Manufacturing method of membrane electrode structure and the membrane electrode structure

Abstract

To provide a manufacturing method of a membrane electrode structure and the membrane electrode structure capable of peeling off only a protective sheet when peeling off the protective sheet.SOLUTION: A manufacturing method of a membrane electrode structure 10 includes a frame-shaped member mounting step of mounting a frame-shaped member 4 on an adsorption plate 5, an electrode catalyst layer mounting step of mounting an electrode catalyst layer 3 on the frame-shaped member 4 so that an outer peripheral edge part 3a of the electrode catalyst layer 3 overlaps an edge part 4b of an opening 4a, an electrolyte membrane mounting step of mounting an electrolyte membrane 2 on an opposite side of the electrode catalyst layer 3 to the frame-shaped member 4, and a protective sheet peeling step of peeling a protective sheet 6 after stacking the electrolyte membrane 2. An outer peripheral edge part 2a of the electrolyte membrane 2 is disposed outside the outer peripheral edge part 3a of the electrode catalyst layer 3. In the electrolyte membrane placing step, a two-layer part 21 in which the frame-shaped member 4 and the electrolyte membrane 2 are laminated and a three-layer part 22 in which the frame-shaped member 4, the electrode catalyst layer 3, and the electrolyte membrane 2 are laminated are sequentially formed from the outer peripheral edge portion 2a of the electrolyte membrane 2 to an edge part 4b of the opening 4a.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Generally, in a fuel cell membrane electrode assembly, the electrolyte membrane is a very thin and soft sheet that is easily deformed by humidity and ambient temperature, and if foreign matter adheres to the surface, it will affect power generation performance. For this reason, a protective sheet is attached to the electrolyte membrane to protect the surface.

[0003] Also, a known method for manufacturing a membrane electrode assembly is to apply a slurry for an electrode catalyst layer to a release sheet to form an electrode catalyst layer, and then transfer the electrode contact layer to the electrolyte membrane by thermocompression bonding (see, for example, Patent Document 1). In this way, a sheet is used in the membrane electrode assembly of a fuel cell.

[0004] Fig. 9 is a schematic cross-sectional view of a main part showing the structure of a conventional membrane electrode assembly for a fuel cell, and Fig. 10 is a schematic cross-sectional view of a main part showing a state when a protective sheet provided on the membrane electrode assembly is peeled off.

[0005] As shown in Fig. 9, the membrane electrode assembly 100 is formed by joining a membrane electrode assembly 200, which is made up of an electrode catalyst layer 210 and an electrolyte membrane 220, to a frame member 300 with an adhesive layer 400. The membrane electrode assembly 100 is covered with a protective sheet 500. The protective sheet 500 is then peeled off by pulling it up with adhesive tape 600, as shown in Fig. 10. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 3465209 Summary of the Invention [Problem to be solved by the invention]

[0007] However, when the adhesive tape 600 is pulled upward to peel off the protective sheet 500, a peeling load F100 is applied to the interface between the protective sheet 500 and the electrolyte membrane 220. In addition, an interfacial strength F200 is applied to the interior of the electrode catalyst layer 210, the interface between the electrolyte membrane 220 and the electrode catalyst layer 210, and the interface between the electrode catalyst layer 210 and the frame member 300.

[0008] In this case, the peel load F100 of the protective sheet 500 cannot be overcome by the interfacial strength F200 between the electrolyte membrane 220 and the electrode catalyst layer 210, and between the electrode catalyst layer 210 and the frame member 300, causing peeling at the interface between them. Furthermore, when peeling the protective sheet 500, electrode damage 210a sometimes occurred inside the electrode catalyst layer 210.

