspect, wherein the second separator has an adjacent groove provided adjacent to the seal groove and connected to the seal groove. Is.

  According to this, by having the adjacent groove provided adjacent to the seal groove in the second separator, the first separator is placed, and the first separator and the second separator are stacked. When the unvulcanized seal portion is cross-linked by pressurizing and heating in the direction, the surplus portion of the gasket can be released to the adjacent groove, and the separator can be prevented from being damaged due to the volume expansion of the gasket.

According to a sixth aspect of the present invention, there is provided a method for producing a fuel cell member, wherein the unvulcanized seal portion in any one of the first to fifth aspects includes unvulcanized fluororubber.

According to this, in any one of the first to fifth inventions, the radical resistance and acid resistance of the gasket of the non-power generation part can be further strengthened, and a highly reliable stack can be achieved.

According to a seventh aspect of the present invention, there is provided a method for manufacturing a fuel cell member, comprising: the other surface of the first separator having a gas channel formed on one surface; and the second separator having a gas channel formed on one surface. A cooling medium flow path between the first separator and the second separator so as to surround a portion where the cooling medium flow path is formed. A method for manufacturing a fuel cell member in which the first separator and the second separator are closely integrated with each other, wherein the cooling medium flow path is provided between the first separator and the second separator. A gasket is transferred to a predetermined position on the surface of the first separator and the second separator on which the gas flow path is formed, and a seal portion forming step for forming an unvulcanized seal member at a predetermined position on the surface to be configured It ’s to do A gasket portion forming step of forming an unvulcanized gasket member at a predetermined position of the mold, and the second separator in the first separator in which the unvulcanized seal portion is formed in the seal portion forming step. The surface constituting the cooling medium flow path is overlapped with the first separator of the second separator on the surface constituting the cooling medium flow path between the first separator and the first separator. Placing the gasket member together with the mold at a predetermined position on the surface of the second separator where the gas flow path is formed.
And the first separator, the second separator, the gasket member, and the mold, which are stacked in the placing step, are pressurized and heated in the stacking direction, and the first unvulcanized seal member The separator and the second separator are closely integrated with each other, and the gasket is transferred to a predetermined position on the surface of the first separator and the second separator where the gas flow path is formed. And a pressure heating step for crosslinking the seal portion.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.

In the following description, the same or corresponding elements are denoted by the same reference symbols throughout all the drawings, and redundant description thereof is omitted.
(Embodiment 1)
<Configuration of cell stack>
FIG. 1 is a schematic view of a cell stack 100 in which polymer electrolyte fuel cells (hereinafter referred to as “fuel cells”) are stacked for each unit cell 9. The cell stack 100 is a stacked body 2 in which unit cells 9 are stacked in series. FIG. 2 shows a partial cross-sectional view when two unit cells 9 are taken out and cut along a plane parallel to the stacking direction.

  The cell stack 100 has gas inlet / outlet pipes 5 and 6 and cooling medium inlet / outlet pipes 7 and 8 at the end in the stacking direction of the stack 2, and the stack 2 with the bolt 1 at the end of the stack 2 in the stacking direction. Is concluded. Further, an end plate 3 is disposed at the upper and lower outermost ends (in the stacking direction of the stacked body 2) of the cell stack 100, and a current collector plate 4 is disposed inside the end plate 3. At this time, the cell stack 100 is generally formed by stacking the unit cells 9 in about 2 to 200 stages according to the required output.

  As shown in FIG. 2, the oxidant gas flow path 18 in the separator 21 in which the gas flow path to be the oxidant gas flow path 18 is formed on one surface and the cooling medium flow path 20 is formed on the other surface is formed. The fuel gas flow path 19 in the separator 10 is formed so that the gas flow path that becomes the fuel gas flow path 19 is formed on one surface and the other surface is in close contact with the surface on which the cooling medium flow path 20 in the separator 21 is formed. The formed surface sandwiches an MEA (Membrene-Electrode-Assembly) having a catalyst layer (not shown) and gas diffusion layers 12 and 13 on both sides of the polymer electrolyte membrane 11, and the electrode It has a structure.

  Further, the MEA and the separator are provided by a gasket 15 disposed between the polymer electrolyte membrane 11 and the separators 10 and 21 and a seal lip 17 provided on the gasket 15 so as to surround the electrode composed of the catalyst layer and the gas diffusion layers 12 and 13. 10 and 21 are sealed.

