Membrane electrode assembly assembly roll, membrane electrode assembly, and solid polymer fuel cell

Abstract

This aggregate roll is a roll obtained by winding a strip-shaped body provided with: a plurality of layered bodies each provided with a polyelectrolyte membrane and a pair of electrode catalyst layers; and a supporting member which includes a plurality of frame-shaped portions aligned in one direction, and in which each frame-shaped portion supports one layered body. The frame-shaped portions surround the outside of the electrode catalyst layers and are in contact with the electrode catalyst layers, and sandwich an outer peripheral portion of the polyelectrolyte membrane within the frame-shaped portion, in a thickness direction.

Description

Technical Field

[0001] The present disclosure relates to an assembly roll of membrane electrode assemblies, membrane electrode assemblies, and solid polymer fuel cells.

Background Art

[0002] A fuel cell generates electric power by utilizing a chemical reaction between a fuel such as hydrogen and an oxidant such as oxygen. A fuel cell is attracting attention as a power generation method that has high power generation efficiency and can reduce environmental load and noise compared with conventional power generation methods using oil and the like. Among fuel cells, solid polymer fuel cells are expected to be used as portable power sources, household power sources, in-vehicle power sources, etc. because they can operate at low temperatures and be miniaturized.

[0003] A solid polymer fuel cell includes a membrane electrode assembly having an electrode catalyst layer constituting a fuel electrode as an anode, an electrode catalyst layer constituting an air electrode as a cathode, and a polymer electrolyte membrane sandwiched between these two electrode catalyst layers. A frame-shaped gasket member is disposed outside each electrode catalyst layer. The gasket member reinforces the membrane electrode assembly centered on the polymer electrolyte membrane with low rigidity and suppresses leakage of the gas supplied to the fuel electrode and the air electrode. Further, a gas diffusion layer for diffusion of the supplied gas is laminated on each electrode catalyst layer. One cell of the solid polymer fuel cell is formed by sandwiching the membrane electrode assembly between a pair of separators having flow paths for gas supply.

[0004] A fuel gas containing hydrogen is supplied to the fuel electrode, and an oxidant gas containing oxygen is supplied to the air electrode. Protons and electrons are generated from the fuel gas supplied to the fuel electrode by the action of the catalyst contained in the electrode catalyst layer. The protons are conducted by the polymer electrolyte contained in the electrode catalyst layer and the polymer electrolyte membrane, and move through the polymer electrolyte membrane to the air electrode. The electrons are taken out from the fuel electrode to the external circuit and move through the external circuit to the air electrode. In the air electrode, the oxidant gas reacts with the protons and electrons that have moved from the fuel electrode to generate water. Thus, an electric current is generated when the electrons pass through the external circuit.

[0005] The formation of polymer electrolyte membranes and electrode catalyst layers requires expensive materials such as polymer electrolytes and platinum-based precious metals that function as catalysts. Therefore, there is a need to reduce the manufacturing cost of membrane electrode assemblies. One means of reducing manufacturing costs is the use of the roll-to-roll method (see, for example, Patent Document 1). Generally, the roll-to-roll method is suitable for mass production and is considered to be able to reduce manufacturing costs by improving the efficiency of the manufacturing process compared to the sheet-type method in which each product is manufactured one by one. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] International Publication No. 2019 / 035424 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] In a typical roll-to-roll manufacturing process, a strip-shaped polymer electrolyte membrane is produced by coating it with an electrode catalyst layer. This strip is then cut to form a membrane electrode assembly. However, since the polymer electrolyte membrane is present not only in areas essential for the membrane electrode assembly, such as the peripheral regions for coating the electrode catalyst layer and transporting the strip, the reduction in manufacturing costs is insufficient from the perspective of reducing material usage.

[0008] Furthermore, since the polymer electrolyte membrane is continuous along the length of the strip, when a gasket member is placed on the strip, the size of the polymer electrolyte membrane and the gasket member will be the same in the aforementioned length direction. As a result, the area where the polymer electrolyte membrane and the gasket member overlap outside the electrode catalyst layer tends to be large. When the overlap between the polymer electrolyte membrane and the gasket member is large, wrinkles occur in the membrane electrode assembly due to the difference in the amount of thermal shrinkage between the polymer electrolyte membrane and the gasket member during the thermocompression bonding of the gas diffusion layer. When wrinkles occur in the membrane electrode assembly, it becomes difficult to assemble the separator to the membrane electrode assembly, and there is also a risk of gas leakage supplied to the fuel electrode and air electrode.

[0009] Furthermore, rolls consisting of a strip-like structure with multiple membrane electrode assemblies connected together are desired not only for the purpose of reducing manufacturing costs, but also for the purpose of facilitating the storage and transportation of membrane electrode assemblies. [Means for solving the problem]

[0010] A roll for solving the above problems is a roll around which a strip-shaped body is wound, the strip-shaped body comprising a plurality of layered bodies each having a polymer electrolyte membrane and a pair of electrode catalyst layers sandwiching the polymer electrolyte membrane in the thickness direction and in contact with the polymer electrolyte membrane, and a plurality of frame-shaped parts arranged continuously along one direction, with each frame-shaped part supporting one of the layered bodies, wherein, when viewed from a direction along the thickness direction of the polymer electrolyte membrane, the polymer electrolyte membrane has an outer peripheral part which is the part that protrudes to the outside of the electrode catalyst layer, the outer shape of the frame-shaped part is larger than the outer shape of the polymer electrolyte membrane, the frame-shaped part surrounds the outside of the electrode catalyst layer and is in contact with the electrode catalyst layer, and sandwiches the outer peripheral part within the frame-shaped part in the thickness direction, when viewed from a direction along the thickness direction of the polymer electrolyte membrane, the width of the outer peripheral part is 1 mm or more, and the ratio of the area of ​​the outer peripheral part to the area of ​​the electrode catalyst layer is 0.2 or less.

[0011] A roll for solving the above problems is a roll around which a strip of material is wound, comprising: a plurality of layered bodies each having a polymer electrolyte membrane and a pair of electrode catalyst layers sandwiching the polymer electrolyte membrane in the thickness direction and in contact with the polymer electrolyte membrane; a plurality of frame-shaped parts arranged along one direction, each of which supports one of the layered bodies; and fixing parts connecting adjacent frame-shaped parts. When viewed from a direction along the thickness direction of the polymer electrolyte membrane, the polymer electrolyte membrane has an outer peripheral portion which is the part that protrudes outside the electrode catalyst layer, and the outer shape of the frame-shaped parts is larger than the outer shape of the polymer electrolyte membrane, and the frame-shaped parts surround the outside of the electrode catalyst layer and are in contact with the electrode catalyst layer, and sandwich the outer peripheral portion within the frame-shaped parts in the thickness direction.

[0012] A membrane electrode assembly for solving the above problems is a membrane electrode assembly in which the assembly roll is divided into sections for each frame-shaped section that supports the layered body. A membrane electrode assembly for solving the above problems comprises a layered body having a polymer electrolyte membrane and a pair of electrode catalyst layers sandwiching the polymer electrolyte membrane in the thickness direction and in contact with the polymer electrolyte membrane, and a frame-shaped portion supporting the layered body, wherein, when viewed from a direction along the thickness direction of the polymer electrolyte membrane, the polymer electrolyte membrane has an outer peripheral portion which is the portion that protrudes to the outside of the electrode catalyst layers, the outer shape of the frame-shaped portion is larger than the outer shape of the polymer electrolyte membrane, the frame-shaped portion surrounds the outside of the electrode catalyst layers and is in contact with the electrode catalyst layers, and sandwiches the outer peripheral portion within the frame-shaped portion in the thickness direction, when viewed from a direction along the thickness direction of the polymer electrolyte membrane, the width of the outer peripheral portion is 1 mm or more, the ratio of the area of ​​the outer peripheral portion to the area of ​​the electrode catalyst layers is 0.2 or less, and the membrane electrode assembly has an end face which is a single continuous surface in the thickness direction and is located at the end of the frame-shaped portion.