[0009] Therefore, an object of the present invention is to provide a method for manufacturing a membrane electrode assembly and a membrane electrode assembly that can reduce the impact on the electrode catalyst layer when the protective sheet is peeled off. [Means for solving the problem]

[0010] As a means for solving the above-mentioned problems, the present invention provides a method for manufacturing a membrane electrode assembly by joining an electrolyte membrane to which a protective sheet is attached, an electrode catalyst layer laminated on the side of the electrolyte membrane opposite to the protective sheet, and a frame-shaped member having an opening in the center and laminated on the outer periphery of the electrolyte membrane and the electrode catalyst layer, the method comprising: a frame-shaped member placing step of placing the frame-shaped member on an adsorption plate; and an electrode catalyst layer placing step of placing the electrode catalyst layer on the frame-shaped member so that the outer periphery of the electrode catalyst layer overlaps the edge of the opening. a step of placing the electrolyte membrane on the side of the electrode catalyst layer opposite the frame-shaped member; and a step of peeling off the protective sheet after laminating the electrolyte membrane, wherein the outer peripheral edge of the electrolyte membrane is positioned outside the outer peripheral edge of the electrode catalyst layer, and in the electrolyte membrane placing step, a two-layer portion in which the frame-shaped member and the electrolyte membrane are stacked, and a three-layer portion in which the frame-shaped member, the electrode catalyst layer, and the electrolyte membrane are stacked are formed sequentially from the outer peripheral edge of the electrolyte membrane to the edge of the opening. [Effects of the Invention]

[0011] The present invention can provide a method for producing a membrane electrode assembly and a membrane electrode assembly that can reduce the impact on an electrode catalyst layer when a protective sheet is peeled off. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 2 is a diagram illustrating a method for manufacturing a membrane electrode assembly and a membrane electrode assembly according to an embodiment of the present invention, and is a schematic cross-sectional view of a main part illustrating a state in which an adhesive tape is attached to a protective sheet. [Figure 2] 4 is a schematic cross-sectional view of a main part showing a state in which the protective sheet is pulled up with an adhesive tape and peeled off from the electrolyte membrane. FIG. [Figure 3] 3 is a schematic cross-sectional view of a main part showing the state when the protective sheet shown in FIG. 2 is further pulled up with adhesive tape. FIG. [Figure 4] FIG. 3 is an enlarged view of a main part of FIG. 2. [Figure 5A] FIG. 2 is a plan view showing an installation state of a protective sheet attached to a membrane electrode assembly. [Figure 5B] 5B is a cross-sectional view taken along the line VB-VB in FIG. 5A. [Figure 5C] 5B is a cross-sectional view taken along the line VC-VC in FIG. 5A. [Figure 6] 4 is a graph showing the interfacial strength of each member of the membrane electrode assembly. [Figure 7A] FIG. 4 is a diagram illustrating a protective sheet positioning step in the method for manufacturing a membrane electrode assembly, and is a schematic plan view of the membrane electrode assembly. [Figure 7B] FIG. 2 is a schematic cross-sectional view of a membrane electrode assembly showing an adsorption step in a method for manufacturing a membrane electrode assembly. [Figure 7C] 3 is a schematic view showing an adhesive tape gripping and cutting step in the method for producing a membrane electrode assembly. FIG. [Figure 7D] 5A and 5B are schematic diagrams illustrating a tape posture correction step in the method for manufacturing a membrane electrode assembly. [Figure 7E] 3 is a schematic cross-sectional view of a main part illustrating an adhesive tape attaching step in a method for manufacturing a membrane electrode assembly. FIG. [Figure 7F] 4 is a schematic cross-sectional view of a main part illustrating a protective sheet peeling step in a method for manufacturing a membrane electrode assembly. FIG. [Figure 7G] FIG. 4 is a schematic plan view showing a protective sheet peeling step in the method for manufacturing a membrane electrode assembly. [Figure 8] FIG. 10 is a cross-sectional view showing a modified example of a membrane electrode assembly. [Figure 9] FIG. 1 is a schematic cross-sectional view showing a main part of the structure of a conventional membrane electrode assembly for a fuel cell. [Figure 10] 3 is a schematic enlarged cross-sectional view of a main part showing a state in which a protective sheet provided on a membrane electrode assembly is peeled off. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, a method for manufacturing a membrane electrode assembly 10 according to an embodiment of the present invention and the membrane electrode assembly 10 will be described with reference to FIG. For convenience, the vertically upper side of the membrane electrode assembly 10 shown in Figure 1 will be referred to as "top," the vertically lower side as "bottom," and the width direction as "left" and "right." Hereinafter, common members in each figure will be assigned the same reference numerals, and their description will be omitted.

