Method for manufacturing fuel cell monomer and fuel cell monomer

Abstract

The present invention relates to a method for manufacturing a fuel cell monomer and a fuel cell monomer. The method for manufacturing a fuel cell monomer comprises a preparation step, a configuration step and a bonding step. In the preparation step, a thermoplastic adhesive 4 is prepared as a double-layer adhesive sheet, wherein the double-layer adhesive sheet has a first bonding layer 41 and a second bonding layer 42. In the configuration step, the thermoplastic adhesive 4 is configured between the membrane electrode assembly 21 and the resin frame 3 in a state where the first bonding layer 41 is opposite to the membrane electrode assembly 21 and the second bonding layer 42 is opposite to the resin frame 3. In the bonding step, the thermoplastic adhesive 4 is heated to plasticize it, and then the temperature of the plasticized thermoplastic adhesive 4 is lowered to solidify it, thereby bonding the membrane electrode assembly 21 to the resin frame 3 via the thermoplastic adhesive 4.

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a fuel cell and a fuel cell. Background Art

[0002] In the past, an invention regarding a method for manufacturing a fuel cell monomer is known (Patent Document 1 described below). The method for manufacturing a fuel cell monomer described in Patent Document 1 includes an adhesive coating step, in which an adhesive is coated on a membrane electrode assembly by screen printing. The printing plate used in the screen printing is formed so that the mesh diameter of the portion for printing the outer side of the membrane electrode assembly is smaller than that of the portion for printing the inner side of the membrane electrode assembly (Abstract, Claim 1, paragraph 0006, etc. of Patent Document 1). According to this conventional method for manufacturing a fuel cell stack, it is possible to prevent the adhesive from adhering to the mounting table when the membrane electrode assembly is bonded to the three-layer sheet using the adhesive (Paragraph 0009 of Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2020-149886 Summary of the invention

[0006] Problems to be solved by the invention

[0007] For example, in order to avoid the undesirable conditions that may occur when using a liquid adhesive, such as adhesive coating spots and bubbles mixed into the adhesive, as in the above-mentioned conventional fuel cell monomer manufacturing method, it is possible to consider using a sheet-shaped thermoplastic adhesive instead of a liquid adhesive. However, the surface properties of the membrane electrode assembly and the resin frame joined by the sheet-shaped thermoplastic adhesive are different. Therefore, when using a sheet-shaped thermoplastic adhesive, there is a problem that it is difficult to ensure the required bonding strength for both the membrane electrode assembly and the resin frame.

[0008] The present disclosure provides a method for manufacturing a fuel cell unit and a fuel cell unit that can ensure a desired bonding strength for both a membrane electrode assembly and a resin frame having different surface properties.

[0009] Means used to solve problems

[0010] One embodiment of the present disclosure is a method for manufacturing a fuel cell monomer, in which a membrane electrode assembly and a resin frame are bonded via a sheet-like thermoplastic adhesive, and is characterized in that the method for manufacturing a fuel cell monomer comprises: a preparation step, wherein a double-layer adhesive sheet is prepared as the thermoplastic adhesive, the double-layer adhesive sheet having a first bonding layer and a second bonding layer, the first bonding layer having better bonding properties to the membrane electrode assembly than the first bonding layer having better bonding properties to the resin frame, and the second bonding layer having better bonding properties to the resin frame than the second bonding layer having better bonding properties to the membrane electrode assembly. The bonding property of the electrode assembly is better; a configuration process, wherein the double-layer adhesive sheet is configured between the membrane electrode assembly and the resin frame in a state where the first bonding layer is opposite to the membrane electrode assembly and the second bonding layer is opposite to the resin frame; and a bonding process, wherein the double-layer adhesive sheet configured between the membrane electrode assembly and the resin frame in the configuration process is heated to plasticize it, and then the temperature of the plasticized double-layer adhesive sheet is reduced to solidify it, thereby bonding the membrane electrode assembly to the resin frame via the thermoplastic adhesive.

[0011] In the method for manufacturing a fuel cell unit of the above aspect, the arranging step may include: placing the double-layer adhesive sheet on the membrane electrode assembly; and placing the resin frame on the double-layer adhesive sheet placed on the membrane electrode assembly.