[0013] A membrane electrode assembly for solving the above problems comprises a layered body having a polymer electrolyte membrane and a pair of electrode catalyst layers sandwiching the polymer electrolyte membrane in the thickness direction and in contact with the polymer electrolyte membrane, a frame-shaped portion supporting the layered body, and a fixing portion extending along the outer edge of the frame-shaped portion on the end of the frame-shaped portion when viewed from a direction along the thickness direction of the polymer electrolyte membrane, wherein when viewed from a direction along the thickness direction of the polymer electrolyte membrane, the polymer electrolyte membrane has an outer peripheral portion which is a portion that protrudes to the outside of the electrode catalyst layer, the outer shape of the frame-shaped portion is larger than the outer shape of the polymer electrolyte membrane, the frame-shaped portion surrounds the outside of the electrode catalyst layer and is in contact with the electrode catalyst layer, and sandwiches the outer peripheral portion within the frame-shaped portion in the thickness direction, and the fixing portion contains an adhesive or bonding agent and is bonded to the frame-shaped portion.

[0014] According to the above configuration, since multiple membrane electrode assemblies are bundled together in a roll, storage and transportation of the membrane electrode assemblies are easy. Furthermore, the layered structure is located in a part of the assembled roll, and the polymer electrolyte membrane and electrode catalyst layer are not located near the outer edge of the membrane electrode assemblies. Therefore, compared to rolls in which the polymer electrolyte membrane is formed continuously, it is possible to reduce the amount of polymer electrolyte membrane material required to form the membrane electrode assemblies.

[0015] Furthermore, because the outer circumference of the polymer electrolyte membrane is 1 mm or more in width, the adhesion of the frame-shaped part to the outer circumference is enhanced, thereby suppressing the peeling of the support member from the polymer electrolyte membrane. Also, because the ratio of the area of ​​the outer circumference to the area of ​​the electrode catalyst layer is 0.2 or less, the amount of polymer electrolyte membrane material required to form the membrane electrode assembly can be effectively reduced. Moreover, because the area of ​​the region where the polymer electrolyte membrane and the frame-shaped part overlap is not too large, the occurrence of wrinkles at the edges of the membrane electrode assembly during thermocompression bonding of the gas diffusion layer is suppressed. By suppressing the occurrence of wrinkles, leakage of gas supplied to the electrode catalyst layer can be reduced.

[0016] A solid polymer fuel cell for solving the above problems comprises the membrane electrode assembly and a pair of separators sandwiching the membrane electrode assembly. According to the above configuration, in the membrane electrode assembly, it is possible to reduce the material and suppress gas leakage. Therefore, it is possible to reduce the manufacturing cost of the solid polymer fuel cell and suppress the decrease in output due to gas leakage.

Effect of the Invention

[0017] According to the present disclosure, the storage and transportation of the membrane electrode assembly can be facilitated.

Brief Description of the Drawings

[0018] [Figure 1] The figure which shows the perspective structure of the collective roll of the membrane electrode assembly of 1st Embodiment. [Figure 2] The figure which shows the cross-sectional structure of the collective roll of the membrane electrode assembly of 1st Embodiment. [Figure 3] The figure which shows the cross-sectional structure of the membrane electrode assembly of 1st Embodiment. [Figure 4] The figure which shows typically the structure of the electrode catalyst layer which the membrane electrode assembly of 1st Embodiment has. [Figure 5] The figure which shows decomposing | disassembling and showing the perspective structure of the solid polymer fuel cell of 1st Embodiment. [Figure 6] The figure which shows the perspective structure of the collective roll of the membrane electrode assembly of 2nd Embodiment. [Figure 7] The figure which shows the cross-sectional structure of the collective roll of the membrane electrode assembly of 2nd Embodiment.

Mode for Carrying Out the Invention

[0019] (First Embodiment) Referring to FIGS. 1 to 5, a first embodiment of a collective roll of a membrane electrode assembly, a membrane electrode assembly, and a solid polymer fuel cell will be described. Note that the description “at least one of A and B” in this specification should be understood to mean “only A, only B, or both A and B”.

[0020] [Collective Roll] As shown in Figure 1, the assembled roll 100 of membrane electrode assemblies has a structure in which strip-shaped bodies that can be divided into multiple membrane electrode assemblies 10 are wound in a roll shape.

[0021] The assembly roll 100 comprises a plurality of layered bodies 15, each having a polymer electrolyte membrane 11 and a pair of electrode catalyst layers 12A and 12C, and a support member 20. The support member 20 has a plurality of frame-shaped portions 26 that are continuously arranged along one direction, and each frame-shaped portion 26 supports one layered body 15. The direction in which the plurality of frame-shaped portions 26 are arranged is the longitudinal direction of the support member 20, that is, the longitudinal direction of the assembly roll 100. The layered bodies 15 that are adjacent to each other along the longitudinal direction of the assembly roll 100 are separated, and the frame-shaped portions 26 support the layered bodies 15 so as to surround the outer periphery of the layered bodies 15. In other words, the support member 20 has a plurality of openings 25 that are arranged along its longitudinal direction, and the layered bodies 15 are incorporated at the position of each opening 25.

[0022] The membrane electrode assembly 10 is composed of a layered body 15 and a frame-shaped portion 26. In the assembly roll 100, multiple membrane electrode assembly 10 are arranged along the length direction of the assembly roll 100. As shown in Figure 2, the polymer electrolyte membrane 11 is sandwiched between electrode catalyst layers 12A and 12C in its thickness direction. Electrode catalyst layer 12A is in contact with one of the two surfaces of the polymer electrolyte membrane 11 and constitutes the fuel electrode, which is the anode of the polymer electrolyte fuel cell. Electrode catalyst layer 12C is in contact with the other of the two surfaces of the polymer electrolyte membrane 11 and constitutes the air electrode, which is the cathode of the polymer electrolyte fuel cell.

[0023] When viewed from a direction along the thickness direction of the polymer electrolyte membrane 11, the outer shapes of the electrode catalyst layer 12A and electrode catalyst layer 12C are identical. However, the outer shape of the polymer electrolyte membrane 11 is larger than the outer shapes of these electrode catalyst layers 12A and 12C. That is, when viewed from a direction along the thickness direction, the polymer electrolyte membrane 11 has an outer peripheral portion 11e that extends beyond the electrode catalyst layers 12A and 12C. When viewed from a direction along the thickness direction, the outer peripheral portion 11e has a frame shape that surrounds the electrode catalyst layers 12A and 12C.

[0024] The external shapes of the polymer electrolyte membrane 11 and the electrode catalyst layers 12A and 12C are not particularly limited; for example, they may be rectangular. Between adjacent membrane electrode assemblies 10 of the assembly roll 100, the polymer electrolyte membrane 11 is discontinuous, and the electrode catalyst layer 12A is also discontinuous, as is the electrode catalyst layer 12C.

[0025] The support member 20 has a structure in which an adhesive sheet 23A, which is a laminate of a support base material 21A and an adhesive layer 22A, and an adhesive sheet 23C, which is a laminate of a support base material 21C and an adhesive layer 22C, are bonded together so that the adhesive layers 22A and 22C face each other. The opening 25 that penetrates the support member 20 has the same shape as the electrode catalyst layers 12A and 12C when viewed from a direction along the thickness direction of the polymer electrolyte membrane 11. Also, when viewed from the same direction along the thickness direction, the outer shape of the frame-shaped portion 26 is larger than the outer shape of the polymer electrolyte membrane 11.