  At this time, the polymer electrolyte membrane 11 is composed of a cation exchange resin that selectively transports hydrogen ions, and the catalyst layer is composed mainly of carbon powder supported by a metal having a catalytic function such as platinum. ing. Further, the gas diffusion layers 12 and 13 have a function of having both the breathability of the reaction gas (fuel gas and oxidant gas) and the conductivity of electrons. Hereinafter, the catalyst layer and the gas diffusion layers 12 and 13 may be collectively referred to as electrodes.

  On the other hand, as shown in FIG. 2, the separator 10 that seals the cooling medium is disposed so as to be in close contact with the surface of the separator 21 on which the cooling medium flow path 20 is formed. The gasket 15 disposed between the separator 10 and the separator 21 so as to surround the formed portion and the gasket 15 that has flowed into the adjacent groove 14 formed on the surface of the separator 10, 21 as a relief groove of the gasket 15 are sealed. .

  Due to the structure of the separator 21 in which the oxidant gas flow path 18 through which the oxidant gas flows is formed on the surface opposite to the surface on which the cooling medium flow path 20 is formed, the separator for cooling is not stacked excessively. The number of stacked layers can be reduced.

  An anode surface gasket and a cathode surface gasket (not shown) of the unit cell 9 have, for example, an annular shape, and are disposed on both surfaces of the MEA so as to surround the electrodes composed of the catalyst layer and the gas diffusion layers 12 and 13. Yes.

The gasket 15 is preferably made of a synthetic resin having appropriate mechanical strength and flexibility. As a constituent material, for example, a compound such as a rubber material, a thermoplastic elastomer, or an adhesive can be used.

  Specific examples of the gasket material of the gasket 15 include fluorine rubber, silicone rubber, natural rubber, EPDM, butyl rubber, butyl chloride rubber, butyl bromide rubber, butadiene rubber, styrene-butadiene copolymer, ethylene-vinyl acetate rubber, acrylic rubber, poly rubber. Adhesives using thermoplastic elastomers such as isopropylene polymer, perfluorocarbon, polybenzimidazole, polystyrene, polyolefin, polyester and polyamide, or latex such as isoprene rubber and butadiene rubber, liquid polybutadiene, polyisoprene, Examples of the adhesive include polychloroprene, silicone rubber, fluororubber, and acrylonitrile-butadiene rubber, but are not limited to these compounds. These compounds may be used alone or in combination of two or more. Specifically, in view of durability, it is preferable to use fluororubber. The shape of the gasket 15 is not particularly limited, but in the first embodiment, it is a substantially rectangular ring.

  The separators 10 and 21 of the unit cell 9 are disposed outside the anode surface gasket and the cathode surface gasket. The flow path formed on the inner surfaces of the separators 10 and 21 (the surface facing the electrode composed of the MEA catalyst layer and the gas diffusion layers 12 and 13) supplies a reaction gas (fuel gas or oxidant gas) to the catalyst layer. The reaction gas flow path (the oxidant gas flow path 18 on the inner surface of the separator 21 and the fuel gas flow path 19 on the inner surface of the separator 10), the flow path formed on the outer surface of the separator 21, uses a cooling medium as a unit cell 9. The cooling medium flow path 20 flows between the separators 10 and 21, and a gasket 15 is formed on the cooling medium surface in the vicinity thereof.

  At this time, the heat generated by the MEA can be used as the heat energy by recovering with the cooling water. Further, the separators 10 and 21 used in the cell stack 100 have conductivity, and adjacent MEAs are electrically connected to each other in series.

The gas flow paths (oxidant gas flow path 18 and fuel gas flow path 19) and cooling medium flow path 20 formed in the separators 10 and 21 are connected to the supply manifold hole at the upstream end and the discharge manifold at the downstream end. Connected to the hole. Further, manifold holes are provided in the peripheral edge portion of the MEA so as to correspond to the manifold holes of the separators 10 and 21. Therefore, when the cell stack 100 is assembled by stacking the unit cells 9 composed of separators and MEAs, the manifold holes of the separators and MEAs are connected to each other and communicate with each other. Thereby, a manifold (flow path) of a fluid such as a reaction gas or cooling water is formed.
<Seal formation process>
FIG. 3 is a schematic cross-sectional view showing an extrusion molding process in which a gasket member is formed at a predetermined position of the separator 10 in order to form the gasket 15 of the fuel cell.