[0012] In the method for manufacturing a fuel cell unit of the above aspect, the first bonding layer may be composed of a thermoplastic resin containing an amide group, and the second bonding layer may be composed of an olefin-based thermoplastic resin.

[0013] In addition, one embodiment of the present disclosure is a fuel cell monomer, wherein a membrane electrode assembly and a resin frame are bonded via a sheet-shaped thermoplastic adhesive, characterized in that the thermoplastic adhesive is a double-layer adhesive sheet, the double-layer adhesive sheet having a first bonding layer and a second bonding layer, the first bonding layer having better bonding properties to the membrane electrode assembly than the first bonding layer having better bonding properties to the resin frame, the second bonding layer having better bonding properties to the resin frame than the second bonding layer having better bonding properties to the membrane electrode assembly, and when the membrane electrode assembly is bonded to the first bonding layer and the resin frame is bonded to the second bonding layer, the membrane electrode assembly and the resin frame are bonded via the double-layer adhesive sheet.

[0014] Effects of the Invention

[0015] According to the above-described aspects of the present disclosure, it is possible to provide a method for manufacturing a fuel cell unit and a fuel cell unit that can ensure a desired bonding strength for both a membrane electrode assembly and a resin frame having different surface properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic top view showing one embodiment of a fuel cell unit according to the present disclosure.

[0017] Figure 2 To express that Figure 1 A top view of a fuel cell unit with the separator removed.

[0018] Figure 3 For along Figure 1 An enlarged cross-sectional view of a fuel cell monomer along line III-III.

[0019] Figure 4 This is a flow chart showing one embodiment of a method for manufacturing a fuel cell unit according to the present disclosure.

[0020] Figure 5 To express Figure 4 A flowchart showing details of a configuration step in a method for manufacturing a fuel cell unit.

[0021] Explanation of symbols

[0022] 1 Fuel cell monomer

[0023] 21 Membrane Electrode Assembly (MEA)

[0024] 3 Resin frame

[0025] 4 Thermoplastic adhesive (double-layer adhesive sheet)

[0026] 41 First bonding layer

[0027] 42 Second bonding layer

[0028] M Method for manufacturing a fuel cell monomer

[0029] P1 Preparation process

[0030] P2 Configuration process

[0031] P21 Double-layer adhesive sheet placement process

[0032] P22 Process of placing resin frame

[0033] P3 Gluing process DETAILED DESCRIPTION

[0034] Hereinafter, a method for manufacturing a fuel cell unit and an embodiment of a fuel cell unit according to the present disclosure will be described with reference to the accompanying drawings. Hereinafter, first, an embodiment of a fuel cell unit according to the present disclosure will be described, and then a method for manufacturing the fuel cell unit will be described.

[0035] (Fuel Cell Monomer)

[0036] Figure 1 It is a schematic top view showing one embodiment of a fuel cell unit 1 according to the present disclosure. Figure 2 To express that Figure 1 FIG. 1 is a top view of a fuel cell unit 1 with the separator 5 removed. Figure 3 For along Figure 1 An enlarged cross-sectional view of the fuel cell unit 1 taken along line III-III.

[0037] The fuel cell unit 1 includes, for example, a membrane electrode gas diffusion layer assembly (Membrane Electrode and Gas Diffusion Layer Assembly: hereinafter referred to as "MEGA") 2, a resin frame 3, a thermoplastic adhesive 4, a cathode side separator 5, and an anode side separator 6. Although not shown in the figure, a fuel cell stack is formed by stacking a plurality of fuel cell units 1, and a fuel cell is manufactured using the fuel cell stack.

[0038] MEGA2 includes a membrane electrode assembly (Membrane Electrode Assembly: hereinafter referred to as “MEA”) 21 , a cathode-side gas diffusion layer (Gas Diffusion Layer: hereinafter referred to as “GDL”) 22 , and an anode-side GDL 23 .

[0039] The MEA 21 includes an electrolyte membrane 21a, a cathode catalyst layer 21b, and an anode catalyst layer 21c. The cathode catalyst layer 21b is bonded to one surface of the electrolyte membrane 21a, and the anode catalyst layer 21c is bonded to the other surface of the electrolyte membrane 21a.