[0026] The outer periphery 11e of the polymer electrolyte membrane 11 is sandwiched between the adhesive layer 22A and the adhesive layer 22C. In the region outside the polymer electrolyte membrane 11, the adhesive layer 22A and the adhesive layer 22C are in direct contact. That is, in the region between adjacent polymer electrolyte membranes 11, in other words, at the boundary portion of adjacent membrane electrode assemblies 10, the adhesive layer 22A and the adhesive layer 22C are in direct contact.

[0027] The electrode catalyst layers 12A and 12C are located within the opening 25, and the end faces of the electrode catalyst layers 12A and 12C are in contact with the inner circumferential surface of the opening 25 in the support member 20. More specifically, the outside of electrode catalyst layer 12A is surrounded by adhesive sheet 23A, and the outside of electrode catalyst layer 12C is surrounded by adhesive sheet 23C.

[0028] In this configuration, the frame-shaped portion 26 of the support member 20 surrounds the outside of the electrode catalyst layers 12A and 12C and is in contact with the electrode catalyst layers 12A and 12C, while sandwiching the outer peripheral portion 11e of the polymer electrolyte membrane 11 within the frame-shaped portion 26 in the thickness direction. In this configuration, the electrode catalyst layer 12A is exposed from the side of the opening 25 where the adhesive sheet 23A is located, and the electrode catalyst layer 12C is exposed from the side of the opening 25 where the adhesive sheet 23C is located, while the polymer electrolyte membrane 11 is not exposed to the outside of the assembly roll 100.

[0029] The placement of the support member 20 increases the rigidity of the strip-shaped material constituting the collective roll 100, making it easier to wind the strip-shaped material into a roll. Furthermore, since the layered material 15 does not protrude from the support member 20 in the thickness direction, it prevents the layered material 15 from being crushed by contacting other layered material 15 or the support member 20 when wound into a roll.

[0030] In the aggregate roll 100, the layered body 15 is partially located, and the polymer electrolyte membrane 11 and electrode catalyst layers 12A and 12C are not positioned near the outer edge of the membrane electrode assembly 10. Therefore, compared to a roll in which the polymer electrolyte membrane 11 is continuously formed, it is possible to reduce the amount of polymer electrolyte membrane 11 material required to form the membrane electrode assembly 10. For example, the portion necessary for supporting the strip-shaped body extending from the aggregate roll 100 during transport, winding, and cutting of the aggregate roll 100, and which does not contribute to the electrode reaction in the membrane electrode assembly 10, can be composed only of the support member 20.

[0031] Such a bundled roll 100 can be incorporated into a roll-to-roll manufacturing method and can reduce the amount of expensive materials used. Furthermore, since multiple membrane electrode assemblies 10 are bundled together in a roll, storage and transportation of the membrane electrode assemblies 10 are also easy.

[0032] The width W1 of the outer peripheral portion 11e when viewed from a direction along the thickness direction of the polymer electrolyte membrane 11 is 1 mm or more. A width W1 of 1 mm or more enhances the adhesion of the frame-shaped portion 26 to the outer peripheral portion 11e, thereby suppressing the peeling of the support member 20 from the polymer electrolyte membrane 11. Furthermore, the smaller the width W1, the less material is needed for the polymer electrolyte membrane 11 to form the membrane electrode assembly 10.

[0033] When viewed from a direction along the thickness direction, the area of ​​the region where the electrode catalyst layers 12A and 12C are located is denoted as the catalyst layer area Se, and the area of ​​the outer periphery 11e is denoted as the outer periphery area Sm. In this case, the ratio of the outer periphery area Sm to the catalyst layer area Se (Sm / Se) is 0.2 or less. Because the above ratio is 0.2 or less, the polymer electrolyte membrane 11 is not too large relative to the region where the electrode catalyst layers 12A and 12C are formed, i.e., the region where the electrode reaction occurs, so the amount of polymer electrolyte membrane 11 material required to form the membrane electrode assembly 10 can be appropriately reduced. Furthermore, because the above ratio is 0.2 or less, the area of ​​the region where the polymer electrolyte membrane 11 and the support member 20 overlap is not too large relative to the region where the electrode catalyst layers 12A and 12C are formed. Therefore, when the gas diffusion layer is laminated onto the electrode catalyst layers 12A and 12C and heat-compressed, the occurrence of wrinkles at the edges of the membrane electrode assembly 10 due to the difference in the magnitude of thermal contraction between the polymer electrolyte membrane 11 and the support member 20 is suppressed. By suppressing the occurrence of wrinkles, leakage of gas supplied to the electrode catalyst layers 12A and 12C can be suppressed.

[0034] The assembly roll 100 is divided into individual membrane electrode assemblies 10 by dividing it into frame-shaped portions 26 that support the layered bodies 15. More specifically, the assembly roll 100 is divided by cutting along the thickness direction of the boundary portions of adjacent frame-shaped portions 26, that is, the regions consisting only of the support members 20 between adjacent polymer electrolyte membranes 11. For cutting, for example, a cutting tool such as a cutter or a laser can be used.

[0035] [Membrane electrode assembly] Figure 3 shows the membrane electrode assembly 10 formed by the division of the assembly roll 100 described above. The membrane electrode assembly 10 comprises a polymer electrolyte membrane 11, a pair of electrode catalyst layers 12A and 12C sandwiching the polymer electrolyte membrane 11, and a frame-shaped portion 26 consisting of a pair of gasket members 13A and 13C.

[0036] The gasket members 13A and 13C are formed by cutting the support member 20. Gasket member 13A is a member obtained by cutting the adhesive sheet 23A, and gasket member 13C is a member obtained by cutting the adhesive sheet 23C. The laminate of gasket member 13A and gasket member 13C corresponds to one frame-shaped portion 26 of the support member 20.

[0037] The outer periphery 11e of the polymer electrolyte membrane 11 is sandwiched between gasket members 13A and 13C. When viewed from a direction along the thickness direction of the polymer electrolyte membrane 11, the width W2 of the frame-shaped portion 26 is greater than the width W1 of the outer periphery 11e. As described above, the smaller the width W1, the less material of the polymer electrolyte membrane 11 required to form the membrane electrode assembly 10 can be reduced, so it is preferable that the width W1 is 1 / 2 or less of the width W2. Also, since the width W2 is 2 times or more the width W1, sufficient length can be secured between adjacent polymer electrolyte membranes 11 in the collection roll 100, making it easy to set the cutting position of the collection roll 100.

[0038] The gasket member 13A surrounds the outside of the electrode catalyst layer 12A, and the gasket member 13C surrounds the outside of the electrode catalyst layer 12C. The outer peripheral portion 11e of the polymer electrolyte membrane 11 is completely covered by the frame-shaped portion 26 on the outside of the electrode catalyst layers 12A and 12C, thereby suppressing gas leakage from the vicinity of the outer peripheral portion 11e.

[0039] The membrane electrode assembly 10 has an end face 19S, which is a single continuous surface in the thickness direction. The end face 19S is a surface formed by cutting the assembly roll 100 and is located at the end of the membrane electrode assembly 10 in a direction corresponding to the longitudinal direction of the assembly roll 100. That is, the end face 19S is located at the end of the frame-shaped portion 26. When the membrane electrode assembly 10 is formed by separating it from other membrane electrode assemblies 10 located on either side of it in the longitudinal direction of the assembly roll 100, the membrane electrode assembly 10 has an end face 19S at each of its ends in a direction corresponding to the longitudinal direction of the assembly roll 100.

[0040] For example, when the bundled roll 100 is cut with a blade such as a cutter, the end face 19S is flat. Also, when the bundled roll 100 is cut with a laser, the end face 19S is a surface that includes deformation and alteration due to the heat of the laser. When the gasket members 13A and 13C are cut individually beforehand and then bonded together, a step, i.e., a discontinuous portion, is formed on the end face of the film electrode assembly, which is a minute misalignment between the members. In contrast, the end face 19S of the film electrode assembly 10 of this embodiment is a single continuous surface that does not include the above-mentioned discontinuous portion.