[0014] ≪Membrane electrode structure≫ The membrane electrode structure 10 is used in a polymer electrolyte fuel cell. The membrane electrode structure 10 is formed by joining a membrane electrode assembly 1 and a frame member 4. The membrane electrode structure 10 is placed on an adsorption plate 5.

[0015] <Membrane electrode assembly> The membrane electrode assembly 1 comprises an electrolyte membrane 2 with a protective sheet 6 attached to one side thereof, and an electrode catalyst layer 3 laminated on the other side of the electrolyte membrane 2. The membrane electrode assembly 1 is manufactured by joining the electrolyte membrane 2, a frame-shaped member 4 joined to the outer peripheral edge 2a of the electrolyte membrane 2, and the electrode catalyst layer 3.

[0016] <Adsorption plate> The adsorption plate 5 is a plate-like member made of a breathable material. A suction mechanism 8 that attracts the adsorption plate 5 is provided below the adsorption plate 5. Therefore, when the adsorption plate 5 is pulled downward by the suction mechanism 8, the electrode catalyst layer 3, the electrolyte membrane 2, and the protective sheet 6 can be attracted and adhered to the adsorption plate 5 side (see FIG. 7B). The adsorption plate 5 also constitutes part of a transport mechanism 50 that transports the membrane electrode assembly 1.

[0017] <Suction mechanism> As shown in FIG. 1, the suction mechanism 8 is a suction device that, when peeling the protective sheet 6 from the electrolyte membrane 2, sucks the electrode catalyst layer 3 and the electrolyte membrane 2 using an adsorption plate 5 to prevent peeling (see FIG. 7B).

[0018] Fig. 5A is a plan view showing the state in which the protective sheet 6 is attached to the membrane electrode assembly 10. Fig. 5B is a cross-sectional view taken along VB-VB in Fig. 5A. Fig. 5C is a cross-sectional view taken along VC-VC in Fig. 5A.

[0019] <Frame-shaped member> As shown in FIG. 1, the frame member 4 is a subgasket that is integrally joined to the outer periphery of the electrolyte membrane 2. The frame member 4 has a central opening 4a and is made of a substantially rectangular annular member that is formed along the outer periphery of the electrolyte membrane 2 so as to surround the electrolyte membrane 2 (see FIGS. 5A to 5C). The frame member 4 is made of a sheet-like resin film. The frame member 4 is joined to the outer periphery 2a of the electrolyte membrane 2 and placed on the adsorption plate 5. An adhesive layer 43 is provided on the upper surface of the frame member 4 to bond the outer periphery 3a of the electrode catalyst layer 3 and the edge 4b ​​of the frame member 4 to the frame member 4.

[0020] <Electrode catalyst layer> The electrode catalyst layer 3 is made of a porous material that is permeable to gases. An electrolyte membrane 2 is placed on top of the electrode catalyst layer 3. A breathable adsorption plate 5 is placed below the electrode catalyst layer 3. This allows the electrolyte membrane 2 to be adsorbed onto the electrode catalyst layer 3 by a suction mechanism 8 located below the adsorption plate 5, which attracts the adsorption plate 5 and the electrode catalyst layer 3. Because the electrode catalyst layer 3 is attracted toward the adsorption plate 5 by the suction mechanism 8, it is possible to prevent the electrode catalyst layer 3 from lifting up (see FIG. 4 ). The outer peripheral edge 3a of the electrode catalyst layer 3 is placed on the edge 4b ​​of the opening 4a of the frame member 4, forming an overlapping portion 31 where the electrode catalyst layer 3 overlaps the frame member 4. In a fuel cell using the membrane electrode assembly 1, a pair of electrode catalyst layers 3 are formed on both sides of the electrolyte membrane 2, with one of the pair of electrode catalyst layers 3 serving as the anode and the other as the cathode. Note that one of the electrode catalyst layers 3 is omitted in FIGS. 1 to 7 .