[0040] The electrolyte membrane 21a is, for example, an ion exchange membrane formed of a polymer electrolyte resin as a solid polymer material (perfluorosulfonic acid (PFSA) ionomer, etc.), and a polymer membrane having ion conductivity as an electrolyte. The electrolyte membrane 21a blocks the flow of electrons and gases and has a function of moving protons from the anode side catalyst layer 21c to the cathode side catalyst layer 21b.

[0041] The cathode catalyst layer 21b is bonded to the cathode GDL 22 by an adhesive. The cathode catalyst layer 21b includes a conductive carrier carrying a catalyst such as platinum or a platinum alloy, for example, an electrode catalyst layer formed by coating carbon particles such as carbon particles carrying a catalyst with an ionomer having proton conductivity.

[0042] The ionomer includes a polymer electrolyte resin, which is a solid polymer material such as a fluorine-based resin having the same properties as the electrolyte membrane 21a. The ionomer has proton conductivity due to the presence of ion exchange groups. The cathode catalyst layer 21b has a function of generating water from protons, electrons and oxygen.

[0043] The anode side catalyst layer 21c is formed of the same material as the cathode side catalyst layer 21b, but unlike the cathode side catalyst layer 21b, it has the function of decomposing hydrogen (H2) into protons and electrons. The anode side catalyst layer 21c is formed larger than the cathode side catalyst layer 21b, and is stacked relative to the resin frame 3 with the electrolyte membrane 21a sandwiched therebetween. In addition, the anode side catalyst layer 21c is stacked relative to the cathode side GDL 22 with the electrolyte membrane 21a and the cathode side catalyst layer 21b interposed therebetween.

[0044] The cathode side GDL 22 is formed of a material having air permeability and conductivity, such as a porous fiber substrate such as carbon fiber such as carbon paper, graphite fiber, etc. The cathode side GDL 22 is bonded to the outside of the cathode side catalyst layer 21b, and has the function of diffusing air as an oxidant gas so that it becomes uniform and spreads throughout the cathode side catalyst layer 21b.

[0045] The anode side GDL 23 is formed of a porous fiber substrate such as carbon fiber such as carbon paper, graphite fiber, etc., similarly to the cathode side GDL 22. The anode side GDL 23 is bonded to the outside of the anode side catalyst layer 21c and has the function of making hydrogen gas, which is a fuel gas, diffuse uniformly and spread throughout the anode side catalyst layer 21c.

[0046] The resin frame 3 is, for example, Figure 2 As shown in FIG. 1 , the resin frame 3 is formed into a rectangular frame shape and has a rectangular opening 3a in the center. Figure 3 The three-layer sheet shown has a three-layer structure including a core material 31 , an adhesive layer 32 formed on one surface of the core material 31 , and an adhesive layer 33 formed on the other surface of the core material 31 .

[0047] As the material of the core material 31, for example, a thermoplastic synthetic resin such as polyethylene naphthalate (PEN) or polyethylene terephthalate (PET) can be used. The adhesive layers 32 and 33 have, for example, higher rigidity, elasticity, and viscosity than the electrolyte membrane 21a. As the material of the adhesive layers 32 and 33, for example, an adhesive containing polypropylene (PP) or epoxy resin can be used.

[0048] The resin frame 3 is bonded to the cathode side separator 5 via an adhesive layer 32, and bonded to the anode side separator 6 via another adhesive layer 33. In addition, the resin frame 3 is bonded to the MEA 21 exposed at the end of the MEGA 2 via a thermoplastic adhesive 4. The resin frame 3 prevents cross leakage and electrical short circuit between catalyst electrodes. Cross leakage is a phenomenon in which trace amounts of gas such as hydrogen (H2) of the fuel electrode and oxygen (O2) of the air electrode leak through the electrolyte membrane 21a.

[0049] The thermoplastic adhesive 4 is disposed, for example, between the MEA 21 and the resin frame 3 to bond the MEA 21 to the resin frame 3. The thermoplastic adhesive 4 is provided, for example, in a rectangular frame shape or a picture frame shape corresponding to the shape of the opening 3a of the resin frame 3. Figure 3 As shown, the outer edge of the thermoplastic adhesive 4 is disposed in a region outside the opening 3 a of the resin frame 3 , and the inner edge of the thermoplastic adhesive 4 is disposed in a region inside the opening 3 a of the resin frame 3 .

