JP2020064814A - Manufacturing method of fuel battery cell - Google Patents

Abstract

To provide a manufacturing method of a fuel battery cell which can suppress leakage of reaction gas by reducing air bubbles remaining between an adhesive part of a frame body and an adhesive applied to a membrane electrode joint body when bonding the membrane electrode joint body to the frame body.SOLUTION: A method of manufacturing a fuel battery cell 10 by bonding an MEA 21 to a three-layer sheet 14 having a polypropylene (PP) layer includes: a groove formation step (step S1) of forming a groove 14e being the groove 14e which becomes gradually deep from an opening 14c side of the three-layer sheet 14 toward an outer peripheral end of the three-layer sheet 14 and continues to the outer side with respect to the outer peripheral end of the MEA 21 on an adhesive part 14d of the three-layer sheet 14; a lamination step (step S2) of laminating the MEA 21 on the three-layer sheet 14 with an adhesive 15 held between the MEA 21 and the adhesive part 14d of the three-layer sheet 14; and a heating press step (step S3) of heating the MEA 21 and the three-layer sheet 14 to press them in the lamination direction.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method for manufacturing a fuel cell unit in which a membrane electrode assembly frame and a membrane electrode assembly are bonded together.

  As a method for manufacturing a fuel cell of this type, a membrane electrode assembly, a pair of gas diffusion layers sandwiching the membrane electrode assembly, and a membrane electrode assembly frame (hereinafter referred to as three layers) as a support frame for supporting the membrane electrode assembly. (Also referred to as a sheet) and a three-layer sheet and a pair of separators sandwiching a gas diffusion layer, and a method for adhering the three-layer sheet and the membrane electrode assembly is disclosed. (See Patent Document 1).

JP, 2016-162651, A

  However, in the conventional method for manufacturing a fuel cell, there is a risk that air bubbles may enter during the bonding of the three-layer sheet and the membrane electrode assembly to leak the reaction gas. Specifically, as shown in FIG. 6, in the step of adhering the membrane electrode assembly 1 and the three-layer sheet 2, first, the UV adhesive 3 is applied to the membrane electrode assembly 1 by screen printing. Next, the membrane electrode assembly 1 and the three-layer sheet 2 are laminated, and after air bubbles are removed by pressurization, UV (ultraviolet rays) is irradiated toward the adhesive portion, and the UV adhesive 3 is cured. The air bubbles remaining between the three-layer sheet and the UV adhesive 3 in the laminating and pressing step remain as they are after the curing.

  As shown in FIG. 7 (a), a membrane electrode gas diffusion layer assembly (MEGA: MEGA: Membrane Electrode and Gas Diffusion Layer Assembly, hereinafter referred to as MEGA) 5 including a membrane electrode assembly 1 and a pair of gas diffusion layers 4 includes: It is adhered to the three-layer sheet 2 with the UV adhesive 3 interposed therebetween. As shown in FIG. 7B, in the laminating press, the MEGA subassembly (hereinafter referred to as S / A) in which the UV adhesive 3 is applied to the membrane electrode assembly 1 and the three-layer sheet 2 are laminated. Pressurized. Since the surface of the UV adhesive 3 applied to the membrane electrode assembly 1 has irregularities, by laminating the flat three-layer sheet 2 on the surface, the UV adhesive 3 is interposed between the UV adhesive 3 and the three-layer sheet 2. Bubbles B may be mixed.

