JP2010186711A - Fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell effectively solving problems wherein a crack in an electrolyte film or the like is liable to occur due to space defined among a protective film, a catalyst layer and a gas permeable layer, and where a sufficient amount of gas supply to the catalyst layer becomes difficult, in the fuel cell including an electrode element with the protective film formed on a peripheral edge of the catalyst layer between a gas diffusion layer and an electrolyte film, an end of the protective film being laminated on (lapped over) the catalyst layer, and a gasket formed on a peripheral edge of the electrode element by injection molding. <P>SOLUTION: In the fuel cell, the protective films 7A, 7B are interposed between exposed regions of the peripheral edge of the electrolyte film 1 which are not covered with the catalyst layers 2, 3 and the gas diffusion layers 5, 6 and the space h which is defined by ends of the protective films 7A, 7B, the catalyst layers 2, 3, and the gas permeable layers 5, 6, is plugged with a water repellent or hydrophobic filler 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel cell having a protective film between a gas permeable layer and an electrolyte membrane at the periphery of a catalyst layer.

  In a fuel cell of a polymer electrolyte fuel cell, a membrane electrode assembly (MEA) is formed from an ion-permeable electrolyte membrane and an anode-side and cathode-side catalyst layer sandwiching the electrolyte membrane. An electrode body (MEGA: Membrane Electrode & Gas Diffusion Layer Assembly) is formed from this MEA and the anode-side and cathode-side gas diffusion layers (GDL) sandwiching the MEA, and provides fuel gas or oxidant gas to the electrode body In addition, a gas flow path layer made of a metal porous body for collecting electricity generated by an electrochemical reaction and a separator are arranged on both sides of the electrode body. In addition, the fuel cell in which the gas flow channel groove is formed in the separator is also a conventional one, and in this case, the metal porous body that becomes the gas flow channel layer is unnecessary. An actual fuel cell stack is formed by stacking and stacking a number of fuel cell cells according to required power.

  In the fuel cell described above, hydrogen gas or the like is provided as a fuel gas to the anode electrode, oxygen or air is provided as the oxidant gas to the cathode electrode, and each electrode has a unique gas flow path layer (or formed in a separator). The gas flows in the in-plane direction in the gas channel groove), and then the gas diffused in the gas diffusion layer is guided to the electrode catalyst layer to cause an electrochemical reaction.

  As a form of the gas diffusion layer described above, a gas diffusion layer composed of a diffusion layer base material and a current collecting layer (MPL: Micro Porous Layer) is generally known. In general, the catalyst layer has a smaller planar area (smaller planar area) than the electrolyte membrane, and the exposed area at the periphery of the catalyst layer where the electrolyte membrane is not covered with the catalyst layer protects the polymer material. A structure in which a film is disposed (including a form in which the protective film is wrapped on the current collecting layer) and the protective film is interposed between the diffusion layer base material and the electrolyte membrane is generally used. By interposing the protective film between the diffusion layer substrate and the electrolyte membrane in the peripheral region of the catalyst layer, the electrolyte membrane having the catalyst layer and the gas diffusion layer are, for example, about 1 to 3 MPa in a high temperature atmosphere of about 100 to 130 ° C. It is possible to prevent the fluff protruding from the surface of the fibrous diffusion layer base material from being pierced into the electrolyte membrane when thermocompression bonding is performed with a compression force of (a thermocompression bonding condition that does not affect the electrolyte membrane).

  Further, in the fuel cell described above, the electrode body is provided with a gasket for sealing a fluid such as a fuel gas or an oxidant gas supplied to the membrane electrode assembly, and a cooling water for suppressing the temperature rise of the cell. In addition, it is molded by injection molding or compression molding around the periphery of a porous metal body. For example, in a fuel cell having a metal porous body serving as a gas flow path, one metal porous body on the anode side or cathode side is accommodated in the cavity of the mold, and then the electrode body is accommodated, and then the anode side or Gasket molding is performed by injecting a resin into the gasket forming cavity at the periphery of the electrode body and the metal porous body in a posture in which the other metal porous body on the cathode side is accommodated. There is also a method in which either the anode side or the cathode side separator is first accommodated in the cavity, and then the above-described constituent members are accommodated for injection molding.