[0041] [Materials for assembled rolls and membrane electrode assemblies] The following describes the materials of the components of the assembly roll 100 and the membrane electrode assembly 10.

[0042] The polymer electrolyte membrane 11 contains a polymer electrolyte. The polymer electrolyte used in the polymer electrolyte membrane 11 can be any polymer electrolyte having proton conductivity, such as a fluorine-based polymer electrolyte or a hydrocarbon-based polymer electrolyte. A fluorine-based polymer electrolyte is, for example, a polymer electrolyte having a tetrafluoroethylene skeleton, and an example of such a polymer electrolyte is Nafion (registered trademark: manufactured by DuPont). An example of a hydrocarbon-based polymer electrolyte is sulfonated polyether ketone, sulfonated polyether sulfone, sulfonated polyether ether sulfone, sulfonated polysulfide, sulfonated polyphenylene, etc.

[0043] As shown in Figure 4, the electrode catalyst layers 12A and 12C contain a catalyst material 31, a conductive carrier 32, and an aggregate of polymer electrolyte 33. Furthermore, the electrode catalyst layers 12A and 12C may also contain a fibrous material 34. The compositions of the two electrode catalyst layers 12A and 12C may be the same or different.

[0044] The catalyst material 31 is, for example, platinum group elements such as platinum, palladium, ruthenium, iridium, rhodium, and osmium, or metals such as iron, lead, copper, chromium, cobalt, nickel, manganese, vanadium, molybdenum, gallium, and aluminum, or their alloys, oxides, complex oxides, and carbides. In particular, the catalyst material 31 is preferably platinum or a platinum alloy.

[0045] The conductive carrier 32 can be any carrier that is conductive and not affected by the catalyst. The conductive carrier 32 supports the catalyst material 31. The conductive carrier 32 is, for example, carbon particles. The carbon material used as carbon particles is, for example, a powdered carbon material consisting of carbon black, graphite, activated carbon, carbon nanotubes, carbon nanofibers, fullerenes, etc. The average primary particle size of the carbon particles is preferably 10 nm or more and 1000 nm or less, and more preferably 10 nm or more and 100 nm or less. If the average primary particle size of the carbon particles is above the above lower limit, the carbon particles will not be packed too densely in the electrode catalyst layers 12A and 12C, so a decrease in the gas diffusivity of the electrode catalyst layers 12A and 12C can be suppressed. If the average primary particle size of the carbon particles is below the above upper limit, the occurrence of cracks in the electrode catalyst layers 12A and 12C can be suppressed.

[0046] The polymer electrolyte aggregate 33 is a mass formed by the aggregation of ionomer polymer electrolytes due to cohesive forces. These cohesive forces include Coulomb forces and van der Waals forces acting between the ionomers.

[0047] The polymer electrolyte constituting the aggregate 33 can be any polymer electrolyte having proton conductivity, and various electrolytes exemplified above as materials for the polymer electrolyte membrane 11 can be used. The polymer electrolytes used in the polymer electrolyte membrane 11 and the aggregate 33 may be the same or different. In order to reduce resistance at the interface between the polymer electrolyte membrane 11 and the electrode catalyst layers 12A and 12C, and to reduce the difference in dimensional change rates between the polymer electrolyte membrane 11 and the electrode catalyst layers 12A and 12C due to humidity changes, it is preferable that the polymer electrolytes used in the polymer electrolyte membrane 11 and the aggregate 33 are the same or similar electrolytes.

[0048] The fibrous material 34 is an electronically conductive fiber or a proton-conducting fiber. An electronically conductive fiber is, for example, a fibrous structure in which carbon is a constituent element. Materials used as electronically conductive fibers include, for example, carbon fibers, carbon nanotubes, carbon nanohorns, and conductive polymer nanofibers. Among these, carbon nanofibers are preferred from the viewpoint of good conductivity and dispersibility.

[0049] Electronically conductive fibers may also have catalytic activity. It is preferable that the electronically conductive fibers have catalytic activity because it reduces the amount of catalyst material 31 made of noble metals used. Examples of electronically conductive fibers with catalytic activity to be included in the electrode catalyst layer 12C constituting the air electrode include carbon alloy catalysts made from carbon nanofibers. Alternatively, the electronically conductive fibers with catalytic activity may be fibers formed from the electrode active material for the fuel electrode. The electrode active material can contain at least one transition metal element selected from the group consisting of Ta, Nb, Ti, and Zr. Examples of materials containing transition metal elements include partial oxides of carbonitrides of transition metal elements, conductive oxides of transition metal elements, and conductive oxynitrides of transition metal elements.

[0050] Proton-conducting fibers are fibers made by processing a polymer electrolyte with proton conductivity into a fibrous form. The polymer electrolyte constituting the proton-conducting fiber can be, for example, a fluorine-based polymer electrolyte or a hydrocarbon-based polymer electrolyte. Examples of fluorine-based polymer electrolytes include Nafion (registered trademark: manufactured by DuPont), Flemion (registered trademark: manufactured by Asahi Glass Co., Ltd.), Aciplex (registered trademark: manufactured by Asahi Kasei Corporation), and Gore Select (registered trademark: manufactured by Gore Corporation). Examples of hydrocarbon-based polymer electrolytes include sulfonated polyether ketones, sulfonated polyethersulfones, sulfonated polyetherethersulfones, sulfonated polysulfides, sulfonated polyphenylenes, sulfonated polyimides, and acid-doped polybenzoazoles.

[0051] The polymer electrolyte constituting the proton-conducting fibers may or may not be the same as the polymer electrolyte constituting the polymer electrolyte membrane 11 or the aggregate 33. If the polymer electrolyte constituting the polymer electrolyte membrane 11, the aggregate 33, and the proton-conducting fibers are the same or similar electrolytes, it is possible to reduce the resistance at the interface between the polymer electrolyte membrane 11 and the electrode catalyst layers 12A and 12C, and to reduce the difference in the rate of dimensional change between the polymer electrolyte membrane 11 and the electrode catalyst layers 12A and 12C due to changes in humidity.

[0052] The fibrous material 34 contained in the electrode catalyst layers 12A and 12C may consist only of electron-conducting fibers or only of proton-conducting fibers. Alternatively, the fibrous material 34 contained in the electrode catalyst layers 12A and 12C may contain both electron-conducting fibers and proton-conducting fibers. Preferably, the electrode catalyst layers 12A and 12C contain at least one of carbon nanofibers, carbon nanotubes, and proton-conducting fibers. However, the electrode catalyst layers 12A and 12C do not necessarily contain the fibrous material 34.

[0053] The fiber diameter of the fibrous material 34 is preferably 0.5 nm to 500 nm, and more preferably 5 nm to 200 nm. If the fiber diameter is within the above range, voids are accurately formed within the electrode catalyst layers 12A and 12C, thereby improving the output of the fuel cell.

[0054] The fiber length of the fibrous material 34 is preferably 1 μm to 50 μm, and more preferably 1 μm to 20 μm. If the fiber length is within the above range, the strength of the electrode catalyst layers 12A and 12C can be appropriately increased, thereby suppressing the occurrence of cracks during the formation of the electrode catalyst layers 12A and 12C. Furthermore, since voids are appropriately formed within the electrode catalyst layers 12A and 12C, it is possible to improve the output of the fuel cell.

[0055] The support base materials 21A and 21C provided by the support member 20 are, for example, fluororesins such as ethylene tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroperfluoroalkyl vinyl ether copolymer (PFA), and polytetrafluoroethylene (PTFE), or films made of polyethylene terephthalate, polyethylene naphthalate, syndiotactic polystyrene, polytetrafluoroethylene, polyimide, etc. The materials of the adhesive layers 22A and 22C on the support member 20 are, for example, epoxy resin, acrylic resin, urethane resin, silicone resin, etc.

