JP5835366B2 - Method for manufacturing fuel cell electrode, method for manufacturing electrode-electrolyte membrane laminate, method for manufacturing fuel cell, and method for manufacturing fuel cell - Google Patents

Description

  The present invention relates to an electrode for a fuel cell, a method for producing an electrode for a fuel cell, an electrode-electrolyte membrane laminate, a fuel cell, and a fuel cell, and in particular, an electrode for a fuel cell using an anion conductive solid polymer electrolyte, The present invention relates to a method for manufacturing an electrode for a fuel cell, an electrode-electrolyte membrane laminate, a fuel cell, and a fuel cell.

  In recent years, fuel cells are promising as one of the next-generation energy systems. There are various types of fuel cells such as alkaline fuel cells, phosphoric acid fuel cells, polymer electrolyte fuel cells, solid oxide fuel cells, and molten carbonate fuel cells. It has characteristics. Among them, solid polymer fuel cells have the features of operating at a low temperature and high power density compared to other types of fuel cells, so there are various types such as home use, automobile use, and portable use. Development is underway for various applications.

  Conventionally, a polymer electrolyte fuel cell has a structure in which a cation (proton) conductive solid polymer electrolyte membrane is used as an electrolyte membrane, and a catalyst layer and an electrode substrate are laminated on both sides and sandwiched between separators. A polymer electrolyte fuel cell is well known. A catalyst layer disposed on both sides of an electrolyte membrane (that is, a catalyst layer / electrolyte membrane / catalyst layer structure) is called a catalyst layer-electrolyte membrane laminate, and an electrode substrate is further disposed on both sides thereof. A thing (namely, the thing of the layer structure of an electrode base material / catalyst layer / electrolyte membrane / catalyst layer / electrode base material) is called the electrode-electrolyte film | membrane laminated body.

  When fuel is supplied to one of the electrodes of the electrode-electrolyte membrane laminate and an oxidant is supplied to the other, hydrogen is separated into protons and electrons on the electrode (hydrogen electrode) catalyst supplied with fuel (hydrogen). These protons move through the electrolyte membrane, and the electrons pass through the external circuit and go to the electrode (oxygen electrode) catalyst supplied with air (oxygen) as an oxidant, where oxygen, electrons, and protons react to produce water. Is done. As a result, current flows and power generation is performed.

  However, polymer electrolyte fuel cells using proton-conducting polymer electrolyte membranes use expensive platinum in the catalyst layer, which increases the cost of the industry, so it is difficult to introduce them into the market. is the current situation.

  On the other hand, recently, alkaline fuel cells have attracted attention again from the viewpoint of low-temperature operation, high efficiency, high power density, and in particular, not using expensive platinum as a catalyst. In particular, as in the polymer electrolyte fuel cell, there is an expectation for a solid alkaline fuel cell using a solid polymer electrolyte membrane as an electrolyte using hydroxide ions as an ionic conductor. For example, a fuel cell using a fluorine-based anion exchange membrane as an anion (hydroxide ion) conductive solid polymer electrolyte membrane is disclosed (for example, see Patent Document 1).

JP 2006-244961 A

  However, in an electrode for an alkaline fuel cell, there is a problem that the catalyst layer forming paste tends to have a low viscosity due to dispersion of the catalyst metal particles and the ion conductive electrolyte contained in the catalyst forming paste. Sometimes the problem is that the shape cannot be maintained. Further, the electrode end face has a problem in that the catalyst layer is peeled off due to the sagging of the paste for forming the catalyst layer with reduced viscosity. On the other hand, when the viscosity is increased, the shape can be maintained, but there are problems that formation of the catalyst layer is difficult and cracking of the catalyst layer is likely to occur.

  As described above, a technique for forming a catalyst layer without losing the characteristics and shape of the catalyst layer is desired, but it has not yet been developed.

  An object of the present invention is to form an uneven portion on an electrode, so that even if the paste for forming a catalyst has a low viscosity or a high viscosity, it is excellent in securing a shape when forming a catalyst layer, and can suppress peeling of the electrode. An object of the present invention is to provide a fuel cell electrode excellent in reaction, a method for producing a fuel cell electrode, an electrode-electrolyte membrane laminate, a fuel cell, and a fuel cell.

In order to achieve the above object, according to the first aspect of the present invention, there is provided a step of forming a spacer member at a peripheral portion of the electrode substrate surface, and a catalyst paste is applied to a region surrounded by the spacer member. A method for producing an electrode for a fuel cell, comprising: a step; and a step of pressing the surface of the electrode base material at room temperature to form a catalyst layer after drying the catalyst paste.
The invention according to claim 2 is a method for producing an electrode-electrolyte membrane laminate in which an anion-conductive polymer electrolyte membrane is sandwiched between a spacer member and a fuel cell electrode to produce an electrode-electrolyte membrane laminate. And in the manufacturing process of the said electrode for fuel cells, the process of forming the said spacer member in the peripheral part of the electrode base-material surface, and the process of apply | coating a catalyst paste to the area | region enclosed by the said spacer member And a step of pressing the catalyst paste onto the surface of the electrode base material to form a catalyst layer, and a method for producing an electrode-electrolyte membrane laminate.
The invention described in claim 3 is a method of manufacturing a fuel cell by sandwiching the electrode-electrolyte membrane stack manufactured by the method of manufacturing an electrode-electrolyte membrane stack according to claim 2 between a pair of separators. This is a method for manufacturing a fuel cell.
According to a fourth aspect of the present invention, a fuel cell is manufactured by stacking a plurality of fuel cells manufactured by the method for manufacturing a fuel cell according to the third aspect. It is a manufacturing method.