  The structure of the conventional fuel cell provided with the above-mentioned protective film and gasket is shown in FIG. In the electrode assembly, a membrane electrode assembly c is formed from the electrolyte membrane a and the catalyst layers b1 and b2 on the cathode side and the anode side. The membrane electrode assembly c is formed into a gas diffusion layer d ( A diffusion layer base material d1 and a current collecting layer d2) are sandwiched and formed. The catalyst layers b1 and b2 are narrower than the electrolyte membrane a, and the cathode-side and anode-side protective films e1 and e2 are arranged in the exposed regions where the electrolyte membrane a is not covered with the catalyst layers b1 and b2. These are interposed between the electrolyte membrane a and the diffusion layer base material d1. In the illustrated example, a metal porous body f serving as a gas flow path is provided on the cathode side and the anode side, and the periphery of the electrode body and the metal porous body f is injection-molded, and fluid circulation is provided in the inside thereof. A gasket G having a manifold M and having an endless rib g1 surrounding the manifold M is formed on the periphery of the manifold M at the end thereof.

  As in the illustrated example, the protective film e1, e2 generally has its catalyst layer side ends wrapped (laminated) on the catalyst layers b1, b2. When the fluff of the diffusion layer base material pierces the electrolyte membrane a at the time of thermocompression bonding, the protective films e1 and e2 promote gas cross leak, and the cross leak durability of the fuel cell is reduced. It is provided in order to solve the problem of being directly linked to a decrease in power generation performance. In other words, the region where the electrolyte membrane a is in contact with the catalyst layers b1 and b2 is the region where the electrolyte membrane a is protected from fluff sticking by the catalyst layers b1 and b2, while the exposed region of the electrolyte membrane a described above. Is protected from fluff sticking by protective films e1, e2. Here, in order to avoid the fluff from leading to the electrolyte membrane a from the ends of the catalyst layers b1 and b2, as shown in the drawing, the ends of the protective films e1 and e2 are wrapped on the catalyst layers b1 and b2. Yes. The fuel cell stack is formed by stacking and stacking a plurality of fuel cells. The compressive force at the time of stacking is transmitted to each fuel cell, and as shown in the drawing, the membrane electrode assembly c On the other hand, it acts as a compressive force P from above and below to excite desired power generation while minimizing the interfacial resistance between the cell constituent members. Note that Patent Document 1 can be cited as an open technique in which the end of a protective film (reinforcing film) is wrapped with a catalyst layer as shown in FIG.

  Since the catalyst layer side ends of the protective films e1 and e2 wrap with the catalyst layers b1 and b2, the protective films e1 and e2 extend from the electrolyte membrane a over the catalyst layers b1 and b2 bonded to the surface thereof. A gap h naturally occurs between the protective films e1, e2, the catalyst layers b1, b2, and the gas diffusion layer d.

  In the fuel cell, particularly within the electrode body, moisture is transferred between the anode side and the cathode side due to movement of accompanying water during proton conduction and back diffusion of generated water generated at the cathode side electrode. However, the presence of the gap h described above causes the moving water to flow into the gap h, thereby forming a water pool w.

  Then, due to the presence of the above-described water pool w, for example, the water pool w freezes when it is below freezing point, and a problem arises that the catalyst layer and the electrolyte membrane are cracked starting from this. This is one of the urgent issues in the field.

  Further, since the gap h exists in the vicinity of the catalyst layer, a gas (air or hydrogen) that often flows in an easy-to-flow part or in a direction in which the gas flows easily flows into the gap h, and the gas sufficiently flows into the catalyst layer. The problem that it is not provided in the case may arise. Therefore, also from the viewpoint of providing sufficient gas to the catalyst layer, measures against the gap h described above are required.

JP 2002-216789 A

  The present invention has been made in view of the above problems, and is an electrode body provided with a protective film at the periphery of the catalyst layer between the gas diffusion layer and the electrolyte membrane, and cathode and anode electrode bodies. In a fuel cell in which a gas permeable layer and a separator are sandwiched, a puddle is formed in a gap formed between the end of the protective film, the catalyst layer, and a gas permeable layer such as a gas diffusion layer. This effectively eliminates the problem that the catalyst layer, the electrolyte membrane, etc. are likely to be cracked due to the above, or the problem that it is difficult to provide sufficient gas to the catalyst layer when air or hydrogen flows into the gap. An object of the present invention is to provide a fuel cell that can handle the above.