[0056] [Polymer electrolyte fuel cell] Referring to Figure 5, a polymer electrolyte fuel cell 40 equipped with the membrane electrode assembly 10 described above will be explained.

[0057] As shown in Figure 5, the polymer electrolyte fuel cell 40 comprises a membrane electrode assembly 10, a pair of separators 41A and 41C, and a pair of gas diffusion layers 45A and 45C. The membrane electrode assembly 10 is sandwiched between the gas diffusion layer 45A and the gas diffusion layer 45C, with the gas diffusion layer 45A in contact with the electrode catalyst layer 12A, and the gas diffusion layer 45C in contact with the electrode catalyst layer 12C. The gas diffusion layers 45A and 45C are conductive and have the function of diffusing the gas supplied to the electrode catalyst layers 12A and 12C. For example, carbon cloth or carbon paper can be used as the gas diffusion layers 45A and 45C.

[0058] The laminate of the membrane electrode assembly 10 and the gas diffusion layers 45A and 45C is sandwiched between separators 41A and 41C. Separators 41A and 41C are made of a conductive and gas-impermeable material. On separator 41A, a gas channel 42A is formed on the surface facing the gas diffusion layer 45A, and a cooling water channel 43A is formed on the surface opposite to the gas diffusion layer 45A. Similarly, on separator 41C, a gas channel 42C is formed on the surface facing the gas diffusion layer 45C, and a cooling water channel 43C is formed on the surface opposite to the gas diffusion layer 45C.

[0059] In the above configuration, the anode fuel electrode is formed from the electrode catalyst layer 12A and the gas diffusion layer 45A, and the cathode air electrode is formed from the electrode catalyst layer 12C and the gas diffusion layer 45C.

[0060] When the polymer electrolyte fuel cell 40 is in use, a fuel gas such as hydrogen flows through the gas passage 42A of the separator 41A on the fuel electrode side, and an oxidizing gas such as air or oxygen flows through the gas passage 42C of the separator 41C on the air electrode side. Cooling water also flows through the cooling water passages 43A and 43C of each separator 41A and 41C. Then, fuel gas is supplied to the fuel electrode from the gas passage 42A, and oxidizing gas is supplied to the air electrode from the gas passage 42C. As a result, the reaction shown in (Equation 1) below occurs at the fuel electrode, and the reaction shown in (Equation 2) below occurs at the air electrode, generating an electromotive force between the fuel electrode and the air electrode. Organic fuel such as methanol may be supplied to the fuel electrode. H2 → 2H + + 2e - ...(Formula 1) 1 / 2O2+2H + + 2e - →H2O...(Formula 2)

[0061] The polymer electrolyte fuel cell 40 may be used as a single cell as shown in Figure 5, or multiple single cells may be stacked and connected in series to form a single polymer electrolyte fuel cell.

[0062] [Manufacturing method for stacked rolls] The manufacturing method for the assembled roll 100 described above will now be explained. First, the manufacturing method for the electrode catalyst layers 12A and 12C will be explained.

[0063] The electrode catalyst layers 12A and 12C are formed by applying a catalyst layer slurry containing the materials for the electrode catalyst layers 12A and 12C to a substrate to form a coating film, and then drying the coating film. The slurry for the catalyst layer is prepared by mixing the materials for the electrode catalyst layers 12A and 12C in a dispersion medium, and then subjecting the mixture to a dispersion treatment.

[0064] The dispersion medium can be a liquid agent that does not erode the materials of the electrode catalyst layers 12A and 12C, and that can dissolve the polymer electrolyte while maintaining high fluidity of the dispersion medium, or that can disperse the polymer electrolyte as a fine gel. The dispersion medium preferably contains a volatile liquid organic solvent. If the liquid organic solvent is a lower alcohol, it is preferable to mix water into the dispersion medium to reduce the risk of ignition. However, the dispersion medium may also contain water to the extent that turbidity and solidification of the catalyst layer slurry caused by the separation of the polymer electrolyte are suppressed. Distributed processing can be performed using, for example, planetary ball mills, bead mills, ultrasonic homogenizers, etc.

[0065] The substrate to which the catalyst layer slurry is applied can be a transfer substrate that is peeled off after the formation of the electrode catalyst layers 12A and 12C, or a polymer electrolyte membrane 11.

[0066] The method for applying the catalyst layer slurry to the substrate is not particularly limited. Examples of application methods for the catalyst layer slurry include die coating, roll coating, curtain coating, spray coating, and squeegee application. Among these, die coating is preferred. Die coating is preferred because it allows for stable film thickness during the application period and enables intermittent coating.

[0067] For drying the coating film, methods such as drying using a hot air oven, IR (far-infrared) drying, drying using a hot plate, and vacuum drying can be used. The drying temperature is preferably in the range of 40°C to 200°C, and more preferably in the range of 40°C to 120°C. The drying time is preferably in the range of 0.5 minutes to 1 hour, and more preferably in the range of 1 minute to 30 minutes.

[0068] First, we will explain the manufacturing method of the assembled roll 100 when a transfer substrate is used as the substrate to which the catalyst layer slurry is applied. When using a transfer substrate, a catalyst layer slurry is applied to the transfer substrate to form a coating film, and then the coating film is dried to create a transfer substrate with the electrode catalyst layer laminated on it. Then, for example, the electrode catalyst layer and the polymer electrolyte membrane 11 are bonded together by heating and pressurizing while the surface of the electrode catalyst layer on the transfer substrate is in contact with the polymer electrolyte membrane 11. After that, the transfer substrate is peeled off from the electrode catalyst layer. By bonding the electrode catalyst layer to both sides of the polymer electrolyte membrane 11, a layered body 15 is obtained, which is a laminate of the polymer electrolyte membrane 11 and the electrode catalyst layers 12A and 12C.

[0069] Furthermore, an adhesive sheet 23A is formed in a laminated sheet of support substrate 21A and adhesive layer 22A by forming openings of the same shape as the electrode catalyst layer 12A, such that multiple openings are aligned along the length direction of the laminated sheet. Similarly, an adhesive sheet 23C is formed in a laminated sheet of support substrate 21C and adhesive layer 22C by forming openings of the same shape as the electrode catalyst layer 12C, such that multiple openings are aligned along the length direction of the laminated sheet.

[0070] The adhesive sheets 23A and 23C are wound, for example, into a roll. The adhesive sheet 23A is pulled out from the roll and attached to one side of the outer periphery 11e of the polymer electrolyte membrane 11 in the layered body 15, while aligning the position of the opening with the position of the electrode catalyst layer 12A. The adhesive sheet 23C is pulled out from the roll and attached to the other side of the outer periphery 11e, while aligning the position of the opening with the position of the electrode catalyst layer 12C. As a result, multiple layered bodies 15 are sandwiched between the adhesive sheets 23A and 23C in a sequential manner, forming a combined roll 100.

[0071] Various polymer films, such as films formed from fluororesins, can be used as transfer substrates. Films using fluororesins exhibit excellent transferability. Examples of fluororesins include ethylene tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroperfluoroalkyl vinyl ether copolymer (PFA), and polytetrafluoroethylene (PTFE). Other polymer materials that can be used as transfer substrates include, for example, polyimide, polyethylene terephthalate, polyamide (nylon®), polysulfone, polyethersulfone, polyphenylene sulfide, polyether / etherketone, polyetherimide, polyarylate, and polyethylene naphthalate.

