fuel cells

Abstract

To provide a fuel battery using an electrolyte film-electrode-frame bonding body, capable of suppressing the leakage of a fuel gas and an oxidant gas to an external part from a gap generated by peeling an electrolyte film having a weak bonding power and a frame body without increasing a cost by an increase of a use amount of a rubber system adhesion agent.SOLUTION: A fuel battery in a present disclosure, comprises: an electrolyte film-electrode bonding body constructed by an electrolyte film, a catalyst layer arranged on both main surfaces in an inner side by a frequency end part of the electrolyte film, and a gas diffusion layer arranged on both outer side of the catalyst layer while nipping the electrolyte film; a pair of separators arranged on both external parts of the gas diffusion layer; a first frame body that is arranged between one gas diffusion layer and the catalyst layer, and is formed along a surface of the electrolyte film to an external peripheral direction of one catalyst layer; a second frame body that is arranged between the other gas diffusion layer and the catalyst layer, and is formed along the surface of the outer peripheral direction of the other catalyst layer; and a rubbery system bonding agent that adheres the first frame body, the second frame body, the electrolyte film between the pair of separators.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to fuel cells. [Background technology]

[0002] Patent Document 1 discloses a fuel cell in which a membrane electrode assembly is formed from an electrolyte membrane and catalyst layers that have a smaller planar area than the electrolyte membrane and are in contact with the electrolyte membrane on both sides, and a gas permeation layer and a separator are disposed on both sides of the membrane electrode assembly to form a fuel cell, and the fuel cell is provided with a gasket that seals between the separators or between the fuel cell cells in the stacked fuel cell, and a protective film is provided at least between the gas diffusion layer and the exposed peripheral area of ​​the electrolyte membrane that is not covered with the catalyst layer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-186711 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a fuel cell that can suppress increases in costs due to increased use of rubber-based adhesives and can also suppress leakage of fuel gas and oxidant gas to the outside through gaps that arise when an electrolyte membrane and a frame, which have weak bonding strength, peel off from each other. [Means for solving the problem]

[0005] The fuel cell of the present disclosure comprises an electrolyte membrane-electrode assembly consisting of an electrolyte membrane, a catalyst layer, and a gas diffusion layer, a separator, a first frame, a second frame, and a rubber-based adhesive, wherein the peripheral edge of the first frame is located outside the peripheral edge of the electrolyte membrane, and the peripheral edge of the second frame is located inside the peripheral edge of the electrolyte membrane, and the side surface of the peripheral edge of the first frame is not covered with the rubber-based adhesive, but the side surface of the peripheral edge of the electrolyte membrane and the side surface of the peripheral edge of the second frame are covered with the rubber-based adhesive.

[0006] The catalyst layers are disposed on both main surfaces of the electrolyte membrane, inside the peripheral edge thereof.

[0007] The gas diffusion layers are arranged on both outer sides of the catalyst layer, with the electrolyte membrane sandwiched between them.

[0008] A pair of separators are disposed on both outer sides of the gas diffusion layer.

[0009] The first frame is disposed between one of the gas diffusion layers and the catalyst layer, and is formed along the surface of the electrolyte membrane in the outer circumferential direction of the one of the catalyst layers.

[0010] The second frame is disposed between the other gas diffusion layer and the catalyst layer, and is formed along the surface of the electrolyte membrane in the outer circumferential direction of the other catalyst layer.

[0011] The rubber adhesive bonds the first frame, the second frame, and the electrolyte membrane between the pair of separators. [Effects of the Invention]

[0012] The fuel cell of the present disclosure is an electrolyte membrane-electrode-frame assembly in which an electrolyte membrane is sandwiched between a first frame body and a second frame body, and the peripheral portion of the electrolyte membrane is positioned and joined between the peripheral portion of the first frame body and the peripheral portion of the second frame body, and the first frame body, the second frame body, and the electrolyte membrane can be bonded and sealed between separators using a rubber-based adhesive, with the side surface of the peripheral portion of the first frame body of the electrolyte membrane exposed.