  If the air bubbles B are mixed between the UV adhesive 3 and the three-layer sheet 2 due to the lamination, there is a possibility that all the air bubbles B will not escape during pressurization and some will remain. As shown in FIG. 7C, the bubble B between the UV adhesive 3 and the three-layer sheet 2 moves under pressure. Then, some of the bubbles B reach the end of the adhesive portion and are discharged from the end. However, the bubble B has a portion that escapes from the adhesive portion and a portion that does not escape because the outlet is blocked, and the inevitable portion remains between the UV adhesive 3 and the three-layer sheet 2. When the air bubbles B remain between the surface of the UV adhesive 3 and the three-layer sheet 2, the effective width of the seal by the UV adhesive 3 decreases, the cross leak resistance performance deteriorates when the fuel cell is used, and the reaction gas leaks. There is a problem that there is a risk of

  The present invention has been made to solve such a problem, and when the membrane electrode assembly is bonded to the three-layer sheet, the adhesive portion of the three-layer sheet and the adhesive applied to the membrane electrode assembly are provided. An object of the present invention is to provide a method for manufacturing a fuel cell, which can reduce bubbles remaining in the space and suppress leakage of reaction gas.

  A method for producing a fuel cell according to the present invention is a method for producing a fuel cell by adhering a membrane electrode assembly to a frame having a polypropylene layer, wherein the frame is opened from the opening side of the frame. A groove forming step of forming a groove that gradually deepens as it moves toward the outer peripheral end and continues to the outside of the outer peripheral end of the membrane electrode assembly in the adhesive portion of the frame; A laminating step of laminating the membrane electrode assembly on the frame body with an adhesive sandwiched between the membrane electrode assembly and the adhesive portion of the frame body, and heating the membrane electrode assembly and the frame body. And a hot pressing step of pressing in the stacking direction.

  The method for manufacturing a fuel cell according to the present invention is a groove for a membrane electrode assembly, in which the groove is gradually deepened in the bonded portion of the frame body from the opening side of the frame toward the outer peripheral end of the frame body. A groove that extends to the outside of the outer peripheral edge of the membrane electrode assembly is formed, and the membrane electrode assembly is laminated on the frame body with an adhesive sandwiched between the membrane electrode assembly and the bonding portion of the frame body. The frame body is heated and pressed in the stacking direction.

  Therefore, the air bubbles mixed between the membrane electrode assembly and the adhesive portion of the frame body when stacked are moved along the groove from the opening side of the frame body toward the outer peripheral end side of the frame body to form the membrane. It can be discharged from the outer peripheral end of the electrode assembly. When hot-pressed, the polypropylene (PP) layer is melted in the hot-pressing step, and the groove is gradually filled from the opening side of the frame toward the outer peripheral end side of the frame. Therefore, air bubbles do not remain between the membrane electrode assembly and the bonded portion of the frame, and the frame and the membrane electrode assembly are effectively bonded.

  ADVANTAGE OF THE INVENTION According to this invention, when a membrane electrode assembly and a three-layer sheet which is a frame body are adhere | attached with an adhesive agent, the bubble which remains between a membrane electrode assembly and the adhesion part of a three-layer sheet is reduced, and a reaction gas. It is possible to provide a method for manufacturing a fuel cell unit capable of suppressing the leakage of fuel.

FIG. 3 is an exploded perspective view of the fuel cell according to the embodiment of the present invention. It is a figure of a fuel cell concerning an embodiment of the present invention, Drawing 2 (a) shows a partial section view of a fuel cell, and Drawing 2 (b) is a three-layer sheet in the state where an adhesive agent was applied. 2 is a plan view and a partially enlarged enlarged plan view of FIG. FIG. 4 is a process drawing of the method for manufacturing a fuel cell according to the embodiment of the present invention. Explanatory drawing explaining the process in the manufacturing method of the fuel cell which concerns on embodiment of this invention. 5 is a table of examples and comparative examples in the method for manufacturing a fuel cell according to the embodiment of the present invention. Explanatory drawing explaining the process which adhere | attaches the three-layer sheet | seat and the membrane electrode assembly in the conventional manufacturing method of a fuel cell, and the partial enlarged view of the adhesion part in the state which the air bubble has mixed. It is a figure of the fuel cell in the manufacturing method of the conventional fuel cell, Drawing 7 (a) shows a partial sectional view of a fuel cell, and Drawing 7 (b) shows an explanatory view of lamination and pressurization. FIG. 7 (c) is an explanatory view showing the state of bubbles in the adhesive portion at the time of stacking / pressurizing.

