JP2008066270A - FUEL CELL AND METHOD FOR PRODUCING FUEL CELL GAS CHANNEL FORMING MEMBER - Google Patents

Abstract

An electrolyte layer is prevented from being damaged in a fuel cell having a metal channel in a gas flow path.
A fuel cell includes an electrolyte layer, an electrode, and a gas flow path. The gas flow path forming members 22 and 23 for forming the gas flow path are formed by a metal mesh 50 in which fine mesh wires 51 are woven, and the fine mesh wires 51 cover the metal wires 51a and the metal wires 51a. The conductive resin coat layer 51b is provided.
[Selection] Figure 3

Description

  The present invention relates to a fuel cell and a method for producing a fuel cell gas flow path forming member.

  The fuel cell is formed in units of a structure called a single cell. The single cell includes an electrolyte layer, a catalyst layer provided on both sides of the electrolyte layer, and a gas flow path provided further outside the catalyst layer. It has. As an example of the structure of a fuel cell, one in which the gas flow path is made of a sheet metal material made by weaving metal wires is known (see, for example, Patent Document 1). In such a fuel cell, the gas subjected to the electrochemical reaction that proceeds on the catalyst passes through the space between the metal wires formed in the sheet metal material. In addition to the gas diffusion function described above, the sheet metal material has a role of electron conduction with the separator disposed outside the single cell.

JP-A-6-349508

However, in the conventional fuel cell, the sheet metal material is affected by the expansion and contraction of other members during the operation of the fuel cell and rubs between the metal wires, so that metal ions are discharged and the electrolyte layer is damaged. A problem that gives you. For example, the polymer electrolyte fuel cell electrolyte layer is constituted by a solid polymer membrane, during the electrochemical reaction, hydrogen peroxide (H ₂ O ₂₎ occurs by side reactions. Hydrogen peroxide reacts with the metal ions to generate radicals with extremely strong oxidizing power. The generated radicals cause a reaction that sequentially decomposes the solid polymer film and damages the solid polymer film. Such damage to the electrolyte layer caused deterioration of fuel cell performance and shortened life.

  The present invention has been made to solve the above-described conventional problems, and an object thereof is to prevent damage to an electrolyte layer in a fuel cell having a configuration in which a metal wire is used for a gas flow path.

In order to achieve the above object, the fuel cell of the present invention comprises:
An electrolyte layer;
An electrode comprising a catalyst formed on the electrolyte layer;
A gas flow path that is disposed on the electrode and is formed of a sheet-like metal material made by combining metal wires, and in which a space between the metal wires serves as a flow path for gas supplied to and discharged from the electrode; A fuel cell comprising:
The gist of the present invention is that the metal wire is coated with a conductive polymer material.

  Since the conductive polymer material exerts an anticorrosion effect on the metal, according to the fuel cell having the above configuration, the anticorrosion property of the metal wire used in the gas flow path is coupled with the covering effect of covering the metal wire. Can be increased. For this reason, since the fuel cell of the present invention can suppress discharge of metal ions from the metal wire, it has the effect of preventing damage to the electrolyte layer. Therefore, the fuel cell of the present invention can prevent the performance deterioration of the fuel cell and extend the life. In addition, since the conductive polymer material is excellent in electron conductivity, the role of electron conduction with the electrode is not impaired.

  Note that the conductive polymer material acts on the metal surface when brought into contact with the metal, and enhances the corrosion resistance of the surface by enhancing the corrosion resistance of the surface. For this reason, even if the coating of the conductive polymer material is deficient, the anticorrosion function can be maintained. As a result, since it is possible to prevent corrosion to a certain size, it is possible to further reliably prevent the electrolyte layer from being damaged.

  The conductive polymer material may be a conductive resin composition in which a conductive filler is contained in a resin. According to this configuration, the conductivity can be easily adjusted depending on the content of the conductive filler. Moreover, moldability can also be improved.

  The conductive resin composition may be configured using a resin paint having hydrophobicity as the resin. According to this configuration, the anticorrosion property of the metal wire can be further improved due to the hydrophobic nature. Further, compared with the case where the hydrophobic treatment is performed again, it is possible to suppress the narrowing of the pore diameter due to the hydrophobic treatment, so that the gas easily spreads to the catalyst. As a result, performance degradation due to flooding can be prevented.

