JP2006269122A - Membrane electrode assembly and its manufacturing method, fuel cell, and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a membrane electrode assembly realizing a fuel cell having flexibility and capable of making thin while high adhesion is kept, to provide a manufacturing method of the membrane electrode assembly, and to provide a fuel cell and electronic equipment. <P>SOLUTION: The membrane electrode assembly is formed by stacking an anode flexible membrane, an anode conductive layer, an anode catalyst layer, an electrolyte membrane, a cathode catalyst layer, a cathode conductive layer, and a cathode flexible membrane in order, and uniting them, and the manufacturing method of the membrane electrode assembly, the fuel cell using the membrane electrode assembly, and the electronic equipment are provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a membrane electrode assembly for a fuel cell, a method for producing the same, and a fuel cell and an electronic device using the membrane electrode assembly.

  In recent years, as a power source for portable electronic devices that support the information-oriented society, the efficiency of a single power generation device is high, and therefore, expectations for fuel cells are increasing. The fuel cell electrochemically oxidizes and reduces fuel at the anode electrode and oxygen in the air at the cathode electrode, and generates electricity through this reaction. In addition, an electrolysis apparatus that generates hydrogen and oxygen by electrolyzing pure water by utilizing a reverse reaction of the above reaction has been studied.

  Among various types of fuel cells, a polymer electrolyte fuel cell (hereinafter referred to as “PEFC”) using a solid polymer ion exchange membrane as an electrolyte has a thin electrolyte membrane and a reaction temperature of 100 ° C. The temperature is relatively low as compared with the following fuel cells such as phosphoric acid type and solid oxide type. For this reason, since a large-scale auxiliary machine is not required, a small fuel cell system can be realized.

  On the other hand, a direct methanol fuel cell (hereinafter referred to as “DMFC”) that generates electricity by directly extracting protons from methanol does not require a reformer, and has a volumetric energy density compared to gas fuel. Therefore, it is possible to make the fuel container smaller than a high-pressure gas cylinder represented by hydrogen. For this reason, attention is attracting attention from the viewpoint of application to a power supply for small equipment, in particular, a secondary battery alternative use for portable equipment. In addition, since DMFC is a liquid fuel, it is possible to use a narrow curved space as a fuel space, which was a dead space in conventional fuel cell systems. It has the merit that it can be used for electronic equipment.

For example, Patent Document 1 discloses a conventional DMFC that is reduced in thickness and size in accordance with such a situation. The fuel cell disclosed in Patent Document 1 includes a membrane electrode assembly, a substrate, and a housing. The membrane electrode assembly is composed of an electrolyte membrane, a fuel electrode, and an air electrode. The substrate is formed using a thin material having flexibility and capable of patterning a conductor. The substrate is formed by patterning a pair of conductive layers and extraction electrodes on one side corresponding to both sides of the membrane electrode assembly. The substrate is folded with the membrane electrode assembly sandwiched therebetween, and the membrane electrode assembly is sandwiched between a pair of conductive layers. With such a structure, the thickness of the flexible substrate on which the conductive layer serving as a current collector is formed can be reduced, so that the fuel cell can be reduced in thickness and size.
JP 2004-200064 A

  However, in the configuration described in Patent Document 1, a half body is fastened by a fastening member, a housing is provided outside the substrate, and a pressing pressure is required, and the adhesion between the fuel electrode, the air electrode, and the conductor layer is improved. It is necessary to secure it. In such a configuration, it is required to ensure a uniform pressing pressure on the entire surface. For this reason, the casing formed of a half body is required to have rigidity and a certain thickness is required, which limits the reduction in thickness and size of the fuel cell. Further, as the area for ensuring a uniform pressing pressure increases, the casing is required to have higher rigidity. Therefore, the thickness of the casing increases and it is difficult to reduce the thickness and size.

  In addition, although the substrate has flexibility, since the casing has rigidity, the fuel cell does not have flexibility as a result. This limits the design of the fuel cell.

  Further, as described in the embodiment of Patent Document 1, when a fuel electrode or an air electrode made of carbon paper is used, a uniform pressing pressure is not ensured over the entire surface by the casing having rigidity. Then, the resistance in the surface thickness direction of the carbon paper increases, and good power generation characteristics cannot be obtained.

  The present invention has been made to solve the above-mentioned problems, and the object of the present invention is to provide a membrane electrode capable of realizing a flexible and thin fuel cell while ensuring good adhesion. It is to provide a composite and a method for producing the same. It is another object of the present invention to provide a fuel cell and an electronic device using the membrane electrode assembly.

  The membrane electrode assembly of the present invention has a structure in which an anode flexible membrane, an anode conductive layer, an anode catalyst layer, an electrolyte membrane, a cathode catalyst layer, a cathode conductive layer, and a cathode flexible membrane are sequentially laminated and integrally formed. It is characterized by providing.

  Here, the cathode flexible membrane is preferably insulative.

  In the membrane electrode assembly of the present invention, the anode flexible membrane and the cathode flexible membrane are preferably polymer membranes having heat resistance of 100 ° C. or higher.

  In the membrane electrode assembly of the present invention, at least one of the anode flexible membrane and the cathode flexible membrane is preferably polyimide.

The membrane electrode assembly of the present invention preferably has any of the following configurations (1) to (4).
(1) A porous material is integrally formed on the cathode flexible membrane.
(2) A porous material is integrally formed on the anode flexible membrane.
(3) A hydrophilic layer is formed on the surface of either the anode flexible membrane or the cathode flexible membrane.
(4) A water repellent layer is formed on the surface of either the anode flexible membrane or the cathode flexible membrane.

  Here, the membrane electrode assembly having the configuration (2) can be particularly preferably used for a fuel cell using liquid fuel.

  The anode conductive layer and the cathode conductive layer in the membrane electrode assembly of the present invention are metal foils containing at least one element selected from the group consisting of Au, Ag, Pt, Ni, Cu, Al, W and Ti. Is preferred.

  The anode conductive layer and the cathode conductive layer are preferably covered with a noble metal containing at least one element selected from the group consisting of Au, Pt, Pd and Ru.

  The combination of the anode flexible membrane and cathode flexible membrane and the anode conductive layer and cathode conductive layer in the present invention is preferably a polyimide film and a copper foil.

The present invention also provides a method for producing the above-described membrane electrode assembly of the present invention having at least one of the following characteristics (1) to (5).
(1) A flexible film and a conductive layer are integrally formed, and a plurality of openings are formed by punching.
(2) A flexible film and a conductive layer are integrally formed, and a plurality of openings are formed by photoetching.
(3) A flexible film and a conductive layer are integrally formed and an aperture is formed by a focused laser;
(4) A flexible film and a conductive layer are integrally formed, and a plurality of apertures are formed by irradiating a laser using the conductive layer as a mask.
(5) The electrolyte membrane on which the catalyst layer is formed, the flexible membrane and the conductive layer are integrally formed and a collector electrode having an opening is wound in a roll shape, and thermocompression bonded using a heat roller.