  A method for manufacturing the fuel cell 10 according to the embodiment to which the method for manufacturing a fuel cell according to the present invention is applied will be described with reference to the drawings. First, the configuration of the fuel cell unit 10 will be described.

  As shown in FIG. 1, the fuel cell 10 includes a MEGA 11, a cathode side separator 12, an anode side separator 13, a three-layer sheet 14, a gasket (not shown), and an adhesive 15 shown in FIG. 2 (a). It is composed by.

  A plurality of fuel cells 10 are stacked to form a fuel cell stack (not shown), and a fuel cell is manufactured using the fuel cell stack.

  As shown in FIG. 2A, the MEGA 11 includes a membrane electrode assembly (MEA: Membrane Electrode Assembly, hereinafter referred to as MEA) 21 and a cathode gas diffusion layer (GDL: Gas Diffusion Layer, hereinafter referred to as GDL) 22. And has the anode side GDL 23. The MEGA 11 is configured by laminating the cathode side GDL 22 on one surface of the MEA 21 and laminating the anode side GDL 23 on the other surface of the MEA 21. The MEGA 11 is formed such that the cathode side GDL 22 is smaller than the MEA 21 and the anode side GDL 23, and the MEA 21 is exposed over a predetermined range from the outer peripheral end 21t of the MEA 21. The MEGA 11 is laminated such that the exposed portion of the outer peripheral end 22t of the cathode-side GDL 22 faces the three-layer sheet 14, and the cathode-side GDL 22 is arranged in the opening 14c of the three-layer sheet 14.

  The MEA 21 has a joined body of an electrolyte membrane 31, a cathode side catalyst layer 32, and an anode side catalyst layer 33. The cathode-side catalyst layer 32 is laminated on one surface of the electrolyte membrane 31, and the anode-side catalyst layer 33 is laminated on the other surface of the electrolyte membrane 31. In the MEA 21, the cathode side catalyst layer 32 is formed smaller than the electrolyte membrane 31 and the anode side catalyst layer 33, and the MEA 21 is configured to expose the electrolyte membrane 31 over a predetermined range from the outer peripheral end 21t of the MEA 21. The MEA 21 is arranged such that the portion exposed from the outer peripheral end 32t of the cathode-side catalyst layer 32 faces the bonding portion 14d of the three-layer sheet 14 and is bonded by the adhesive 15. The cathode side catalyst layer 32 is formed smaller than the cathode side GDL 22, and the outer peripheral end portion 32t of the cathode side catalyst layer 32 is arranged at a position retracted from the outer peripheral end portion 22t of the cathode side GDL22. . The outer peripheral end 22t of the cathode side GDL 22 and the electrolyte membrane 31 are opposed to each other in the stacking direction and are bonded to each other with an adhesive 15.

  The electrolyte membrane 31 is formed of a polymer electrolyte resin, which is a solid polymer material such as perfluorosulfonic acid (PFSA) ionomer, and is an ion exchange membrane using a polymer membrane having ion conductivity as an electrolyte. The electrolyte membrane 31 has a function of blocking the flow of electrons and gas and moving protons from the anode side catalyst layer 33 to the cathode side catalyst layer 32.

  The cathode-side catalyst layer 32 is made of a conductive carrier carrying a catalyst such as platinum or a platinum alloy, and is an electrode formed by coating carbon particles such as catalyst-supporting carbon particles with an ionomer having proton conductivity. It consists of a catalyst layer.

  The ionomer is made of a polymer electrolyte resin that is a solid polymer material such as a fluororesin having the same quality as that of the electrolyte membrane 31, and has proton conductivity due to an ion exchange group. The cathode side catalyst layer 32 has a function of generating water from protons, electrons and oxygen.