[0013] Therefore, since there is no need to cover the side surfaces of the peripheral edge of the first frame body, it is possible to suppress increases in costs due to the increased use of rubber-based adhesive, and it is also possible to suppress leakage of fuel gas and oxidant gas to the outside through gaps that arise when the electrolyte membrane and the frame body, which have weak bonding strength, peel off. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is an external perspective view showing the configuration of a fuel cell stack according to a first embodiment. [Figure 2]2 is a cross-sectional view of the fuel cell stack according to the first embodiment taken along line AA in FIG. 1. [Figure 3] 2 is a cross-sectional schematic diagram of the electrolyte membrane-electrode-frame assembly in the first embodiment taken along line AA in FIG. 1. [Figure 4] 2 is a cross-sectional view of the cell according to the first embodiment taken along line AA in FIG. 1. [Figure 5] 2 is an exploded cross-sectional view of the cell according to the first embodiment taken along line AA in FIG. 1. [Figure 6] 1 is a schematic diagram of an electrolyte membrane-electrode-frame assembly according to the first embodiment, viewed from the cathode gas diffusion layer side. DETAILED DESCRIPTION OF THE INVENTION

[0015] (Findings that formed the basis of this disclosure) At the time when the inventors arrived at the present disclosure, there existed fuel cells in which an electrolyte membrane-electrode assembly was formed from an electrolyte membrane and catalyst layers, each having a smaller planar area than the electrolyte membrane and in contact with the electrolyte membrane on both sides, and a gas diffusion layer and a separator were disposed on both sides of the electrolyte membrane-electrode assembly to form a fuel cell, and which were provided with gaskets that provided sealing between the separators or between the stacked fuel cell cells.

[0016] One technology used in this fuel cell is to interpose a frame between the gas diffusion layer and the exposed peripheral area of ​​the electrolyte membrane, where the electrolyte membrane is not covered with a catalyst layer, and to bond the electrolyte membrane and the frame using hydrogen bonding or the like using a hot press without using adhesive, and to seal the gas by embedding the peripheral edges of both frames and the peripheral edge of the electrolyte membrane in a gasket.

[0017] In this technology, the gasket has an endless rib that surrounds the manifold at the periphery of the manifold at its end, and the molding method is generally such that the anode-side gas diffusion layer, the electrolyte membrane-electrode assembly, and the cathode-side gas diffusion layer are placed in this order and clamped in a mold, and resin is injected into the gasket cavity on the side of the electrolyte membrane-electrode assembly (injection molding).

[0018] However, when a highly durable rubber-based adhesive is applied between separators in a fuel cell, the rubber-based adhesive shrinks after hardening, causing the rubber-based adhesive that adheres to the electrolyte membrane and frame between the separators to be pulled toward the separator, applying a force that tries to open the interface where the electrolyte membrane and frame are joined to the rubber-based adhesive.

[0019] A rubber-based adhesive is used to accommodate these dimensional changes, but the electrolyte membrane and frame are joined by hydrogen bonding, a weak chemical interaction, without any adhesive. This means that moisture contained in the gas supplied to the fuel cell or moisture generated during power generation can penetrate between the electrolyte membrane and the frame, causing the electrolyte membrane and frame to peel apart, resulting in the leakage of fuel gas and oxidant gas to the outside.

[0020] To solve this problem, a conventional method has been to completely cover the frame and electrolyte membrane with a rubber-based adhesive. However, this method requires an increased amount of rubber-based adhesive to cover the frame and electrolyte membrane, which increases costs.

[0021] Under these circumstances, the inventors were inspired by the fact that rubber-based adhesives have excellent adhesive strength even to electrolyte membranes, and that the frame itself is gas-impermeable, so there is no problem even if it is exposed to the surface, and this idea led to the formation of the subject matter of the present disclosure.