[0021] <Electrolyte membrane> The electrolyte membrane 2 shown in FIG. 1 is made of a rectangular sheet that is very thin, soft, and easily deformable (see FIGS. 5A to 5C). The electrolyte membrane 2 is formed, for example, from a perfluorosulfonic acid polymer such as Nafion (registered trademark). The outer peripheral edge 2a of the electrolyte membrane 2 is disposed outward from the outer peripheral edge 3a of the electrode catalyst layer 3. The portion where the outer peripheral edge 2a of the electrolyte membrane 2 and the frame member 4 are laminated is referred to as the two-layer portion 21. Furthermore, the portion inside the two-layer portion 21 where the electrolyte membrane 2, the outer peripheral edge 3a of the electrode catalyst layer 3, and the frame member 4 are laminated is referred to as the three-layer portion 22. The two-layer portion 21 and the three-layer portion 22 are formed sequentially from the outer peripheral edge 2a of the electrolyte membrane 2 to the edge 4b ​​of the opening 4a.

[0022] <Protective sheet> The protective sheet 6 is a backing film that covers and protects the surface of the membrane electrode assembly 10. By covering the electrolyte membrane 2, the protective sheet 6 can prevent foreign matter from adhering to the electrolyte membrane 2. The protective sheet 6 is peeled off from the electrolyte membrane 2 after the electrolyte membrane 2 is laminated on the electrode catalyst layer 3 with the electrolyte membrane 2 interposed therebetween.

[0023] Fig. 2 is a schematic cross-sectional view of the main part showing the state when the protective sheet 6 is pulled up with the adhesive tape 7 and peeled off from the electrolyte membrane 2. Fig. 3 is a schematic cross-sectional view of the main part showing the state when the protective sheet 6 in the state shown in Fig. 2 is further pulled up with the adhesive tape 7. Fig. 4 is an enlarged view of the main part of Fig. 2.

[0024] <Adhesive tape> 1 and 2, the adhesive tape 7 is a tape for peeling off the protective sheet 6 from the electrolyte membrane 2 to which it is attached. The adhesive tape 7 is removably attached to the outermost edge 6a of the protective sheet 6. As shown in FIGS. 2 to 4, the adhesive tape is preferably peeled off in a diagonal direction (the direction of arrow b) relative to the rectangular protective sheet 6 while pulling up a corner 6b (see FIG. 7G) of the outermost edge 6a of the protective sheet 6.

[0025] FIG. 6 is a graph showing the interfacial strength of each member of the membrane electrode assembly 10. As shown in FIG. As shown in FIG. 6, the components of the membrane electrode assembly 10 are configured such that the interface strength increases in the order of protective sheet 6, electrolyte membrane 2, electrode catalyst layer 3, and adhesive layer 43.

[0026] <Method for manufacturing membrane electrode assembly> Next, a method for manufacturing the membrane electrode assembly 10 will be described in order of steps. The processing order in the manufacturing method is an example and may be changed as appropriate.

[0027] <Frame-shaped member placing step> When manufacturing the membrane electrode assembly 10, first, a frame-shaped member placing step is performed in which the frame-shaped member 4 shown in FIG.

[0028] <Frame-shaped member determination process> FIG. 7A is a diagram illustrating a frame-shaped member determining step in the manufacturing method of the membrane electrode assembly 10, and is a schematic plan view of the membrane electrode assembly 10. FIG. Next, a frame-shaped member positioning step is carried out in which the floating device 91 presses the frame-shaped member 4 onto the suction plate 5 from all sides to position it, and the outer edge of the frame-shaped member 4 is aligned with a predetermined position.

