Manufacturing method and manufacturing apparatus for membrane electrode assembly for fuel cell

Abstract

To harden an adhesive in a short time with a simple configuration.SOLUTION: A method for manufacturing a membrane electrode assembly for a fuel cell includes attaching a gas diffusion layer to an assembly in which a catalyst-coated membrane, which has an electrolyte membrane and an electrode catalyst layer provided on its surface, is supported by a resin frame member. The method includes the steps of placing the assembly on a base, applying an adhesive to the assembly placed on the base along a joining position between the catalyst-coated membrane and the resin frame member, placing a gas diffusion layer on the adhesive-coated assembly, and pressing the gas diffusion layer placed on the assembly along the joining position while spraying a curing accelerator onto the adhesive applied to the assembly along the joining position through the gas diffusion layer.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a method and an apparatus for manufacturing a membrane electrode assembly for a fuel cell. [Background technology]

[0002] In recent years, technological developments related to fuel cells that contribute to energy efficiency have been underway to ensure that more people have access to affordable, reliable, sustainable, and advanced energy. A known method for manufacturing a membrane electrode structure used in this type of fuel cell is a method in which a resin frame member is bonded to a membrane electrode assembly (MEA) (see, for example, Patent Document 1). In the method described in Patent Document 1, an adhesive is applied to a resin frame member placed on a heat sink, and the membrane electrode assembly is placed on the adhesive, and then the membrane electrode assembly is heated and pressed while cooling the resin frame member via the heat sink. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-239316 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when a heat-curing adhesive is used as in Patent Document 1, it is necessary to protect the resin frame member from deformation due to heat, making it difficult to cure the adhesive in a short time using a simple configuration. [Means for solving the problem]

[0005] One aspect of the present invention is a method for manufacturing a membrane electrode assembly for a fuel cell, which comprises attaching a gas diffusion layer to an assembly in which a catalyst-coated membrane, having an electrolyte membrane with an electrode catalyst layer provided on its surface, is supported by a resin frame member. The method includes the steps of placing the assembly on a base, applying an adhesive to the assembly mounted on the base along a joint position between the catalyst-coated membrane and the resin frame member, placing a gas diffusion layer on the adhesive-coated assembly, and pressing the gas diffusion layer mounted on the assembly along the joint position while spraying a curing accelerator onto the adhesive applied to the assembly along the joint position through the gas diffusion layer.

[0006] Another aspect of the present invention is an apparatus for manufacturing a membrane electrode assembly for a fuel cell, which attaches a gas diffusion layer to an assembly in which a catalyst-coated membrane, having an electrolyte membrane with an electrode catalyst layer provided on its surface, is supported by a resin frame. The apparatus for manufacturing a membrane electrode assembly for a fuel cell includes a base on which the assembly is placed, an application device that applies adhesive to the assembly placed on the base along the joining position between the catalyst-coated membrane and the resin frame, and a transport device that places the gas diffusion layer on the adhesive-coated assembly. The transport device has a suction mechanism that covers the gas diffusion layer, a pressing surface that presses the gas diffusion layer placed on the assembly along the joining position, and an injection hole that injects a curing accelerator onto the gas diffusion layer along the joining position. [Effects of the Invention]

[0007] According to the present invention, the adhesive can be cured in a short time with a simple configuration. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view schematically showing the overall configuration of a fuel cell stack including a membrane electrode assembly for a fuel cell according to an embodiment of the present invention; [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 2 is a front view showing a schematic configuration of the fuel cell membrane electrode assembly of FIG. [Figure 4]4 is a cross-sectional view of the fuel cell membrane electrode assembly during the manufacturing process taken along line IV-IV in FIG. 3. [Figure 5] 1 is a cross-sectional view showing an example of a configuration of a main part of a manufacturing apparatus for a membrane electrode assembly for a fuel cell according to an embodiment of the present invention. [Figure 6] 6 is a cross-sectional view for explaining the manufacturing apparatus for the fuel cell membrane electrode assembly of FIG. 5. [Figure 7] FIG. 7 is a front view showing an example of the arrangement of supply holes in FIG. 6. [Figure 8A] FIG. 7 is a front view showing an example of the arrangement of the injection holes in FIG. 6. [Figure 8B] FIG. 7 is a front view showing another example of the arrangement of the injection holes in FIG. 6. [Figure 9] 3A to 3C are diagrams illustrating an example of a method for manufacturing a membrane electrode assembly for a fuel cell according to an embodiment of the present invention. [Figure 10] FIG. 6 is a diagram showing a modification of FIG. 5. [Figure 11] FIG. 7 is a diagram showing a modification of FIG. 6. [Figure 12] FIG. 10 is a diagram showing a modification of FIG. 9; DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to Figs. 1 to 12. A membrane electrode assembly for a fuel cell according to an embodiment of the present invention constitutes a power generation cell and is included in a fuel cell stack, which is the main body of the fuel cell. The fuel cell is mounted on, for example, a vehicle and generates electric power for driving the vehicle. First, the overall configuration of the fuel cell stack will be described in brief. Note that the fuel cell stack may also be simply referred to as a fuel cell.