The anode side catalyst layer 33 is formed of the same material as the cathode side catalyst layer 32, but unlike the cathode side catalyst layer 32, it has a function of decomposing hydrogen gas (H ₂ ) into protons and electrons. . The anode-side catalyst layer 33 is formed to be larger than the cathode-side catalyst layer 32, is laminated so as to face the three-layer sheet 14 with the electrolyte membrane 31 sandwiched therebetween, and sandwiches the electrolyte membrane 31 and the cathode-side catalyst layer 32. And is laminated so as to face the cathode side GDL 22.

  The cathode side GDL 22 is formed of a material having gas permeability and conductivity, for example, a carbon fiber such as carbon paper or a porous fiber base material such as graphite fiber. The cathode-side GDL 22 is joined to the outside of the cathode-side catalyst layer 32, and has a function of diffusing air as an oxidant gas to make it uniform and to spread it to the cathode-side catalyst layer 32.

  The anode-side GDL 23 is formed of a material having gas permeability and conductivity, for example, a carbon fiber such as carbon paper or a porous fiber base material such as graphite fiber, like the cathode-side GDL 22. The anode-side GDL 23 is joined to the outside of the anode-side catalyst layer 33, and has a function of diffusing hydrogen gas as a fuel gas to make it uniform and spread it to the anode-side catalyst layer 33.

  The cathode side separator 12 is formed of a metal plate such as a steel plate, a stainless steel plate and an aluminum plate. The cathode-side separator 12 is bonded to the cathode-side GDL 22 and the three-layer sheet 14, and an oxidant gas flow path (not shown) for flowing air as the oxidant gas is formed along the surface of the cathode-side GDL 22. A titanium (Ti) thin film is formed on the surface of the cathode-side separator 12, and a carbon layer is formed on the titanium thin film.

  Like the cathode-side separator 12, the anode-side separator 13 is formed of a metal plate such as a steel plate, a stainless steel plate, and an aluminum plate. The anode-side separator 13 is joined to the anode-side GDL 23, and a fuel gas flow path (not shown) for flowing hydrogen as a fuel gas is formed along the surface of the anode-side GDL 23. Similar to the surface of the cathode side separator 12, a titanium (Ti) thin film is formed on the surface of the anode side separator 13, and a carbon layer is formed on the titanium thin film.

  The three-layer sheet 14 constitutes a frame body in the method for manufacturing a fuel cell according to the present invention. The three-layer sheet 14 is provided with an opening 14c that is closed by adhering the MEGA 11 thereto. As shown in FIGS. 2A and 2B, the three-layer sheet 14 has a three-layer structure having a core material 14a and adhesive layers 14b formed on the front and back surfaces of the core material 14a. ing. In the three-layer sheet 14, the cathode side separator 12 is adhered by the adhesive layer 14b, and the adhesive layer 14b and the electrolyte membrane 31 are adhered by the adhesive 15. The adhesive layer 14b of the three-layer sheet 14 according to this embodiment corresponds to the polypropylene (PP) layer in the method for producing a fuel cell according to the present invention.

In the three-layer sheet 14, hydrogen gas (H ₂ ) at the fuel electrode and oxygen gas (O ₂ ) at the air electrode pass through the electrolyte membrane 31 in a small amount and leak, so-called cross leak or between catalyst electrodes. It has a function to prevent electrical short circuit.

  The core material 14a is formed of a thermoplastic synthetic resin in a frame shape, and has a square opening 14c in the center. Examples of the thermoplastic synthetic resin include polyethylene naphthalate (PEN) and polyethylene terephthalate (PET).

  Each adhesive layer 14b is an adhesive member having higher rigidity, elasticity and viscosity than the electrolyte membrane 31, and is formed in a shape having an opening 14c similar to the core material 14a. Examples of the adhesive member include adhesives made of polypropylene (PP) or epoxy resin.