[0022] Therefore, the present disclosure provides a fuel cell using an electrolyte membrane-electrode-frame assembly in which an electrolyte membrane is sandwiched between a first frame and a second frame, the peripheral edge of the first frame being located outside the peripheral edge of the electrolyte membrane, and the peripheral edge of the second frame being located inside the peripheral edge of the electrolyte membrane, and the electrolyte membrane-electrode-frame assembly is formed from the electrolyte membrane-electrode assembly and the first and second frame bodies, and the side surfaces of the peripheral edge of the first frame are not covered with a rubber-based adhesive, but the side surfaces of the peripheral edge of the electrolyte membrane and the side surfaces of the peripheral edges of the second frame are covered with a rubber-based adhesive and sealed, thereby increasing the adhesive surface area between the electrolyte membrane and the rubber-based adhesive and preventing fuel gas and oxidant gas from leaking to the outside through gaps created by peeling between the electrolyte membrane and the frame bodies, which have a weak adhesive bond, and reducing the amount of rubber-based adhesive used by the amount of the first frame exposed to the outside, thereby preventing costs from increasing due to the increased amount of rubber-based adhesive used.

[0023] Hereinafter, embodiments will be described in detail with reference to the drawings. However, unnecessary detailed description may be omitted. For example, detailed description of well-known matters or redundant description of substantially the same configuration may be omitted.

[0024] The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0025] (Embodiment 1) Hereinafter, the first embodiment will be described with reference to FIGS.

[0026] [1-1.Configuration] In FIG. 1, a fuel cell stack 90 has a stack section 91 made up of stacked cells sandwiched between current collector plates 40, 41, with end plates 70, 77 arranged on the outside thereof, and bolts 80 fastening the end plates together to apply pressure.

[0027] The end plate 70 is provided with a fuel gas inlet 71 and a fuel gas outlet 72 for introducing and discharging hydrogen as a fuel gas, an oxidant gas inlet 73 and an oxidant gas outlet 74 for introducing and discharging air as an oxidant gas, and a cooling medium inlet 75 and a cooling medium outlet 76 for introducing and discharging ion-exchanged water as a cooling medium.

[0028] In Figure 2, stack section 91 is formed by stacking multiple cells 100, with current collector plate 40 and current collector plate 41 at both ends, insulating plate 42 and insulating plate 43 on the outside thereof, and end plate 70 and end plate 77 on the outside thereof.

[0029] In FIG. 3, the electrolyte membrane-electrode-frame assembly 10 includes an electrolyte membrane-electrode assembly 13 having an electrolyte membrane 1, a cathode catalyst layer 2, and an anode catalyst layer 3, a cathode gas diffusion layer 4, an anode gas diffusion layer 5, a first frame 6, and a second frame 7.

[0030] The electrolyte membrane 1 is a polymer electrolyte membrane having hydrogen ion conductivity, and specifically, a fluorine-based polymer electrolyte membrane made of perfluorocarbon sulfonic acid (Nafion (registered trademark) manufactured by DuPont, USA) is used.

[0031] The cathode catalyst layer 2 is disposed on one main surface of the electrolyte membrane 1 and is a layer containing a catalyst for the reduction reaction of oxygen. Specifically, it uses a porous material whose main components are carbon powder supporting a platinum-based metal catalyst and a polymer material with proton conductivity.

[0032] The anode catalyst layer 3 is disposed on the other main surface of the electrolyte membrane 1 and is a layer containing a catalyst for the oxidation reaction of hydrogen. Specifically, a porous member is used whose main components are carbon powder supporting a platinum-based metal catalyst and a polymer material with proton conductivity.

[0033] The cathode gas diffusion layer 4 and the anode gas diffusion layer 5 are porous members having electrical conductivity and water repellency. In this embodiment, the members are made by dispersing PTFE (polytetrafluoroethylene), a water repellent polymer resin such as fluororesin, in a conductive substrate having a porous structure made from carbon paper.

[0034] The cathode gas diffusion layer 4 is laminated on the surface of the cathode catalyst layer 2 of the electrolyte membrane-electrode assembly 13 opposite to the electrolyte membrane 1 side.