[0010] FIG. 1 is a perspective view showing a schematic overall configuration of a fuel cell stack 100 including a fuel cell membrane electrode assembly according to an embodiment of the present invention. Hereinafter, for convenience, three mutually orthogonal axial directions as shown in the figure are defined as the front-rear direction, the left-right direction, and the up-down direction, and the configuration of each part will be described according to these definitions. These directions are not necessarily the same as the front-rear direction, the left-right direction, and the up-down direction of a vehicle. For example, the front-rear direction in FIG. 1 may be the front-rear direction, the left-right direction, or the up-down direction of a vehicle.

[0011] As shown in FIG. 1, a fuel cell stack 100 has a cell stack 101 formed by stacking a plurality of power-generating cells 1 in the front-rear direction, and end units 102 arranged at both front and rear ends of the cell stack 101, and has a generally rectangular parallelepiped shape as a whole. The length of the cell stack 101 in the left-right direction is longer than the length in the up-down direction. For convenience, FIG. 1 shows a single power-generating cell 1. The power-generating cell 1 has an electrode assembly 2 having an assembly including an electrolyte membrane and electrodes, and a pair of front and rear separators 3, 3 arranged on both the front and rear sides of the electrode assembly 2 and sandwiching the electrode assembly 2 between them. The electrode assemblies 2 and the separators 3 are arranged alternately in the front-rear direction.

[0012] Fig. 2 is a cross-sectional view (a cross-sectional view taken along line II-II in Fig. 1) of a portion of the cell stack 101. As shown in Fig. 2, the separator 3 has a front plate 31 and a rear plate 32, which are a pair of front and rear thin metal plates with a corrugated cross section. The outer peripheries of the front plate 31 and the rear plate 32 are joined together by welding or the like to form the separator 3. A conductive material with excellent corrosion resistance is used for the separator 3, and examples of materials that can be used include stainless steel, titanium, and titanium alloys.

[0013] A cooling flow path PAw through which a coolant flows is formed inside the separator 3 surrounded by the front plate 31 and the rear plate 32, and the flow of the coolant cools the power generation surface of the power generation cell 1. Water, for example, can be used as the coolant. The surfaces (front and rear surfaces) of the separator 3 facing the electrode assembly 2 are formed unevenly by press molding or the like to form gas flow paths between the separator 3 and the electrode assembly 2. More specifically, the separator 3 has rib portions 33 that protrude toward the electrode assembly 2 and recesses 34 that are connected to the rib portions 33 and have a concave shape.

[0014] The rib portions 33 abut against the front and rear surfaces of the electrode assembly 2. A compressive load F is applied to the cell stack 101 in the front-to-rear direction during assembly of the fuel cell stack 100, and this compressive load F is maintained after assembly of the fuel cell stack 100 is complete. As a result, a predetermined surface pressure due to the compressive load F acts on the electrode assembly 2 in the front-to-rear direction via the rib portions 33.

[0015] An anode flow path PAa through which a fuel gas flows is formed between the front surface of the electrode assembly 2 and the rear plate 32 of the separator 3 facing this front surface by the recess 34. A cathode flow path PAc through which an oxidant gas flows is formed between the rear surface of the electrode assembly 2 and the front plate 31 of the separator 3 facing this rear surface by the recess 34. Hydrogen gas, for example, can be used as the fuel gas, and air, for example, can be used as the oxidant gas.

[0016] FIG. 3 is a front view showing a schematic configuration of an electrode assembly 2 as a membrane electrode structure (so-called UEA; Unitized Electrode Assembly). As shown in FIG. 3, the electrode assembly 2 has a substantially rectangular assembly 20 and a frame 21 that supports the assembly 20. The assembly 20 is a membrane electrode assembly (so-called MEA; Membrane Electrode Assembly). As shown in the detailed view of part A in FIG. 2, the assembly 20 has an electrolyte membrane 23, an anode electrode 24 provided on the front surface of the electrolyte membrane 23, and a cathode electrode 25 provided on the rear surface of the electrolyte membrane 23.

[0017] The electrolyte membrane 23 is, for example, a solid polymer electrolyte membrane, and a thin film of a perfluorosulfonic acid polymer containing water can be used. The electrolyte membrane 23 is not limited to a fluorine-based electrolyte membrane, and a hydrocarbon-based electrolyte membrane can also be used.

[0018] The anode 24 is provided on the front surface of the electrolyte membrane 23 and includes an electrode catalyst layer 24a that serves as a reaction field for the electrode reaction, and a gas diffusion layer 24b that is provided on the front surface of the electrode catalyst layer 24a and diffuses and supplies a fuel gas. An intermediate layer (base layer) may be provided between the electrode catalyst layer 24a and the gas diffusion layer 24b. The cathode 25 is provided on the rear surface of the electrolyte membrane 23 and includes an electrode catalyst layer 25a that serves as a reaction field for the electrode reaction, and a gas diffusion layer 25b that is provided on the rear surface of the electrode catalyst layer 25a and diffuses and supplies an oxidant gas. An intermediate layer (base layer) may be provided between the electrode catalyst layer 25a and the gas diffusion layer 25b.