  The invention according to claim 2 is the electrode for a fuel cell according to claim 1, wherein the spacer member is further arranged in the central portion.

  The invention according to claim 3 is the fuel cell electrode according to claim 1 or 2, wherein the spacer member is made of an alkali-resistant resin.

  The invention according to claim 4 is the fuel cell electrode according to claim 3, wherein the alkali-resistant resin contains a conductive substance.

  The invention according to claim 5 is the electrode for a fuel cell according to any one of claims 1 to 4, wherein the electrode substrate is made of a metal porous body.

  The invention according to claim 6 includes a step of forming a spacer member at a peripheral portion of the surface of the electrode substrate, a step of applying a catalyst paste to a region surrounded by the spacer member, and the catalyst paste. And a step of pressure-bonding to form a catalyst layer, and a method for producing an electrode for a fuel cell.

  The invention according to claim 7 comprises the fuel cell electrode according to any one of claims 1 to 5 and an anion conductive solid polymer electrolyte membrane, wherein the anion conductive solid polymer. The electrolyte membrane is an electrode-electrolyte membrane laminate, which is sandwiched between the fuel cell electrodes.

  The invention according to claim 8 includes the electrode-electrolyte membrane laminate according to claim 7 and a pair of separators, wherein the electrode-electrolyte membrane laminate is sandwiched between the separators. This is a featured fuel cell.

  The invention according to claim 9 is a fuel cell comprising a plurality of the fuel cells according to claim 8 stacked.

  According to the present invention, by forming uneven portions on the electrode, even if the paste for forming the catalyst has a low viscosity or a high viscosity, it is excellent in securing the shape when forming the catalyst layer and can suppress the peeling of the electrode. A fuel cell electrode excellent in reaction, a method for producing a fuel cell electrode, an electrode-electrolyte membrane laminate, a fuel cell, and a fuel cell can be provided.

1 is a schematic cross-sectional structure diagram of an electrode for a fuel cell according to a first embodiment of the present invention. It is explanatory drawing of the manufacturing method of the electrode for fuel cells which concerns on the 1st Embodiment of this invention, Comprising: (a) Process drawing which forms the spacer member 2 in the peripheral part of the electrode base material 1, (b) Spacer member 2 is a process diagram for forming a catalyst layer 3 in a region surrounded by 2; 3A and 3B are schematic structural views of a fuel cell electrode according to a second embodiment of the present invention, in which FIG. 3A is a cross-sectional view taken along the line II in FIG. 3B, and FIG. The top view of electrode 12A which is a shape, (c) The top view of electrode 12B where the shape of the spacer member 5 is a grid | lattice form, (d) The top view of electrode 12C where the shape of the spacer member 5 is a dot shape. The typical cross-section figure of the electrode-electrolyte membrane laminated body which concerns on the 3rd Embodiment of this invention. It is explanatory drawing of the manufacturing method of the electrode-electrolyte membrane laminated body which concerns on the 3rd Embodiment of this invention, Comprising: (a) The cathode electrode 8 is formed in one main surface of the anion conductive solid polymer electrolyte membrane 10 FIG. 4B is a process diagram for forming the anode electrode 9 on the other main surface of the anion conductive solid polymer electrolyte membrane 10. The typical cross-section figure of the fuel cell which concerns on the 4th Embodiment of this invention.

  Hereinafter, an electrode for a fuel cell, a manufacturing method thereof, an electrode-electrolyte membrane laminate, a fuel cell, and a fuel cell according to embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, differ from actual ones, and also include portions having different dimensional relationships and ratios between the drawings.

[First embodiment]
(Electrode structure)
As shown in FIG. 1, the fuel cell electrode 11 according to the first exemplary embodiment of the present invention includes an electrode base material 1 and a spacer member disposed so as to surround the central portion at the peripheral edge of the surface of the electrode base material 1. 2 and a catalyst layer 3 disposed in a region surrounded by the spacer member 2.

(Electrode substrate)
The electrode substrate 1 is a base of the electrode, and has, for example, a substantially square shape in a plan view, and has a thickness of, for example, about 100 μm to 2 mm, and preferably about 300 μm to 1 mm. The degree is more preferably about 500 to 800 μm. The shape is not limited to a substantially rectangular shape in plan view, and may be a polygonal shape, a substantially circular shape, a substantially elliptical shape, or the like.

  The material of the electrode substrate 1 is not particularly limited as long as it has conductivity and is porous. Preferably, it is a porous metal body made of a metal mesh, a metal foam or the like in order to diffuse liquid fuel and oxidant gas into the catalyst layer described later. By using a metal body, conductivity is increased. Further, it is known that, for example, when a base metal is used as the metal body, it can contribute well to the fuel cell reaction. In particular, it has been confirmed from experiments that the anode electrode (fuel electrode side electrode) side has better performance when using a base material of a base metal such as nickel, for example, than a conductive porous base material that does not use a base metal. Yes.