  In order to achieve the above object, a fuel cell according to the present invention includes a membrane electrode assembly formed of an electrolyte membrane and a catalyst layer that has a smaller planar area than the catalyst layer and abuts on both sides of the electrolyte membrane. A gas permeable layer and a separator are arranged on both sides of a joined body to form a fuel cell, and a fuel cell having a gasket for sealing between separators in a stacked fuel cell or between fuel cells, At least, a protective film is interposed between an exposed region on the periphery where the electrolyte membrane is not covered with the catalyst layer and the gas permeable layer, and an end portion of the protective film, the catalyst layer, and the gas permeable layer. The space defined by the layer is closed with a water-repellent or hydrophobic filler.

  The cell structure constituting the fuel cell of the present invention comprises a membrane electrode assembly (MEA) having a gas diffusion layer comprising a diffusion layer base material and a current collecting layer on both the anode side and the cathode side, the anode side and the cathode. Either one of the sides includes both of the forms including only the current collecting layer (the diffusion layer base material is discarded). In the present specification, any of these forms is referred to as an electrode body (MEGA). In addition to a configuration in which separators having gas flow channel grooves formed on both sides of the electrode body are directly arranged, a gas flow channel layer (a porous metal such as an expanded metal) is formed between a so-called flat type separator and the electrode body. Body) is included. Furthermore, the “gas permeable layer” is meant to include both a gas diffusion layer and a gas flow path layer. Therefore, in a cell configuration that does not include a gas flow path layer, a “gas permeable layer” means a “gas diffusion layer”, and in a cell configuration that includes both a gas diffusion layer and a gas flow path layer, The “permeation layer” means either or both of “gas diffusion layer” and “gas flow path layer”.

  The fuel cell of the present invention is formed from a fuel cell having a protective film in the exposed region at the periphery of the electrolyte membrane, and the end of the protective film, which can often occur in the case of this cell structure, and a catalyst The space defined by the layer and the gas permeable layer is filled with a water-repellent or hydrophobic filler to close the space. For example, when the protective film is thicker than the catalyst layer, the above-described space is formed on the catalyst layer. In addition, the fuel cell of the present invention includes a fuel cell in which an end portion of the protective film is laminated (wrapped) on the catalyst layer as in the cell structure disclosed in Patent Document 1 described above. Needless to say, even in this embodiment, the above-described space is formed on the catalyst layer.

  Here, both “water repellency” and “hydrophobicity” have characteristics opposite to “hydrophilicity”, and the above-mentioned space is filled with water (generated water, associated water, etc.) generated or moved in the electrode body. It is possible to avoid staying in the filled material, and to exhibit a characteristic of promptly sending it to the gas permeable layer.

  Due to the water-repellent or hydrophobic filler clogging the space, the problem described above, that is, water stays in the space and freezes, freezing propagates from this and damages the catalyst layer, etc. Or the problem that it is difficult to provide sufficient gas to the catalyst layer due to the gas flowing into the space.

  The water-repellent and hydrophobic fillers are not particularly limited. For example, fluorocarbon derivatives, fluoroalkyl acrylate polymers, fluoroolefin vinyl ether copolymers, polytetrafluoroethylene (PTFE) and other fluorine-based compounds, , Organosilicon compounds such as organopolysiloxane and silicone oil, polymer compounds having water repellency, such as polymer compounds containing fluorine in the main chain skeleton and polymer compounds containing silicon in the main chain skeleton be able to. In particular, since polytetrafluoroethylene is also used for water repellent treatment of the gas diffusion layer, it is preferable to use this material.

  As can be understood from the above description, according to the fuel cell of the present invention, the water-repellent or hydrophobic filler blocks the space defined by the catalyst layer, the gas diffusion layer, and the protective film. Problems that may arise due to the presence of water, that is, water stays in the space and freezes, and freezing is propagated from this to cause damage to the catalyst layer, etc., or gas flows into the space and the catalyst layer The problem that it is difficult to provide gas can be effectively solved.

It is the longitudinal cross-sectional view which expanded a part of electrode body and gasket of the fuel cell of this invention. It is the longitudinal cross-sectional view which expanded a part of electrode body and the gasket of the conventional fuel cell.