  The gasket material of the gasket 15 is melted and supplied by a well-known method for imparting shear compression below the vulcanization temperature. In this case, the hot runner pipe 23 heated to circulate the material is heated from the outer periphery 22 of the hot runner pipe at a constant temperature. Further, in order to form a predetermined amount in the separator 10, the upper mold 24 is configured to be driven up and down between the lower mold 27 that restrains the separator 10 with a spring 25. The bead shape in the vicinity of the outlet of the gasket 15 is determined by the shape of the extrusion outlet 26.

  The extrusion outlet 26 of the molding lower mold 27 connected to the molding upper mold 24 and the spring 25 is provided with a recess 28 in a part so as not to interfere with the shape of the separator 10 to be installed, and the separator 10 is damaged. Can be prevented.

  When the gasket member is installed in the separator 10, the adjacent groove 14 is formed in advance in the separator 10, and part of the gasket 15 enters the adjacent groove 14, thereby improving the adhesion with the separator 10, and Since the volume expansion of the gasket 15 at the time of crosslinking flows into the adjacent groove 14, the separator 10 can be prevented from being damaged.

  FIG. 4 is a schematic cross-sectional view showing an extrusion molding process in which a gasket member is formed at a predetermined position of the mold 29 in order to form the gasket 15 of the fuel cell as in FIG.

  The mold 29 has a seal lip groove 30 in advance. By forming a lip shape after transfer, the fastening force of the gasket 15 can be controlled.

  As the material of the mold 29 here, a known material such as an alloyed steel material such as die steel made of molybdenum-tungsten or the like on an iron-carbon-chromium-based alloy can be used. In particular, a cemented carbide capable of preventing wear is preferably used.

  Known from the viewpoint of durability and quality assurance, such as electroless nickel plating, hard chrome plating, physical vapor deposition (PVD: Physical-Vapor-Deposition) film, and TiC film treatment by chemical vapor deposition (CVD: Chemical-Vapor-Deposition) The surface treatment can be used.

  In the present embodiment, in the seal portion forming step for forming an unvulcanized seal portion on the surface of the separator 10, a known method such as extrusion molding that forms an appropriate amount of material can be used, but from the viewpoint of mass productivity. Injection molding or similar molding methods are preferably used.

  FIG. 5 is a schematic cross-sectional view of a bridging process in which the gasket 15 molded in the process shown in FIGS. 3 and 4 together with the separator 21 facing the separator 10 is heated and pressurized in the laminating direction to cause the gasket 15 to undergo a crosslinking reaction. It is.

In the crosslinking step, it was heated to 100 ° C. to 180 ° C., and it is desirable to pressurize the 1 kPa / cm ² to 100 kPa / cm ^2. This is because the temperature range of the gasket 15 in extrusion molding is normal temperature for most materials, and the crosslinking reaction does not proceed. However, from the viewpoint of improving the tact, a necessary and sufficient crosslinking reaction is caused in a short time, and the gasket 15 is sealed. High temperature and pressure are preferred for imparting performance such as reaction force.

  In order to apply heating and pressurization in the crosslinking step, a known method such as a heating press or a pressure vessel is used. FIG. 5 shown in Embodiment 1 shows a heating press, and by pressing the upper and lower pressing plates 31, pressurization and heating can be performed simultaneously.

  In the part where the gasket 15 is installed on the separator 21, the adjacent groove 14 is provided, and in the crosslinking step, the gasket 15 enters the adjacent groove 14, thereby improving the adhesion with the separators 10 and 21, and at the time of crosslinking. By effectively escaping the volume expansion of the gasket 15, the separators 10 and 21 can be prevented from being damaged.