  Therefore, as the metal used for the porous metal body, a base metal such as nickel or palladium, silver, stainless steel, or the like can be used, and nickel or silver is preferably used. Moreover, when a metal foam is used, the porosity is, for example, about 50 to 99%, and preferably about 80 to 98%.

  When the electrode 11 is a cathode electrode (oxygen electrode side electrode), in addition to the metal porous body, a conductive carbon-based material, for example, a conductive porous body such as carbon paper or carbon cloth is used. it can. In this case, the thickness is, for example, about 100 to 500 μm, and preferably about 150 to 300 μm.

  Further, in the cathode electrode, as described later, since water is generated during the reaction, it is preferable to impart water repellency to the electrode 11. In order to impart water repellency, for example, a method of forming an MPL (Micro Porous Layer) layer made of a fluororesin and carbon on the porous body can be used. In this case, the thickness of the MPL layer is, for example, about 10 to 200 μm, and preferably about 30 to 100 μm.

(Spacer member)
The spacer member 2 is for holding the shape of the catalyst layer 3 described later, and has a substantially square frame shape in plan view, and has a thickness of, for example, about 10 to 500 μm. Yes, preferably about 30 to 300 μm, more preferably about 50 to 250 μm. The shape of the spacer member 2 is not limited to a substantially square frame shape in plan view, and may be a polygonal frame shape, a substantially circular frame shape, a substantially elliptical frame shape, or the like. Preferably, it is suitable for the shape of the electrode substrate 1.

  The material of the spacer member 2 is not particularly limited, but is preferably a resin having alkali resistance. For example, a phenol resin, an acrylic resin, a fluorine resin, an epoxy resin, a urethane resin, a polystyrene resin, a polyvinyl chloride resin, etc. can be mentioned.

  From the viewpoint of strong alkali resistance, polyvinyl chloride, polyvinylidene chloride, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene-acrylonitrile copolymer, high-density polyethylene, medium-density polyethylene, low-density polyethylene, ethylene-acetic acid Vinyl copolymer, polypropylene, polyacetal copolymer, methacryl-styrene copolymer, ethylene trifluoride chloride, tetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoro Alkoxyethylene copolymers, tetrafluoroethylene-ethylene copolymers, vinylidene fluoride and the like are preferable.

  Among them, from the viewpoint of further processing, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene-acrylonitrile copolymer, high density polyethylene, medium density polyethylene, low density polyethylene, ethylene-vinyl acetate copolymer, polypropylene, etc. Is more preferable.

  The alkali-resistant resin described above preferably contains a conductive substance. Examples of the conductive material include carbon materials such as carbon black, carbon nanowires, and carbon nanotubes.

(Catalyst layer)
The catalyst layer 3 is composed of catalyst metal particles, a carrier for supporting the catalyst metal particles, and an ion conductive electrolyte. The thickness of the catalyst layer 3 is preferably about the same as the thickness of the spacer member 2 described above, and is, for example, about 10 to 500 μm, preferably about 30 to 300 μm, more preferably about 50. It is good that it is about ~ 250 μm.

The catalyst weight of the catalyst layer 3 is, for example, about 0.5 to 20 mg / cm ² on the cathode electrode side, and preferably about 1 to 15 mg / cm ² . On the anode electrode side, for example, it is about 5 to 60 mg / cm ² , and preferably about 10 to 50 mg / cm ² .

  The catalyst metal particles have an average particle diameter of, for example, about 0.05 to 20 nm, preferably about 0.1 to 10 nm, and more preferably about 0.3 to 5 nm.

  Examples of the material of the catalytic metal particles include metals such as iron, cobalt, nickel, palladium, silver, ruthenium, iridium, molybdenum, manganese, and platinum, and metal compounds thereof, or two or more of these metals. An alloy etc. can be mentioned.

  From the viewpoint of cost, the metal is preferably iron, cobalt, nickel, palladium, silver or the like excluding platinum. The alloy is preferably an alloy formed by combining two or more of iron, cobalt, and nickel. Examples of such an alloy include an iron-cobalt alloy, a cobalt-nickel alloy, and an iron-nickel alloy. Further, an iron-cobalt-nickel alloy obtained by further compounding these may be used. The ratio of each metal of these alloys is not particularly limited and can be set as appropriate.

The support is for supporting the above-described catalyst metal particles. The average particle diameter of the carrier is, for example, about 0.01 to 1 μm, preferably about 0.01 to 0.2 μm, as average primary particles. The specific surface area of the carrier is not particularly limited, but is, for example, about 10 to 1500 m ² / g, and preferably about 10 to 500 m ² / g.

  Examples of the material for the carrier include alumina, silica, and carbon powder. Preferably, carbon powder is preferable from the viewpoint of conductivity.

  As carbon powder, if it is carbon powder which has electroconductivity, it will not specifically limit. Preferably, materials having high corrosion resistance and conductivity, for example, carbon black such as acetylene black, furnace black, channel black and ketjen black, graphite, activated carbon, carbon fiber, carbon nanotube, carbon nanowire and the like can be mentioned. These carbonaceous materials may be used alone or in combination of two or more.

The ion conductive electrolyte is not particularly limited as long as it is an anion conductive electrolyte capable of conducting hydroxide ions (OH ⁻ ) as ions. For example, a hydrocarbon-based electrolyte or a fluororesin-based electrolyte can be used.