  Embodiments of the present invention will be described below with reference to the drawings. In the illustrated example, a porous metal body serving as a gas flow path is disposed on both sides of the electrode body, and this is a configuration in which a separator having a three-layer structure is further disposed to form a fuel cell. However, in the case of a fuel cell in which a gas channel groove is formed in the separator and a metal porous body is unnecessary, the upper and lower end surfaces of the gasket are located near the end surfaces of the gas diffusion layers on the cathode side and the anode side. Moreover, the form which exhibited what was called a base material-less structure where the diffusion layer base material of the gas diffusion layer was abolished from any one of the anode side and the cathode side may be used. Furthermore, the illustrated example shows a structure in which the end portion of the protective film is wrapped on the catalyst layer. In addition to this form, the end portion of the protective film does not wrap on the catalyst layer. The fuel cell may have a structure in which the protective film is thicker than the catalyst layer. Also in this embodiment, a space is formed between the catalyst layer, the end of the protective film, and the gas permeable layer (for example, a gas diffusion layer), and this space is filled with a water repellent or hydrophobic filler. This is plugged.

  FIG. 1 is an enlarged longitudinal sectional view of a part of an electrode body and a gasket of a fuel cell according to the present invention. In this electrode body, a membrane electrode assembly 4 is formed from the electrolyte membrane 1 and the catalyst layers 2 and 3 on the cathode side and the anode side, and sandwiched between the gas diffusion layers 5 and 6 on the cathode side and the anode side. Is formed. In the illustrated example, porous bodies 8A and 8B serving as cathode and anode gas flow paths are arranged on both sides of the electrode body, and a resin material gasket 9 is formed on the periphery of the electrode body and the porous bodies 8A and 8B. Has been.

  Here, the catalyst layers 2 and 3 have a smaller area than the electrolyte membrane 1, and therefore the catalyst layers 2 and 3 do not exist at the periphery of the catalyst layers 2 and 3 on both sides of the electrolyte membrane 1. An exposed area is formed.

  In the exposed region, the cathode-side and anode-side protective films 7A and 7B are arranged, and more specifically, the catalyst layer side ends of the protective films 7A and 7B are wrapped on the catalyst layers 2 and 3, respectively. The fuzz protruding from the gas diffusion layers 5 and 6 is prevented from sticking into the electrolyte membrane 1.

  Here, the electrolyte membrane 1 constituting the membrane electrode assembly 4 is, for example, a fluorine ion exchange membrane having a sulfonic acid group or a carbonyl group, a substituted phenylene oxide, a sulfonated polyaryletherketone, a sulfonated polyarylethersulfone, It is formed from a non-fluorine polymer such as sulfonated phenylene sulfide.

  The catalyst layers 2 and 3 are formed by mixing a conductive carrier (particulate carbon carrier or the like) on which a catalyst is supported, an electrolyte, and a dispersion solvent (organic solvent) to form a catalyst solution (catalyst ink). Then, this is stretched in layers with a coating blade on a substrate such as the electrolyte membrane 1 or the gas diffusion layers 5 and 6 to form a coating film, and dried in a hot air drying furnace or the like to form a catalyst layer. . Here, the electrolyte forming the catalyst solution is a proton conductive polymer, an ion exchange resin having a skeleton of an organic fluorine-containing polymer, such as a perfluorocarbon sulfonic acid resin, a sulfonated polyether ketone, a sulfonated polyether. Sulfonated plastic electrolytes such as sulfone, sulfonated polyetherethersulfone, sulfonated polysulfone, sulfonated polysulfide, sulfonated polyphenylene, sulfoalkylated polyetheretherketone, sulfoalkylated polyethersulfone, sulfoalkylated polyetherethersulfone And sulfoalkylated plastic electrolytes such as sulfoalkylated polysulfone, sulfoalkylated polysulfide, and sulfoalkylated polyphenylene. Examples of commercially available materials include Nafion (registered trademark, manufactured by DuPont) and Flemion (registered trademark, manufactured by Asahi Glass Co., Ltd.). Examples of the dispersion solvent include alcohols such as methanol, ethanol, 1-propanol, 2-propanol, ethylene glycol, and diethylene glycol, acetone, methyl ethyl ketone, dimethylformamide, dimethylimidazolidinone, dimethyl sulfoxide, dimethylacetamide, and N-methylpyrrolidone. , Propylene carbonate, esters such as ethyl acetate and butyl acetate, and various aromatic or halogen solvents, and these can be used alone or as a mixed solution. Furthermore, regarding a conductive carrier carrying a catalyst, examples of the conductive carrier include carbon materials such as carbon black, carbon nanotubes, and carbon nanofibers, and carbon compounds typified by silicon carbide. As this catalyst (metal catalyst), for example, any one of platinum, platinum alloy, palladium, rhodium, gold, silver, osmium, iridium, etc. can be used, preferably platinum or platinum alloy is used. It is good to do. Furthermore, as this platinum alloy, for example, platinum, aluminum, chromium, manganese, iron, cobalt, nickel, gallium, zirconium, molybdenum, ruthenium, rhodium, palladium, vanadium, tungsten, rhenium, osmium, iridium, titanium and lead An alloy with at least one of them can be mentioned.