  As shown in FIG. 2B, the adhesive layer 14b of the three-layer sheet 14 is provided with an adhesive portion 14d at a portion facing the MEA 21. The adhesive portion 14d is formed in a strip shape over the entire circumference along the edge of the opening 14c of the three-layer sheet 14. The adhesive portion 14d is adhered to the electrolyte membrane 31 of the MEA 21 with the adhesive 15 interposed therebetween.

  A plurality of grooves 14e are provided in the adhesive portion 14d. Each groove 14e gradually becomes deeper as it moves from the opening 14c side of the three-layer sheet 14 toward the outer peripheral end of the three-layer sheet 14, and continues to the outside of the outer peripheral end 21t of the MEA 21. Each groove 14e is formed so as to be gradually deepened as it moves from the opening 14c side of the three-layer sheet 14 toward the outer peripheral end of the three-layer sheet 14. The groove 14e has a size such that the adhesive portion 14d is melted and completely filled by a heating and pressing process described later, and the inclination thereof melts from the opening 14c side so that the groove 14e is gradually filled in a deeper direction. Has become.

  As shown in FIG. 2A, the groove 14e is a portion separated from the starting point near the opening 14c by a distance L1 from the outer peripheral end 21t of the MEA 21 in a state where the three-layer sheet 14 and the MEA 21 are stacked. It is formed with a length L2 (mm) up to the end point. The groove 14e has a depth of 0 mm at the start point near the opening 14c, and has a depth D (mm) at the end point from the outer peripheral end 21t of the MEA 21 to L1.

  Further, as shown in the enlarged view of FIG. 2B, the groove 14e has a width of 0 mm at the starting point near the opening 14c and gradually widens at the end point of the portion separated from the outer peripheral end 21t of the MEA 21 by the distance L1. It is formed to have a width W (mm). A plurality of grooves 14e are formed at equal intervals of pitch P (mm) over the entire circumference of the edge of the opening 14c.

  The depth D, the distance L1, the length L2, the pitch P, and the width W in the groove 14e are based on the setting parameters of the fuel cell unit 10 and the data such as the shape, size, material, processing conditions and experimental values. It is selected appropriately. If the groove 14e is too small, the bubbles mixed in the adhesive 15 may be difficult to escape, and if too large, the groove 14e may not be filled in the process of making the fuel cell 10 and the necessary sealing property may not be secured. There is.

  Specifically, the groove 14e has a width W of about 0.1 mm to 1 mm, a distance L1 of about 0.5 mm to 2 mm, a depth D of about the upper limit of the thickness (mm) of the adhesive layer 14b, and a pitch P. Is preferably about 1 mm to 5 mm.

  The gasket (not shown) is formed of an elastic material such as rubber or thermoplastic elastomer, and is bonded to the oxidant gas flow path side of the cathode side separator 12. When a plurality of fuel battery cells 10 are stacked, the gasket contacts the surface of another adjacent fuel battery cell 10 and seals the space between the two fuel battery cells 10.

  As shown in FIG. 2, the adhesive 15 is sandwiched between the adhesive portion 14d of the three-layer sheet 14 and the electrolyte membrane 31 of the MEA 21, and the inner wall surface portion 14n of the three-layer sheet 14 and the outer peripheral end of the cathode side GDL 22. It is also applied so as to contact the portion 22t. The adhesive 15 is interposed between the outer peripheral end portion 22t of the cathode side GDL 22 and the inner wall surface portion 14n of the three-layer sheet 14, and is cured to ensure the airtightness of the MEA 21 and the three-layer sheet 14. The adhesive 15 also enters between the cathode side GDL 22 and the electrolyte membrane 31 and between the cathode side GDL 22 and the cathode side catalyst layer 32 to adhere them to each other.

  The adhesive 15 is a UV (ultraviolet) curable adhesive that contains polyisobutylene (PIB: Polyisobutylene) that remains tacky after being cured and that is cured by being irradiated with ultraviolet rays. The adhesive 15 is composed of, for example, a UV curable adhesive made of a cationically polymerizable resin such as an epoxy resin.