FIG. 6 shows a cross-sectional view of the molded product obtained in the crosslinking step of FIG.
<Effect>
The method for manufacturing a member for a fuel cell according to the present embodiment includes a separator 10 as a first separator and a separator 21 as a second separator, and the separator 10 and the separator 21 are adhered and stacked. MEA (Membrane Electrode Assembly) as a power generation unit formed by sandwiching the polymer electrolyte membrane 11 between the anode and cathode catalyst layers and the gas diffusion layers 12 and 13, and an electrode comprising the MEA catalyst layer and the gas diffusion layers 12 and 13 A method of manufacturing a member for a fuel cell used for a fuel cell including a non-power generation part disposed for cooling a part, wherein a gasket member (unvulcanized seal part) to be a gasket 15 is formed on the surface of a separator 10 Sealing portion forming step, placing the separator 21 on the seal forming surface of the separator 10, and stacking of the separator 10 and the separator 21 Pressurizing and the heating to by crosslinking a gasket member made in the gasket 15 (unvulcanized sealing portion) having a cross-linking step of sealing.

  In addition, the fuel cell member manufacturing method of the present embodiment includes a MEA (membrane electrode assembly) as a power generation unit in which the polymer electrolyte membrane 11 is sandwiched between the anode and cathode catalyst layers and the gas diffusion layers 12 and 13. ) Between the separator 10 as the first separator and the separator 21 as the second separator. The cooling medium flow path 20 through which the cooling medium that cools the electrode portion composed of the catalyst layer and the gas diffusion layers 12 and 13 is configured. A method of manufacturing a member for a fuel cell, in which a gasket member (unvulcanized seal portion) to be a gasket 15 is formed at a predetermined position on a surface constituting the cooling medium flow path 20 between the separator 10 and the separator 21. And a separator 10 formed with a gasket member (unvulcanized seal portion) that becomes the gasket 15 in the seal portion forming step. The mounting step of overlapping the surface constituting the cooling medium flow path 20 between the separator 21 and the separator 10 in the separator 21 on the surface constituting the cooling medium flow path 20 between the separator 21 and the separator 21 described above. The gasket member (unvulcanized seal portion) that becomes the gasket 15 by pressurizing the separator 10 and the separator 21 in the laminating direction is brought into close contact with the separator 21 and heated to become the gasket 15 (unvulcanized seal). Part)).

  By forming the gasket 15 directly on the separator 10 by extrusion molding, an appropriate amount of gasket material can be formed on the separator 10 and the material cost can be reduced. Moreover, since the metal mold | die 29 which carries out extrusion molding to the separator 10 becomes unnecessary, expense can be reduced. Moreover, a tact can be improved because the bridge | crosslinking process using the metal mold | die 29 of the separator 10 reduces.

  Furthermore, as a known release agent for transferring the gasket 15 from the mold 29 as a fuel cell, silicon-based, wax-based and fluorine-based release agents are used, but an excellent fluorine-based release agent is preferably used in continuous molding.

On the other hand, when these release agents are eluted into the cooling medium, they can become sources of contamination. However, the present invention in which no transfer is performed in the gasket molding process of the cooling medium surface is effective in cleaning the cooling medium generated from the cell stack, and the manufacturing process can be made more efficient. (Embodiment 2)
7 and 8 show state sectional views of a process of simultaneously crosslinking the gasket 15 molded by the mold 29 separately from the extrusion molding on both sides of the separator 10 at the same time in order to circulate the cooling medium on both the front and back sides of the separator 10. .

  FIG. 9 shows a cross-sectional view in the assembled state of the stack of fuel cells 101 formed according to the second embodiment.

In the second embodiment, the oxidant gas flow path 18 in the separator 21 in which the gas flow path that becomes the oxidant gas flow path 18 is formed on one surface and the cooling medium flow path 20 is formed on the other surface is formed. And a surface on which the fuel gas channel 19 is formed in the separator 21 in which the gas channel serving as the fuel gas channel 19 is formed on one surface and the cooling medium channel 20 is formed on the other surface. An MEA having a catalyst layer (not shown) and gas diffusion layers 12 and 13 is sandwiched between both surfaces of the molecular electrolyte membrane 11, and a separator 10 for sealing a cooling medium is connected to an oxidant gas channel 18 on one surface. In the separator 21 in which the gas flow path is formed and the cooling medium flow path 20 is formed on the other surface, the surface on which the cooling medium flow path 20 is formed and the gas flow path that becomes the fuel gas flow path 19 is formed on one surface. The cooling medium flow path 2 formed on the other surface There is sandwiched between the formed surface cooling medium passage 20 is formed in the separator 21 was.