  The gas diffusion layers 5 and 6 are made of diffusion layer base materials 51 and 61 and current collection layers 52 and 62 (MPL). The diffusion layer base materials 51 and 61 have low electric resistance and current collection. Is not particularly limited as long as it can perform, for example, a material mainly composed of a conductive inorganic substance, and examples of the conductive inorganic substance include a fired body from polyacrylonitrile, a pitch from Examples thereof include carbon materials such as fired bodies, graphite and expanded graphite, nanocarbon materials thereof, stainless steel, molybdenum, and titanium. In addition, the form of the conductive inorganic substance of the diffusion layer base materials 51 and 61 is not particularly limited, and for example, it is used in the form of fibers or particles, but is an inorganic conductive fiber from the viewpoint of gas permeability, Carbon fiber is particularly preferable. As the diffusion layer base materials 51 and 61 using inorganic conductive fibers, a woven fabric or non-woven fabric structure can be used, and examples thereof include carbon paper and carbon cloth. The woven fabric is not particularly limited, such as plain weaving, crest weaving, and binding weaving, and examples of the nonwoven fabric include those made by a papermaking method, a needle punching method, and a water jet punching method. Further, examples of the carbon fiber include phenol-based carbon fiber, pitch-based carbon fiber, polyacrylonitrile (PAN) -based carbon fiber, and rayon-based carbon fiber. Furthermore, the current collecting layers 52 and 62 serve as electrodes for collecting electrons from the catalyst layers 3 and 2 on the anode side and the cathode side, and also have a water repellency function for draining generated water and the like generated in the catalyst layer. It can be formed from platinum, palladium, ruthenium, rhodium, iridium, gold, silver, copper and their compounds or alloys, conductive carbon materials, and the like.

  The porous bodies 8A and 8B are made of expanded metal or a metal fired sintered body, and in this fired sintered body, a metal material having excellent corrosion resistance such as titanium, stainless steel, copper, and nickel is preferably used. Furthermore, it may be a foam in which chromium carbide or iron-chromium carbide is dispersed in stainless steel.

  Further, the protective films 7A and 7B are made of polytetrafluoroethylene, PVDF (polyvinyl difluoride), polyethylene, polyethylene naphthalate (PEN), polycarbonate, polyphenylene ether (PPE), polypropylene, polyester, polyamide, copolyamide, polyamide elastomer. , Polyimide, polyurethane, polyurethane elastomer, silicone, silicone rubber, silicon-based elastomer, and the like.

  The gasket 9 has an endless rib 9a surrounding the manifold M on the periphery of the manifold M at the end thereof. The outline of the molding method is as follows. The anode side porous body 8B, the anode side gas diffusion layer 6, the membrane electrode assembly 4, the cathode side gas diffusion layer 5, and the cathode side porous body 8A are placed in a molding die (not shown). This is performed by a method such as sequentially accommodating and closing the mold, and injecting resin into the gasket cavity on the side of the membrane electrode assembly 4 (injection molding). Here, as the material of the gasket, methanol-resistant epoxy resin, epoxy-modified silicone resin, silicone resin, fluorine resin, urethane RTV rubber, butyl rubber resin, silicone RTV rubber, EPDM resin, etc. are used. it can.