  The present invention also provides a fuel cell comprising the above-described membrane electrode assembly of the present invention and a fuel supply means for supplying liquid fuel to the anode catalyst layer of the membrane electrode assembly.

  The present invention also provides an electronic device in which the above-described fuel cell of the present invention is mounted such that the cathode flexible membrane side of the fuel cell is in contact with the atmosphere.

  The present invention further provides an electronic device in which the above-described fuel cell of the present invention is mounted on a hinge portion.

  The membrane electrode assembly of the present invention has a structure in which the collector electrode and the catalyst layer are integrally formed adjacent to each other. For this reason, it is possible to manufacture a membrane electrode assembly with good yield, which ensures good conductivity of the collector electrode and the catalyst layer, even in the absence of an external pressing pressure.

  Further, in the membrane electrode assembly of the present invention, the flexible collector electrode and the electrolyte membrane in which the flexible membrane and the conductive layer are integrally formed and the electrolyte membrane are directly formed on the catalyst layer, so that it is bent. However, it is possible to maintain a good output voltage and to design a fuel cell with high design without being restricted by the size and shape of the membrane electrode assembly.

  In addition, since the collector electrode follows the electrolyte membrane that contracts and swells in the external atmosphere, it is difficult for peeling to occur and adhesion can be improved, and long-term reliability can be ensured.

  Furthermore, since the membrane electrode assembly is flexible, for example, the membrane electrode assembly according to the present invention can be installed in a hinge portion or a movable portion of an electronic device. It can also be used for wearable device applications.

  Hereinafter, the membrane electrode assembly structure according to the present invention will be described with reference to the drawings, taking a direct methanol fuel cell as an example, but is not limited thereto.

  FIG. 1 is an exploded perspective view schematically showing a membrane electrode assembly of a preferred first example of the present invention, and FIG. 2 is a plan view of the membrane electrode assembly shown in FIG. 1 as viewed from above. FIG. 3 is a cross-sectional view taken along section line III-III in FIG. In the membrane electrode assembly 1 of the present invention, an anode flexible membrane 2a, an anode conductive layer 3a, an anode catalyst layer 7a, an electrolyte membrane 6, a cathode conductive layer 3b, and a cathode flexible membrane 2b are sequentially laminated and integrally formed. Yes. Here, “integral formation” refers to a state in which each member of the membrane electrode assembly 1 is not separated even if no pressure is applied from the outside, specifically, bonded by a chemical bond, an anchor effect, or an adhesive force. It means a state.

  The anode flexible membrane 2a and the cathode flexible membrane 2b in the membrane electrode assembly 1 of the present invention basically have a function of mechanically reinforcing and protecting the anode conductive layer 3a and the cathode conductive layer 3b. In order to reinforce the anode conductive layer 3a and the cathode conductive layer 3b with the anode flexible membrane 2a and the cathode flexible membrane 2b, respectively, and to enable easy handling even when the anode conductive layer 3a and the cathode conductive layer 3b are thin, The membrane 2a, the anode conductive layer 3a, the cathode flexible membrane 2b, and the cathode conductive layer 3b are preferably integrally formed before the membrane electrode assembly 1 is integrally formed. Furthermore, in order to ensure the positional accuracy of the apertures 4 formed in the anode flexible membrane 2a and the anode conductive layer 3a and the apertures 4 formed in the cathode flexible membrane 2b and the cathode conductive layer 3b, a description will be given later. More preferably, the opening 4 is integrally formed before the opening 4 is formed.

  The anode flexible membrane 2a and the cathode flexible membrane 2b are not particularly limited as long as they have the above functions and exhibit flexibility, but at least the cathode flexible membrane 2b (preferably the anode flexible membrane 2b) Both the membrane 2a and the cathode flexible membrane 2b) preferably have insulating properties. The anode flexible film 2a and the cathode flexible film 2b are preferably polymer films having heat resistance of 100 ° C. or higher. Thereby, in the process of integrally forming the membrane electrode assembly by thermocompression bonding described later, the anode flexible film 2a and the cathode flexible film 2b are not softened, and the anode conductive layer 3a and the cathode conductive layer 3b are machined. The function to reinforce and protect and the function to electrically insulate are not lost, and the problem of closing the opening 4 described later is eliminated. Examples of the material for forming such a polymer film having a heat resistance of 100 ° C. or higher include polyimide, polyarylate, polyether ether ketone, polyether imide, polyether sulfone, polyphenylene oxide, and polytetrafluoroethylene. Polyvinylidene fluoride and the like can be mentioned, and polyimide having excellent heat resistance and flexibility is particularly preferable.

  The anode flexible membrane 2a and the cathode flexible membrane 2b preferably have a thickness of 1 μm or more in order to ensure an electrically insulating function. Moreover, in order to ensure sufficient supply of methanol and oxygen from the opening 4 described later, the thickness is preferably 1.0 mm or less, and further, the thickness is 0.3 mm or less that can be easily bent. More preferred. In order to ensure reinforcement of the anode conductive layer 3a and the cathode conductive layer 3b, the anode flexible film 2a and the cathode flexible film 2b preferably have a thickness of 10 μm or more.

  By selecting the thickness of the anode flexible film 2a and the cathode flexible film 2b as described above, the anode flexible film 2a and the cathode conductive layer 3b are flexible and can be easily bent. Even if the thickness of the membrane electrode is thin, it is reinforced by the anode flexible membrane 2a and the anode flexible membrane 2b, respectively, so that it can be easily handled, and the yield when integrally forming the membrane electrode assembly 1 is increased. improves. Furthermore, when the membrane electrode assembly 1 is integrally formed, the anode conductive layer 3a and the cathode conductive layer 3b are prevented from being exposed, and can be electrically insulated from the outside, thereby improving safety.

  The anode conductive layer 3a and the cathode conductive layer 3b in the membrane electrode assembly 1 of the present invention have a function of performing electron transfer with the anode catalyst layer 7a and the cathode catalyst layer 7b and a function of electrical wiring, respectively. It is integrally formed on one surface of the anode flexible membrane 2a and the cathode flexible membrane 2b.

  The material of the anode conductive layer 3a and the cathode conductive layer 3b includes at least one element selected from the group consisting of Au, Ag, Pt, Ni, Cu, Al, W and Ti in order to suppress a voltage drop as a wiring. It is preferable to use a metal foil, and more preferably Au or Cu having very good stretchability.

  The thickness of the anode conductive layer 3a and the cathode conductive layer 3b varies depending on the specific resistance value of the metal material used, but is preferably 0.1 μm or more in order to suppress a voltage drop as a wiring. In the step of integrally forming the body by thermocompression bonding described later, the thickness is more preferably 3 μm or more in order to suppress disconnection. By using the anode conductive layer 3a and the cathode conductive layer 3b selected to have such a thickness, a voltage drop can be reduced by wiring, and a high output voltage can be obtained. In addition, in order to ensure a sufficient supply of methanol and oxygen from the opening 4 described later, the thickness of the anode conductive layer 3a and the cathode conductive layer 3b is preferably 1.0 mm or less, and further, it can be easily bent. More preferably, the thickness is 0.1 mm or less.