[0050] Thermoplastic adhesive 4 covers MEA 21 exposed at the outer edge of MEGA 2. More specifically, the outer edge of MEGA 2 is a portion outside the power generation unit of MEGA 2 disposed inside the opening 3a of the resin frame 3. At the outer edge of MEGA 2, cathode-side GDL 22 is removed to expose cathode-side catalyst layer 21b of MEA 21.

[0051] The thermoplastic adhesive 4 extends, for example, from the inner side of the power generation section of the MEGA 2 (which is the area inside the opening 3a of the resin frame 3) to the outer edge of the MEGA 2 (which is the portion obtained by removing the cathode side gas diffusion layer 22 on the outer side of the power generation section). Thus, the thermoplastic adhesive 4 covers the entire surface of the cathode side catalyst layer 21b of the membrane electrode assembly 21 exposed at the outer edge of the MEGA 2 inside the opening 3a of the resin frame 3.

[0052] The thermoplastic adhesive 4 is, for example, a double-layer adhesive sheet having a double-layer structure having a first bonding layer 41 and a second bonding layer 42. The thermoplastic adhesive 4 is, for example, formed in a sheet shape before being heated and plasticized. The thermoplastic adhesive 4 is heated and plasticized while being arranged between the resin frame 3 and the membrane electrode assembly 21, and then the temperature is lowered and cured, thereby heat-fusion bonding the resin frame 3 and the membrane electrode assembly 21 via the thermoplastic adhesive 4.

[0053] The first bonding layer 41 of the thermoplastic adhesive 4 has better bonding to the MEA 21 than to the resin frame 3. More specifically, the first bonding layer 41 has better bonding to, for example, the cathode catalyst layer 21b of the MEA 21 than to the adhesive layer 33 of the resin frame 3. The first bonding layer 41 is composed of, for example, a thermoplastic resin containing an amide group that is easily bonded to a sulfonic group. More specifically, the first bonding layer 41 uses, for example, a polyamide (nylon) resin material as a main material.

[0054] The second bonding layer 42 of the thermoplastic adhesive 4 has better bonding to the resin frame 3 than to the membrane electrode assembly 21. More specifically, the bonding of the second bonding layer 42 to the adhesive layer 33 of the resin frame 3 is better than to the cathode catalyst layer 21b of the MEA 21. The second bonding layer 42 is, for example, composed of an olefin thermoplastic resin. More specifically, the second bonding layer 42 uses a resin material such as polyethylene or polypropylene as a main material. It should be noted that there is no particular limitation on the bonding method of the first bonding layer 41 and the second bonding layer 42.

[0055] The cathode side separator 5 is formed of a metal plate such as a steel plate, a stainless steel plate, or an aluminum plate. The cathode side separator 5 is bonded to the cathode side GDL 22 and the resin frame 3 to form an oxidant gas flow path for allowing air as an oxidant gas to flow along the surface of the cathode side GDL 22. A titanium (Ti) thin film is formed on the surface of the cathode side separator 5, and a carbon layer is formed on the titanium thin film.

[0056] The anode side separator 6 is formed of a metal plate such as a steel plate, a stainless steel plate, or an aluminum plate, similarly to the cathode side separator 5. The anode side separator 6 is joined to the anode side GDL 23 and the resin frame 3 to form a fuel gas flow path for hydrogen gas, which is a fuel gas, to flow along the surface of the anode side GDL 23. Similar to the cathode side separator 5, the anode side separator 6 has a titanium (Ti) thin film formed on the surface, and a carbon layer is formed on the titanium thin film.

[0057] (Method for manufacturing fuel cell monomer)

[0058] Figure 4 The present invention is a flowchart showing an embodiment of a method for manufacturing a fuel cell unit according to the present disclosure. The method for manufacturing a fuel cell unit M according to the present embodiment is a method for manufacturing a fuel cell unit 1 obtained by bonding an MEA 21 and a resin frame 3 via a sheet-like thermoplastic adhesive 4. The method for manufacturing a fuel cell unit M according to the present embodiment includes a preparation step P1, a configuration step P2, and a bonding step P3.