  The resin paint may be made of a fluororesin. Here, the fluororesin is a polymer compound containing a fluorine atom (F).

  The conductive resin composition may have a configuration using a curable resin as the resin. According to this configuration, since a drying step for evaporating the solvent is not necessary, it is possible to improve the production speed, reduce the size of the production facility by eliminating the need for the solvent recovery facility, and the like.

  In the fuel cell of the present invention, the conductive polymer material may be a conductive polymer.

The method for producing a gas flow path forming member for a fuel cell of the present invention comprises:
A method of manufacturing a fuel cell gas flow path forming member for manufacturing a fuel cell gas flow path forming member, comprising:
Coating a metal wire with an anticorrosive material;
Forming a sheet-like member by weaving a metal wire coated with the anticorrosive material, and using the member as the gas flow path forming member.

  According to the method for manufacturing a fuel cell gas flow path forming member having the above-described structure, the gas flow path forming member is woven using a metal wire covered with an anticorrosive material, and therefore the metal wire is protected against corrosion. Can increase the sex. When the corrosion resistance of the metal wire is high, the discharge of metal ions from the metal wire can be suppressed, so that the electrolyte layer can be prevented from being damaged when incorporated in a fuel cell.

  In the manufacturing method of the fuel cell gas flow path forming member having the above-described configuration, the anticorrosive material may be a conductive polymer material.

  The present invention can be realized in various forms other than those described above. For example, the present invention can be realized in the form of a fuel cell system including the fuel cell of the present invention.

Next, embodiments of the present invention will be described in the following order based on examples.
A. Fuel cell configuration:
B. Manufacturing method of gas flow path forming member:
C. Action / Effect:
D. Other embodiments:

A. Fuel cell configuration:
A fuel cell according to an embodiment of the present invention is a polymer electrolyte fuel cell and has a stack structure in which a plurality of single cells are stacked. FIG. 1 is a schematic cross-sectional view showing an outline of the configuration of the fuel cell of this embodiment. As shown in FIG. 1, the fuel cell of the present embodiment is configured by stacking a plurality of single cells 20. The unit cell 20 includes an MEA (Membrane Electrode Assembly) 21 including an electrolyte layer, gas flow path forming members 22 and 23 that sandwich the MEA 21 from both sides to form a sandwich structure, and this sandwich structure. Further, separators 24 and 25 sandwiched from both sides are provided.

  The MEA 21 includes an electrolyte layer 30 and an anode 31 and a cathode 32 that are electrodes formed on the surface of the electrolyte layer 30 with the electrolyte layer 30 interposed therebetween. The electrolyte layer 30 is a proton conductive ion exchange membrane formed of a solid polymer material such as a fluorine resin, and exhibits good electrical conductivity in a wet state. In this example, a Nafion membrane (manufactured by DuPont) was used. The anode 31 and the cathode 32 include a catalyst that promotes an electrochemical reaction, for example, platinum or an alloy made of platinum and another metal. In order to form the anode 31 and the cathode 32, for example, carbon powder carrying platinum or an alloy made of platinum and another metal is produced, and the carbon powder carrying the catalyst is dispersed in a suitable organic solvent, and an electrolyte is prepared. A paste may be prepared by adding an appropriate amount of a solution (for example, Aldrich Chemical, Nafion Solution). By applying this paste on the electrolyte layer 30 by a method such as screen printing, the anode 31 and the cathode 32 can be formed.

  FIG. 2 is an explanatory view showing a metal mesh 50 constituting the gas flow path forming members 22 and 23. As shown in the drawing, the metal mesh 50 is created by weaving fine mesh wires 51.

  FIG. 3 is an explanatory view showing a cross section of the fine wire 51 for mesh. As illustrated, the fine wire for mesh 51 includes a metal wire 51a and a conductive resin coat layer 51b that covers the metal wire 51a. For the metal wire 51a, a metal species having excellent corrosion resistance against acid is used. For example, stainless steel, titanium alloy, nickel alloy, or the like is used. The line width of the metal wire 51a is 5 to 300 μm, preferably 15 to 100 μm, and more preferably 20 to 75 μm. The line width is not limited to this size.