  Further, when corrosion of the anode conductive layer 3a and / or the cathode conductive layer 3b becomes a problem, corrosion resistance that does not elute metal ions on the surface in an acidic aqueous solution atmosphere or an oxygen atmosphere and does not form a nonconductive layer. The anode conductive layer 3a and / or the cathode conductive layer 3b is preferably covered with a noble metal such as Au, Pt, Pd, and Ru having the property. As a result, there is no possibility that metal ions eluted into the electrolyte of the anode catalyst layer 7a and the cathode catalyst layer 7b, which will be described later, and the electrolyte membrane 6 are mixed. Furthermore, since no non-conductive layer is formed, the long-term reliability of the membrane electrode assembly 1 can be obtained. Further, since the coating has flexibility, the flexibility of the anode conductive layer 3a and the cathode conductive layer 3b in the present invention is not impaired.

  The anode flexible film 2a and the anode conductive layer 3a, and the cathode flexible film 2b and the anode conductive layer 3b may be integrally formed using an adhesive that does not deteriorate the adhesion in the power generation atmosphere of the fuel cell. it can. As a power generation condition, it is preferable to use an adhesive mainly composed of an organic polymer. Furthermore, an adhesive mainly composed of imide is preferable as the organic polymer. Further, when the other is directly formed on one of the flexible films 2a and 2b or the conductive layers 3a and 3b, the flexible films 2a and 2b can be integrally formed without using the adhesive.

  As described above, the anode collector electrode 5a in which the anode flexible membrane 2a and the anode conductive layer 3a are integrally formed and the cathode collector electrode 5b in which the cathode flexible membrane 2b and the cathode conductive layer 3b are integrally formed are Even if it is bent, the interface between the anode flexible film 2a and the anode conductive layer 3a and the interface between the cathode flexible film 2b and the cathode conductive layer 3b are hardly separated.

  The anode collector electrode 5a and the cathode collector electrode 5b are most preferably a combination in which the anode flexible film 2a and the cathode flexible film 2b are made of polyimide, and the anode conductive layer 3a and the cathode conductive layer 3b are made of copper foil. preferable. By adopting such a configuration, it is possible to produce the anode collector electrode 5a and the cathode collector electrode 5b by using an existing apparatus for a flexible substrate used in an electronic device or the like, and it is possible to reduce the manufacturing cost.

In the membrane electrode assembly 1 of the present invention, the anode collector electrode 5a (the anode flexible membrane 2a and the anode conductive layer 3a) and the cathode collector electrode 5b (the cathode flexible membrane 3a and the cathode conductive layer 3b) 4 is formed. The opening 4 only needs to form a through hole in the thickness direction of the anode collector electrode 5a and the cathode collector electrode 5b, and the shape thereof is not particularly limited, but the aperture ratio may be in the range of 10% to 95%. preferable. Here, the aperture ratio of the anode collector electrode 5a, when the area of the anode catalyst layer 7a S _A, the sum of the areas of apertures 4 formed on the anode collector electrode 5a was S _B, S _{B /} S _A It is defined by a value calculated by x100. Further, the aperture ratio of the cathode collector electrode 5b is similarly defined.

  In order to sufficiently supply methanol to the anode catalyst layer 7a and oxygen to the cathode catalyst layer 7b, the opening ratio is more preferably 40% or more. Further, when the aperture ratio increases, the resistance of the anode conductive layer 3a and the cathode conductive layer 3b increases, or the reinforcement of the anode flexible film 2a and the cathode flexible film 2b is lost. More preferably, it is 90% or less. Thus, by setting the aperture ratio within a more preferable range of 40 to 90%, it is possible to manufacture the membrane electrode assembly 1 in which the decrease in the output voltage due to insufficient supply of methanol and oxygen is suppressed.

  FIG. 4 is a schematic cross-sectional view for explaining the function of the anode catalyst layer 7a in the membrane electrode assembly 1 of the present invention. In the present invention, the “anode catalyst layer” refers to a layer in which a substance supplied from outside causes a chemical reaction to generate protons and electrons, and the “cathode catalyst layer” refers to a substance supplied from outside. Refers to a layer that takes in protons and electrons, causes a chemical reaction, and produces water.

  As shown in FIG. 4, the anode catalyst layer 7 a is composed of anode catalyst-supporting conductive particles in which anode catalyst particles 8 are supported on anode conductive particles 9 and an electrolyte 10. In the anode catalyst layer 7a, the anode catalyst particles 8 have a function of generating carbon dioxide, protons and electrons from methanol, the electrolyte 10 has a function of conducting the generated protons to the electrolyte membrane 6, and anode conductive particles 9 Has a function of conducting the generated electrons to the anode conductive layer 3a.

  Although not shown, in the cathode catalyst layer 7b, the cathode catalyst particles have a function of generating water from oxygen, protons and electrons, and the electrolyte has a function of conducting protons from the electrolyte membrane to the vicinity of the cathode catalyst particles, The cathode conductive particles have a function of conducting electrons from the cathode conductive layer in the vicinity of the cathode catalyst particles.

  In general, the anode catalyst particles 8 and the cathode catalyst particles are composed of noble metal particles mainly composed of platinum, and the anode conductive particles 9 and the cathode catalyst particles are composed of carbon particles.

  The thickness of the anode catalyst layer 7a and the cathode catalyst layer 7b is preferably 0.1 mm or less in order to reduce the resistance of proton conduction and the resistance of electronic conduction and supply methanol or oxygen to the inside, and sufficient catalyst In order to improve the output voltage by obtaining the carrying amount, it is preferably 0.1 μm or more.

  According to the structure of the membrane electrode assembly 1 of the present invention, the anode conductive layer 3a and the electrolyte membrane 6 are integrally formed so as to be adjacent to the anode catalyst layer 7a, and the cathode conductive layer is adjacent to the cathode catalyst layer 7b. Since 3b and the electrolyte membrane 6 are integrally formed, protons and electrons can be easily exchanged with the outside, and voltage drop at each interface can be suppressed. Further, since the electrolyte 10 serves as an adhesive and high adhesion to the anode conductive layer 3a and the cathode conductive layer 3b is obtained, the interface does not easily peel off even when bent.