[0029] <Electrode catalyst layer placement step> Subsequently, an electrode catalyst layer placing step is performed in which the electrode catalyst layer 3 is placed on the frame member 4 so that the outer peripheral edge 3a of the electrode catalyst layer 3 overlaps the edge 4b ​​of the opening 4a.

[0030] <Electrolyte membrane placement process> Next, an electrolyte membrane placing step is performed in which the electrolyte membrane 2 is placed on the side of the electrode catalyst layer 3 opposite the frame member 4. In the electrolyte membrane placing step, a two-layer portion 21 including the frame member 4 and the electrolyte membrane 2 and a three-layer portion 22 including the frame member 4, the electrode catalyst layer 3, and the electrolyte membrane 2 are formed sequentially from the outer peripheral edge portion 2a of the electrolyte membrane 2 to the edge portion 4b of the opening 4a.

[0031] <Adhesive layer protection process> Next, as shown in FIG. 7E, an adhesive layer protection step is performed in which a frame-shaped protective sheet 42 is placed over the adhesive layer 43 provided on the outer side of the electrolyte membrane 2 to protect the adhesive layer 43.

[0032] <Adsorption process> FIG. 7B is a diagram illustrating the adsorption step in the method for producing the membrane electrode assembly 10, and is a schematic cross-sectional view of the membrane electrode assembly 10. Next, as shown in FIG. 7B, an adsorption process is performed in which the protective sheet 6, electrolyte membrane 2, electrode catalyst layer 3, and frame-shaped member 4 placed on the adsorption plate 5 are sucked in the direction of the adsorption plate 5 (in the direction of arrow d) through the porous adsorption plate 5 by the suction mechanism 8, thereby adsorbing each of them entirely.

[0033] <Adhesive tape gripping and cutting process> FIG. 7C is a schematic diagram showing the adhesive tape gripping and cutting step in the method for producing the membrane electrode assembly 10. 7C, an adhesive tape gripping and cutting step is performed in which one end 7a of the adhesive tape 7 is bent so as to fold and gripped with a tape clamp 92, and the other end 7b of the adhesive tape 7 is cut to an appropriate length with a tape cutter 93. In this case, it is preferable to use a tape cutter device equipped with a tip bending mechanism and tape clamp 92 as the tape cutter 93.

[0034] <Tape posture correction process> FIG. 7D is a schematic diagram showing a tape posture correction step in the method for manufacturing the membrane electrode assembly 10. As shown in FIG. 7D, one end 7a of the adhesive tape 7 is held by a tape clamp 92. The other end 7b of the adhesive tape 7 is supported by a presser 94, while a tape roller 95 presses the adhesive tape 7 toward the presser 94 (in the direction of arrow e), thereby performing a tape posture correction step in which the adhesive tape 7 is bent and corrected into a desired shape.

[0035] <Adhesive tape application process> FIG. 7E is a schematic cross-sectional view of a main part showing the adhesive tape attaching step in the manufacturing method of the membrane electrode assembly 10. As shown in FIG. 7E is performed, in which peeling adhesive tape 7 is applied to the outermost edge 6a of protective sheet 6. During the adhesive tape application process, adhesive tape 7 is firmly attached by pressing the upper surface of the outer periphery of protective sheet 6 with presser 94 in the direction of arrow g so that the other end 7b side of adhesive tape 7 is positioned from above two-layer portion 21 to above three-layer portion 22.

[0036] <Protective sheet peeling process> 7F is a schematic cross-sectional view of a main part showing the protective sheet peeling step in the method for manufacturing the membrane electrode assembly 10. FIG. Next, a protective sheet peeling step is carried out to peel off protective sheet 6 shown in FIGS. 7F and 7G. First, a lifting step is performed in which the tape clamp 92 gripping one end 7a of the adhesive tape 7 is lifted in the separation direction (arrow h direction) while the presser 94 presses the curved portion 6c of the protective sheet 6 toward the electrolyte membrane 2 (arrow f direction), thereby peeling off the corner portion 6b of the protective sheet 6. During the lifting step and the protective sheet peeling step, the suction mechanism 8 sucks the suction plate 5 in the direction of the suction plate 5 (arrow d direction), thereby preventing the membrane electrode assembly 10 from peeling off from the suction plate 5 (see FIG. 7B ).