  Examples of the hydrocarbon electrolyte include an electrolyte obtained by aminating a chloromethylated product of a copolymer of aromatic polyether sulfonic acid and aromatic polythioether sulfonic acid. Examples of the fluororesin-based electrolyte include a polymer obtained by treating the terminal of a perfluorocarbon polymer having a sulfonic acid group with a diamine and quaternizing it, or a polymer such as quaternized polychloromethylstyrene. Especially, what has solvent solubility is preferable.

  When the above-described ion conductive electrolyte is used to prepare a catalyst layer forming paste, which will be described later, in an organic solvent such as alcohol or ether, or a mixed solvent of an organic solvent and water, for example, at a concentration of about 1 to 30% by mass. Used in a dispersed manner.

(Method for manufacturing electrode)
As shown in FIG. 2, the method for manufacturing a fuel cell electrode according to the first embodiment of the present invention includes a step of forming a spacer member 2 on the peripheral edge of the surface of the electrode substrate 1, and a spacer. A step of applying a catalyst paste to a region surrounded by the member 2; and a step of forming a catalyst layer 3 by pressure bonding after drying the catalyst paste.

Below, a manufacturing process is explained in full detail.
(A) First, as shown in FIG. 2A, for example, an electrode substrate 1 made of a metal foam having a thickness of about 10 to 50 mm and a thickness of about 100 to 500 μm is prepared. Next, the spacer member 2 is formed in a frame shape on the peripheral portion of the surface of the electrode substrate 1 by applying a paste of an alkali resistant resin. The width of the frame of the spacer member 2 is, for example, about 2 to 10 mm in plan view, and the thickness is about 50 to 250 μm. The spacer member 2 can be formed by melting and extruding an alkali-resistant resin, or by printing or the like.

(B) Next, for forming a catalyst layer comprising a catalytic metal particle made of silver or nickel having an average particle diameter of, for example, about 0.3 to 5 nm, carbon black carrying the same, and a hydrocarbon ion conductive electrolyte. A paste (hereinafter referred to as catalyst paste) is prepared.

  The ratio of the catalyst metal particles and the ion conductive electrolyte contained in the catalyst paste is preferably adjusted so that the mass ratio after drying is, for example, about 3: 1 to 1: 3.

  A solvent for adjusting the viscosity may be used in the catalyst paste. The solvent for adjusting the viscosity is not particularly limited, and can be appropriately selected within a wide range. Examples thereof include various alcohols, various ethers, various dialkyl sulfoxides, water, or a mixture thereof. Preferably, alcohols are used. Examples of alcohols include monohydric alcohols having 1 to 4 carbon atoms such as methanol, ethanol, n-propanol, isopropanol, n-butanol, and tert-butanol, and various polyhydric alcohols such as propylene glycol and diethylene glycol. It is done.

  Further, a fluororesin may be further added to the catalyst paste. Examples of the fluororesin include polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, vinylidene fluoride-hexafluoropropylene copolymer, and the like. In particular, polytetrafluoroethylene is preferably used from the viewpoints of binding properties and water repellency.

(C) Next, as shown in FIG. 2 (b), the catalyst paste is applied to the region surrounded by the spacer member 2 on the electrode substrate 1 with a thickness of about 50 to 250 μm, for example. The method for applying the catalyst paste is not particularly limited. For example, knife coaters, bar coaters, sprayers, dip coaters, spin coaters, roll coaters, die coaters, curtain coaters, screen printing, extrusion coating, etc. can be used as appropriate.

(D) Next, the catalyst paste is dried to form the catalyst layer 3. The drying temperature is, for example, about 40 to 100 ° C., and preferably about 60 to 80 ° C. Although depending on the drying temperature, the drying time is, for example, about 5 minutes to 2 hours, and preferably about 30 minutes to 1 hour.

(E) Finally, the catalyst layer 3 is pressure-bonded to the electrode substrate 1 by a press device or the like, and the fuel cell electrode 11 shown in FIG. 1 is completed.

  Since the fuel cell electrode 11 forms the catalyst layer 3 in a region surrounded by the frame-like spacer member 2 disposed on the peripheral portion of the electrode base 1 surface, the efficiency of the manufacturing process is improved. Moreover, since the catalyst layer 3 having a desired thickness can be formed, the reaction area of the electrode can be ensured satisfactorily. Thereby, the high-performance fuel cell electrode 11 is obtained.

  Moreover, since the catalyst layer 3 is joined to the electrode substrate 1 by pressure bonding, the adhesion between the catalyst layer 3 and the electrode substrate 1 is increased. In addition, since the catalyst layer 3 is surrounded by the spacer member 2, the shape of the catalyst layer 3 is well maintained even when the viscosity of the catalyst paste is low or when the viscosity is high. Thereby, even if it uses for a long time, it becomes possible to prevent peeling of the catalyst layer 3. FIG.

  According to the fuel cell electrode 11 and the method for manufacturing the same according to the present embodiment, by forming an uneven portion on the electrode, even when the catalyst forming paste has a low viscosity or a high viscosity, the shape is ensured when the catalyst layer is formed. Excellent, can suppress electrode peeling, and is excellent in electrode reaction.