The electrolyte membrane 6 in the membrane electrode assembly 1 of the present invention has a function of conducting only protons without conducting electrons generated in the anode catalyst layer 7a and the cathode catalyst layer 7b. The material of the electrolyte membrane 6 preferably has a proton conductivity of 10 ⁻⁵ S / cm or more, more preferably a perfluorosulfonic acid polymer or a hydrocarbon polymer, in order to obtain high power generation characteristics of the fuel cell. It is desirable to use a polymer electrolyte membrane having a proton conductivity of 10 ⁻³ S / cm or more. The proton conductivity of the electrolyte membrane 6 is a value calculated from AC measurement at 100 kHz in an atmosphere with a relative humidity of 90% or more with the electrolyte membrane 6 sandwiched between metal electrodes.

  The thickness of the electrolyte membrane 6 is preferably 200 μm or less in order to obtain a high output voltage by reducing the resistance, and the long-term stability can be obtained because the output voltage is lowered and the strength is weakened due to fuel crossover. Since it disappears, 1 μm or more is desirable. By using the electrolyte membrane 6 having a thickness selected in this way, flexibility can be exhibited and bending can be performed.

  The membrane electrode assembly 1 of the present invention is preferably formed by integrally forming a porous material on a cathode flexible membrane. FIG. 5 shows that the cathode porous material 11 is integrally formed on the surface of the cathode flexible membrane 2b of the membrane electrode assembly 1 shown in FIG. 3 opposite to the surface on which the cathode conductive layer 3b is formed. It is a figure which shows typically an example. In the example shown in FIG. 5, the cathode porous material 11 is laminated on the cathode flexible membrane 2 b by integrally forming the cathode porous material 11 with the cathode flexible membrane 2 b of the membrane electrode assembly 1. That is, the cathode porous material 11, the cathode flexible membrane 2b, the cathode conductive layer 3b, the cathode catalyst layer 7b, and the electrolyte membrane 6 are laminated in this order.

  As shown in FIG. 5, the cathode porous material 11 is laminated on the cathode flexible membrane 2b, so that the water generated in the cathode catalyst layer 7b is opened in the cathode conductive layer 3b and the cathode flexible membrane 2b. 4 is absorbed into the cathode porous material 11 and emitted to the outside.

  The cathode porous material 11 has a large number of through-holes in the surface thickness direction, and the material is not particularly limited as long as it can be bent, but a fiber nonwoven fabric, cloth, foamed polymer film, glass cloth, or the like is used. It is preferable. For example, a nonwoven fabric such as a fibrous fluorine-based resin, a hydrocarbon-based resin, or a plastic can be used.

  The thickness of the cathode porous material 11 is preferably 1 mm or less in a non-pressurized state in order to make the membrane electrode assembly 1 thin, and is preferably 1 μm or more in order to ensure sufficient supply of oxygen.

  By integrally forming the cathode porous material 11 on the cathode flexible membrane 2b, water generated in the cathode catalyst layer 7b is easily absorbed into the cathode porous material 11 from the apertures 4 and is easily released to the outside. As a result, the supply of oxygen in the air is not hindered, and a high output voltage can be maintained.

  Although not shown, an anode porous material can be integrally formed on the surface of the anode flexible membrane 2a opposite to the surface on which the anode conductive layer 3a is formed. Since the anode porous material is laminated with the anode flexible membrane 2a, the methanol aqueous solution is absorbed by the anode porous material regardless of external force such as gravity or centrifugal force, and the anode flexible membrane 2a. In other words, the anode conductive layer 3a is uniformly supplied to the entire surface of the anode catalyst layer 7a through the openings 4 of the anode conductive layer 3a. Further, since the anode porous material and the opening 4 of the anode collector electrode 5a are adjacent to each other, the aqueous methanol solution can be supplied uniformly and a high output voltage can be maintained. Thus, the membrane electrode assembly in which the porous material is integrally formed on the anode flexible membrane 2a can be particularly suitably used for a fuel cell using a liquid fuel represented by a direct methanol fuel cell. It is.

  The anode porous material and the anode flexible membrane 2a and the cathode porous material 11 and the cathode flexible membrane 2b can be integrally formed using an adhesive that does not lower the adhesion in the power generation atmosphere of the fuel cell. . As a power generation condition, for example, an acidic atmosphere with a temperature of 60 ° C. and a relative humidity of 40% is raised. As the adhesive, an adhesive mainly composed of an organic polymer is preferably used. Furthermore, an adhesive mainly composed of imide is preferable as the organic polymer.

  Alternatively, polymer fibers or glass fibers used for the anode porous material and the cathode porous material 11 can be integrally formed by flocking the surfaces of the anode flexible membrane 2a and the cathode flexible membrane 2b. Thereby, very excellent adhesion can be obtained, and it has flexibility and can be made difficult to peel even when bent.

  In the membrane electrode assembly 1 of the present invention, a water repellent layer may be formed on the surface of either the anode flexible membrane 2a or the cathode flexible membrane 2b.

  When a high-concentration aqueous methanol solution is used as fuel, the methanol concentration in the anode catalyst layer 7a increases, and a phenomenon in which methanol permeates through the electrolyte membrane 6 (methanol crossover phenomenon) occurs remarkably, resulting in a decrease in power generation efficiency. . Therefore, it is possible to suppress supply of more methanol than necessary to the anode catalyst layer 7a by imparting a water repellency function to the surface of the anode flexible film 2a.

  In addition, when the power generation amount of the fuel cell is increased, a large amount of water is generated in the cathode catalyst layer 7b, so that the phenomenon that the cathode catalyst layer 7b gets wet with water (flooding phenomenon) occurs remarkably, and power generation efficiency is increased. Will fall. Therefore, it is possible to prevent the entire surface of the cathode catalyst layer 7b from getting wet by providing a water repellent function to the surface of the cathode flexible film 2b.

  In the membrane electrode assembly 1 of the present invention, a hydrophilic layer may be formed on the surface of either the anode flexible membrane 2a or the cathode flexible membrane 2b.

  By imparting a hydrophilic function to the surface of the anode flexible membrane 2a, it becomes possible to uniformly supply a methanol aqueous solution to the anode catalyst layer 7a.

  Further, by imparting a hydrophilic function to the surface of the cathode flexible membrane 2b, it is possible to absorb water generated in the cathode catalyst layer 7b and to diverge it into the atmosphere using the surface of the cathode flexible membrane 2b. Become.

  For imparting water-repellent or hydrophilic functions to the anode flexible membrane 2a and the cathode flexible membrane 2b, an appropriate combination is adopted depending on the power generation amount used as a fuel cell and the usage environment such as temperature and humidity. be able to.

  Examples of a method for imparting a water repellency or hydrophilic function include a method of forming a layer mainly composed of a polymer exhibiting the above function.

FIG. 6 is a diagram showing an example in which the anode hydrophilic layer 14a and the cathode hydrophilic layer 14b are formed on the surfaces of the anode flexible membrane 2a and the cathode flexible membrane 2b, respectively, in the membrane electrode assembly 1 shown in FIG. It is. The anode hydrophilic layer 14a and the cathode hydrophilic layer 14b are a composite layer composed of hydrophilic particles such as SiO ₂ and TiO ₂ and an organic polymer, or a functional group exhibiting hydrophilic properties such as a hydroxyl group, a sulfone group, a carbonyl group, and an amide group. An organic polymer layer having a group can be used.