[0035] The anode gas diffusion layer 5 is laminated on the surface of the anode catalyst layer 3 of the electrolyte membrane-electrode assembly 13 opposite to the electrolyte membrane 1 side.

[0036] The peripheral edge of the electrolyte membrane 1 exposed from the electrolyte membrane-electrode assembly 13 is sandwiched between a frame-shaped first frame 6 and a frame-shaped second frame 7, with the peripheral edge of the first frame 6 located outside the peripheral edge of the electrolyte membrane 1 and the peripheral edge of the second frame 7 located inside the peripheral edge of the electrolyte membrane 1. In other words, the peripheral edge of the electrolyte membrane 1 is located between the peripheral edge of the first frame 6 and the peripheral edge of the second frame 7.

[0037] The first frame 6 and the second frame 7 are made of resin members with appropriate mechanical strength, heat resistance, and excellent chemical resistance. Specifically, they are made by punching out 10 μm thick polyphenylene sulfide (PPS) with a Thomson blade.

[0038] In FIG. 6, the first frame 6 has a plurality of manifold holes 25 that are individually connected to a fuel gas inlet and a fuel gas outlet for introducing and discharging hydrogen as a fuel gas, an oxidant gas inlet and an oxidant gas outlet for introducing and discharging air as an oxidant gas, and a cooling medium inlet and a cooling medium outlet for introducing and discharging ion-exchanged water as a cooling medium.

[0039] On both outer main surfaces of the cathode gas diffusion layer 4 and the anode gas diffusion layer 5 of the electrolyte membrane-electrode-frame assembly 10, an outer peripheral portion 8 having manifold holes 25 in the frame is formed.

[0040] Specifically, the distance between the peripheral edge of the cathode gas diffusion layer 4 and the peripheral edge of the second frame 7 is 5 mm, and the distance between the peripheral edge of the electrolyte membrane 1 and the peripheral edge of the second frame 7 is 2 mm. The peripheral edge of the first frame 6 has the same size as the outer shape of the separator, and the distance between the peripheral edge of the electrolyte membrane 1 and the peripheral edge of the first frame 6 is secured to be 4 mm or more.

[0041] 4, the cell 100 is constructed by sandwiching an electrolyte membrane-electrode-frame assembly 10 between a cathode separator 20 and an anode separator 21, and bonding and sealing them with a first rubber-based adhesive 11 and a second rubber-based adhesive 12. The side surfaces of the peripheral edge of the first frame 6 are not covered with the first rubber-based adhesive 11 or the second rubber-based adhesive 12.

[0042] The cathode separator 20 and the anode separator 21 have appropriate mechanical strength and electrical conductivity. Specifically, they are made of members formed by heat-molding a mixture of graphite powder and thermosetting resin.

[0043] The cathode separator 20 has an oxidant gas passage 22 formed on one main surface facing the cathode gas diffusion layer 4 of the electrolyte membrane-electrode-frame assembly 10, through which air flows as an oxidant gas, and a cooling surface 26 formed on the other main surface, which comes into contact with the cooling medium passage 24 of the anode separator 21 of another cell 100 when the cell 100 is superimposed on the other main surface.

[0044] The cathode separator 20 has a plurality of manifold holes 25 that are individually connected to the fuel gas inlet, fuel gas outlet, oxidant gas inlet, oxidant gas outlet, and cooling medium inlet and cooling medium outlet, and the oxidant gas inlet and oxidant gas outlet are connected to the oxidant gas path 22 (not shown).

[0045] The anode separator 21 has a fuel gas path 23 formed on one main surface facing the anode gas diffusion layer 5 of the membrane-electrode-frame assembly 10, through which hydrogen flows as a fuel gas, and a cooling medium path 24 formed on the other main surface, through which ion-exchanged water flows as a cooling medium, by abutting against the cooling surface 26 of the cathode separator 20 of another cell 100 when the cells 100 are stacked. The cooling medium path 24 is sealed (not shown) to prevent the cooling medium from leaking to the outside.