  The conductive resin coat layer 51b is a conductive resin composition containing a conductive filler (conductivity imparting agent) in a resin. In this embodiment, a resin paint having hydrophobicity is used as the resin. Yes. As the conductive filler, those excellent in corrosion resistance against acid are preferable, and carbon black, carbon fiber, carbon filament, noble metal fine particles, and conductive ceramic fine particles are used. The particle size of the conductive filler is 50 μm or less, preferably 10 μm or less, and more preferably 0.01 to 5 μm. The particle size is not limited to this size. According to the conductive resin composition in which a conductive filler is contained in a resin, the conductivity can be easily adjusted depending on the content of the conductive filler. Moreover, moldability can also be improved.

  As a resin coating having hydrophobicity, a resin coating made of a fluororesin excellent in hydrophobicity and acid resistance is suitable. Polytetrafluoroethylene, ethylenetetrafluoroethylene copolymer, polyvinylidene fluoride, polyvinyl fluoride, fluoride, Ethylene propylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, and the like can be used. A conductive filler is contained in such a resin coating, the resin coating containing the conductive filler is coated on the metal wire 51a, and the metal mesh 51 is manufactured by weaving the coated metal wire 51a.

  The metal mesh 50 is a sheet, and the thickness of the metal mesh 50 is 30 to 2000 μm, preferably 50 to 700 μm, and more preferably 10 to 500 μm. This thickness is not limited to this size. The manufacturing method of the metal mesh 50 will be described in more detail later.

  As shown in FIG. 1, the gas flow path forming members 22 and 23 made of the metal mesh 50 having such a configuration are arranged so as to occupy the entire space formed between the electrode and the separator. Gas for electrochemical reaction passes through a space formed between 51 and the fine mesh wire 51. That is, the space formed by the metal mesh 50 inside the gas flow path forming member 22 between the anode 31 and the separator 24 forms a fuel gas flow path in a single cell through which the fuel gas containing hydrogen passes. The space formed by the metal mesh 50 inside the gas flow path forming member 23 between the cathode 32 and the separator 25 forms an oxidizing gas flow path in a single cell through which an oxidizing gas containing oxygen passes. The gas flow path forming members 22 and 23 made of such a metal mesh 50 also collect current by contacting the anode 31 or the cathode 32.

  The separators 24 and 25 are gas-impermeable members formed of a material having electron conductivity, and can be formed of, for example, a metal member such as stainless steel or a carbon member. The separators 24 and 25 of the present embodiment are formed in a thin plate shape having a flat surface without unevenness.

In addition, a sealing member such as a gasket is disposed on the outer peripheral portion of the single cell 20 in order to ensure gas sealing performance in the single-cell fuel gas flow path and the single-cell oxidizing gas flow path. In addition, a plurality of gas manifolds (not shown) through which fuel gas or oxidizing gas flows are provided in the outer peripheral portion of the stack structure in which the single cells 20 are stacked in parallel with the stacking direction of the single cells 20. . The fuel gas flowing through the fuel gas supply manifold among the plurality of gas manifolds is distributed to each single cell 20 and is supplied to an electrochemical reaction in each single cell fuel gas flow path (gas flow path forming member 22). And then collect in the fuel gas discharge manifold. Similarly, the oxidant gas flowing through the oxidant gas supply manifold is distributed to each single cell 20 and passes through each single cell oxidant gas flow path (gas flow path forming member 23) while being subjected to an electrochemical reaction, and thereafter Collect in the oxidizing gas discharge manifold. In FIG. 1, the fuel gas (H ₂ ) in the single-cell fuel gas flow path and the oxidizing gas (O ₂ ) in the single-cell oxidizing gas flow path are shown to flow in parallel. Depending on the arrangement of the gas manifold, the flow may flow in different directions such as facing and orthogonal, in addition to the above-described parallel.

  As the fuel gas supplied to the fuel cell, a hydrogen rich gas obtained by reforming a hydrocarbon-based fuel may be used, or a high purity hydrogen gas may be used. For example, air can be used as the oxidizing gas supplied to the fuel cell.

  In the fuel cell shown in FIG. 1, the refrigerant flow path is further between adjacent single cells, that is, between the separator 24 constituting a certain single cell and the separator 25 provided in the single cell adjacent to this single cell. A forming member 26 is disposed. The refrigerant flow path forming member 26 is a plate-like member formed of a material having electronic conductivity, and is formed of, for example, a metal member such as stainless steel or a carbon member such as dense carbon. The coolant channel forming member 26 is provided with a through hole having a predetermined shape that penetrates the coolant channel forming member 26 in the thickness direction. The through hole is sandwiched between the separator 24 and the separator 25 adjacent to the refrigerant flow path forming member 26 to form the refrigerant flow path 35.