[0019] The electrode catalyst layers 24a, 25a contain a catalytic metal that promotes the electrochemical reaction between hydrogen contained in the fuel gas and oxygen contained in the oxidant gas, a proton-conductive electrolyte (e.g., ionomer), and electron-conductive carbon particles. The gas diffusion layers 24b, 25b are made of a gas-permeable conductive material, such as a porous carbon material. The gas diffusion layers 24b, 25b are primarily composed of carbon and fluorine, and therefore have water-repellent properties.

[0020] At the anode electrode 24, the fuel gas (hydrogen) supplied via the anode flow path PAa is ionized by the action of a catalyst and moves through the electrolyte membrane 23 toward the cathode electrode. The electrons generated at this time pass through an external circuit and are extracted as electrical energy. At the cathode electrode 25, the oxidant gas (oxygen) supplied via the cathode flow path PAc reacts with the hydrogen ions introduced from the anode electrode 24 and the electrons that have moved from the anode electrode 24, producing water. The produced water provides an appropriate humidity to the electrolyte membrane 23, and excess water is discharged to the outside of the electrode assembly 2 along the gas flow.

[0021] The frame 21 in FIG. 3 is a thin plate having a substantially rectangular shape and a thickness of about 0.05 to 0.1 mm, and can be made of insulating resin, rubber, or the like. For example, PEN (Poly Ethylene Naphthalate) or PPS (Poly Phenylene Sulfide) can be used as the constituent material. In particular, in this embodiment, PPS is used as the constituent material of the frame 21. When PEN is used while immersed in water, hydrolysis occurs, and its strength decreases over time. In contrast, PPS has high hydrolysis resistance and shows almost no decrease in strength over time.

[0022] A substantially rectangular opening 21g is provided in the center of the frame 21, and the joining body 20 is provided so as to cover the entire opening 21g. The frame 21 has a substantially rectangular outer edge 21h and a substantially rectangular inner edge 21i inside the outer edge 21h. The outer edge 21h refers to the outer edge of the frame 21 and its surrounding area, and the inner edge 21i refers to the inner edge of the frame 21 and its surrounding area. An adhesive is applied to the periphery of the opening 21g (inner edge 21i) to provide a frame-shaped adhesive portion 40.

[0023] Point P in Fig. 3 is a center point passing through the middle of opening 21g in the vertical and horizontal directions. Three through holes 21a to 21c that penetrate frame 21 in the front-to-rear direction are opened lined up in the vertical direction on the left side of opening 21g of frame 21, and three through holes 21d to 21f that penetrate frame 21 in the front-to-rear direction are opened lined up in the vertical direction on the right side of opening 21g.

[0024] As shown in FIG. 1, the front and rear separators 3 of the electrode assembly 2 are provided with through holes 3a to 3f, respectively, that penetrate the separators 3 in the front-rear direction at positions corresponding to the through holes 21a to 21f of the frame 21. The through holes 3a to 3f are connected to the through holes 21a to 21f of the frame 21, respectively. A collection of these mutually communicating through holes 21a to 21f and 3a to 3f form flow paths PA1 to PA6 (indicated by arrows for convenience) that penetrate the cell stack 101 and extend in the front-rear direction. The flow paths PA1 to PA6 are sometimes called manifolds. The flow paths PA1 to PA6 are connected to a manifold external to the fuel cell stack 100.

[0025] A flow path PA1 (solid arrow) extending forward via the through holes 21a and 3a is a fuel gas supply flow path. A flow path PA6 (solid arrow) extending rearward via the through holes 21f and 3f is a fuel gas discharge flow path. The fuel gas supply flow path PA1 and the fuel gas discharge flow path PA6 are connected to an anode flow path PAa (FIG. 2) provided opposite the front surface of the assembly 20, and as shown by the solid arrows, fuel gas flows in the left-right direction through the anode flow path PAa via the fuel gas supply flow path PA1 and the fuel gas discharge flow path PA6. Communication between the anode flow path PAa and the other flow paths PA2 to PA5 is blocked by a seal portion (not shown).

[0026] A flow path PA4 (dotted arrow) extending forward through the through holes 21d and 3d is an oxidant gas supply flow path. A flow path PA3 (dotted arrow) extending rearward through the through holes 21c and 3c is an oxidant gas discharge flow path. The oxidant gas supply flow path PA4 and the oxidant gas discharge flow path PA3 communicate with a cathode flow path PAc ( FIG. 2 ) provided opposite the rear surface of the assembly 20, and as indicated by the dotted arrows, the oxidant gas flows laterally through the cathode flow path PAc via the oxidant gas supply flow path PA4 and the oxidant gas discharge flow path PA3. The communication between the cathode flow path PAc and the other flow paths PA1, PA2, PA5, and PA6 is blocked by a seal (not shown).