[0046] The anode separator 21 has a plurality of manifold holes 25 that are individually connected to a fuel gas inlet, a fuel gas outlet, an oxidant gas inlet, an oxidant gas outlet, a cooling medium inlet, and a cooling medium outlet, and the fuel gas inlet and fuel gas outlet are connected to a fuel gas path 23, and the cooling medium inlet and cooling medium outlet are connected to a cooling medium path 24 (not shown).

[0047] FIG. 5 shows the state before the cathode separator 20, anode separator 21, and electrolyte membrane-electrode-frame assembly 10 that make up the cell 100 are bonded together using a first rubber-based adhesive 11 and a second rubber-based adhesive 12.

[0048] The first rubber adhesive 11 is arranged in a frame shape so as to surround the oxidant gas passage 22 of the cathode separator 20, and is also arranged so as to surround the manifold hole 25.

[0049] The second rubber adhesive 12 is arranged in a frame shape so as to surround the fuel gas path 23 of the anode separator 21, and is also arranged so as to surround the manifold hole 25.

[0050] In other words, the first rubber adhesive 11 and the second rubber adhesive 12 face each other and are disposed at the outer periphery 8 of the electrolyte membrane-electrode-frame assembly 10 .

[0051] The first rubber adhesive 11 and the second rubber adhesive 12 are made of synthetic resins that are highly durable and have mechanical strength and flexibility. Specifically, the adhesives used are made primarily of fluororubber, which has excellent durability in terms of chemical resistance and mechanical resistance.

[0052] [1-2. Manufacturing method] The manufacturing method and operation of the cell 100 configured as above will be described below. First, the manufacturing method will be described with reference to FIG.

[0053] First, a cathode catalyst layer 2 and an anode catalyst layer 3 are disposed on both main surfaces of an electrolyte membrane 1 to form an electrolyte membrane-electrode assembly 13 .

[0054] The first frame 6 is positioned with its peripheral edge outside the peripheral edge of the electrolyte membrane 1, and the second frame 7 is positioned with its peripheral edge inside the peripheral edge of the electrolyte membrane 1, and they are bonded together using a heat press without using any adhesive, maintaining a heating temperature in the range of 50°C to 70°C for 5 minutes.

[0055] As a result, the cathode catalyst layer 2 side of the outer periphery 8 of the electrolyte membrane-electrode-frame assembly 10 has the surfaces of the first frame 6, electrolyte membrane 1, and second frame 7 exposed, and the anode catalyst layer 3 side of the outer periphery 8 of the electrolyte membrane-electrode-frame assembly 10 has the surface of the first frame 6 exposed, and no adhesive is used between the electrolyte membrane 1 and the first frame 6, and between the electrolyte membrane 1 and the second frame 7, but they are joined by hydrogen bonding, which is a weak chemical interaction.

[0056] The cathode gas diffusion layer 4 is disposed so that the cathode catalyst layer 2 and the second frame 7 are sandwiched between the electrolyte membrane 1 and the cathode gas diffusion layer 4, with the cathode catalyst layer 2 being located at the center of the cathode gas diffusion layer 4. The anode gas diffusion layer 5 is disposed so that the anode catalyst layer 3 and the first frame 6 are sandwiched between the electrolyte membrane 1 and the cathode gas diffusion layer 4, with the anode catalyst layer 3 being located at the center of the anode gas diffusion layer 5. As with the first frame 6 and the second frame 7, they are bonded together by using a heat press without using an adhesive, at a heating temperature of 130°C to 150°C, and maintaining this temperature for 5 to 15 minutes.

[0057] Next, the rest of the manufacturing method will be explained with reference to FIG.

[0058] The first rubber adhesive 11 and the second rubber adhesive 12 are applied to the outer periphery 8 of the cathode separator 20 and the anode separator 21 with their viscosities reduced by a solvent such as methyl ethyl ketone. In this embodiment, a dispenser is used to apply the first rubber adhesive 11 and the second rubber adhesive 12, but screen printing or the like can also be used. The first rubber adhesive 11 and the second rubber adhesive 12 can also be applied in the form of sheets in a semi-cured state.