  In addition to the above-described manifold for supplying and discharging gas, a refrigerant supply manifold and a refrigerant discharge manifold for supplying and discharging refrigerant are provided on the outer peripheral portion of the stack structure in which the single cells 20 are stacked (not shown). ) The refrigerant flowing through the refrigerant supply manifold is distributed between the single cells to the refrigerant flow path 35 formed by the refrigerant flow path forming member 26, cools the stack structure while flowing in the refrigerant flow path 35, and then the refrigerant discharge manifold. To gather. The through hole provided in the refrigerant flow path forming member 26 can have an arbitrary shape as long as it can function as such a refrigerant flow path.

B. Manufacturing method of gas flow path forming member:
FIG. 4 is a flowchart showing a manufacturing method for manufacturing the metal mesh 50 as the gas flow path forming members 22 and 23. In general, the manufacturing method is to create the fine mesh wire 51 in steps S1 to S3, and to manufacture the metal mesh 50 by weaving the fine mesh wire 51 in step S4. Details will be described below.

  As shown in the figure, when the process is started, the operator performs a process of setting the metal wire M that can be the metal wire 51a of the fine mesh wire 51 in the resin coating machine (step S1). The metal wire M is formed as a uniform metal conductor by a method such as melt extrusion. In this manufacturing method, a nickel wire having a line width of 50 μm is used.

  FIG. 5 is an explanatory diagram showing a schematic configuration of the resin coating machine 100. The resin coating machine 100 includes a resin paint storage tank 105, a drying furnace 110, and a transport mechanism 120. The transport mechanism 120 includes a metal wire roll 122 in which the metal wire M is wound and accommodated, a plurality of transport rollers 124 for transporting the metal wire M, and a metal wire sent by the transport roller 124. And a take-up roller 126 for taking up and storing M. A resin paint storage tank 105 and a drying furnace 110 are provided in the middle of the conveyance path determined by the conveyance roller 124. The resin paint reservoir tank 105 is located on the upstream side (metal wire roll 122 side) of the conveyance path, and the drying furnace 110 is located on the downstream side (winding roller 126 side).

  The resin paint storage tank 105 stores a fluororesin coat liquid (Cytop, manufactured by Asahi Glass Co., Ltd.), which is a resin paint (hydrophobic resin paint) for forming the conductive resin coat layer 51b described above. Yes. Note that carbon black as a conductive filler is dispersed in the fluororesin coating liquid. Specifically, carbon black (Ketjen Black, manufactured by Lion Corporation) having a primary particle size of 50 nm is dispersed in the fluororesin coating solution at a ratio of 60% by weight to the coating solution weight. The drying furnace 110 is general and dries the metal wire M that passes therethrough. As drying conditions, 190 ° C. and 10 minutes or more are realized.

  Returning to FIG. 4, in step S <b> 1, in detail, a process of setting the metal wire M to the transport mechanism 120 provided in the resin coating machine 100 configured as described above is performed. Next, the resin coating machine 100 is started and the metal wire M is sent by the transport mechanism 120, so that the metal wire M accommodated in the metal wire roll 122 is converted into a solution stored in the resin paint storage tank 105, that is, carbon black. A treatment of immersing in the dispersed fluororesin coating solution is performed (step S2). Then, the metal wire M immersed in the resin coating material storage tank 105 is sent to the drying furnace 110 and dried (step S3). As a result, the metal wire M covered with the conductive resin coat layer 51b is created.

  After execution of step S3, a process of winding the dried metal wire M around the winding roller 126 is performed (step S4). Steps S2 to S4 are operations performed by the resin coating machine 100. Through the processing up to step S4, the fine mesh wire 51 in which the conductive wire coat layer 51b is coated on the metal wire 51a described above is created. Subsequently, an operation of weaving the fine mesh wire 51 with an automatic loom is performed (step S5). Since the automatic loom is a general one that weaves a fabric using yarn, a detailed description is omitted here. As a result of step S5, a sheet-like metal mesh 50 having a thickness of 500 μm and a porosity of 85% is obtained.