  In addition, although not shown in the drawing, instead of the anode hydrophilic layer 14a and the cathode hydrophilic layer 14b, as an anode water repellent layer and a cathode water repellent layer, an organic material mainly composed of a fluorine-based resin typified by PTFE (PolyTetraFluoroEthylene) is used. A polymer layer can also be used as the water repellent layer.

  The anode / cathode water repellent layer or the anode / cathode hydrophilic layers 14a and 14b are not necessarily formed as layers. For example, the surfaces of the anode flexible film 2a and the cathode flexible film 2b are modified. The method of doing is also mentioned. The anode flexible film 2a and the cathode flexible film 2b can impart water repellency to the surface by laser irradiation in a dry atmosphere, and the surface can be made hydrophilic by laser irradiation in an aqueous solution. Can be granted. Further, the surfaces of the anode flexible membrane 2a and the cathode flexible membrane 2b are chemically treated with a chemical solution to chemically bond functional groups having hydrophilicity such as hydroxyl groups, sulfonic acid units, carbonyl groups, and amide groups. You can also.

  By imparting the water repellency and hydrophilicity by such surface modification of the anode flexible membrane 2a and the cathode flexible membrane 2b, the thickness of the membrane electrode assembly 1 is hardly increased. The same function as that obtained by forming the anode porous material and the cathode porous material 11 can be provided. This eliminates the need to use the anode porous material and the cathode porous material 11, thereby eliminating the possibility of the anode porous material and the cathode porous material 11 being peeled off and simplifying the process.

  Next, a fuel cell using the membrane electrode assembly 1 of the present invention will be described by taking a direct liquid supply type fuel cell as an example. FIG. 7 is a schematic cross-sectional view of a direct liquid supply fuel cell 20 using the membrane electrode assembly 1. In the fuel cell 20 of the example shown in FIG. 7, a cover film 23 provided with a fuel supply material 21 and an exhaust hole 22 is laminated on the anode electrode side of the membrane electrode assembly 1, and one end of the fuel supply material 21 is a liquid storage. The tank 24 is in contact with the liquid fuel filled.

  In the fuel cell 20 of the present invention, the fuel supply material 21 has a function of supplying liquid fuel from the liquid storage tank 24 to the anode electrode side of the membrane electrode assembly 1. The material of the fuel supply material 21 is not particularly limited as long as it absorbs liquid fuel and has flexibility. However, it is preferable to use a fiber nonwoven fabric, a glass cloth, a foamed polymer film, a glass cloth, or the like. For example, nonwoven fabrics such as fibrous fluorine-based resins, hydrocarbon-based resins, and engineering plastics can be used.

  In the fuel cell 20 of the present invention, the cover film 23 has a function of suppressing volatilization and leakage of the liquid fuel 24. The cover film 23 is not particularly limited as long as it has the above function and is flexible and impermeable to liquid fuel, but is made of polyethylene, polyethylene terephthalate, polyetheretherketone, polyethersulfone, or the like. The polymer film is preferably a polyimide film, and more preferably a polyimide having heat resistance and excellent flexibility.

  In the fuel cell 20 of the present invention, the exhaust hole 22 has a function of discharging the generated carbon dioxide, and is preferably formed in at least one place on the cover film 23. As a result, the fuel cell 20 of the present invention does not lose flexibility, and a good output voltage can be obtained even in a bent state or a bent state.

  FIG. 8 is a diagram schematically showing an example of an electronic device 25 using the fuel cell 20 of the present invention shown in FIG. FIG. 8 shows an example in which the fuel cell 20 is mounted on the hinge portion 26 of the electronic device 25.

  In the electronic device 25 of the present invention, the fuel cell stack 28 has several fuel cells 20 connected in series and connected to the DC / DC converter 29 so that the extraction voltage is about 1 to 4V, and a voltage of about 3.7V. And is connected to the electronic device 25.

  The fuel cell 20 is mounted such that the anode collector electrode side is in contact with the electronic device 25, the cathode collector electrode side is mounted so as to be in contact with the atmosphere, and a part is disposed on the hinge portion 26. Liquid fuel is supplied to the fuel cell 20 from the fuel cell cartridge 27.

  The fuel cell cartridge 27 has a function of supplying liquid fuel therein to the fuel cell 20 by being connected to the electronic device 25, and a function of taking in oxygen in the atmosphere.

  According to the present invention, a flexible anode collector electrode 5a in which the anode flexible membrane 2a and the anode conductive layer 3a are integrally formed, and the electrolyte membrane 6 are directly formed on the anode catalyst layer 7a. The cathode electrode 5b and the electrolyte membrane 6 having flexibility, in which the conductive membrane 2b and the cathode conductive layer 3b are integrally formed, are directly formed on the cathode catalyst layer 7b. Even if it is bent, it is possible to maintain a good output voltage, and it is possible to design a fuel cell with high design that is not limited by the size and shape of the membrane electrode assembly 1.

  In addition, since the anode collector electrode 5a and the cathode collector electrode 5b follow the electrolyte membrane 6 that contracts and swells in the external atmosphere, peeling is unlikely to occur and adhesion can be improved, and long-term reliability can be ensured.

  Furthermore, since the membrane electrode assembly 1 has flexibility, for example, the membrane electrode assembly 1 according to the present invention can be installed in a hinge part or a movable part of an electronic device. It can also be used for wearable device applications.

  The method for producing the membrane electrode assembly of the present invention is not particularly limited as long as it has the above-described structure, but is produced by the following method for producing a membrane electrode assembly of the present invention. It is preferred that

  That is, the present invention includes: [1] a step of integrally forming a flexible film and a conductive layer to create a collector electrode (collector electrode creation step); and [2] a step of forming a plurality of apertures in the collector electrode. (Open hole forming step), [3] a step of forming a catalyst layer (catalyst layer forming step), and [4] a step of integrally forming the collector electrode and the electrolyte membrane with the catalyst layer interposed therebetween (integral forming step), A method for producing a membrane electrode assembly is provided. Hereinafter, each step will be described.

[1] Collecting electrode preparation process As the collecting electrode preparation process, for example, a flexible adhesive in which a polymer adhesive liquid is formed on the surface of the flexible film to a predetermined thickness by roll coating and the adhesive liquid is applied by a heat roller. A step of creating a collector electrode can be employed by superimposing the film surface and the conductive layer and thermocompression bonding. Thereby, a collector electrode can be produced continuously and can be manufactured at low cost.

  Alternatively, an imide-based resin may be formed on the conductive layer to a predetermined thickness by roll coating or the like and polymerized so as to be integrally formed with the flexible film to produce a collector electrode. Thereby, in addition to the effect in the case of using the heat roller described above, the thickness of the flexible film can be reduced and the adhesion can be improved.