[0059] By sandwiching the cathode separator 20 and the anode separator 21, the surfaces of the second frame 7, the electrolyte membrane 1, and the first frame 6 located at the outer periphery 8 between the cathode separator 20 and the electrolyte membrane-electrode-frame assembly 10 are bonded with the first rubber-based adhesive 11. Furthermore, the surface of the first frame 6 located at the outer periphery 8 between the anode separator 21 and the electrolyte membrane-electrode-frame assembly 10 is bonded with the second rubber-based adhesive 12.

[0060] [1-3. Effects, etc.] As described above, in this embodiment, the cell 100 comprises an electrolyte membrane-electrode assembly 13 constituted by an electrolyte membrane 1, a cathode catalyst layer 2, an anode catalyst layer 3, a cathode gas diffusion layer 4, and an anode gas diffusion layer 5, a cathode separator 20, an anode separator 21, a second frame 7, a first frame 6, a first rubber-based adhesive 11, and a second rubber-based adhesive 12.

[0061] The first frame 6 is disposed between the anode catalyst layer 3 and the anode gas diffusion layer 5 , and is formed along the surface of the electrolyte membrane 1 in the outer circumferential direction of the anode catalyst layer 3 .

[0062] The second frame 7 is disposed between the cathode catalyst layer 2 and the cathode gas diffusion layer 4, and is formed along the surface of the electrolyte membrane 1 in the outer circumferential direction of the cathode catalyst layer 2.

[0063] The first rubber adhesive 11 and the second rubber adhesive 12 bond the first frame 6, the second frame 7 and the electrolyte membrane 1 between the cathode separator 20 and the anode separator 21.

[0064] In addition, in this embodiment, the cell 100 is configured such that the peripheral portion of the first frame 6 is located outside the peripheral portion of the electrolyte membrane 1, and the peripheral portion of the second frame 7 is located inside the peripheral portion of the electrolyte membrane 1, and the side surfaces of the peripheral portion of the first frame 6 are not covered with the first rubber-based adhesive 11 and the second rubber-based adhesive 12, but the side surfaces of the peripheral portion of the electrolyte membrane 1 and the side surfaces of the peripheral portion of the second frame 7 are covered with the second rubber-based adhesive 12.

[0065] As a result, the electrolyte membrane 1, the first frame body 6, and the second frame body 7 are bonded with the first rubber-based adhesive 11 or the second rubber-based adhesive 12, respectively, and when the first rubber-based adhesive 11 and the second rubber-based adhesive 12 contract, the electrolyte membrane 1 and the first frame body 6, and the electrolyte membrane 1 and the second frame body 7, which have weak bonding strength, peel off from each other, and this prevents fuel gas and oxidant gas from leaking to the outside through gaps.

[0066] Furthermore, by extending the first frame 6 until the side surfaces are exposed, the amounts of the first rubber-based adhesive 11 and the second rubber-based adhesive 12 used can be reduced accordingly.

[0067] In this embodiment, the first frame 6 and the second frame 7 of the fuel cell stack 90 may be made of a non-conductive resin film or sheet.

[0068] As a result, since the non-conductive first frame 6 is present on the outer periphery 8 of the anode separator 21 and the cathode separator 20, the non-power generation area outside the gas diffusion layer between the anode separator 21 and the cathode separator 20 is reliably insulated.

[0069] However, since the first rubber-based adhesive 11 and the second rubber-based adhesive 12 are non-conductive, the separators can be insulated even if the first frame body 6 and the second frame body 7 are made of a conductive material, so the first frame body 6 and the second frame body 7 do not necessarily have to be made of a non-conductive material.

[0070] Furthermore, in this embodiment, the first frame 6 and the second frame 7 of the fuel cell stack 90 may have hydroxy groups on the surfaces that come into contact with the electrolyte membrane 1 and the first rubber-based adhesive 11 and second rubber-based adhesive 12. The hydroxy groups can be provided by surface modification such as corona treatment or plasma treatment. In this embodiment, corona treatment is used. In addition to hydroxy groups, functional groups such as carbonyl groups and carboxy groups may also be provided on the surfaces.