[0059] The preparation step P1 is a step of preparing a double-layer adhesive sheet of a double-layer structure as the thermoplastic adhesive 4. As described above, the thermoplastic adhesive 4 as the double-layer adhesive sheet has a first bonding layer 41 and a second bonding layer 42, wherein the first bonding layer 41 has better bonding properties to the membrane electrode assembly 21 than to the resin frame 3, and the second bonding layer 42 has better bonding properties to the resin frame 3 than to the MEA 21. When the preparation of the thermoplastic adhesive 4 is completed and the preparation step P1 is completed, the configuration step P2 is implemented.

[0060] The arrangement step P2 is a step of arranging the thermoplastic adhesive 4 as a double-layer adhesive sheet between the MEA 21 and the resin frame 3. In the arrangement step P2, the thermoplastic adhesive 4 is arranged between the membrane electrode assembly 21 and the resin frame 3 in a state where the first bonding layer 41 is opposite to the MEA 21 and the second bonding layer 42 is opposite to the resin frame 3.

[0061] Figure 5 To express Figure 4 Flow chart of an example of the arrangement step P2 in the manufacturing method M of a fuel cell monomer. The arrangement step P2 includes, for example, a step P21 and a step P22. In the step P21, the thermoplastic adhesive 4 as a double-layer adhesive sheet is placed on the MEA 21; in the step P22, the resin frame 3 is placed on the thermoplastic adhesive 4 as a double-layer adhesive sheet placed on the MEA 21. Thus, the thermoplastic adhesive 4 as a double-layer adhesive sheet is arranged between the MEA 21 and the resin frame 3. After the arrangement step P2 is completed, the bonding step P3 is implemented.

[0062] The bonding step P3 is a step of bonding the MEA 21 and the resin frame 3 via the thermoplastic adhesive 4. In the bonding step P3, the thermoplastic adhesive 4 as a double-layer adhesive sheet disposed between the MEA 21 and the resin frame 3 in the disposition step P2 is heated to be plasticized, and the temperature of the plasticized double-layer adhesive sheet is lowered to solidify. Thus, the MEA 21 and the resin frame 3 are thermally welded and bonded via the thermoplastic adhesive 4.

[0063] Then, the cathode side GDL 22 of the MEGA 2 to which the resin frame 3 is bonded via the thermoplastic adhesive 4 is opposed to the cathode side separator 5, and the anode side GDL 23 of the MEGA 2 is opposed to the anode side separator 6. Then, by bonding the MEGA 2 to the cathode side separator 5 and the anode side separator 6, the fuel cell unit 1 is manufactured.

[0064] Hereinafter, the method M for manufacturing a fuel cell and the operation of the fuel cell 1 according to the present embodiment will be described.

[0065] In the conventional fuel cell monomer manufacturing method described in Patent Document 1, a liquid adhesive is used to bond the membrane electrode assembly to the resin frame. However, the liquid adhesive may have coating spots or bubbles mixed in. In addition, when coating spots or bubbles are mixed in the adhesive, the adhesive may be partially damaged, which may cause cross leakage and reduce the durability of the membrane electrode assembly.

[0066] In order to solve this problem, it is possible to use a sheet-like thermoplastic adhesive instead of a liquid adhesive. However, the surface properties of the membrane electrode assembly and the resin frame bonded by the sheet-like thermoplastic adhesive are different. Therefore, when a sheet-like thermoplastic adhesive is used, it is difficult to ensure the required bonding strength for both the membrane electrode assembly and the resin frame.

[0067] In contrast, the manufacturing method M of the fuel cell monomer of the present embodiment is a manufacturing method of the fuel cell monomer 1 obtained by bonding the membrane electrode assembly 21 and the resin frame 3 via the sheet-shaped thermoplastic adhesive 4 as described above. The manufacturing method M of the fuel cell monomer has the preparation step P1, the configuration step P2 and the bonding step P3 as described above. The preparation step P1 is a step of preparing a double-layer adhesive sheet as the thermoplastic adhesive 4, the double-layer adhesive sheet having a first bonding layer 41 and a second bonding layer 42, the first bonding layer 41 having better bonding properties to the membrane electrode assembly 21 than to the resin frame 3; and the second bonding layer 42 having better bonding properties to the resin frame 3 than to the membrane electrode assembly 21. The configuration step P2 is a step of configuring the thermoplastic adhesive 4 between the membrane electrode assembly 21 and the resin frame 3 in a state where the first bonding layer 41 is opposite to the membrane electrode assembly 21 and the second bonding layer 42 is opposite to the resin frame 3. The bonding step P3 is a step of heating the thermoplastic adhesive 4 arranged between the membrane electrode assembly 21 and the resin frame 3 in the arrangement step P2 to plasticize it, and then lowering the temperature of the plasticized thermoplastic adhesive 4 to solidify it, thereby bonding the membrane electrode assembly 21 and the resin frame 3 via the thermoplastic adhesive 4.