  The adhesive 15 is applied to the application region of the three-layer sheet 14 or the like by, for example, a screen printing method or a dispenser application method. After the application, when a predetermined ultraviolet ray is applied to the application area, the curing gradually progresses with the passage of time according to the irradiation conditions, and the state of having fluidity becomes almost non-fluid and the curing is completed.

  Next, a method for manufacturing the fuel cell unit 10 according to the present embodiment will be described with reference to the drawings.

  As shown in FIG. 3, the manufacturing method of the fuel cell 10 includes a groove forming step, a laminating step, and a hot pressing step. Each process is sequentially performed. As a pre-process of the groove forming process, for example, there is a known process for producing the three-layer sheet 14, and as a next process after the melting process, for example, there is a known cooling process for cooling the fuel cell unit 10 formed by melting. is there.

  In the groove forming step, the groove 14e shown in FIGS. 2A and 2B is formed in the manufactured three-layer sheet 14 (step S1). The groove 14e is processed by, for example, a press process for imparting a groove shape such as a roll press when manufacturing the roll of the three-layer sheet 14.

  In the laminating step, as shown on the left side of FIG. 4, the three-layer sheet 14 and the MEA 21 are laminated so that the adhesive 15 is sandwiched between the adhesive portion 14d of the three-layer sheet 14 and the electrolyte membrane 31 of the MEA 21 (step S2), forming MEGA S / A. The adhesive 15 is applied in advance to the portion of the electrolyte membrane 31 exposed from the cathode-side catalyst layer 32, and the three-layer sheet 14 is superposed and laminated thereon. The surface of the adhesive 15 applied to the electrolyte membrane 31 has large irregularities as compared with the surface of the electrolyte membrane 31, and when the adhesive portion 14d of the flat three-layer sheet 14 is superposed on the adhesive 15. Bubbles B are mixed between the adhesive portion 14d of the three-layer sheet 14 and the adhesive 15.

  In this embodiment, the groove 14e is provided in the adhesive portion 14d of the three-layer sheet 14, and when the electrolyte membrane 31 is laminated on the three-layer sheet 14, the gap between the adhesive portion 14d of the three-layer sheet 14 and the adhesive 15 is formed. It is possible to collect the bubbles B mixed into the groove 14e. Then, the bubbles B can be moved from the opening 14c side of the three-layer sheet 14 toward the outer peripheral end side of the three-layer sheet 14 along the groove 14e to be efficiently discharged from the outer peripheral end 21t of the MEA 21. it can.

  In the cell forming and hot pressing steps, as shown on the right side of FIG. 4, the MEGA S / A is set in the lower die of the press die having an upper die and a lower die, and the press die is heated to a predetermined temperature (° C.). ), And pressure is applied to the MEGA S / A by the upper mold and the lower mold, respectively, so-called hot pressing of MEGA S / A is performed (step S3).

  By this hot pressing, the adhesive layer 14b of the three-layer sheet 14 is melted, and the groove 14e is gradually filled from the opening 14c side of the three-layer sheet 14 toward the outer peripheral end side of the three-layer sheet 14. Therefore, it is possible to prevent bubbles from remaining in the groove 14e, effectively bond the three-layer sheet 14 and the electrolyte membrane 31, and ensure the sealing property.

  When the hot pressing step is completed, as shown in the rightmost drawing of FIG. 4, the air in the groove 14e escapes to fill the entire groove 14e, and the three-layer sheet 14 and the electrolyte membrane 31 are bonded. . The completed fuel cell 10 is sent to the next step.

  Next, the effects of the method of manufacturing the fuel cell 10 according to the present embodiment were verified by manufacturing the fuel cells according to the examples and the comparative examples. The fuel cell according to the example and the fuel cell according to the comparative example will be described.