[0027] A flow path PA5 (indicated by a dashed-dotted arrow) extending forward through through-holes 21e and 3e is a cooling medium supply flow path. A flow path PA2 (indicated by a dashed-dotted arrow) extending rearward through through-holes 21b and 3b is a cooling medium discharge flow path. The cooling medium supply flow path PA5 and the cooling medium discharge flow path PA2 communicate with a cooling flow path PAw (FIG. 2) provided inside separator 3, and the cooling medium flows through the cooling flow path PAw via the cooling medium supply flow path PA5 and the cooling medium discharge flow path PA2. Communication between the cooling flow path PAw and the other flow paths PA1, PA3, PA4, and PA6 is blocked by a seal portion (not shown).

[0028] End units 102, arranged on both the front and rear sides of the cell stack 101, each include a terminal plate 4, an insulating plate 5, and an end plate 6. The rear end unit 102 has a plurality of through holes 102a-102f that penetrate the end unit 102 in the front-to-rear direction. The through hole 102a is opened on an extension of the fuel gas supply channel PA1 and communicates with the fuel gas supply channel PA1. The through hole 102b is opened on an extension of the coolant discharge channel PA2 and communicates with the coolant discharge channel PA2. The through hole 102c is opened on an extension of the oxidant gas discharge channel PA3 and communicates with the oxidant gas discharge channel PA3. The through hole 102d is opened on an extension of the oxidant gas supply channel PA4 and communicates with the oxidant gas supply channel PA4. The through hole 102e is opened on an extension of the coolant supply channel PA5 and communicates with the coolant supply channel PA5. The through-hole 102f is opened on an extension of the fuel gas discharge passage PA6 and communicates with the fuel gas discharge passage PA6.

[0029] More specifically, a fuel gas tank storing high-pressure fuel gas is connected to through-hole 102a via an ejector, an injector, etc., and the fuel gas is supplied to the fuel cell stack 100 via through-hole 102a. The fuel gas is discharged from through-hole 102f. A compressor for supplying oxidant gas is connected to through-hole 102d, and the oxidant gas compressed by the compressor is supplied to the fuel cell stack 100 via through-hole 102d. The oxidant gas is discharged from through-hole 102c. A pump for supplying a cooling medium is connected to through-hole 102e, and the cooling medium is supplied to the fuel cell stack 100 via through-hole 102e. The cooling medium is discharged from through-hole 102b. The discharged cooling medium is cooled by heat exchange in the radiator and supplied again to the fuel cell stack 100 via through-hole 102e.

[0030] The above is a schematic configuration of the fuel cell stack 100. Next, a description will be given of a manufacturing method and manufacturing apparatus for a fuel cell membrane electrode assembly according to an embodiment of the present invention. FIG. 4 is a cross-sectional view of the electrode assembly 2 as a fuel cell membrane electrode assembly during the manufacturing process, taken along line IV-IV in FIG. 3, showing the configuration around the right inner edge 21i of the frame 21. Note that the configuration around the inner edge 21i is the same along the entire periphery of the inner edge 21i along the opening 21g. Hereinafter, the leftward direction in FIG. 4, i.e., the direction toward the center point P in FIG. 3 (the center side), will be referred to as the inward direction or inward, and the left side in FIG. 4 will be referred to as the inside. Furthermore, the rightward direction in FIG. 4, i.e., the direction toward the outer edge 21h in FIG. 3, will be referred to as the outward direction or outward, and the right side in FIG. 4 will be referred to as the outside.

[0031] The frame 21 is a resin frame member made of PPS, and in the example of Fig. 4, it has a pair of front and rear frames 21. An electrode catalyst layer 25a of a cathode 25 is provided on the rear surface of the electrolyte membrane 23 by coating or the like. Hereinafter, the electrolyte membrane 23 having the electrode catalyst layers 24a, 25a provided on its surfaces (front and rear surfaces) may be referred to as a catalyst coated membrane (CCM) 50.

[0032] The front surface of the catalyst coated membrane 50 is bonded to the rear surface of the inner edge 21i of the front frame 21 via an adhesive 60 made of an adhesive. The front surface of the rear frame 21 is bonded to the rear surface of the front frame 21 to which the catalyst coated membrane 50 is bonded via the adhesive 60. More specifically, at the inner edge 21i, the front surface of the rear frame 21 is bonded to the rear surface of the catalyst coated membrane 50 (electrode catalyst layer 25a), and on the outer side of the inner edge 21i, the front surface of the rear frame 21 is bonded to the rear surface of the front frame 21. Hereinafter, the catalyst coated membrane 50 supported by the frame 21 serving as a resin frame member may be referred to as an assembly part 70.

[0033] In the manufacturing method of the fuel cell membrane electrode assembly according to the embodiment of the present invention, the gas diffusion layers 24b, 25b are attached to the assembly 70 via the adhesive 40, which is made of an adhesive. As an example, the following describes attaching the gas diffusion layer 25b of the cathode electrode 25 to the assembly 70 shown in FIG.