[0068] According to the manufacturing method M of the fuel cell monomer of the present embodiment, the membrane electrode assembly 21 and the resin frame 3 are joined by heat-melting via the sheet-like thermoplastic adhesive 4, thereby preventing the adhesive from being damaged when a liquid adhesive is used. Therefore, according to the manufacturing method M of the fuel cell monomer of the present embodiment, cross leakage can be more reliably prevented compared to the case where a liquid adhesive is used in joining the membrane electrode assembly 21 and the resin frame 3, thereby improving the durability of the membrane electrode assembly 21.

[0069] In addition, according to the manufacturing method M of the fuel cell monomer of the present embodiment, as described above, a double-layer adhesive sheet is used as the thermoplastic adhesive 4, and the double-layer adhesive sheet has a first bonding layer 41 and a second bonding layer 42, wherein the first bonding layer 41 has good bonding properties to the membrane electrode assembly 21; and the second bonding layer 42 has good bonding properties to the resin frame 3. As a result, the thermoplastic adhesive 4 can ensure the required bonding strength for both the membrane electrode assembly 21 and the resin frame 3 having different surface properties. Therefore, according to the manufacturing method M of the fuel cell monomer of the present embodiment, the thermoplastic adhesive 4 can be closely bonded to both the membrane electrode assembly 21 and the resin frame 3 to provide a seal with electrical insulation.

[0070] In addition, in the manufacturing method M of the fuel cell unit of the present embodiment, the arrangement step P2 includes a step P21 and a step P22. In the step P21, the thermoplastic adhesive 4 as a double-layer adhesive sheet is placed on the membrane electrode assembly 21; and in the step P22, the resin frame 3 is placed on the thermoplastic adhesive 4 placed on the membrane electrode assembly 21. With such a configuration, the thermoplastic adhesive 4 can be easily arranged between the membrane electrode assembly 21 and the resin frame 3 in a state where the first bonding layer 41 of the thermoplastic adhesive 4 is opposite to the membrane electrode assembly 21 and the second bonding layer 42 of the thermoplastic adhesive 4 is opposite to the resin frame 3.

[0071] In addition, in the manufacturing method M of the fuel cell unit of the present embodiment, the first bonding layer 41 of the thermoplastic adhesive 4 is composed of a thermoplastic resin containing an amide group, and the second bonding layer 42 of the thermoplastic adhesive 4 is composed of an olefin-based thermoplastic resin. With such a configuration, the first bonding layer 41 of the thermoplastic adhesive 4 can be firmly bonded to the membrane electrode assembly 21, and the second bonding layer 42 of the thermoplastic adhesive 4 can be firmly bonded to the resin frame 3. Therefore, according to the manufacturing method M of the fuel cell unit of the present embodiment, it is possible to prevent the resin frame 3 from peeling off from the membrane electrode assembly 21.

[0072] In addition, the fuel cell unit 1 of the present embodiment adheres the membrane electrode assembly 21 to the resin frame 3 via a sheet-shaped thermoplastic adhesive 4. The thermoplastic adhesive 4 is a double-layer adhesive sheet having a first bonding layer 41 and a second bonding layer 42, wherein the bonding property of the first bonding layer 41 to the membrane electrode assembly 21 is better than the bonding property of the first bonding layer 41 to the resin frame 3; and the bonding property of the second bonding layer 42 to the resin frame 3 is better than the bonding property of the second bonding layer 42 to the membrane electrode assembly 21. In the fuel cell unit 1, in a state where the membrane electrode assembly 21 is bonded to the first bonding layer 41 and the resin frame 3 is bonded to the second bonding layer 42, the membrane electrode assembly 21 and the resin frame 3 are bonded via the thermoplastic adhesive 4 as a double-layer adhesive sheet.