[0072] When transferring the electrode catalyst layers 12A and 12C from the transfer substrate to the polymer electrolyte membrane 11, the pressure and temperature applied to the electrode catalyst layers 12A and 12C may affect the power generation performance of the membrane electrode assembly 10. To obtain a membrane electrode assembly 10 with high power generation performance, it is preferable that the pressure during the transfer of the electrode catalyst layers 12A and 12C be within the range of 0.1 MPa to 20 MPa. By keeping the pressure below 20 MPa, excessive compression of the electrode catalyst layers 12A and 12C is suppressed. By keeping the pressure above 0.1 MPa, a decrease in the bonding between the electrode catalyst layers 12A and 12C and the polymer electrolyte membrane 11 is suppressed, thereby suppressing a decrease in power generation performance. From the viewpoint of improving the bonding at the interface between the polymer electrolyte membrane 11 and the electrode catalyst layers 12A and 12C and suppressing interfacial resistance, it is preferable that the temperature during transfer be near the glass transition temperature of the polymer electrolyte contained in the polymer electrolyte membrane 11 or the electrode catalyst layers 12A and 12C.

[0073] Next, we will explain how to manufacture the assembly roll 100 when a polymer electrolyte membrane 11 is used as the substrate to which the catalyst layer slurry is applied. First, the adhesive sheets 23A and 23C, formed in the same manner as described above and pulled out from the roll, are attached to the polymer electrolyte membrane 11 while aligning the positions of the openings in the adhesive sheets 23A and 23C with the planned positions for the formation of the electrode catalyst layers 12A and 12C on the polymer electrolyte membrane 11. This forms a strip-shaped body in which the polymer electrolyte membrane 11 is sandwiched between the adhesive sheets 23A and 23C.

[0074] Next, a slurry for the catalyst layer is applied to the polymer electrolyte membrane 11 exposed through the openings of the adhesive sheets 23A and 23C to form a coating film, and the coating film is dried. This forms the electrode catalyst layers 12A and 12C on the polymer electrolyte membrane 11, and the assembly roll 100 is formed.

[0075] Furthermore, even when a polymer electrolyte membrane 11 is used as the substrate to which the slurry for the catalyst layer is applied, the assembled roll 100 may be formed by first forming the electrode catalyst layers 12A and 12C on the polymer electrolyte membrane 11, and then attaching the adhesive sheets 23A and 23C to the polymer electrolyte membrane 11.

[0076] [Examples] The assembly roll and membrane electrode assembly described above will be explained using specific examples and comparative examples.

[0077] (Example 1) A polymer electrolyte membrane (Nafion211: manufactured by DuPont) was formed to a size where each side was positioned 1 mm outside the planned electrode catalyst layer. The planned electrode catalyst layer has a rectangular shape with a long side of 300 mm and a short side of 100 mm.

[0078] Next, an adhesive sheet with multiple openings of the same shape as the electrode catalyst layer to be formed was attached to one side of the polymer electrolyte membrane so that the centers of the openings coincided with the centers of the polymer electrolyte membrane. Then, a similar adhesive sheet was attached to the other side of the polymer electrolyte membrane so that the positions of the openings overlapped with the adhesive sheet attached to the first side. The support substrate constituting the adhesive sheet was a polyethylene naphthalate film (Teonex Q51: manufactured by Teijin Corporation) with a thickness of 0.025 mm. This formed a strip-shaped body comprising the support member and the polymer electrolyte membrane.

[0079] Next, a slurry for the catalyst layer was prepared. First, a mixture was prepared by mixing platinum-supported carbon (TEC10E50E: manufactured by Tanaka Kikinzoku Kogyo Co., Ltd.), a conductive carrier supporting the catalyst material; a dispersion of polymer electrolyte (Nafion dispersion: manufactured by Wako Pure Chemical Industries, Ltd.); carbon nanofibers (VGCF-H: manufactured by Showa Denko Corporation), which are electronically conductive fibers; water; and 1-propanol. Platinum-supported carbon is carbon particles on which platinum, the catalyst material, is supported.

[0080] The above mixture was dispersed using a planetary ball mill at 300 rpm for 60 minutes. During this process, zirconia balls with a diameter of 5 mm were added to fill approximately one-third of the zirconia container. This yielded a slurry for the catalyst layer. In the slurry for the catalyst layer, the mass of the polymer electrolyte was 100% by mass relative to the mass of the carbon particles, the mass of the electronically conductive fibers was 100% by mass relative to the mass of the carbon particles, the proportion of water in the dispersion medium was 50% by mass, and the solid content in the slurry for the catalyst layer was 10% by mass.

[0081] A slurry for the catalyst layer was applied to the openings on both sides of the polymer electrolyte membrane in the strip-shaped body using a slit die coater to form a coating film. The thickness of the coating film corresponding to the air electrode was 150 μm, and the thickness of the coating film corresponding to the fuel electrode was 100 μm. The coating film was then dried using a hot air oven at 80 degrees Celsius. This formed a strip-shaped body comprising a layered structure consisting of a polymer electrolyte membrane and a pair of electrode catalyst layers, and a support member. The assembled roll of Example 1 was obtained by winding up the strip-shaped body. Furthermore, the assembled roll was cut into a rectangular shape with a long side of 350 mm and a short side of 150 mm, with the electrode catalyst layer at the center, to obtain a membrane electrode assembly. In the assembled roll and membrane electrode assembly of Example 1, the width W1 of the outer periphery of the polymer electrolyte membrane is 1.0 mm, and the ratio of the outer periphery area Sm to the catalyst layer area Se is 0.03.

[0082] (Example 2) The assembled roll and membrane electrode assembly of Example 2 was obtained using the same materials and processes as in Example 1, except that the polymer electrolyte membrane was formed to a size where each side was positioned 3 mm outside the electrode catalyst layer to be formed. The planar shape of the electrode catalyst layer to be formed is a rectangle with a long side of 300 mm and a short side of 100 mm. In the assembled roll and membrane electrode assembly of Example 2, the width W1 of the outer periphery of the polymer electrolyte membrane is 3.0 mm, and the ratio of the outer periphery area Sm to the catalyst layer area Se is 0.08.

[0083] (Example 3) The assembled roll and membrane electrode assembly of Example 3 was obtained using the same materials and processes as in Example 1, except that the polymer electrolyte membrane was formed to a size where each side was positioned 7 mm outside the electrode catalyst layer to be formed. The planar shape of the electrode catalyst layer to be formed is a rectangle with a long side of 300 mm and a short side of 100 mm. In the assembled roll and membrane electrode assembly of Example 3, the width W1 of the outer periphery of the polymer electrolyte membrane is 7.0 mm, and the ratio of the outer periphery area Sm to the catalyst layer area Se is 0.19.

[0084] (Comparative Example 1) Comparative Example 1's assembled roll and membrane electrode assembly was obtained using the same materials and processes as in Example 1, except that the polymer electrolyte membrane was formed to a size where each side was positioned 0.5 mm outside the electrode catalyst layer to be formed. The planar shape of the electrode catalyst layer to be formed is rectangular with a long side of 300 mm and a short side of 100 mm. In Comparative Example 1's assembled roll and membrane electrode assembly, the width W1 of the outer periphery of the polymer electrolyte membrane is 0.5 mm, and the ratio of the outer periphery area Sm to the catalyst layer area Se is 0.01.

[0085] (Comparative Example 2) Comparative Example 2's assembled roll and membrane electrode assembly was obtained using the same materials and processes as in Example 1, except that the size of the electrode catalyst layer to be formed was changed, and the polymer electrolyte membrane was formed to a size where each side was positioned 7 mm outside the electrode catalyst layer to be formed. The planar shape of the electrode catalyst layer to be formed is a rectangle with a long side of 240 mm and a short side of 100 mm. In Comparative Example 2's assembled roll and membrane electrode assembly, the width W1 of the outer periphery of the polymer electrolyte membrane is 7.0 mm, and the ratio of the outer periphery area Sm to the catalyst layer area Se is 0.21.

[0086] (evaluation) <Peeling off of support member> For each example and comparative example, we observed whether peeling of the support member from the outer periphery of the polymer electrolyte membrane occurred during winding of the assembly roll and during separation of the membrane electrode assembly from the assembly roll. If no peeling occurred during either winding or separation, it was marked as "○", and if peeling occurred during at least one of the winding or separation, it was marked as "×".