[0037] 7G, while supporting the curved portion 6c of the protective sheet 6 with a tape roller 95 for posture correction, the tape clamp 92 with the adhesive tape 7 pulled is moved from the corner 6b in the diagonal direction of the protective sheet 6 (the direction of arrow b) to peel off the protective sheet 6. In this way, the protective sheet 6 can be easily peeled off from the electrolyte membrane 2.

[0038] <Adhesive tape protective sheet disposal process> Subsequently, an adhesive tape and protective sheet discarding step is carried out in which the peeled adhesive tape 7 and protective sheet 6 are discarded in a discard box, thereby completing all steps in the method for manufacturing a membrane electrode assembly.

[0039] As described above, the present invention shown in FIG. 1 is a method for manufacturing a membrane electrode assembly 10 by joining an electrolyte membrane 2 to which a protective sheet 6 is attached, an electrode catalyst layer 3 laminated on the side of the electrolyte membrane 2 opposite to the protective sheet 6, and a frame-shaped member 4 having an opening 4a in the center and laminated on the outer periphery of the electrolyte membrane 2 and the electrode catalyst layer 3, the method comprising the steps of: a frame-shaped member placing step of placing the frame-shaped member 4 on an adsorption plate 5; an electrode catalyst layer placing step of placing the electrode catalyst layer 3 on the frame-shaped member 4 so that the outer periphery 3a of the electrode catalyst layer 3 overlaps the edge 4b ​​of the opening 4a; and a protective sheet peeling step of peeling off the protective sheet 6 after laminating the electrolyte membrane 2, wherein the outer peripheral edge 2a of the electrolyte membrane 2 is positioned outside the outer peripheral edge 3a of the electrode catalyst layer 3, and in the electrolyte membrane placing step, a two-layer portion 21 in which the frame-shaped member 4 and the electrolyte membrane 2 are laminated, and a three-layer portion 22 in which the frame-shaped member 4, the electrode catalyst layer 3, and the electrolyte membrane 2 are laminated are formed sequentially from the outer peripheral edge 2a of the electrolyte membrane 2 to the edge 4b ​​of the opening 4a, and in the protective sheet peeling step, the protective sheet is peeled off from the two-layer portion 21 toward the three-layer portion 22.

[0040] According to this configuration, the present invention has an outer peripheral edge 2a of the electrolyte membrane 2 located outside the outer peripheral edge 3a of the electrode catalyst layer 3, and has, from the outside, a two-layer portion 21 in which the frame member 4 and the electrolyte membrane 2 are stacked, and a three-layer portion 22 in which the frame member 4, the electrode catalyst layer 3, and the electrolyte membrane 2 are stacked, in this order. As a result, the adhesive interface at which peeling starts is the two-layer portion 21 between the electrolyte membrane 2 and the frame member 4, and is located away from the electrode catalyst layer 3. Therefore, when peeling the protective sheet 6, it is possible to peel only the protective sheet 6 from the membrane electrode assembly 10 while reducing the impact on the electrode catalyst layer 3.

[0041] The adsorption plate 5 shown in FIG. 1 is a part of a transport mechanism 50 that transports the membrane electrode assembly 1.

[0042] According to this configuration, the adsorption plate 5 is a conveying mechanism 50 that conveys the membrane electrode assembly 1, and by moving the adsorption plate 5, the entire membrane electrode assembly 1 can be moved, thereby enabling the membrane electrode structure 10 to be manufactured efficiently.

[0043] As shown in FIG. 7B, the adsorption plate 5 includes a suction mechanism 8 that sucks the adsorption plate 5, and the suction mechanism 8 sucks the adsorption plate 5 in the protective sheet peeling step.