[0073] According to the fuel cell unit 1 of the present embodiment, the membrane electrode assembly 21 and the resin frame 3 are joined by heat welding via the sheet-like thermoplastic adhesive 4, so that it is possible to prevent the adhesive from being damaged when a liquid adhesive is used. Therefore, according to the fuel cell unit 1 of the present embodiment, compared with the case where a liquid adhesive is used in the joining between the membrane electrode assembly 21 and the resin frame 3, it is possible to more reliably prevent cross leakage and improve the durability of the membrane electrode assembly 21.

[0074] In addition, according to the fuel cell monomer 1 of the present embodiment, as described above, a double-layer adhesive sheet having a first bonding layer 41 and a second bonding layer 42 is used as the thermoplastic adhesive 4, and the first bonding layer 41 has good bonding properties to the membrane electrode assembly 21; and the second bonding layer 42 has good bonding properties to the resin frame 3. As a result, the thermoplastic adhesive 4 can ensure the required bonding strength for both the membrane electrode assembly 21 and the resin frame 3 having different surface properties. Therefore, according to the fuel cell monomer 1 of the present embodiment, the thermoplastic adhesive 4 can be closely bonded to both the membrane electrode assembly 21 and the resin frame 3 to provide a seal with electrical insulation.

[0075] In addition, in the fuel cell monomer 1 of the present embodiment, the cathode side catalyst layer 21b of the membrane electrode assembly 21 is exposed at the outer edge of the MEGA 2, and the exposed cathode side catalyst layer 21b is covered with the thermoplastic adhesive 4. In this way, by covering the cathode side catalyst layer 21b that generates more water with the thermoplastic adhesive 4, the hydrolysis of the amide bond is suppressed, and the swelling of the membrane electrode assembly 21 is suppressed, and the durability of the MEGA 2 is improved.

[0076] As described above, according to the present embodiment, it is possible to provide a fuel cell manufacturing method M and a fuel cell 1 that can ensure the required bonding strength for both the membrane electrode assembly 21 and the resin frame 3 having different surface properties.

[0077] The manufacturing method of the fuel cell monomer and the implementation method of the fuel cell monomer involved in the present disclosure are described in detail above using the accompanying drawings, but the specific structure is not limited to this implementation method. Even if there are design changes within the scope of the main purpose of the present disclosure, these are also included in the present disclosure.

Claims

1. A method for manufacturing a fuel cell monomer, in which a membrane electrode assembly and a resin frame are bonded via a sheet-like thermoplastic adhesive, characterized in that: The manufacturing method has the following features: A preparation step, wherein a double-layer adhesive sheet is prepared as the thermoplastic adhesive, the double-layer adhesive sheet having a first bonding layer and a second bonding layer, the first bonding layer having better bonding property to the membrane electrode assembly than the first bonding layer having better bonding property to the resin frame, and the second bonding layer having better bonding property to the resin frame than the second bonding layer having better bonding property to the membrane electrode assembly; an arranging step of arranging the double-layer adhesive sheet between the membrane electrode assembly and the resin frame in a state where the first bonding layer is opposed to the membrane electrode assembly and the second bonding layer is opposed to the resin frame; and a bonding step, wherein the double-layer adhesive sheet disposed between the membrane electrode assembly and the resin frame in the disposing step is heated to plasticize the double-layer adhesive sheet, and the temperature of the plasticized double-layer adhesive sheet is lowered to solidify the double-layer adhesive sheet, thereby bonding the membrane electrode assembly to the resin frame via the thermoplastic adhesive, The membrane electrode assembly includes an electrolyte membrane, a cathode catalyst layer and an anode catalyst layer, wherein the cathode catalyst layer exposed at the outer edge is covered with the thermoplastic adhesive. The resin frame has a three-layer structure of a core material, an adhesive layer formed on one surface of the core material, and an adhesive layer formed on the other surface of the core material, wherein the adhesive layer is an adhesive formed of polypropylene or epoxy resin, wherein the first bonding layer is composed of a thermoplastic resin containing an amide group, and The second bonding layer is made of an olefin-based thermoplastic resin.

2. The method for manufacturing a fuel cell monomer according to claim 1, characterized in that: The arranging step includes: a step of placing the two-layer adhesive sheet on the membrane electrode assembly; and a step of placing the resin frame on the two-layer adhesive sheet placed on the membrane electrode assembly.

Images