[0087] <Wrinkle formation> A gas diffusion layer (GDL SIGRACET 22BB: manufactured by SGL Corporation) was thermocompressed onto the electrode catalyst layer of the membrane electrode assembly in each example and comparative example. The heating temperature during thermocompression was 120°C, the pressure was 1 MPa, and the pressurization time was 3 minutes. After that, the edges of the membrane electrode assembly were observed for wrinkles. "○" indicated that no wrinkles were present, and "×" indicated that wrinkles were present.

[0088] (Evaluation results) Table 1 shows the width W1 of the outer periphery of the polymer electrolyte membrane, the ratio of the outer periphery area Sm to the catalyst layer area Se, the evaluation results for delamination of the support member, the evaluation results for wrinkle formation, and the overall evaluation for each example and comparative example. The overall evaluation was marked "○" if both the delamination and wrinkle evaluations were "○", and "×" if at least one of the delamination and wrinkle evaluations was "×".

[0089] [Table 1]

[0090] As shown in Table 1, in Examples 1 to 3 and Comparative Example 2, where the width W1 of the outer periphery of the polymer electrolyte membrane was 0.1 mm or more, no peeling of the support member occurred at the outer periphery. In contrast, in Comparative Example 1, where the width W1 was less than 0.1 mm, peeling of the support member was observed. Therefore, it was confirmed that if the width W1 of the outer periphery is 0.1 mm or more, peeling of the support member from the polymer electrolyte membrane can be suppressed.

[0091] Furthermore, in Examples 1 to 3 and Comparative Example 1, where the ratio of the outer peripheral area Sm to the catalyst layer area Se was 0.2 or less, no wrinkles were observed at the edges of the film electrode assembly. In contrast, in Comparative Example 2, where the ratio exceeded 0.2, wrinkles were observed. Therefore, it was confirmed that wrinkles at the edges of the film electrode assembly can be suppressed if the ratio is 0.2 or less.

[0092] As described above using the examples, the aggregate roll, membrane electrode assembly, and polymer electrolyte fuel cell of the first embodiment provide the following advantages. (1) Since multiple membrane electrode assemblies 10 are bundled together in a roll, the membrane electrode assemblies 10 are easy to store and transport.

[0093] (2) In the combined roll 100, the polymer electrolyte membrane 11 and electrode catalyst layers 12A and 12C are not arranged near the outer edge of the membrane electrode assembly 10. Therefore, compared to a roll in which the polymer electrolyte membrane 11 is continuously formed, it is possible to reduce the amount of polymer electrolyte membrane 11 material required to form the membrane electrode assembly 10. Such a combined roll 100 can be incorporated into a roll-to-roll manufacturing method and can reduce the amount of expensive materials used.

[0094] (3) The width W1 of the outer peripheral portion 11e of the polymer electrolyte membrane 11 is 1 mm or more. This improves the adhesion of the frame-shaped portion 26 to the outer peripheral portion 11e, thereby suppressing the peeling of the support member 20 from the polymer electrolyte membrane 11.

[0095] (4) The ratio of the outer peripheral area Sm to the catalyst layer area Se is 0.2 or less. This allows for a precise reduction in the amount of polymer electrolyte membrane 11 material required to form the membrane electrode assembly 10. Furthermore, because the area of ​​the region where the polymer electrolyte membrane 11 and the support member 20 overlap is not too large, the occurrence of wrinkles at the edges of the membrane electrode assembly 10 during thermocompression bonding of the gas diffusion layer is suppressed. By suppressing the occurrence of wrinkles, leakage of gas supplied to the electrode catalyst layers 12A and 12C can be reduced.

[0096] (Second Embodiment) Referring to Figures 6 and 7, a second embodiment of the membrane electrode assembly assembly, the membrane electrode assembly, and the polymer electrolyte fuel cell will be described. In the following, the differences between the second embodiment and the first embodiment will be described in detail, and components similar to those in the first embodiment will be denoted by the same reference numerals and their descriptions will be omitted.

[0097] As shown in Figure 6, the assembly roll 110 of the membrane electrode assembly in the second embodiment differs from the first embodiment in that multiple frame-shaped parts 26 are connected by a fixing part 50. The combined roll 110 comprises a plurality of layered bodies 15 having the same configuration as in the first embodiment, and a support member 20. The support member 20 has a plurality of frame-shaped portions 26 arranged along one direction, and each frame-shaped portion 26 supports one layered body 15. The relationship between the position and size of the layered bodies 15 and the frame-shaped portions 26 is the same as in the first embodiment.

[0098] The adjacent frame-shaped portions 26 are separate members and not continuous, and a fixing portion 50 extending along the width direction of the assembled roll 110 is located at the boundary between adjacent frame-shaped portions 26. The fixing portion 50 contains an adhesive or bonding agent and is joined to the frame-shaped portion 26. The fixing portion 50 may be, for example, an adhesive tape, or it may be formed from a hot melt adhesive or an ultraviolet curing adhesive.

[0099] Furthermore, if it is possible to connect adjacent frame-shaped parts 26, the fixing parts 50 may be arranged along the entire width of the collective roll 110 or along only a portion of it. Also, the fixing parts 50 may be arranged intermittently along the width of the collective roll 110.

[0100] Furthermore, when the strip-shaped body comprising the layered body 15, the support member 20, and the fixing portion 50 is wound into a roll, a protective film may be laminated on at least one of the front and back surfaces of the strip-shaped body to prevent the fixing portion 50 from coming into contact with the layered body 15 that overlaps with the fixing portion 50.

[0101] As shown in Figure 7, the end faces of adjacent frame-shaped portions 26 are in contact with each other. In other words, the frame-shaped portions 26 are arranged such that the surfaces of adjacent frame-shaped portions 26, i.e., the surfaces of the support base material 21A, are aligned along one surface, and the back surfaces of adjacent frame-shaped portions 26, i.e., the surfaces of the support base material 21C, are aligned along one surface.

[0102] Furthermore, fixing portions 50 are positioned on the front and back surfaces of the boundary portions of adjacent frame-shaped portions 26. Specifically, the fixing portion 50 is positioned on the surface of the support base material 21A so as to straddle the support base material 21A of adjacent frame-shaped portions 26, and the fixing portion 50 is positioned on the surface of the support base material 21C so as to straddle the support base material 21C of adjacent frame-shaped portions 26.

[0103] Furthermore, if it is possible to connect adjacent frame-shaped portions 26, the fixing portion 50 may be placed only on one of the front or back surfaces at the boundary of the frame-shaped portion 26. From the viewpoint of increasing the strength of the connection between the frame-shaped portions 26, it is preferable to provide the fixing portion 50 on both the front and back surfaces at the boundary. On the other hand, if the fixing portion 50 is provided on only one of the front or back surfaces at the boundary, the step formed by the arrangement of the fixing portion 50 at the boundary can be reduced compared to the case where the fixing portion 50 is provided on both the front and back surfaces. Therefore, it becomes easier to roll the strip-shaped material into a roll.

[0104] The width of the fixing portion 50 is preferably small enough to connect adjacent frame-shaped portions 26, for example, preferably 20 mm or less. Furthermore, in order to reduce the step height in the area where the fixing portion 50 is placed and to improve the ease of the work of placing the fixing portion 50, the thickness of the fixing portion 50 is preferably 50 μm or less. The lower limit of the thickness of the fixing portion 50 is, for example, 10 μm.