[0034] If a moisture-curing adhesive that cures upon reaction with moisture in the air is used for the adhesive portion 40, it will take a long time to cure. If a heat-curing adhesive that cures by activating a curing agent in the resin when heated is used for the adhesive portion 40, the curing time can be shortened by exposing it to high temperatures, but the surrounding resin components may be deformed by thermal stress. In particular, if the frame 21 is exposed to temperatures exceeding the glass transition temperature (96°C) of the PPS component, it may undergo deformation such as warping or undulation due to thermal contraction, which may result in insufficient sealing performance between the frame 21 and the separators 3 (Figure 1) before and after it. Furthermore, if a cooling device is installed to suppress thermal contraction deformation of the frame 21, the overall configuration of the device becomes complex.

[0035] When an ultraviolet-curing adhesive, in which the molecules inside are activated and polymerized when irradiated with ultraviolet light, is used for the adhesive portion 40, it can be cured in a short time and at a relatively low temperature, but this is difficult to apply when the adhesive portion 40 is covered with a member that does not transmit ultraviolet light. More specifically, when the adhesive portion 40 is sandwiched between members that do not transmit ultraviolet light (the frame 21 and the gas diffusion layer 25b in the example of FIG. 4), it is difficult to apply an ultraviolet-curing adhesive.

[0036] Therefore, in this embodiment, a manufacturing method and manufacturing apparatus for a membrane electrode assembly for a fuel cell are configured as follows so that the adhesive can be hardened in a short time with a simple configuration by using a hardening accelerator.

[0037] FIG. 5 is a cross-sectional view showing an example of the main components of a fuel cell membrane electrode assembly manufacturing apparatus (hereinafter, "apparatus") 200 according to an embodiment of the present invention, illustrating the spraying of a curing accelerator onto the adhesive bond 40 shown in FIG. 4 by the apparatus 200. In the example shown in FIG. 5, the apparatus 200 has a nozzle-shaped spray unit 201 for spraying the curing accelerator, and sprays an appropriate curing accelerator through spray holes 202 drilled in the spray unit 201. For example, when an instant adhesive based on 2-cyanoacrylate, a moisture-curing adhesive, is used for the adhesive bond 40, an amine-based compound can be used as the curing accelerator. The curing accelerator is a gas. As shown in FIG. 5, the curing accelerator sprayed onto the gas diffusion layer 25b through the spray holes 202 permeates the gas diffusion layer 25b, reaches the adhesive bond 40, and promotes the curing of the adhesive.

[0038] The tip (front surface) of the injection part 201 has a flat pressing surface 203 formed around the injection hole 202, which presses against the rear surface of the gas diffusion layer 25b. The pressing surface 203 of the injection part 201 presses against the gas diffusion layer 25b to press the gas diffusion layer 25b and the assembly part 70 together, and the curing accelerator is sprayed into the adhesive joint 40 through the injection hole 202, thereby enabling the gas diffusion layer 25b to be reliably attached to the assembly part 70 in a short time. Furthermore, by locally pressing the periphery of the adhesive joint 40 with the pressing surface 203 around the injection hole 202, the curing accelerator can be concentrated in the adhesive joint 40, allowing for efficient curing.

[0039] Fig. 6 is a cross-sectional view for explaining the apparatus 200 of Fig. 5. As shown in Fig. 6, the apparatus 200 includes a base 210 on which the assembly component 70 is placed, an application device 220 (not shown) that applies adhesive to the assembly component 70 placed on the base 210, a transport device 230 (not shown) that transports the gas diffusion layer 25b and places it on the assembly component 70 to which the adhesive has been applied, and an injection device 240 that injects a curing accelerator onto the adhesive (adhesive portion 40).

[0040] The base 210 has a suction mechanism and is configured as, for example, a belt conveyor. A plurality of holes are uniformly provided on the entire mounting surface of the base 210, and a vacuum pump is used to suck air through the holes, thereby sucking the mounted component (assembly component 70) (suction mechanism). Such a suction mechanism is provided over a wider area than the front surface of the assembly component 70 so that the entire mounted assembly component 70 can be sucked uniformly. The components of the electrode assembly 2, including the assembly component 70 and the gas diffusion layer 25b, are each very thin (for example, the electrolyte membrane is approximately 15 μm, and the gas diffusion layer is approximately 110 to 130 μm), and soft. By uniformly sucking the entire mounting surface using the suction mechanism, bending and deformation of each component can be suppressed.

[0041] Applicator 220 is configured as a discharge gun provided on a robot arm, and applies adhesive to assembly component 70 placed on base 210 along inner edge 21i (FIGS. 3 and 4) where catalyst coated membrane 50 and frame 21 are joined. When assembly component 70 is placed on base 210, applicator 220 is lowered by the robot arm toward assembly component 70 placed on base 210, and applies adhesive (adhesive portion 40) to assembly component 70 (frame 21) along inner edge 21i. After applying adhesive to assembly component 70, applicator 220 is retracted by the robot arm.

[0042] The transport device 230 has a suction mechanism and is attached to a robot arm (not shown). The suction mechanism of the transport device 230 is provided over a wider area than the gas diffusion layer 25b (rear surface) so that the entire gas diffusion layer 25b being transported can be uniformly sucked, and covers the gas diffusion layer 25b. When the coating device 220 retracts, the transport device 230, while sucking the gas diffusion layer 25b with the suction mechanism, descends by the robot arm toward the assembly part 70 to which the adhesive portion 40 has been applied, and places the gas diffusion layer 25b on the assembly part 70 (adhesive portion 40). After placing the gas diffusion layer 25b on the assembly part 70, the transport device 230 stops suction of the gas diffusion layer 25b with the suction mechanism and retracts by the robot arm.