  2A of the MEGA S / A and the three-layer sheet 14 in the fuel cell according to the embodiment, the electrolyte membrane 31 of the MEGA S / A and the adhesive layer 14b of the three-layer sheet 14 are effective. The portion bonded to, that is, the seal width was measured, and the bonded state was verified by comparing with the seal width of the fuel cell according to the comparative example. The seal width is the width from the opening 14c of the three-layer sheet 14 to the outer peripheral end 21t of the MEA 21 in the adhesive portion 14d.

  In the fuel cell according to the example, the width W of the groove 14e of the three-layer sheet 14 formed in the groove forming step (step S1) was 0.5 mm. The length L2 of the groove 14e is set such that the starting point is a point 1 mm away from the opening 14c of the three-layer sheet 14 and the ending point is a portion 1 mm away from the outer peripheral end 21t of the MEA 21.

  The depth D of the groove 14e was such that the starting point of the length L2 was 0 mm and the ending point of the length L2 was the same depth as the thickness of the adhesive layer 14b of the three-layer sheet 14. Grooves 14e were formed around the openings 14c of the three-layer sheet 14 at a pitch P of 3 mm and over the entire circumference.

  In the laminating step (step S2), as shown in FIG. 4, the adhesive 15 was laminated so as to be sandwiched between the three-layer sheet 14 and the electrolyte membrane 31. Then, in the hot pressing step (step S3), the press die is heated to a predetermined temperature (° C.), and the MEGA S / A is pressurized at a predetermined pressure by the upper die and the lower die to obtain the fuel according to the embodiment. A battery cell was produced.

  The comparative example has the same structure as the fuel cell 10 according to the present example except that the groove is not formed in the three-layer sheet 14, and the sealing width of the comparative example is set to 1 and compared with the example. did.

  The seal width of the fuel cell according to the example was 1.4 as shown in FIG. 5, which was 1.4 times the seal width 1 of the conventional product. Therefore, in the fuel cell according to the embodiment, when the MEA 21 and the three-layer sheet 14 are bonded with the adhesive 15, the bubbles B remaining between the bonding portion 14d of the three-layer sheet 14 and the adhesive 15 are reduced. It was confirmed that the reaction gas can be prevented and the leakage of the reaction gas can be suppressed.

  Therefore, in the method for manufacturing the fuel cell 10 according to the embodiment, the effect of improving the productivity of the fuel cell 10 and reducing the defective rate of the leak in the fuel cell can be obtained. Further, the effect of improving the sealability inside the cell of the fuel cell stack configured by the fuel cell 10 and improving the reliability of the cross leak durability performance can be obtained.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various designs can be made without departing from the spirit of the present invention described in the claims. You can make changes.

10 ... Fuel cell, 11 ... MEGA, 12 ... Cathode side separator, 13 ... Anode side separator, 14 ... Three-layer sheet (frame body), 14a ... Core material, 14b ... Adhesive layer (polypropylene layer), 14c ... Opening , 14d ... Adhesive portion, 14e ... Groove, 14n ... Inner wall surface portion, 15 ... Adhesive agent, 21 ... MEA (membrane electrode assembly), 21t, 22t, 31t, 32t ... Outer peripheral end portion, 22 ... Cathode side GDL, 23 ... Anode side GDL, 31 ... Electrolyte membrane, 32 ... Cathode side catalyst layer, 33 ... Anode side catalyst layer

Claims (1)

A method for producing a fuel cell by adhering a membrane electrode assembly to a frame having a polypropylene layer,
A groove that gradually becomes deeper as it moves from the opening side of the frame toward the outer peripheral end of the frame and continues to the outside of the outer peripheral end of the membrane electrode assembly. A step of forming a groove on the bonding portion of
A stacking step of stacking the membrane electrode assembly on the frame body with an adhesive sandwiched between the membrane electrode assembly and the adhesive portion of the frame body;
A heating press step of heating the membrane electrode assembly and the frame body to press in the stacking direction,
A method of manufacturing a fuel cell, comprising:

Images