C. Action / Effect:
As described above in detail, in the fuel cell of the present embodiment, the gas flow path forming members 22 and 23 are formed by the metal mesh 50 in which the fine mesh wire 51 is woven, and the fine mesh wire 51 includes the metal wire 51a and the metal wire. A conductive resin coat layer 51b that covers the wire 51a is provided. Since the conductive resin coat layer 51b exhibits an anticorrosion effect on the metal, the anticorrosion property of the metal wire 51a can be enhanced in combination with a covering effect that covers the metal wire 51a. For this reason, since the fuel cell of the present embodiment can suppress the discharge of metal ions from the metal wire 51a, there is an effect that damage to the electrolyte layer 30 can be prevented. Therefore, the fuel cell of the present embodiment can prevent the deterioration of the performance of the fuel cell and extend the life. In addition, since the conductive resin coat layer 51b is excellent in electron conductivity, the role of electron conduction from the electrodes is not impaired.

  In this embodiment, the conductive resin coat layer 51b acts on the metal surface when brought into contact with the metal, and enhances the corrosion resistance by promoting the corrosion resistance of the surface. For this reason, even if the conductive resin coat layer 51b has a defect, the anticorrosion function can be maintained. As a result, since it is possible to prevent corrosion even to a certain size (for example, about 2 mm), the damage to the electrolyte layer 30 can be further reliably prevented.

  Furthermore, by coating the metal wire 51a with the conductive resin coat layer 51b, various effects can be obtained as described below. By covering the metal wire 51a with the conductive resin coat layer 51b, the friction coefficient between the fine wires for mesh 51 is reduced, the slip is improved, and the metal mesh 50 as a whole becomes flexible. For this reason, damage to the electrolyte layer 30 can be further prevented. Conventionally, a fuel cell gas flow path forming member may be formed of a metal sintered body. In such a case, carbon paper or carbon cloth is sandwiched between the catalyst layer and the metal sintered body to protect the catalyst layer. There was a need. Also, in the case of a metal mesh, such carbon paper or carbon cloth is necessary. However, in the present embodiment, since the metal mesh 50 is flexible, the metal mesh 50 is used as a catalyst (anode 31 and cathode 32). ), The catalyst and the electrolyte layer 30 are not damaged. For this reason, there is an effect of reducing the number of parts. Further, as described above, since the metal mesh 50 as a whole is flexible, in-plane thickness variation is also flexible, so that the metal mesh 50 can be assembled uniformly.

  In this embodiment, as described above, the metal wire M is immersed in the fluororesin coating liquid in which carbon black as the conductive filler is dispersed, thereby covering the metal wire 51a with the conductive resin coat layer 51b. The metal mesh 50 as a gas flow path forming member is manufactured by weaving the metal wire 51a covered with the conductive resin coat layer 51b to produce a sheet-like member. For this reason, since the metal wire 51a is covered with the conductive resin coat layer 51b, the corrosion resistance of the metal wire 51a can be improved. When the corrosion resistance of the metal wire 51a is high, discharge of metal ions from the metal wire 51a can be suppressed. Therefore, when the metal wire 51a is incorporated in a fuel cell, damage to the electrolyte layer can be prevented.

D. Other embodiments:
The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

D1. Modification 1:
In the above embodiment, a resin paint having hydrophobicity is used as the resin for forming the conductive resin coat layer 51b. However, instead of this, a resin paint having no hydrophobicity may be used. . As such a resin coating, a heat-flexible resin having a softening point of 90 ° C. or higher, preferably 120 ° C. or higher, excellent in acid resistance, and excellent in solubility in a solvent is suitable. Specifically, polyacrylate, polymethyl methacrylate, polyester, polycarbonate, polyimide, polyamide, polyamideimide, polyetherimide, polyacetal, polyetheretherketone, polyethersulfone, polynorbornene resin, polyarylate, polypropylene, polymethylpentene Silicone resin, polyphenylene oxide, polyketone, LCP, acrylonitrile butadiene styrene copolymer, and the like can be used. Note that the fuel cell of Modification 1 can have the same configuration as that of the above embodiment except for the resin paint. Further, the method for producing the gas flow path forming member can be produced by the same method as in the above-described embodiment only by changing the resin paint.