[0043] The sprayer 240 has the spray unit 201 of FIG. 5 and is mounted on a robot arm (not shown). The sprayer 240 also has a supply hole 204 through which the curing accelerator is supplied from a dispenser (not shown) or the like, and a flow path 205 connecting the supply hole 204 and the injection hole 202. The sprayer 240 (front surface) is configured to have substantially the same shape as the gas diffusion layer 25b (rear surface) and covers the gas diffusion layer 25b so that the curing accelerator can be injected all at once along the inner edge portion 21i. By injecting the curing accelerator all at once through the supply hole 204, the flow path 205, and the injection hole 202, the curing accelerator can be sprayed evenly along the inner edge portion 21i.

[0044] FIG. 7 is a front view showing an example of the arrangement of the supply holes 204, and FIGS. 8A and 8B are front views showing an example of the arrangement of the injection holes 202. As shown in FIG. 7, the supply holes 204 are formed, for example, in the center of the rear surface of the injection device 240. As shown in FIGS. 8A and 8B, the injection holes 202 are formed along the inner edge portion 21i (FIGS. 3 and 4). In the example of FIG. 8A, a plurality of circular injection holes 202 are formed at equal intervals. In the example of FIG. 8B, a continuous groove-shaped injection hole 202 is formed. The shape and arrangement of the supply holes 204 are not limited to those shown in the example, and for example, they may be formed at positions other than the center of the rear surface of the injection device 240. Furthermore, a plurality of supply holes 204 may be provided. The shape and arrangement of the injection holes 202 are also not limited to those shown in the example, and for example, a plurality of groove-shaped injection holes 202 may be provided.

[0045] When the transport device 230 is retracted, the spraying device 240 is lowered by the robot arm toward the gas diffusion layer 25b placed on the assembly part 70 (adhesive portion 40). As shown in Figures 5 and 6, when the spraying device 240 is lowered, the pressing surface 203 of the spraying part 201 presses the gas diffusion layer 25b along the inner edge portion 21i, and the curing accelerator is sprayed onto the adhesive portion 40 through the injection holes 202 and the gas diffusion layer 25b. This causes the adhesive (adhesive portion 40) to cure quickly.

[0046] 9 is a diagram illustrating an example of a manufacturing method for a fuel cell membrane electrode assembly according to an embodiment of the present invention. As shown in FIG. 9, first, in step S1, an assembly component 70 is placed on a base 210. Next, in step S2, an application device 220 applies adhesive (adhesive portion 40) to the assembly component 70 placed on the base 210 along the inner edge portion 21i. Next, in step S3, a transfer device 230 transfers the gas diffusion layer 25b and places the gas diffusion layer 25b on the assembly component 70 (adhesive portion 40) placed on the base 210. Next, in step S4, the transfer device 230 is retracted, and an injection device 240 is lowered toward the gas diffusion layer 25b placed on the assembly component 70 (adhesive portion 40). Next, in step S5, the gas diffusion layer 25b placed on the assembly part 70 (bonding portion 40) is pressed along the inner edge portion 21i by the spraying device 240, and the curing accelerator is sprayed along the inner edge portion 21i through the gas diffusion layer 25b onto the bonding portion 40. When step S5 is completed, the spraying device 240 is retracted.

[0047] In this way, by using the sprayer 240 to press the gas diffusion layer 25b placed on the adhesive joint 40 and spraying the curing accelerator onto the adhesive joint 40 through the gas diffusion layer 25b, the adhesive (adhesive joint 40) can be cured reliably in a short time with a simple configuration. In the manufacturing process of the electrode assembly 2, as shown in FIGS. 4 to 6, after the gas diffusion layer 25b of the cathode electrode 25 is attached to the assembly part 70, the anode electrode 24 is then attached. For example, a catalyst coated diffusion media (CCDM) having an electrode catalyst layer 24a formed on the surface of the gas diffusion layer 24b of the anode electrode 24 is attached. In this case, the assembly part 70 to which the gas diffusion layer 25b of the cathode electrode 25 is attached in steps S1 to S5 is inverted, for example, on the base 210, and then the process proceeds to the step of attaching the catalyst coated diffusion media. By reliably hardening the adhesive (adhesive portion 40) in a short time in step S5, the manufacturing time of the electrode assembly 2 can be shortened while suppressing bending and deformation of each component, misalignment between components, etc. when inverted.

[0048] The device 200 may be configured such that the injection holes 202, the pressing surface 203, the supply holes 204, and the flow paths 205 of the injection device 240 are provided in the transport device 230. Figures 10, 11, and 12 are diagrams showing modifications of Figures 5, 6, and 9, respectively, in which the injection holes 202, the pressing surface 203, the supply holes 204, and the flow paths 205 are provided in the transport device 230.