[2] Opening formation step In the opening formation step, a plurality of openings are formed on a flat surface by using a punching method, an etching method, a laser method, or the like on the collector electrode obtained in the above [1] collector electrode creation step. It is possible to adopt a process to do.

  According to the punching method, an opening can be formed by creating a mold for forming a predetermined opening pattern and pressing and punching it to the collector electrode. Thereby, even if it does not use a special apparatus, a several hole can be formed at once, and it becomes possible to process cheaply. Further, since machining is not applied with heat, it is possible to form a hole that is not restricted by the material of the collector electrode to be selected.

  In the case where an etching method is employed, a photoetching process used in a printed wiring technique or the like can be used. A photosensitive resist is applied or laminated on either side of the collector electrode to form a photosensitive layer, and a resist pattern for the collector electrode to be left by exposure is formed, then developed and etched to form an opening. can do. Thereby, it is possible to form a plurality of apertures at a time and to process a fine aperture pattern.

  When the laser method is employed, an opening can be formed by using a laser such as excimer, carbon dioxide, or xenon. At this time, by using a condensing laser, the collecting electrode can be moved on the XY stage for each single opening to form a predetermined opening pattern. In such a method of forming an opening with a laser, in addition to the effect obtained when the etching method is employed, the flexible film can be processed with high accuracy.

  In the production method of the present invention, it is preferable that the plurality of openings are formed at a time. For example, a resist mask having a predetermined opening pattern is formed on the flexible film using a photoetching process, and after depositing a conductive layer by a CVD method, a PVD method, a plating method, or the like, the mask is peeled off. Next, using the conductive layer as a mask for the opening pattern, laser irradiation is performed on the entire region where the opening is to be formed. This makes it possible to form a plurality of apertures in the flexible membrane at once.

  In addition, after forming a hole in the flexible film by irradiating with a laser through a metal mask, a conductive layer is physically formed using a sputtering method or a vapor deposition method. A conductive layer can be used.

  Furthermore, by using a flexible printed board on which a predetermined conductive layer has been patterned and irradiating the entire surface from the surface of the conductive layer with a laser, the conductive layer can be used as a mask to form a predetermined hole pattern. Thereby, an opening can be formed without using a special mask, and the process can be omitted.

[3] Catalyst layer forming step As the catalyst layer forming step, for example, a paste in which catalyst particles, conductive particles and an electrolyte are dispersed in an organic solvent is uniformly applied using a bar coating method, a screen printing method or a spray coating method. It is possible to employ a step of applying to and removing the organic solvent in the paste. As a result, a catalyst layer having a large number of pores can be formed, and the surface area of effective catalyst particles can be increased.

  The catalyst layer may be formed on the surface of the electrolyte membrane, or may be formed on the surface of the conductive layer of the collector electrode. Thereby, since the catalyst layer is integrally formed with the electrolyte membrane or the conductive layer in advance, it is possible to obtain an interface with good adhesion.

  Furthermore, it can also be formed by forming a catalyst layer on a plastic film or the like (not shown) and then transferring it to the electrolyte layer or the conductive layer of the collector electrode. In such a manufacturing method, the catalyst layer can be separately formed in advance, and in order to improve the dispersibility of the catalyst particles and the conductive particles, an organic solvent or a conductive material that decreases the proton conductivity of the electrolyte membrane. Even an organic solvent that forms an insulating layer on the surface of the layer can be used as a solvent for the paste.

[4] Integrated Formation Step As the integral formation step, for example, a step of integrally forming the membrane electrode assembly by thermocompression bonding can be employed. For example, a plurality of apertures are formed in the catalyst layer surface of the electrolyte membrane in which the catalyst layer is formed in the [3] catalyst layer forming step, and in the plane formed in the [1] collector electrode creating step and [2] aperture forming step. It is possible to employ a process of thermocompression bonding at a temperature exceeding the softening temperature or glass transition temperature of the electrolyte of the electrolyte membrane or the catalyst layer using a hot press machine. .

  As described above, all members according to the membrane electrode assembly of the present invention have flexibility. Therefore, by adopting the integral forming step by the thermocompression bonding, it is possible to integrally form even when there are irregularities at each interface. Moreover, in order to ensure higher adhesiveness, even if the press pressure in the thermocompression bonding step is set high, the member is not destroyed.

  Further, for example, as shown in FIG. 9, the membrane electrode assembly 1 can be integrally formed in a three-dimensional manner by forming a press plate 15 having predetermined irregularities on the hot press surface. Thereby, the area of the catalyst layer formed in the unit area can be increased, the output voltage can be improved, and the flexibility of the membrane electrode assembly 1 can be improved.

  Further, as shown in FIG. 10, a process is adopted in which the electrolyte membrane 16 with the catalyst layer formed and the collector electrode 17 with the holes formed are wound in a roll shape and thermocompression bonded using a heat roller 18. it can. Thereby, in addition to the effect of the manufacturing method using the said hot press machine, the membrane electrode assembly 1 can be integrally formed continuously.

  When forming a porous material, the integral forming step of the porous material is a subsequent step of the [4] integral forming step so that the function of the porous material is not lost by the [4] integral forming step. It is preferable.

  As a step of integrally forming the porous material, for example, a flexible adhesive film formed by forming a polymer adhesive liquid on the surface of the flexible film to a predetermined thickness by a transfer method, etc., and applying the adhesive liquid and the porous material The method of bonding is illustrated. As a result, the thermocompression bonding in the [4] integral forming step enables the integral formation without blocking the pores in the porous material and the openings in the flexible membrane.

  However, when a porous material having heat resistance made of engineering plastics such as polyimide, polyetheretherketone, polyphenyl sulfite is used as the porous material, [4] flexible film before the integral forming step And may be integrally formed.

  The membrane electrode assembly produced by the above manufacturing method can obtain sufficient adhesion at each interface, and can maintain a good output voltage even in a bent state. In addition, a fine hole pattern can be formed, and a decrease in output voltage due to insufficient supply of methanol and oxygen can be suppressed. Furthermore, since the collector electrode follows the electrolyte membrane that contracts and swells due to the external atmosphere, peeling does not easily occur, and long-term reliability can be ensured.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these.

<Example 1>
As the electrolyte membrane, Nafion 117 (manufactured by DuPont) having a size of 40 × 40 mm and a thickness of about 175 μm was used.

  A catalyst paste was prepared by the following procedure. Catalyst-carrying carbon particles (TEC66E50, manufactured by Tanaka Kikinzoku Co., Ltd.) composed of PtRu particles and carbon particles having a Pt retention amount of 32.5 wt% and a Ru loading amount of 16.9 wt%, and an alcohol solution of 20 wt% Nafion (produced by Aldrich) Then, isopropanol and alumina balls were put into a PTFE container at a predetermined ratio and mixed at 500 rpm for 50 minutes using a stirrer to prepare a cathode catalyst paste. Further, a cathode catalyst paste was prepared in the same manner as the anode catalyst paste using catalyst-supported carbon particles (TEC10E50E, manufactured by Tanaka Kikinzoku Co., Ltd.) composed of Pt particles having a Pt support amount of 46.8 wt% and carbon particles.