[0044] 4, when peeling off the protective sheet 6, the suction mechanism 8 sucks the adsorption plate 5, thereby sucking the electrode catalyst layer 3 and the electrolyte membrane 2 in the direction opposite to the peeling direction. Therefore, the suction mechanism 8 can prevent the electrode catalyst layer 3 and the electrolyte membrane 2 from floating up in the peeling direction during the protective sheet peeling step.

[0045] The protective sheet peeling process includes an adhesive tape application process of applying peeling adhesive tape 7 to the outermost edge 6a of the protective sheet 6, as shown in FIG. 7E, and a lifting process of lifting the adhesive tape 7 upward, as shown in FIG. 7F. The adhesive force F1 (see FIG. 1) between the adhesive tape 7 and the protective sheet 6 during the lifting process is set to be greater than the adhesive force F4 (see FIG. 1) between the frame-shaped member 4 and the electrolyte membrane 2.

[0046] 1, in the membrane electrode assembly 10, the adhesive strength F1 between the adhesive tape 7 and the protective sheet 6 is set to be greater than the adhesive strength F4 between the frame member 4 and the electrolyte membrane 2. Therefore, as shown in FIGS. 2 and 3, peeling of the electrolyte membrane 2 from the frame member 4 can be suppressed during the lifting step, and the membrane electrode assembly 10 can prevent peeling. Therefore, in the membrane electrode assembly 10, when peeling the protective sheet 6 from the electrolyte membrane 2, only the protective sheet 6 can be peeled off.

[0047] 7E and 7F, a membrane electrode assembly 10 (of a fuel cell) is formed by joining an electrolyte membrane 2, an electrode catalyst layer 3 laminated on the electrolyte membrane 2, and a frame-shaped member 4 (first frame-shaped member) having an opening 4a in the center and laminated on the outer peripheral edge 3a of the electrolyte membrane 2 and the electrode catalyst layer 3, in which the outer peripheral edge 2a of the electrolyte membrane 2 is positioned outside the outer peripheral edge 3a of the electrode catalyst layer 3, and a two-layer portion 21 in which the frame-shaped member 4 and the electrolyte membrane 2 are laminated, and a three-layer portion 22 in which the frame-shaped member 4, the electrode catalyst layer 3, and the electrolyte membrane 2 are laminated are formed in sequence from the outer peripheral edge 2a of the electrolyte membrane 2 to the edge 4b ​​of the opening 4a.

[0048] 1 and 2, in the membrane electrode assembly 10, the two-layer portion 21 and the three-layer portion 22 are formed from the outer peripheral edge 2a of the electrolyte membrane 2 to the edge 4b ​​of the opening 4a. Therefore, the electrolyte membrane 2 can be bonded to the frame member 4 with the outer peripheral edge 2a completely covering the outer peripheral edge 3a of the electrode catalyst layer 3, thereby increasing the bonding area. This allows the electrolyte membrane 2 to be firmly bonded to the frame member 4, and therefore can be bonded without peeling off from the frame member 4.

[0049] [Variations] The present invention is not limited to the above-described embodiments, and various modifications and changes are possible within the scope of the technical concept thereof. It goes without saying that the present invention also covers such modified and changed inventions. FIG. 8 is a schematic cross-sectional view showing a modified example of a membrane electrode assembly for a fuel cell according to an embodiment of the present invention.

[0050] 8, for example, a second frame member 40 having a central opening 40b is bonded to the surface of a first frame member 41 facing the electrolyte membrane 2 via an adhesive layer 43. The membrane electrode assembly 1 has a two-layer portion 40a in which the first frame member 41 and the electrolyte membrane 2 are stacked, and a three-layer portion 41a in which the second frame member 40, an electrode catalyst layer 3, and the electrolyte membrane 2 are stacked. The first frame member 41 and the second frame member 40 are arranged to sandwich the two-layer portion 40a and the three-layer portion 41a.