[0049] 10 and 11, the ejection holes 202 are formed in the suction surface (front surface) of the transport device 230, and the suction surface around the ejection holes 202 forms the pressing surface 203. The suction mechanism of the transport device 230 is further provided over a wider area than the assembly part 70 (frame 21) (rear surface) so as to uniformly suck and transport the entire assembly part 70 to which the gas diffusion layer 25b is attached, and covers the assembly part 70.

[0050] 12, in step S3, the gas diffusion layer 25b is placed by the transfer device 230 on the assembly component 70 placed on the base 210, and then the process proceeds directly to step S5 without retracting the transfer device 230. Then, in step S5, the transfer device 230 presses the gas diffusion layer 25b placed on the assembly component 70 and sprays a curing accelerator onto the adhesive portion 40. Furthermore, after step S5 is completed, the process proceeds directly to step S6 without retracting the transfer device 230, where the suction mechanism of the transfer device 230 sucks in the assembly component 70 with the gas diffusion layer 25b attached, and the assembly component 70 is transported to the next step by a robot arm.

[0051] In this way, by providing the injection holes 202 and the pressing surface 203 on the conveying device 230 having a suction mechanism, it is not necessary to switch between the conveying device 230 and the injection device 240, and it is possible to further shorten the manufacturing time of the electrode assembly 2. Furthermore, by ensuring the suction surface of the conveying device 230 and configuring it so that it can also convey the assembly part 70 to which the gas diffusion layer 25b is attached, it is possible to shorten the time from when the adhesive portion 40 is cured until when the assembly part 70 to which the gas diffusion layer 25b is attached is conveyed.

[0052] According to this embodiment, the following effects can be achieved. (1) In a method for manufacturing a membrane electrode assembly for a fuel cell, a gas diffusion layer 25b is attached to an assembly 70 in which a catalyst-coated membrane 50 having an electrode catalyst layer 25a provided on the surface of an electrolyte membrane 23 is supported by a frame 21 (FIG. 4). The method for manufacturing a membrane electrode assembly for a fuel cell includes the steps of: step S1 of placing the assembly 70 on a base 210; step S2 of applying an adhesive to the assembly 70 placed on the base 210 along an inner edge 21i where the catalyst-coated membrane 50 and the frame 21 are joined; step S3 of placing a gas diffusion layer 25b on the adhesive-coated assembly 70; and step S5 of pressing the gas diffusion layer 25b placed on the assembly 70 along the inner edge 21i and spraying a curing accelerator onto the adhesive portion 40 of the assembly 70, which is the adhesive applied to the assembly 70, along the inner edge 21i, via the gas diffusion layer 25b (FIGS. 9 and 12).

[0053] In this way, by pressing the gas diffusion layer 25b placed on the adhesive portion 40 and injecting the curing accelerator onto the adhesive portion 40 through the gas diffusion layer 25b, it is possible to cure the adhesive (adhesive portion 40) in a short time with a simple configuration. Furthermore, by reliably curing the adhesive (adhesive portion 40) in a short time, it is possible to reduce the manufacturing time of the electrode assembly 2 and suppress bending and deformation of each component, misalignment between components, etc., during transportation or inversion.

[0054] (2) In the apparatus 200, a gas diffusion layer 25b is attached to an assembly 70 in which a catalyst coated membrane 50 having an electrode catalyst layer 25a provided on the surface of an electrolyte membrane 23 is supported by a frame 21 (FIG. 4). The apparatus 200 includes a base 210 on which the assembly 70 is placed, an application device 220 that applies adhesive to the assembly 70 placed on the base 210 along the inner edge 21i where the catalyst coated membrane 50 and the frame 21 are joined, and a transport device 230 that places the gas diffusion layer 25b on the assembly 70 to which the adhesive has been applied (FIGS. 6 and 11). The conveying device 230 has a suction mechanism that covers the gas diffusion layer 25b, a pressing surface 203 that presses the gas diffusion layer 25b placed on the assembly part 70 along the inner edge portion 21i, and an injection hole 202 that injects a curing accelerator onto the adhesive portion 40, which is the adhesive applied to the assembly part 70, via the gas diffusion layer 25b and along the inner edge portion 21i (FIG. 11).

[0055] In this way, by pressing the gas diffusion layer 25b placed on the adhesive portion 40 and spraying the curing accelerator onto the adhesive portion 40 through the gas diffusion layer 25b, it is possible to cure the adhesive (adhesive portion 40) in a short time with a simple configuration. Furthermore, by reliably curing the adhesive (adhesive portion 40) in a short time, it is possible to reduce the manufacturing time of the electrode assembly 2 while suppressing bending and deformation of each component, misalignment between components, and the like that occurs during transportation and inversion. Furthermore, by providing the injection holes 202 and the pressing surface 203 in the transport device 230 having a suction mechanism, it is not necessary to switch between the transport device 230 and the spray device 240, and it is possible to further reduce the manufacturing time of the electrode assembly 2.