[Second Embodiment]
(electrode)
The fuel cell electrode 12 (A, B, C) according to the second embodiment of the present invention, as shown in FIG. 3, is the same fuel cell electrode as in FIG. 1 shown in the first embodiment. 11, the spacer member 5 is further arranged at the center of the surface of the electrode substrate 1. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

  Although the shape of the spacer member 5 arrange | positioned in the center part of the electrode base material 1 surface is not specifically limited, For example, columnar shapes, such as a substantially square pole and a substantially triangular prism, can be mentioned. For example, in the case of a quadrangular prism, the width is about 0.1 to 2 mm, and the height is preferably at least as low as the thickness of the spacer member 2 at the peripheral edge, for example, about 10 to 500 μm. About 30 to 300 μm, and more preferably about 50 to 250 μm.

  For example, as shown in FIGS. 3 (a) and 3 (b), the columnar spacer member 5 has at least one, preferably a plurality of spacer members 5 at predetermined intervals. It is good to form mutually parallel. The space | interval between the spacer members 5 can be set suitably.

  The spacer member 5 may be formed in a lattice shape as shown in FIG. The width, height, and interval of the lattice can be set to the same level as in the case of the columnar shape described above.

  The spacer member 5 may be formed in a dot shape as shown in FIG. The width, height, and interval of each dot can be set to the same level as in the case of the columnar shape described above.

  The manufacturing method of the fuel cell electrode according to the present embodiment is different from the manufacturing method according to the first embodiment in the method of forming the spacer member 5, and is otherwise the same as the first embodiment. Therefore, a duplicate description is omitted.

  In the method of manufacturing the fuel cell electrode according to the present embodiment, the spacer member 5 is formed by melting and extruding the alkali-resistant resin, or by forming the spacer member 5 using a method such as printing. The fuel cell electrode 12 (A, B, C) shown in FIG.

  According to the present embodiment, since the spacer member 5 is further arranged at the center of the surface of the electrode substrate 1, the reaction area of the catalyst layer 3 is increased, the shape of the catalyst layer 3 is maintained well, and the electrode substrate The peeling from the material 1 can be suppressed.

  According to the fuel cell electrode 12 (A, B, C) and the manufacturing method thereof according to the present embodiment, even if the catalyst forming paste has a low viscosity or a high viscosity, the catalyst is formed by forming irregularities on the electrode. It is excellent in securing the shape when forming the layer, can suppress peeling of the electrode, and is excellent in electrode reaction.

[Third embodiment]
(Electrode-electrolyte membrane laminate)
As shown in FIG. 4, the electrode-electrolyte membrane laminate 13 according to the third embodiment of the present invention has the same fuel cell electrodes (8, 9) as FIG. 1 shown in the first embodiment. And an anion conductive solid polymer electrolyte membrane 10. The anion conductive solid polymer electrolyte membrane 10 is sandwiched between the fuel cell electrodes (8, 9). Since other configurations are the same as those of the first embodiment, description thereof is omitted. Needless to say, the fuel cell electrodes 12 (A, B, C) similar to those shown in FIG. 3 shown in the second embodiment may be used for the fuel cell electrodes (8, 9). .

  The cathode electrode 8 includes an electrode base material 1, a spacer member 2 disposed so as to surround the central portion of the surface of the electrode base material 1, and a catalyst layer 3 disposed in a region surrounded by the spacer member 2. Yes. Similarly, the anode electrode 9 includes an electrode substrate 4, a spacer member 7 disposed so as to surround the central portion of the peripheral portion of the surface of the electrode substrate 4, and a catalyst layer 6 disposed in a region surrounded by the spacer member 7. It has.

  The anion conductive solid polymer electrolyte membrane 10 is for conducting anions (hydroxide ions) generated at the cathode electrode 8 to the anode electrode 9. The thickness is, for example, about 10 to 300 μm, and preferably about 20 to 200 μm.

  As the anion conductive solid polymer electrolyte membrane 10 according to the present embodiment, any one of hydrocarbon type and fluororesin type anion conductive solid polymer electrolyte membrane can be used. When a high-concentration alkaline aqueous solution is used, it is preferable to use a high-concentration alkali-resistant fluororesin-based solid polymer electrolyte membrane. When a low concentration or an aqueous alkali solution is not used, it is preferable to use a hydrocarbon system from the viewpoint of cost. These selections can be optimized as appropriate depending on the system to be applied.

  In the alkaline aqueous solution described above, the high concentration can be appropriately changed depending on the type of the alkaline aqueous solution and the like, but in the present embodiment, it means about 2 mol / liter or more, and the low concentration is about 2 mol / liter. Less than about a liter.

  Examples of the hydrocarbon-based anion-conducting solid polymer electrolyte membrane 10 according to the present embodiment include Aciplex (registered trademark) A-201, 211, 221 and the like manufactured by Asahi Kasei Co., Ltd., and Tokuyama Co., Ltd. Neoceptor (registered trademark) AM-1, AHA or the like can be used. As the fluororesin-based anion conductive solid polymer electrolyte membrane 10, Tosflex (registered trademark) IE-SF34 manufactured by Tosoh Corporation can be used.