  The fuel cell according to this modified example 1 has an effect that it is possible to prevent damage to the electrolyte layer as in the above-described embodiment. Therefore, the fuel cell of this modification 1 can prevent the performance deterioration of the fuel cell and extend the life.

D2. Modification 2:
Moreover, in the said Example, although the resin coating material which has hydrophobicity was used as resin which forms the conductive resin coating layer 51b, it is set as the structure which used curable resin as said resin instead. Can do. The curable resin may be either thermosetting or photocurable. As the curable resin, epoxy resin, acrylic resin, phenol resin, polyimide resin, unsaturated polyester resin, diallyl phthalate resin, vinyl ester resin, furan resin, polyurethane resin, maleic acid resin, melamine resin, urea resin, xylene resin , Guanamine resin, and the like can be used. Examples of the photo-curable resin include monofunctional acrylate resins, polyfunctional acrylate resins, methacrylate resins, epoxy acrylate resins, urethane acrylate resins, polyester acrylate resins, polyptadiene acrylate resins, silicone acrylate resins, photoradical polymerization maleimide resins, and photoradicals. Polymerized polyenethiol resin, photocationic polymerization epoxy resin, photocationic polymerization oxetane resin, photocationic polymerization vinyl ether resin, photocationic polymerization propenyl ether resin, and the like can be used. Note that the fuel cell of Modification 2 can have the same configuration as that of the above embodiment except for the resin.

  As a specific example of a method for producing a metal mesh, carbon black (Ketjen Black, manufactured by Lion Co., Ltd.) having a primary particle size of 50 nm at a ratio of 60% by weight with respect to the weight of the acrylic resin is added to the photocurable acrylic resin monomer solution. Using the coated coating liquid, a nickel wire having a line width of 50 μm is coated with the coating liquid by the same dipping method as in the above embodiment, and irradiated with ultraviolet rays to form a conductive photocurable resin coating layer. Cover the nickel wire. This nickel wire is woven using an automatic loom as in the above embodiment to produce a metal mesh as a gas flow path forming member.

  The fuel cell of the second modification has an effect that the electrolyte layer can be prevented from being damaged as in the above embodiment. Therefore, the fuel cell according to the second modification can prevent the deterioration of the performance of the fuel cell and can extend the life. In particular, in the second modification, in the metal mesh manufacturing method, a drying step for evaporating the solvent is not required, so that the production speed is improved, the production facility is downsized by eliminating the need for the solvent recovery facility, and the environment using the volatile solvent It is possible to achieve effects such as reduction of adverse effects on the body.

D3. Modification 3:
In the said Example, the fine wire 51 for meshes which comprises the metal mesh 50 was the structure which coat | covered the conductive resin composition which made the metal wire 51a contain the conductive filler, ie, the conductive resin coat layer 51b. However, instead of this, a configuration in which a metal wire is coated with a conductive polymer may be employed. As the conductive polymer, polyacetylene, polypyrrole, polythiophene, polyaniline, polyparaphenylene, polyvinylcarbazole, or the like can be used. Specifically, the metal mesh is manufactured by weaving a nickel wire having a line width of 50 μm with an automatic loom to create a conductive mesh having a thickness of 800 μm and a porosity of 90%, and then the supporting electrolyte is made of tetraperchlorate. N-Butylammonium, the solvent is acetonitrile, and a polypyrrole thin film can be formed on the surface of the nickel wire by anodic oxidation. The line width, thickness, and porosity can be arbitrarily changed.

  In the fuel cell of Modification 3, the conductive polymer as the conductive polymer material exerts an anticorrosive effect on the metal, and therefore, in combination with the covering effect of covering the metal wire, enhances the anticorrosive property of the metal wire. be able to. For this reason, since the fuel cell of the modification 3 can suppress discharge | emission of the metal ion from a metal wire, there exists an effect that damage to an electrolyte layer can be prevented. Therefore, the fuel cell of Modification 3 can prevent deterioration of the performance of the fuel cell and extend the life. In addition, since the conductive polymer is excellent in electron conductivity, the role of electron conduction with the electrode is not impaired.