[0071] As a result, the first frame 6 and the electrolyte membrane 1, and the second frame 7 and the electrolyte membrane 1 are bonded together by hydrogen bonding due to heat and pressure bonding.

[0072] Therefore, the electrolyte membrane 1 and the first frame 6, and the electrolyte membrane 1 and the second frame 7 are bonded together without using a rubber-based adhesive, which makes it easy to handle the electrolyte membrane-electrode-frame assembly 10, and also prevents the cathode catalyst layer 2 and the anode catalyst layer 3, which are disposed on both main surfaces of the electrolyte membrane 1, from being poisoned by the solvent contained in the first rubber-based adhesive 11 and the second rubber-based adhesive 12. Furthermore, the first frame 6 and the second frame 7 are bonded together more firmly with the first rubber-based adhesive 11 and the second rubber-based adhesive 12.

[0073] Therefore, even if a force is applied to peel the electrolyte membrane 1 and the first frame 6 and the electrolyte membrane 1 and the second frame 7 apart due to the contraction of the first rubber-based adhesive 11 and the second rubber-based adhesive 12 over a long period of time, the force is reduced and the interfaces do not peel off, thereby improving the durability of the fuel cell.

[0074] Furthermore, bonding with a fluorine-based electrolyte membrane 1, which has poor wettability, is said to have a weak bond. However, since the first rubber-based adhesive 11 and the second rubber-based adhesive 12 are made of low molecular weight materials containing a solvent, by dissolving part of the electrolyte membrane 1 with the solvent and making it compatible, the wettability is improved, and the distance between the interfaces becomes very close, allowing intermolecular forces to come into play, making it easier for physical interactions to form, and strengthening the bonding strength.

[0075] In this embodiment, the first frame 6 and the second frame 7 have a frame-like shape, but they do not have to be frame-like. For example, if necessary for design purposes, they may have a shape like a frame with a part missing.

[0076] In this embodiment, the second frame 7 is used on the cathode catalyst layer 2 side and the first frame 6 is used on the anode catalyst layer 3 side, but it is also possible to use the first frame 6 on the cathode catalyst layer 2 side and the second frame 7 on the anode catalyst layer 3 side.

[0077] (Other embodiments) As described above, the first embodiment has been described as an example of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can be applied to embodiments in which modifications, additions, omissions, etc. are made. Furthermore, it is also possible to combine the components described in the first embodiment above to create new embodiments.

[0078] Therefore, other embodiments will be exemplified below.

[0079] In the first embodiment, as an example of the fuel cell stack 90, the first frame 6 and the second frame 7 are formed by punching 10 μm thick polyphenylene sulfide (PPS) with a Thomson blade. The first frame 6 and the second frame 7 need only reliably insulate the non-power generation regions outside the cathode gas diffusion layer 4 and the anode gas diffusion layer 5 between the anode separator 21 and the cathode separator 20. Therefore, the first frame 6 and the second frame 7 are not limited to being made of 10 μm thick polyphenylene sulfide (PPS).

[0080] The first frame 6 and the second frame 7 can be made of any durable material that does not poison the cathode catalyst layer 2 or the anode catalyst layer 3 of the electrolyte membrane-electrode-frame assembly 10 in the fuel cell stack 90. ​​For example, in addition to members formed by punching expensive polyphenylene sulfide (PPS) with a Thomson blade, members formed by injection molding using inexpensive modified polyphenylene ether or the like may also be used.

[0081] This allows the material costs of the first frame 6 and the second frame 7 to be reduced.

[0082] In the first embodiment, a case where a fluororubber adhesive is used as the first rubber adhesive 11 and the second rubber adhesive 12 has been described as an example of a fuel cell stack 90. ​​The first rubber adhesive 11 and the second rubber adhesive 12 may be any adhesive that contains a thermosetting elastomer as a main component that elastically deforms after hardening. Therefore, the first rubber adhesive 11 and the second rubber adhesive 12 of the fuel cell stack 90 are not limited to being a fluororubber adhesive.