[0105] The assembly roll 110 separates into individual membrane electrode assemblies 10 by cutting the fixing portion 50 at the boundary of the frame-shaped portion 26, or by peeling off the fixing portion 50. When the membrane electrode assemblies 10 are separated by cutting the fixing portion 50, the cut fixing portion 50 remains on the end of the frame-shaped portion 26 in the membrane electrode assemblies 10, i.e., the gasket members 13A, 13C, in the direction corresponding to the length direction of the assembly roll 110. Specifically, when the membrane electrode assemblies 10 are viewed from a direction along the thickness direction of the polymer electrolyte membrane 11, the cut fixing portion 50 extends along the outer edge of the frame-shaped portion 26 on the end of the frame-shaped portion 26. The materials of the membrane electrode assembly 10 and the configuration of the polymer electrolyte fuel cell 40 are the same as in the first embodiment.

[0106] According to the aggregated roll 110 of the second embodiment, since multiple membrane electrode assemblies 10 are bundled together in a roll shape, storage and transportation of the membrane electrode assemblies 10 are easy. Furthermore, since it is easy to incorporate into a roll-to-roll manufacturing method in subsequent processes such as the arrangement of gas diffusion layers 45A and 45C, subsequent processes can be carried out simply.

[0107] Furthermore, compared to a roll in which the polymer electrolyte membrane 11 is continuously formed, it is possible to reduce the amount of polymer electrolyte membrane 11 material required to form the membrane electrode assembly 10, and to suppress wrinkles at the edges of the membrane electrode assembly 10 during thermocompression bonding of the gas diffusion layer.

[0108] In manufacturing the aggregate roll 110 of the second embodiment, first, a layered body 15 is formed in the same manner as in the first embodiment. Then, a gasket member 13A, which is a laminate of a support base material 21A and an adhesive layer 22A, is formed, and similarly, a gasket member 13C, which is a laminate of a support base material 21C and an adhesive layer 22C, is formed. The gasket members 13A and 13C are formed in a shape corresponding to one membrane electrode assembly 10. Then, the gasket members 13A and 13C are bonded to the layered body 15. As a result, a frame-shaped portion 26 that supports the layered body 15 is formed, and the membrane electrode assembly 10 is formed in a state where each one is separated.

[0109] Next, multiple membrane electrode assemblies 10 are lined up and fixing parts 50 are placed at the boundaries between the frame-shaped parts 26, thereby connecting the multiple membrane electrode assemblies 10. A bundled roll 110 is formed when this strip-shaped body of connected membrane electrode assemblies 10 is wound up.

[0110] In the above manufacturing method, in order to shape the outer form of the membrane electrode assembly 10, it is preferable to arrange the two membrane electrode assembly 10 so that the ends of the frame-shaped portions 26 of the two membrane electrode assembly 10 overlap, and then cut the ends of the frame-shaped portions 26 at the overlapping portion. This aligns the fine orientation of the end faces, which are the cut surfaces of the two membrane electrode assembly 10, so that the membrane electrode assembly 10 can be arranged so that their end faces are in contact with each other and fixed with the fixing portion 50, thereby connecting the adjacent frame-shaped portions 26 without any gaps.

[0111] In the above embodiment, a configuration was illustrated in which multiple membrane electrode assemblies 10 are connected in the assembly roll 110 such that the end faces of adjacent frame-shaped portions 26 are in contact with each other. However, the multiple membrane electrode assemblies 10 may be connected such that the ends of adjacent frame-shaped portions 26 overlap in the thickness direction. In this case, although the step formed at the boundary portion of the membrane electrode assemblies 10 will be larger, the load required for alignment and other purposes when joining the membrane electrode assemblies 10 will be reduced.

[0112] As described above, the aggregate roll, membrane electrode assembly, and polymer electrolyte fuel cell of the second embodiment provide the following effects in addition to the effects (1) to (4) of the first embodiment. (5) The assembled roll 110 is formed by joining together the individually formed membrane electrode assemblies 10. Therefore, the assembled roll 110 can be formed using single-wafer manufacturing equipment. [Explanation of symbols]

[0113] 10...Membrane electrode assembly 11...Polymer electrolyte membrane 11e...Outer periphery 12A,12C…electrode catalyst layer 13A, 13C… Gasket components 15...Layered body 19S…End face 20…Support member 21A, 21C…Support base material 22A,22C…Adhesive layer 23A, 23C… Adhesive sheets 25…Aperture 26...Frame-shaped part 31...catalyst material 32... Conductive carrier 33…aggregate 34…Fibrous material 40...Polymer fuel cell 41A, 41C... Separators 45A, 45C… Gas diffusion layer 50…Fixed part 100, 110… Group Role

Claims

1. A plurality of layered bodies each comprising a polymer electrolyte membrane and a pair of electrode catalyst layers that sandwich the polymer electrolyte membrane in the thickness direction and are in contact with the polymer electrolyte membrane, A roll on which a strip-shaped body is wound, comprising a support member having a plurality of frame-shaped parts arranged continuously along one direction, each of which frame-shaped parts supports one of the layered bodies, When viewed from a direction along the thickness direction of the polymer electrolyte membrane, the polymer electrolyte membrane has an outer peripheral portion which is the portion that protrudes outside the electrode catalyst layer, and the outer shape of the frame-shaped portion is larger than the outer shape of the polymer electrolyte membrane. The frame-shaped portion surrounds the outside of the electrode catalyst layer and is in contact with the electrode catalyst layer, and in the thickness direction, the outer peripheral portion is sandwiched within the frame-shaped portion. When viewed from a direction along the thickness direction of the polymer electrolyte membrane, the width of the outer periphery is 1 mm or more, and the ratio of the area of ​​the outer periphery to the area of ​​the electrode catalyst layer is 0.2 or less. A roll of membrane electrode assemblies.

2. A plurality of layered bodies each comprising a polymer electrolyte membrane and a pair of electrode catalyst layers that sandwich the polymer electrolyte membrane in the thickness direction and are in contact with the polymer electrolyte membrane, A plurality of frame-shaped parts arranged along one direction, each of which supports one of the layered bodies, A roll on which a strip-shaped body is wound, comprising fixing parts that connect adjacent frame-shaped parts, When viewed from a direction along the thickness direction of the polymer electrolyte membrane, the polymer electrolyte membrane has an outer peripheral portion which is the portion that protrudes outside the electrode catalyst layer, and the outer shape of the frame-shaped portion is larger than the outer shape of the polymer electrolyte membrane. The frame-shaped portion surrounds the outside of the electrode catalyst layer and is in contact with the electrode catalyst layer, and in the thickness direction, the outer peripheral portion is sandwiched within the frame-shaped portion. A roll of membrane electrode assemblies.

3. A film electrode assembly in which the assembly roll according to claim 1 or 2 is divided into frame-shaped portions that support the layered body.

4. A layered body comprising a polymer electrolyte membrane, and a pair of electrode catalyst layers sandwiching the polymer electrolyte membrane in the thickness direction and in contact with the polymer electrolyte membrane, A membrane electrode assembly comprising a frame-shaped portion that supports the layered body, When viewed from a direction along the thickness direction of the polymer electrolyte membrane, the polymer electrolyte membrane has an outer peripheral portion which is the portion that protrudes outside the electrode catalyst layer, and the outer shape of the frame-shaped portion is larger than the outer shape of the polymer electrolyte membrane. The frame-shaped portion surrounds the outside of the electrode catalyst layer and is in contact with the electrode catalyst layer, and in the thickness direction, the outer peripheral portion is sandwiched within the frame-shaped portion. When viewed from a direction along the thickness direction of the polymer electrolyte membrane, the width of the outer periphery is 1 mm or more, and the ratio of the area of ​​the outer periphery to the area of ​​the electrode catalyst layer is 0.2 or less. The film electrode assembly has an end face that is located at the end of the frame-shaped portion and is a single continuous surface in the thickness direction. Membrane electrode assembly.

5. A membrane electrode assembly according to claim 3 or 4, A pair of separators sandwiching the aforementioned film electrode assembly, A polymer electrolyte fuel cell equipped with the following features.

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