  The conductive polymer acts on the metal surface when brought into contact with the metal, and enhances the corrosion resistance by promoting the corrosion resistance of the surface. For this reason, even if the coating of the conductive polymer material is deficient, the anticorrosion function can be maintained. As a result, since it is possible to prevent corrosion to a certain size, it is possible to further reliably prevent the electrolyte layer from being damaged.

D4. Modification 4:
In the above embodiment, the metal mesh 51 is manufactured by weaving the metal wire 51a coated with the conductive resin coat layer 51b with an automatic loom. However, the weaving is not necessarily performed using the automatic loom, and is performed manually. It can also be configured. Furthermore, it is not always necessary to be woven into a cloth shape, and a metal wire can be combined to form a sheet shape.

D5. Modification 5:
In the said Example, although the separators 24 and 25 were plate-shaped members with the flat surface, it is good also as a different shape. For example, an uneven shape may be formed on the surface on the side where the gas flow path in the single cell is formed. Even in such a case, since the metal mesh 50 is flexible, it is possible to absorb unevenness in the surface pressure due to the uneven shape.

D6. Modification 6:
In the above embodiment, both the gas flow path forming member 22 on the anode 31 side and the gas flow path forming member 23 on the cathode 32 side are composed of the metal mesh 50 covered with the conductive polymer material. Instead, any one of the gas flow path forming member 22 and the gas flow path forming member 23 may be configured by the metal mesh 50. That is, one of the gas flow path forming member 22 and the gas flow path forming member 23 is configured using a metal wire covered with a conductive polymer material, and the other is covered with a conductive polymer material. A configuration using a metal wire that is not, or a configuration of another flow path shape that does not use the metal wire itself may be used.

D7. Modification 7:
Further, the present invention may be applied to a fuel cell of a different type from the above embodiment. For example, it can be applied to a direct methanol fuel cell. Or the fuel cell which has electrolyte layers other than a solid polymer may be sufficient, and the same effect is acquired by applying this invention.

It is a cross-sectional schematic diagram showing the outline of the fuel cell as one Example of this invention. It is explanatory drawing which shows the metal mesh 50 which comprises a gas flow path formation member. It is explanatory drawing showing the cross section of the fine wire 51 for meshes. It is a flowchart which shows the manufacturing method which manufactures the metal mesh 50 as a gas flow path formation member. It is explanatory drawing which shows the schematic structure of the resin coating machine 100. FIG.

Explanation of symbols

20 ... single cell 21 ... MEA
22, 23 ... Gas flow path forming member 24, 25 ... Separator 26 ... Refrigerant flow path forming member 30 ... Electrolyte layer 31 ... Anode 32 ... Cathode 35 ... Refrigerant flow path 50 ... Metal mesh 51 ... Fine wire 51a ... Metal wire 51b ... conductive resin coating layer 100 ... resin coating machine 105 ... resin paint reservoir tank 110 ... drying furnace 120 ... conveying mechanism 122 ... metal wire roll 124 ... conveying roller 126 ... winding roller

Claims (8)

An electrolyte layer;
An electrode comprising a catalyst formed on the electrolyte layer;
A gas flow path that is disposed on the electrode and is formed of a sheet-like metal material made by combining metal wires, and in which a space between the metal wires serves as a flow path for gas supplied to and discharged from the electrode; A fuel cell comprising:
The metal wire is configured to be coated with a conductive polymer material. The fuel cell according to claim 1,
The conductive polymer material is a conductive resin composition in which a conductive filler is contained in a resin. The fuel cell according to claim 2, wherein
The conductive resin composition has a configuration using a resin paint having hydrophobicity as the resin. The fuel cell according to claim 3, wherein
The resin paint is a fuel cell made of a fluororesin. The fuel cell according to claim 2, wherein
The conductive resin composition has a configuration using a curable resin as the resin. The fuel cell according to claim 1,
The conductive polymer material is a conductive polymer. A method of manufacturing a fuel cell gas flow path forming member for manufacturing a fuel cell gas flow path forming member, comprising:
Coating a metal wire with an anticorrosive material;
A method for producing a gas flow path forming member for a fuel cell, comprising: forming a sheet-like member by weaving a metal wire coated with the anticorrosive material; and using the member as the gas flow path forming member. It is a manufacturing method of the gas channel formation member for fuel cells according to claim 7,
The anticorrosive material is a conductive polymer material. A method of manufacturing a gas flow path forming member for a fuel cell.

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