  The manufacturing method of the electrode-electrolyte membrane laminate according to the present embodiment is different from the manufacturing method according to the first embodiment in the method of forming the electrodes (8, 9) on the anion conductive solid polymer electrolyte membrane 10. Since the others are the same as those of the first embodiment, a duplicate description is omitted.

  In the method for producing an electrode-electrolyte membrane laminate according to the present embodiment, as shown in FIG. 5A, the cathode electrode 8 is formed on one main surface of the anion conductive solid polymer electrolyte membrane 10. Next, as shown in FIG. 5 (b), after the anode electrode 9 is formed on the other main surface of the anion conductive solid polymer electrolyte membrane 10, the cathode electrode 8 and the anode electrode 9 are, for example, about 50-80. The electrode-electrolyte membrane laminate 13 shown in FIG. 4 can be manufactured by hot pressing at a temperature of about 0 ° C. and a pressure of about 0.5 to 2 MPa.

  According to the electrode-electrolyte membrane laminate 13 according to the present embodiment, by forming an uneven portion on the electrode, even when the catalyst forming paste has a low viscosity or a high viscosity, it is excellent in securing the shape when forming the catalyst layer, The electrode peeling can be suppressed, and the electrode reaction is excellent.

[Fourth embodiment]
(Fuel battery cell)
The fuel cell 20 according to the fourth embodiment of the present invention is a solid alkaline fuel cell, and, as shown in FIG. 6, the same electrode-electrolyte as in FIG. 4 shown in the third embodiment. A film laminate 13 and a pair of separators (21, 22) are provided. The electrode-electrolyte membrane laminate 13 is sandwiched between separators (21, 22). Other configurations are the same as those of the third embodiment, and thus the description thereof is omitted. In FIG. 6, the cathode electrode 8 and the anode electrode 9 are simply shown with the catalyst layers (3, 6) omitted.

  The separator 21 is for supplying an oxidant gas to the cathode electrode 8 and has an oxidant gas flow path 23 for circulating the oxidant gas. On the other hand, the separator 22 is for supplying fuel to the anode electrode 9 and has a fuel flow path 24 for circulating the fuel.

  The material of the separator (21, 22) is not particularly limited as long as it has liquid and gas barrier properties and has conductivity. For example, graphite, a metal, etc. can be mentioned.

  As will be described later, the separator (21, 22) can have a function as a current collector when used in a fuel cell in which a plurality of fuel cells 20 are stacked.

  Examples of the fuel include hydrogen, monohydric alcohols such as methanol, ethanol and propanol; alcohols such as polyhydric alcohols such as ethylene glycol and propylene glycol; ethers such as dimethyl ether; hydrazine and water. And hydrazines such as hydrazine. You may use these illustrated fuel individually or in combination of 2 or more types.

  As the fuel, an alkaline aqueous solution can be further added. Examples of the alkaline aqueous solution include KOH solution and NaOH solution. A fuel for operating the battery is prepared by mixing these alkali sources with, for example, the alcohol described above.

  The manufacturing method of the fuel battery cell 20 according to the present embodiment is different from the manufacturing method according to the third embodiment in that the separator (21, 22) is formed on the electrode-electrolyte membrane laminate 13. Is the same as that of the third embodiment, and a duplicate description is omitted.

  In the method of manufacturing the fuel battery cell 20 according to the present embodiment, the separator 21 in which the oxidant gas flow path 23 is formed is disposed so that the oxidant gas flow path 23 is in contact with the cathode electrode 8 side, and the fuel flow path 24. The fuel cell 20 shown in FIG. 6 can be manufactured by disposing the separator 22 with the fuel channel 24 in contact with the anode electrode 9 side.

(Operating principle)
The fuel cell 20 according to the present embodiment can generate power as described below.

First, oxygen (O ₂ ) is supplied to the cathode electrode 8 side via the oxidant gas flow path 23, and becomes fuel to the anode electrode 9 side via the fuel flow path 24, for example, ethanol (C ₂ H ₅ OH) supplying an aqueous solution. In the cathode electrode 8, water (H ₂ O) that has reached through the anion conductive solid polymer electrolyte membrane 10 and electrons (e ⁻ ) that have reached through an external circuit (not shown) are converted into the cathode electrode 8. The catalyst of the catalyst layer 3 reacts with the supplied oxygen to generate hydroxide ions (OH ⁻ ), and the reduction reaction of the formula (1) proceeds.
Cathode electrode: O ₂ + 2H ₂ O + 4e ⁻ → 4OH ⁻ (1)

The generated hydroxide ions move from the cathode electrode 8 side to the anode electrode 9 side through the anion conductive solid polymer electrolyte membrane 10. On the anode electrode 9 side, hydroxide ions that have passed through the anion conductive solid polymer electrolyte membrane 10 react with ethanol as fuel to generate electrons, and the oxidation reaction of formula (2) proceeds. .
Anode electrode: (1/3) C ₂ H ₅ OH + 4OH ⁻ → (2/3) CO ₂ + 3H ₂ O + 4e ⁻ (2)

The generated electrons move from the anode electrode 9 side to the cathode electrode 8 side via an external circuit (not shown) and are supplied to the cathode electrode 8. As a whole, the battery reaction of Formula (3) in which ethanol is oxidized by oxygen to generate carbon dioxide and water proceeds to generate power.
Battery reaction: (1/3) C ₂ H ₅ OH + O ₂ → (2/3) CO ₂ + H ₂ O (3)

  Carbon dioxide generated on the anode electrode 9 side is discharged to the outside together with the remaining ethanol aqueous solution. Further, the water generated on the cathode electrode 8 side is discharged to the outside as water vapor together with the remaining oxygen.