The anode catalyst paste was screen-printed on one surface of Nafion 117 so as to be formed at the center of Nafion 117 using a screen printing plate having a shape of 23 × 23 mm so that the amount of catalyst supported was 2 mg / cm ² . . Thereafter, the catalyst paste was dried at room temperature to form an anode catalyst layer having a thickness of about 20 μm.

  Similarly, the cathode catalyst paste was screen-printed at the center of the other surface of Nafion 117 so as to overlap the anode catalyst layer to form a cathode catalyst layer having a thickness of about 20 μm.

  The collector electrode is a polyimide film having a thickness of 50 μm and a size of 40 × 50 mm, a polyimide solution (manufactured by Toray Industries, Inc.) is applied to a predetermined thickness by a bar coating method, and a copper foil having a thickness of 10 μm and a size of 23 × 50 mm is centered on each And integrally formed by heat rolling at a predetermined temperature.

The collector electrode was set in a laser processing machine, and an excimer laser having a wavelength of 248 nm was condensed so as to be 300 μmφ on the processing surface. In addition, the energy density was adjusted to be about 3 J / cm ^{2 on the} surface to be processed to form holes. The hole pattern used had a diameter of 300 μmφ and a pitch of 350 μm, and was formed in a 23 × 23 mm region where the copper foil of the collector electrode was integrally formed. Further, after the opening, a gold plating layer having a thickness of about 1 μm was formed on the copper foil.

Using the two collector electrodes, the copper foil surface and the catalyst layer surface are sandwiched so that the region where the aperture pattern is formed and the region where the catalyst layer of Nafion 117 is formed are in contact with each other. A membrane electrode assembly was prepared by hot pressing at / cm ² for 2 minutes.

Next, in a state where the membrane electrode assembly is bent at about 90 ° at the center so that the anode catalyst layer is on the inside, the cathode catalyst layer side is brought into contact with the L-shaped acrylic plate with the center cut out. The anode catalyst layer side was brought into contact with an acrylic container whose upper part of the prism was opened, and the outer peripheral part of the catalyst layer of the membrane electrode composite was fixed. A 3 mol / L aqueous methanol solution was supplied to the acrylic container from above so that the anode catalyst layer was completely immersed, and the cathode catalyst layer was opened to the atmosphere. Measurement conditions were 40 ° C. and a relative humidity of 40%. When power was generated under a load of 0.1 A / cm ² , the output voltage after 10 minutes was 0.30 V. Further, when the continuous operation was performed under the same load condition, the output voltage after 30 days was 0.29 V, and no peeling occurred.

  From the results of Example 1, it was found that the membrane electrode assembly of the present invention can obtain an output voltage even in a bent state, and can maintain the output without causing separation over a long period of time.

<Example 2>
As the cathode porous material, ether urethane having a thickness of 300 μm and a size of 23 × 23 mm was used. A polyimide solution (manufactured by Toray Industries, Inc.) is applied onto the surface of the polyimide film on the cathode electrode side of the membrane electrode composite produced in Example 1, and the ether-based urethane is overlaid so as to overlap the catalyst layer. The porous material was integrally formed by pressure bonding at 10 kgf / cm ² at room temperature, and a membrane electrode assembly having a thickness of about 550 μm was produced.

  When measured under the same conditions as in Example 1, the output voltage after 10 minutes was 0.32V. Moreover, when the continuous operation was performed under the same conditions as in Example 1, the output voltage after 30 days was 0.29 V, and no peeling occurred.

  From a comparison between Example 1 and Example 2, it was found that the output voltage was improved by integrally forming the polyimide film and the porous material on the cathode electrode side.

<Example 3>
A membrane electrode assembly was produced in the same manner as in Example 2 except that ether-based urethane having a thickness of 300 μm and a size of 23 × 23 mm was used as the anode porous material on the anode electrode side.

  When measured under the same conditions as in Example 1, the output voltage after 10 minutes was 0.34V. Moreover, when the continuous operation was performed under the same conditions as in Example 1, the output voltage after 30 days was 0.32 V, and no peeling occurred.

  From a comparison between Example 1 and Example 3, it was found that the output voltage was improved by integrally forming the polyimide film and the porous material on the anode electrode side.

<Example 4>
The anode current collector prepared in Example 1 was set to a depth of about 5 mm from the water surface so that the anode flexible membrane surface was directed to the water surface, and an excimer laser with a wavelength of 248 nm was applied to the anode flexible membrane surface at the energy level. The hydrophilic treatment was performed by adjusting the density to be about 0.3 J / cm ² and irradiating for 0.5 seconds.

  Further, the water repellent treatment was performed by irradiating the excimer laser on the cathode flexible film surface of the cathode collector electrode under the same conditions in a nitrogen dry atmosphere.

  Two anode collector electrodes and two cathode collector electrodes were integrally formed under the same conditions as in Example 1 to produce a membrane electrode composite having a thickness of about 300 μm.

  When measured under the same conditions as in Example 1, the output voltage after 10 minutes was 0.36V. Moreover, when continuous operation was performed under the same conditions as in Example 1, the output voltage after 30 days was 0.35 V, and no peeling occurred.

  From the comparison between Example 2 and Example 4, the water repellent layer is formed on the surface of the cathode flexible membrane and the hydrophilicity is formed on the surface of the anode flexible membrane, thereby reducing the thickness while maintaining a good output voltage. I found out that

<Example 5>
A die having an opening pattern of 0.5 mmφ and a pitch pattern of 1.0 mm formed in an area of 23 × 23 mm is manufactured and punched with a pressing pressure of 5 kgf / cm ² using a press machine. A membrane electrode assembly was produced in the same manner as in Example 1 except that the openings were formed.

  When measured under the same conditions as in Example 1, the output voltage after 10 minutes was 0.20V. Moreover, when the continuous operation was performed under the same conditions as in Example 1, the output voltage after 30 days was 0.18 V, and no peeling occurred.

  As a result, the membrane electrode assembly of the present invention can form a plurality of apertures at once in a very large area, thereby making it possible to produce a collector electrode having apertures at a low cost. It was found that good output characteristics can be obtained even when used.

<Example 6>
A photodissolvable positive resist film is formed on the flexible film of the collector electrode, and is exposed by an ultraviolet exposure apparatus equipped with a photomask in which an opening pattern with an opening diameter of 100 μmφ and a pitch of 250 μm is formed in a 23 × 23 mm region did. After removing the resist of the opening pattern with a sodium carbonate-based alkaline developer, the opening of the collector electrode was formed by reactive ion etching. Finally, the resist film was peeled off and washed by exposing it to ultraviolet rays without passing through a photomask. A membrane electrode assembly was produced in the same manner as in Example 1 except that such a collector electrode was used.