[0056] (3) The suction mechanism of the transport device 230 further covers the assembly component 70 (FIG. 11). The transport device 230 further transports the assembly component 70 to which the gas diffusion layer 25b is attached. In this way, by ensuring the suction surface of the transport device 230 and configuring it so that it can also transport the assembly component 70 to which the gas diffusion layer 25b is attached, it is possible to shorten the time from when the adhesive portion 40 is cured until when the assembly component 70 to which the gas diffusion layer 25b is attached is transported.

[0057] (4) The conveying device 230 has a plurality of injection holes 202 along the inner edge portion 21i (FIG. 8A). By providing the injection holes 202 along the inner edge portion 21i, the curing accelerator can be efficiently injected onto the adhesive (bonded portion 40) applied along the inner edge portion 21i. In addition, by locally pressing the periphery of the bonded portion 40 with the pressing surface 203 around the injection holes 202, the curing accelerator can be concentrated in the bonded portion 40, allowing for efficient curing.

[0058] (5) The conveying device 230 further has a supply hole 204 for supplying the curing accelerator and a flow path 205 connecting the supply hole 204 and the multiple injection holes 202 (FIGS. 6 and 11). This allows the curing accelerator to be injected at once through the supply hole 204, the flow path 205, and the injection holes 202, and the curing accelerator can be injected uniformly along the inner edge portion 21i, so that the adhesive portion 40 can be cured more efficiently.

[0059] In the above embodiment, the specific configuration and arrangement of the assembly 70 and the gas diffusion layer 25b, as well as an example of a manufacturing process for the electrode assembly 2 including these components, are described using Figure 4 and other figures. However, the manufacturing method and manufacturing apparatus for a fuel cell membrane electrode assembly in which a gas diffusion layer is attached to an assembly in which a catalyst-coated membrane, having an electrode catalyst layer provided on the surface of an electrolyte membrane, is supported by a resin frame member, are not limited to those illustrated. For example, the method may be applied to attaching the gas diffusion layer 24b of the anode 24 as the gas diffusion layer, or to simultaneously attaching the gas diffusion layer 24b of the anode 24 and the gas diffusion layer 25b of the cathode 25. The assembly may also include, for example, only a single frame 21.

[0060] The above description is merely an example, and the present invention is not limited to the above-described embodiment and modifications as long as the features of the present invention are not impaired. One or more of the above-described embodiment and modifications can be arbitrarily combined, and modifications can also be combined with each other. [Explanation of symbols]

[0061] 1 power generation cell, 2 electrode assembly, 21 frame, 23 electrolyte membrane, 24 anode electrode, 25 cathode electrode, 21g opening, 21i inner edge portion, 24a, 25a electrode catalyst layer, 24b, 25b gas diffusion layer, 40 adhesive portion, 50 catalyst coated membrane, 70 assembly part, 100 fuel cell stack, 200 apparatus (manufacturing apparatus for fuel cell membrane electrode structure), 201 injection portion, 202 injection hole, 203 pressing surface, 204 supply hole, 205 flow path, 210 base, 220 coating device, 230 conveying device, 240 injection device

Claims

1. A method for manufacturing a membrane electrode assembly for a fuel cell, comprising: attaching a gas diffusion layer to an assembly in which a catalyst coated membrane, in which an electrode catalyst layer is provided on the surface of an electrolyte membrane, is supported by a resin frame member; placing the assembly on a base; applying an adhesive to the assembly placed on the base along a joining position between the catalyst coated membrane and the resin frame member; placing the gas diffusion layer on the assembly with the adhesive applied; pressing the gas diffusion layer placed on the assembly along the joining position, and injecting a curing accelerator onto the adhesive applied to the assembly along the joining position through the gas diffusion layer.

2. 1. A manufacturing apparatus for a membrane electrode assembly for a fuel cell, comprising: an assembly in which a catalyst coated membrane having an electrode catalyst layer provided on the surface of an electrolyte membrane is supported by a resin frame member; and a gas diffusion layer is attached to the assembly; a base on which the assembly components are placed; an adhesive applying device that applies adhesive to the assembly placed on the base along a joining position between the catalyst coated membrane and the resin frame member; a conveying device that places the gas diffusion layer on the assembly component to which the adhesive has been applied, The conveying device is a suction mechanism covering the gas diffusion layer; a pressing surface that presses the gas diffusion layer placed on the assembly along the joining position; an injection hole for injecting a curing accelerator into the adhesive applied to the assembly parts through the gas diffusion layer along the joining position.

3. 3. The apparatus for manufacturing a membrane electrode assembly for a fuel cell according to claim 2, The suction mechanism further covers the assembly; The manufacturing apparatus for a membrane electrode assembly for a fuel cell, wherein the transport device further transports the assembly component to which the gas diffusion layer is attached.

4. 4. The manufacturing apparatus for a membrane electrode assembly for a fuel cell according to claim 2 or 3, 10. The manufacturing apparatus for a membrane electrode assembly for a fuel cell, wherein the transport device has a plurality of the injection holes along the joining position.

5. 5. The apparatus for manufacturing a membrane electrode assembly for a fuel cell according to claim 4, The conveying device is a supply hole for supplying the curing accelerator; a flow path connecting the supply hole and the plurality of injection holes.

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