  The fuel cell 20 according to the present embodiment is provided with the anion conductive solid polymer electrolyte membrane 10. Therefore, it is possible to obtain the fuel cell 20 having high power generation efficiency by suppressing high membrane strength and permeation of organic fuel (for example, methanol crossover).

  Further, since the spacer member (2, 7) is arranged on the peripheral portion of the surface of the electrode substrate (1, 4), and the catalyst layer (3, 6) is arranged in a region surrounded by the spacer member (2, 7), Stripping of the catalyst layers (3, 6) can be suppressed. Thereby, the fuel cell 20 with high reliability and high efficiency can be obtained.

  According to the fuel battery cell 20 according to the present embodiment, by forming an uneven portion on the electrode, even if the catalyst forming paste has a low viscosity or a high viscosity, it is excellent in securing the shape when forming the catalyst layer, and the electrode is peeled off. Can be suppressed, and the electrode reaction is excellent.

[Fifth embodiment]
(Fuel cell)
In the fuel cell according to the fifth embodiment of the present invention, a plurality of fuel cells 20 similar to those in FIG. 6 shown in the fourth embodiment are stacked. The other configuration is the same as that of the fourth embodiment, and a description thereof will be omitted.

  The fuel cell according to the present embodiment is configured by stacking a plurality of fuel cells 20 via separators (21, 22).

  The fuel cell manufacturing method according to the present embodiment is different from the manufacturing method according to the fourth embodiment in that a method of stacking a plurality of fuel cells 20 is the same as in the fourth embodiment. Because of this, duplicate explanation is omitted.

  In the method of manufacturing a fuel cell according to the present embodiment, for example, a fuel cell can be manufactured by stacking the fuel cells 20 so that the adjacent separators (21, 22) have different electrical polarities. it can.

  According to the fuel cell according to the present embodiment, by forming an uneven portion on the electrode, even when the catalyst forming paste has a low viscosity or a high viscosity, it is excellent in securing the shape when forming the catalyst layer and suppresses peeling of the electrode. It is excellent in electrode reaction.

[Other embodiments]
The present invention has been described in detail with the first to fifth embodiments described above. However, for those skilled in the art, the present invention is limited to the first to fifth embodiments described in this specification. Obviously it is not. The present invention can be implemented as modifications and changes without departing from the spirit and scope of the present invention defined by the description of the scope of claims. Therefore, the description of the present specification is for illustrative purposes and does not have any limiting meaning to the present invention. Hereinafter, modified embodiments in which the first to fifth embodiments described above are partially modified will be described.

  For example, it is possible to change dimensions such as the thickness of the constituent members and the constituent materials.

  In the electrode-electrolyte membrane laminate 13 according to the third embodiment described above, the anion conductive solid polymer electrolyte membrane 10 has been described as an electrolyte, but the electrolyte is impregnated with an alkaline solution or an alkaline solution. The present invention can also be applied to an alkaline porous body.

  Hereinafter, the present invention will be described more specifically based on examples. However, the present invention is not limited to these examples, and various modifications can be made without departing from the scope of the present invention.

[Example 1]
(Catalyst paste)
First, a 5% by mass ion (hydroxide ion) using 1-methoxyethane as a solvent by amination of a chloromethyl compound of a copolymer of aromatic polyether sulfonic acid and aromatic polythioether sulfonic acid. 100 g of conductive electrolyte solution was obtained.

  Then, 10 g of silver-supporting carbon (Ag: 40% by mass, manufactured by E-TEK), 10 g of the 5% by mass ion conductive electrolyte solution obtained above, polytetrafluoroethylene (60% by mass dispersion, manufactured by Aldrich) ) 5 g and 10 g of ethanol were blended and stirred and mixed in a disperser to prepare a cathode electrode 8 side catalyst paste composition.

  Further, 10 g of nickel-supporting carbon (Ni: 40% by mass), 10 g of the 5% by mass ion conductive electrolyte solution obtained above, 5 g of polytetrafluoroethylene (60% by mass dispersion, manufactured by Aldrich), and 10 g of ethanol. The anode electrode 9 side catalyst paste composition was prepared by mixing and stirring and mixing with a disperser.

(electrode)
Next, as the electrode substrate 1 on the cathode electrode 8 side, a metal foam (made by Mitsubishi Materials Corporation, thickness: 500 μm) made of 23 mm square silver was used. A rectangular frame having a width of about 1 mm and a height of about 200 μm is formed on the periphery of the surface of the metal foam with a paste made of epoxy resin (Adeka, Adeka Resin EP-49) and carbon particles (Cabot, Vulcan XC72). The spacer member 2 was formed by coating by screen printing. Next, the cathode electrode 8 side catalyst paste composition prepared above was filled in the region surrounded by the spacer member 2 and dried. After drying, the cathode electrode 8 was formed by pressing at about 1 MPa at room temperature for 30 seconds with a press device. The amount of catalyst applied was adjusted to 5 mg / cm ² .