[0083] However, there are no particular limitations on the first rubber-based adhesive 11 and the second rubber-based adhesive 12, as long as they do not poison the cathode catalyst layer 2 or the anode catalyst layer 3 of the electrolyte membrane-electrode-frame assembly 10 in the fuel cell stack 90. ​​For example, in addition to expensive fluororubber-based adhesives, adhesives using thermosetting elastomers such as silicone rubber, natural rubber, EPDM, and butyl rubber, or latexes such as isoprene rubber and butadiene rubber, and adhesives using liquid polybutadiene, polyisoprene, polychloroprene, silicone rubber, etc. may also be used.

[0084] This allows the material costs of the first rubber adhesive 11 and the second rubber adhesive 12 to be reduced.

[0085] It should be noted that the above-described embodiments are intended to illustrate the technology of the present disclosure, and various modifications, substitutions, additions, omissions, etc. may be made within the scope of the claims or their equivalents. [Industrial Applicability]

[0086] The present disclosure is applicable to solid polymer fuel cells such as fuel cell vehicles and stationary fuel cells, and electrochemical devices. [Explanation of symbols]

[0087] 1 Electrolyte membrane 2. Cathode catalyst layer 3. Anode catalyst layer 4. Cathode gas diffusion layer 5 Anode gas diffusion layer 6 First frame 7 Second frame 8 Outer periphery 10 Electrolyte membrane-electrode-frame assembly 11 First rubber adhesive 12 Second rubber adhesive 13 Electrolyte membrane-electrode assembly 20 Cathode separator 21 Anode separator 22 Oxidant gas pathway 23 Fuel gas route 24 Coolant path 25 manifold hole 26 Cooling surface 40 Current collector plate 41 Current collector plate 42 Insulating plate 43 Insulating plate 70 End Plate 71 Fuel gas inlet 72 Fuel gas outlet 73 Oxidant gas inlet 74 Oxidant gas outlet 75 Cooling medium inlet 76 Coolant outlet 77 End Plate 80 volts 90 Fuel Cell Stack 91 Stack Section 100 cells

Claims

1. an electrolyte membrane-electrode assembly comprising an electrolyte membrane, catalyst layers disposed on both main surfaces of the electrolyte membrane on the inner side of the peripheral edge thereof, and gas diffusion layers disposed on both outer sides of the catalyst layers with the electrolyte membrane interposed therebetween; a pair of separators disposed on both outer sides of the gas diffusion layer; a first frame disposed between one of the gas diffusion layers and the catalyst layer and formed along a surface of the electrolyte membrane in a circumferential direction of the one of the catalyst layers; a second frame disposed between the other gas diffusion layer and the catalyst layer and formed along the surface of the electrolyte membrane in the outer circumferential direction of the other catalyst layer; a rubber-based adhesive that bonds the first frame, the second frame, and the electrolyte membrane between the pair of separators; Equipped with the first frame has a peripheral edge portion located outside the peripheral edge portion of the electrolyte membrane, the second frame has a peripheral edge portion located inside the peripheral edge portion of the electrolyte membrane, a side surface of a peripheral portion of the first frame is not covered with the rubber-based adhesive, but a side surface of a peripheral portion of the electrolyte membrane and a side surface of a peripheral portion of the second frame are covered with the rubber-based adhesive; the first frame and the second frame have hydroxy groups on their surfaces in contact with the electrolyte membrane and the rubber-based adhesive; fuel cell.

2. 2. The fuel cell according to claim 1, wherein the first frame and the second frame are made of a non-conductive resin film or resin sheet.

3. 3. The fuel cell according to claim 1, wherein the rubber adhesive is mainly made of a thermosetting elastomer.

4. 3. The fuel cell according to claim 1, wherein the rubber adhesive is mainly made of fluorine-based rubber.

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