  In the figure, a space h is formed between the end portions of the protective films 7A and 7B, the catalyst layers 2 and 3, and the current collecting layers 52 and 62 forming the gas diffusion layers 5 and 6, The space h is filled with a water repellent or hydrophobic filler 10 to close the space h.

  Here, as the material of the filler 10 having water repellency and hydrophobicity, fluorocarbon derivatives, fluoroalkyl acrylate polymers, fluoroolefin vinyl ether copolymers, fluorine-based compounds such as polytetrafluoroethylene (PTFE), and organopolysiloxane And organic silicon compounds such as silicone oil, polymer compounds having water repellency, for example, polymer compounds containing fluorine in the main chain skeleton and polymer compounds containing silicon in the main chain skeleton. For example, after these materials are made into a paste and the protective films 7A and 7B are disposed so as to be wrapped in the catalyst layers 2 and 3, a sufficient amount of the paste (space h formed in a later step) is formed at the ends thereof. The electrode body is formed in a posture in which the space 10 is closed by the filler 10 by applying a sufficient amount of the gas diffusion layers 5 and 6 and then hot-pressing the gas diffusion layers 5 and 6.

  When the space h is blocked by the water repellent or hydrophobic filler 10, the generated water or the like stays in the space h and freezes, and the freezing is propagated from this to the catalyst layers 2, 3 and the like. Or the gas flows into the space h and it is difficult to provide sufficient gas to the catalyst layers 2 and 3.

  In an actual fuel cell, a separator having a three-layer structure is arranged on both sides of the illustrated porous bodies 8A and 8B to form a fuel cell, and the fuel cell is laminated in a predetermined stage according to a desired power generation amount. A stack is formed. Further, the fuel cell stack includes an end plate, a tension plate, and the like on the outermost side, and a compressive force is applied between the tension plates at both ends to form a fuel cell. A fuel cell system mounted on an electric vehicle or the like includes this fuel cell, various tanks for storing hydrogen gas and air, a blower for supplying these gases to the fuel cell, a radiator for cooling the fuel cell, a fuel The battery is generally composed of a battery that stores electric power generated by the battery, a drive motor that is driven by the electric power, and the like. The separator having a three-layer structure is a form in which an intermediate layer in which a cooling water flow path is formed of a metal material is interposed between two metal plates made of conductive metal (stainless steel, titanium, etc.) This is a separator in which a frame material made of a resin material is used as an intermediate layer and a large number of dimples or ribs for channel definition are projected from one of two metal plates.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. They are also included in the present invention.

DESCRIPTION OF SYMBOLS 1 ... Electrolyte membrane, 2 ... Cathode side catalyst layer, 3 ... Anode side catalyst layer, 4 ... Membrane electrode assembly (MEA), 5 ... Cathode side gas diffusion layer (gas permeable layer), 51 ... Diffusion layer group Material: 52 ... Current collecting layer, 6 ... Gas diffusion layer (gas permeable layer) on the anode side, 61 ... Diffusion layer base material, 62 ... Current collecting layer, 7A ... Protective film on the cathode side, 7B ... Protective film on the anode side , 8A ... porous body on the cathode side, 8B ... porous body on the anode side, 9 ... gasket, 10 ... filler, h ... space (gap)

Claims (3)

A membrane electrode assembly is formed from the electrolyte membrane and a catalyst layer that abuts on both sides of the electrolyte membrane with a smaller plane area than this, and a gas permeable layer and a separator are disposed on both sides of the membrane electrode assembly. A fuel cell comprising a gasket that forms a fuel cell and seals between separators in the stacked fuel cells or between the fuel cells,
At least, a protective film is interposed between the gas permeable layer and the exposed region of the periphery where the electrolyte membrane is not covered with the catalyst layer,
A fuel cell, wherein a water repellent or hydrophobic filler closes a space defined by an end of the protective film, the catalyst layer, and the gas permeable layer.   The fuel cell according to claim 1, wherein an end of the protective film is laminated on the catalyst layer. The gas permeable layer is formed of any one of a gas diffusion layer, a gas flow path layer made of a metal porous body, and a laminated unit of the gas diffusion layer and the gas flow path layer,
3. The fuel cell according to claim 1, wherein the gas permeable layers on both the anode side and the cathode side are formed of either the same form in the plurality of forms or different forms.

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