Since the gasket 15 can be formed on both surfaces of the separator 10 by direct extrusion at the same time, the mold 29 for molding into the separator 10 is not necessary as in the first embodiment, so that the mold cost can be reduced. it can. Furthermore, tact improvement can be achieved by reducing the cross-linking step of transferring to the separator 10 with the metal mold 29. Further, by circulating the cooling medium on both the front and back surfaces of the separator 10, the heat generated by the MEA can be more effectively recovered as the heat energy by recovering with the cooling water.
<Gasket>
(Gasket shape)
10 to 12 show partial sectional views of a gasket shape, a seal lip groove and an adjacent groove of a typical gasket 15. These gasket shapes are merely examples and do not limit the present invention.

  FIG. 10 is a partial cross-sectional view of the separator 21 having the cooling medium flow path and the separator 10 obtained by extruding the gasket 15 at the time of lamination. Among these, the adjacent groove 14 is designed so that the gasket 15 can be volume-expanded in the bridging process of the separators 10 and 21, and at that time, the excess can be avoided in the adjacent groove 14 that has been processed into the separator in advance.

  In this structure, the adjacent groove 14 that allows the excess gasket 15 to escape can be three-dimensionally configured, so that the area of the separator can be reduced.

  FIG. 11 is a partial cross-sectional view of a location where the gasket 15 and the adjacent groove 14 are connected by the connecting portion 16.

  Although the separator needs to be finely processed in advance, the sealing performance can be ensured even when the gasket 15 is filled with a material and the adjacent groove 14 is not filled. Also, manufacturing tolerances can be absorbed. That is, by forming the adjacent grooves 14 around the gasket 15 at regular intervals, the dimensional tolerances of the constituent members such as the separator can be absorbed and adjusted. As a result, it is possible to avoid the separator from being damaged by the volume expansion generated in the crosslinking step.

  FIG. 12 is a partial cross-sectional view in which the separator 10 has a convex portion, the adjacent groove is formed on the separator 10 side, and the connecting portion 16 is in the same location as the adjacent groove.

  In order to provide the adjacent groove in the separator 10, it is necessary to devise such that the gasket 15 does not flow into the adjacent groove 14 during extrusion molding. However, since the both sides of the separators 10 and 21 have dents, higher adhesion is provided. Is possible. Moreover, the area of a separator can be reduced by installing it in the vicinity.

By processing the gasket shape into each other's separator in advance, it is possible to ensure stable adhesion without firmly breaking between the separators.
(Seal line shape)
FIGS. 13 and 14 are schematic views showing an example of a seal line of the gasket 15 of the separator 21 having the cooling medium flow path 20 through which the cooling medium of the unit cell 9 is circulated. These seal line shapes are representative examples and do not limit the present invention.

  Oxidant gas is supplied and discharged to the cathode and anode sides of the MEA through the manifolds 32 and 35 and the fuel gas through the manifolds 34 and 37, respectively. On the other hand, the cooling medium enters from the manifold 33 and is discharged from 36.

  FIG. 13 shows the surface of the separator 21, which forms an adjacent groove on the side of the separator 10 to be laminated, and the gasket 15 is tightly sealed between the separators 10 and 21 in the bridging process.

  FIG. 14 shows the seal line of FIG. An adjacent groove 14 is provided on the separator 10 side, and a part of the adjacent groove 14 and the gasket 15 are connected by a connecting portion 16. As a result, even when an excessive amount of material is extruded into the separator 10, the gasket 15 can be molded in a state in which the gasket 15 does not overflow outside beyond the predetermined groove. Etc. can be avoided.

  According to the method for manufacturing a fuel cell member of the present invention, in the fuel cell member in which the flow path of the cooling medium for cooling the electrode portion is configured between the two separators, the sealing member is simply and accurately positioned between the two separators. Since it can be disposed well and the reliability of the seal can be improved, it is useful for a highly reliable fuel cell such as a solid polymer electrolyte fuel cell.