  When measured under the same conditions as in Example 1, the output voltage after 10 minutes was 0.26V. Further, when continuous operation was performed under the same conditions as in Example 1, the output voltage after 30 days was 0.25 V, and no peeling occurred.

  Thus, it was found that the membrane electrode assembly according to the present invention can form a fine aperture pattern and can produce a collector electrode having a high aperture ratio.

<Example 7>
Using a flexible printed circuit board with a diameter of 300 μmφ and a pitch of 350 μm and having a copper foil non-formation region, an excimer laser with a wavelength of 248 nm adjusted so that the energy density is about 3 J / cm ^{2 on the} copper foil surface is irradiated from the copper foil surface side Then, a membrane electrode assembly was produced in the same manner as in Example 1 except that an opening was formed in the flexible membrane.

  When measured under the same conditions as in Example 1, the output voltage after 10 minutes was 0.31V. Moreover, when the continuous operation was performed under the same conditions as in Example 1, the output voltage after 30 days was 0.30 V, and no peeling occurred. Thus, it was found that the membrane electrode assembly of the present invention can form a fine aperture pattern and can produce a collector electrode having a high aperture ratio.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a disassembled perspective view which shows typically the membrane electrode assembly of the preferable example of this invention. It is the top view which looked at the membrane electrode assembly shown in FIG. 1 from the upper part. It is sectional drawing seen from the cut surface line III-III of FIG. It is a schematic diagram of the cross section for demonstrating the function of the anode catalyst layer 7a in the said membrane electrode assembly 1 of this invention. 3 schematically shows an example in which the cathode porous material 11 is integrally formed on the surface of the cathode flexible membrane 2b of the membrane electrode assembly 1 shown in FIG. 3 opposite to the surface on which the cathode conductive layer 3b is formed. FIG. 4 is a diagram showing an example in which an anode hydrophilic layer 14a and a cathode hydrophilic layer 14b are formed on the surfaces of an anode flexible membrane 2a and a cathode flexible membrane 2b in the membrane electrode assembly 1 shown in FIG. 1 is a diagram schematically showing a cross section of a direct liquid supply type fuel cell 20 using a membrane electrode assembly 1. FIG. It is a figure which shows typically an example of the electronic device 25 using the fuel cell 20 of this invention shown in FIG. It is a schematic diagram for demonstrating an example of the suitable manufacturing method of the membrane electrode assembly of this invention. It is a schematic diagram for demonstrating an example of the suitable manufacturing method of the membrane electrode assembly of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Membrane electrode composite, 2a Anode flexible membrane, 2b Cathode flexible membrane, 3a Anode conductive layer, 3b Cathode conductive layer, 4 Aperture, 5a Anode collector electrode, 5b Cathode collector electrode, 6 Electrolyte membrane, 7a Anode Catalyst layer, 7b Cathode catalyst layer, 8 Anode catalyst particle, 9 Anode conductive particle, 10 Electrolyte, 11 Cathode porous material, 14a Anode hydrophilic layer, 14b Cathode hydrophilic layer, 20 Fuel cell, 21 Fuel supply material, 22 Exhaust hole , 23 Cover film, 24 Liquid storage tank, 25 Electronic equipment, 26 Hinge part, 27 Liquid fuel cartridge, 28 Fuel cell stack, 29 DC / DC converter.

Claims (19)

  A membrane electrode composite having a structure in which an anode flexible membrane, an anode conductive layer, an anode catalyst layer, an electrolyte membrane, a cathode catalyst layer, a cathode conductive layer, and a cathode flexible membrane are sequentially laminated.   The membrane electrode assembly according to claim 1, wherein the cathode flexible membrane is insulative.   The membrane electrode assembly according to claim 1, wherein the anode flexible membrane and the cathode flexible membrane are polymer membranes having heat resistance of 100 ° C or higher.   The membrane electrode assembly according to claim 1, wherein at least one of the anode flexible membrane and the cathode flexible membrane is polyimide.   The membrane electrode assembly according to any one of claims 1 to 4, wherein a porous material is integrally formed on the cathode flexible membrane.   The membrane electrode assembly according to any one of claims 1 to 4, wherein a porous material is integrally formed on the anode flexible membrane, and is used for a fuel cell using liquid fuel.   The membrane electrode assembly according to any one of claims 1 to 4, wherein a hydrophilic layer is formed on the surface of either the anode flexible membrane or the cathode flexible membrane.   The membrane electrode assembly according to any one of claims 1 to 4, wherein a water repellent layer is formed on the surface of either the anode flexible membrane or the cathode flexible membrane.   9. The anode conductive layer and the cathode conductive layer are metal foils containing at least one element selected from the group consisting of Au, Ag, Pt, Ni, Cu, Al, W and Ti. The membrane electrode assembly according to any one of the above.   10. The anode conductive layer and the cathode conductive layer are covered with a noble metal containing at least one element selected from the group consisting of Au, Pt, Pd and Ru. Membrane electrode composite.   The film according to any one of claims 1 to 10, wherein a combination of the anode flexible film and the cathode flexible film and the anode conductive layer and the cathode conductive layer is a polyimide film and a copper foil. Electrode complex.   A method for producing a membrane electrode assembly according to any one of claims 1 to 11, characterized in that a flexible membrane and a conductive layer are integrally formed and a plurality of apertures are formed by punching. A method for producing an electrode composite.   A method for producing a membrane electrode assembly according to any one of claims 1 to 11, wherein the flexible membrane and the conductive layer are integrally formed, and a plurality of apertures are formed by photoetching. A method for producing a membrane electrode assembly.   A method for producing a membrane electrode assembly according to any one of claims 1 to 11, wherein the flexible membrane and the conductive layer are integrally formed, and the aperture is formed by a focused laser. A method for producing an electrode composite.   A method for producing a membrane electrode assembly according to any one of claims 1 to 11, wherein a flexible membrane and a conductive layer are integrally formed, and a plurality of apertures are formed by irradiating a laser using the conductive layer as a mask. A method for producing a membrane electrode assembly, comprising forming the membrane electrode assembly.   A method for producing a membrane electrode assembly according to any one of claims 1 to 11, wherein the electrolyte membrane on which the catalyst layer is formed, the flexible membrane and the conductive layer are integrally formed to form an opening. A method for producing a membrane electrode assembly, wherein the collector electrode is wound into a roll shape and thermocompression bonded using a heat roller.   A fuel cell comprising the membrane electrode assembly according to any one of claims 1 to 11 and fuel supply means for supplying liquid fuel to an anode catalyst layer of the membrane electrode assembly.   An electronic device in which the fuel cell according to claim 17 is mounted so that the cathode flexible membrane side of the fuel cell is in contact with the atmosphere.   The electronic device which mounted the fuel cell of Claim 17 in the hinge part.

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