As the electrode substrate 4 on the anode electrode 9 side, a metal foam (made by Mitsubishi Materials Corporation, thickness: 500 μm) made of 23 mm square nickel was used. A rectangular frame having a width of about 1 mm and a height of about 200 μm is formed on the periphery of the surface of the metal foam with a paste made of epoxy resin (Adeka, Adeka Resin EP-49) and carbon particles (Cabot, Vulcan XC72). The spacer member 7 was formed by coating by screen printing. Subsequently, the area surrounded by the spacer member 7 was filled with the anode electrode 9 side catalyst paste composition prepared above and dried. After drying, the anode electrode 9 was formed by pressing at about 1 MPa at room temperature for 30 seconds with a press device. The coating amount of the catalyst was adjusted to 20 mg / cm ² .

(Electrode-electrolyte membrane laminate)
As anion conductive solid polymer electrolyte membrane 10, Aciplex A-221 (thickness 130 to 190 μm, manufactured by Asahi Kasei Co., Ltd.) was used. After the cathode electrode 8 and the anode electrode 9 prepared above are arranged on both main surfaces of the anion conductive solid polymer electrolyte membrane 10, respectively, they are thermally bonded at about 60 ° C. and about 1 MPa by hot pressing. An electrode-electrolyte membrane laminate 13 as shown in FIG.

[Example 2]
An electrode-electrolyte membrane laminate 13 was produced in the same manner as in Example 1 except that the spacer member 5 was formed on each surface of the electrode base material (1, 4) as follows. That is, the spacer member 5 was formed by forming the spacer member 5 having a rectangular parallelepiped shape with a width of about 1 mm and a height of about 200 μm on each surface of the electrode base material (1, 4) at a spacing of about 2 mm. Here, the amount of the catalyst applied was the same as in Example 1.

[Example 3]
The electrode-electrolyte membrane laminate 13 was prepared in the same manner as in Example 1 except that carbon cloth (manufactured by E-TEK, LT-1200W) was used in place of the electrode base material 1 of the cathode electrode 8 instead of the metal foam. Produced.

[Example 4]
The electrode-electrolyte membrane laminate 13 is formed in the same manner as in Example 2 except that carbon cloth (LT-1200W, manufactured by E-TEK Co.) is used instead of the electrode base material 1 of the cathode electrode 8 instead of the metal foam. Produced.

[Comparative Example 1]
An electrode-electrolyte membrane laminate 13 was produced in the same manner as in Example 1 except that the spacer member (2, 5, 7) was not formed on the surface of the electrode substrate (1, 4).

[Comparative Example 2]
As the electrode base material (1, 4), carbon cloth (manufactured by E-TEK, LT-1200W) in which the spacer member (2, 5, 7) is not formed on both the anode electrode 9 side and the cathode electrode 8 side was used. Except for the above, an electrode-electrolyte membrane laminate 13 was produced in the same manner as in Example 1.

(Performance evaluation)
Separators (21, 22) are respectively disposed on both main surfaces of the electrode-electrolyte membrane laminate 13 obtained in Examples 1 to 4 and Comparative Examples 1 and 2, and a fuel cell 20 as shown in FIG. Fabrication and performance evaluation were performed by examining electromotive force and maximum output density. A power generation test was performed by supplying an oxygen gas to the oxidant gas flow path 23 of the cathode electrode 8 side separator 21 and an ethanol aqueous solution to the fuel flow path 24 of the anode electrode 9 side separator 22.
As a result, Examples 1 to 4 showed higher performance than Comparative Examples 1 and 2 both in electromotive force and maximum output density.

DESCRIPTION OF SYMBOLS 1,4 ... Electrode base material 2,5,7 ... Spacer member 3,6 ... Catalyst layer 8 ... Cathode electrode 9 ... Anode electrode 10 ... Anion conductive solid polymer electrolyte Membrane 11, 12A, 12B, 12C ... Electrode 13 ... Electrode-electrolyte membrane laminate 20 ... Fuel cell 21, 22 ... Separator 23 ... Oxidant gas flow path 24 ... Fuel Flow path

Claims (4)

Forming a spacer member on the peripheral edge of the electrode substrate surface;
Applying a catalyst paste to a region surrounded by the spacer member;
After drying the catalyst paste, forming a catalyst layer by pressure bonding to the electrode substrate surface at room temperature ;
A method for producing an electrode for a fuel cell, comprising:   An electrode-electrolyte membrane laminate production method for producing an electrode-electrolyte membrane laminate by sandwiching an anion conductive solid polymer electrolyte membrane between a spacer member and a fuel cell electrode,
  In the process of manufacturing the fuel cell electrode,
  Forming the spacer member on the peripheral edge of the electrode substrate surface;
  Applying a catalyst paste to a region surrounded by the spacer member;
  After drying the catalyst paste, press-bonding to the electrode substrate surface to form a catalyst layer;
  Is included
  A method for producing an electrode-electrolyte membrane laminate, comprising:   A fuel cell is produced by sandwiching an electrode-electrolyte membrane laminate produced by the electrode-electrolyte membrane laminate production method according to claim 2 between a pair of separators. Method.   A method of manufacturing a fuel cell, comprising manufacturing a fuel cell by stacking a plurality of fuel cells manufactured by the method of manufacturing a fuel cell according to claim 3.

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