DESCRIPTION OF SYMBOLS 1 Bolt 2 Laminated body 3 End plate 4 Current collecting plate 5,6 Gas inlet / outlet piping 7,8 Cooling medium inlet / outlet piping 9 Unit cell 10,21 Separator 11 Polymer electrolyte membrane 12,13 Gas diffusion layer 14 Adjacent groove 15 Gasket 16 Connection Part 17 Seal lip 18 Oxidant gas flow path 19 Fuel gas flow path 20 Cooling medium flow path 22 Hot runner piping outer periphery 23 Hot runner piping 24 Molding upper mold 25 Spring 26 Extrusion outlet 27 Molding lower mold 28 Recessed section 29 Mold 30 Seal Lip groove 31 Presser plate 32, 33, 34, 35, 36, 37 Manifold 100 Cell stack 101 Fuel cell

Claims (7)

Including a first separator and a second separator;
A power generation unit in which the first separator and the second separator are closely stacked and sandwiched between an anode and a cathode catalyst layer and an electrode unit of the power generation unit is arranged for cooling. A method for producing a fuel cell member used in a fuel cell including a power generation unit,
A seal portion forming step of forming an unvulcanized seal portion at a predetermined position on a surface constituting a cooling medium flow path in which a cooling medium for cooling the electrode portion flows between the first separator and the second separator. When,
Placing the second separator on the seal forming surface of the first separator;
A crosslinking step of pressurizing and heating in the stacking direction of the first separator and the second separator to crosslink and seal the unvulcanized seal part;
The manufacturing method of the member for fuel cells which has these. A fuel cell member comprising a cooling medium flow path between a first separator and a second separator, in which a cooling medium for cooling an electrode section of a power generation section formed by sandwiching an electrolyte membrane between an anode and a cathode catalyst layer flows A manufacturing method of
A seal part forming step of forming an unvulcanized seal part at a predetermined position on a surface constituting the cooling medium flow path between the first separator and the second separator;
The surface of the first separator in which the unvulcanized seal portion is formed in the seal portion forming step and the surface of the second separator in the second separator are disposed on the surface of the second separator. A placing step of overlapping a surface constituting the cooling medium flow path with one separator;
The first separator and the second separator stacked in the placing step are pressed in the stacking direction to bring the unvulcanized seal portion into close contact with the second separator, and heated to A crosslinking step of crosslinking the vulcanized seal part;
The manufacturing method of the member for fuel cells which has these.   The method for producing a member for a fuel cell according to claim 2, wherein the seal part forming step of forming an unvulcanized seal part on the surface of the first separator is performed by extrusion molding. The second separator has a seal groove corresponding to the shape of the unvulcanized seal part,
2. The fuel according to claim 1, wherein in the placing step, the second separator is placed on a coolant flow path surface of the first separator so that the unvulcanized seal portion is accommodated in the seal groove. A method for producing a battery member.   5. The method of manufacturing a fuel cell member according to claim 4, wherein the second separator has an adjacent groove provided adjacent to the seal groove and connected to the seal groove. 6.   The method for producing a member for a fuel cell according to any one of claims 1 to 5, wherein the unvulcanized seal portion includes unvulcanized fluororubber. A cooling medium flow path is configured between the other surface of the first separator having a gas flow path formed on one surface and the other surface of the second separator having a gas flow path formed on one surface. Then, the first separator and the second separator are brought into close contact with each other by a seal member disposed between the first separator and the second separator so as to surround the portion where the cooling medium flow path is formed. A method for producing an integrated fuel cell member comprising:
A seal part forming step of forming an unvulcanized seal member at a predetermined position on a surface constituting the cooling medium flow path between the first separator and the second separator;
A gasket for forming an unvulcanized gasket member at a predetermined position of each mold for transferring the gasket to a predetermined position on a surface of the first separator and the second separator where the gas flow path is formed. Part forming step;
The surface of the first separator in which the unvulcanized seal portion is formed in the seal portion forming step and the surface of the second separator in the second separator are disposed on the surface of the second separator. The surface constituting the cooling medium flow path is overlapped with one separator, and the gasket member is placed at a predetermined position on the surface of the first separator and the second separator where the gas flow path is formed. A placement step of overlapping with the mold;
The first separator, the second separator, the gasket member, and the mold that are stacked in the placing step are pressurized and heated in the stacking direction, and the first separator is separated by the unvulcanized seal member. causes close contact integral with said second separator, the said gasket is transferred to a predetermined position of the gas channel is formed faces of the first separator and the second separator the unvulcanized sealing portion A pressure heating step for crosslinking ;
The manufacturing method of the member for fuel cells which has these.