[0051] By doing this, the first frame-shaped member 41 and the second frame-shaped member 40 can be positioned to sandwich the two-layer portion 40a and the three-layer portion 41a, thereby firmly holding the two-layer portion 40a and the three-layer portion 41a. [Explanation of symbols]

[0052] 1 Membrane electrode assembly 2 Electrolyte membrane 2a Outer edge 3 Electrode catalyst layer 3a Outer edge 4. Frame-shaped member (first frame-shaped member) 4a aperture 4b Edge 5 Adsorption plate 6 Protective Sheet 6a Outermost edge 7 adhesive tape 8 Suction mechanism 10 Membrane electrode structure 21 Second layer part 22 Third layer part 43 Adhesive layer 50 Conveyor mechanism F1,F4 Adhesive strength

Claims

1. A method for manufacturing a membrane electrode assembly by joining an electrolyte membrane having a protective sheet attached thereto, an electrode catalyst layer laminated on the side of the electrolyte membrane opposite to the protective sheet, and a frame-shaped member having an opening in the center and laminated on an outer periphery of the electrolyte membrane and the electrode catalyst layer, comprising: a frame-shaped member placing step of placing the frame-shaped member on an adsorption plate; an electrode catalyst layer placing step of placing the electrode catalyst layer on the frame-shaped member so that an outer peripheral edge of the electrode catalyst layer overlaps an edge of the opening; an electrolyte membrane placing step of placing the electrolyte membrane on the side of the electrode catalyst layer opposite the frame-shaped member; a protective sheet peeling step of peeling off the protective sheet after laminating the electrolyte membrane, an outer peripheral edge portion of the electrolyte membrane is disposed outside an outer peripheral edge portion of the electrode catalyst layer; In the electrolyte membrane placing step, a two-layer portion in which the frame-shaped member and the electrolyte membrane are stacked, and a three-layer portion in which the frame-shaped member, the electrode catalyst layer, and the electrolyte membrane are stacked are sequentially formed from the outer peripheral edge of the electrolyte membrane to the edge of the opening. A method for manufacturing a membrane electrode assembly.

2. The adsorption plate is a part of a transport mechanism that transports a membrane electrode assembly. The method for producing a membrane electrode assembly according to claim 1 .

3. the adsorption plate includes a suction mechanism that sucks the adsorption plate; The suction mechanism sucks the suction plate in the protective sheet peeling step. The method for producing a membrane electrode assembly according to claim 1 or 2.

4. The protective sheet peeling step includes: an adhesive tape application step of applying an adhesive tape for peeling to the outermost edge of the protective sheet; a pulling-up step of pulling up the adhesive tape, The adhesive strength between the adhesive tape and the protective sheet during the lifting step is set to be greater than the adhesive strength between the frame-shaped member and the electrolyte membrane. The method for producing a membrane electrode assembly according to claim 1 or 2.

5. A membrane electrode assembly comprising an electrolyte membrane, an electrode catalyst layer laminated on the electrolyte membrane, and a first frame-shaped member having an opening in the center and laminated on an outer periphery of the electrolyte membrane and the electrode catalyst layer, the first frame-shaped member being bonded to the first frame-shaped member, an outer peripheral edge portion of the electrolyte membrane is disposed outside an outer peripheral edge portion of the electrode catalyst layer; a two-layer portion in which the first frame-shaped member and the electrolyte membrane are stacked, and a three-layer portion in which the first frame-shaped member, the electrode catalyst layer, and the electrolyte membrane are stacked, are formed in this order from the outer peripheral edge of the electrolyte membrane to the edge of the opening. Membrane electrode structure.

6. a second frame-shaped member having an opening at its center is bonded to a surface of the first frame-shaped member facing the electrolyte membrane via an adhesive layer; The first frame-shaped member and the second frame-shaped member sandwich the two-layer portion and the three-layer portion. The membrane electrode assembly according to claim 5 .

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