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WO2014174973A1 - Corps d'électrode à diffusion gazeuse, son procédé de fabrication, ensemble membrane-électrode pour pile à combustible utilisant celui-ci, et pile à combustible - Google Patents

Corps d'électrode à diffusion gazeuse, son procédé de fabrication, ensemble membrane-électrode pour pile à combustible utilisant celui-ci, et pile à combustible Download PDF

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Publication number
WO2014174973A1
WO2014174973A1 PCT/JP2014/058694 JP2014058694W WO2014174973A1 WO 2014174973 A1 WO2014174973 A1 WO 2014174973A1 JP 2014058694 W JP2014058694 W JP 2014058694W WO 2014174973 A1 WO2014174973 A1 WO 2014174973A1
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Prior art keywords
gas diffusion
catalyst
electrode body
diffusion electrode
fuel cell
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English (en)
Japanese (ja)
Inventor
圭 小野
慎二 宮川
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Nissan Motor Co Ltd
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Nissan Motor Co Ltd
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
    • H01M4/8605—Porous electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
    • H01M4/88—Processes of manufacture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • H01M8/1004—Fuel cells with solid electrolytes characterised by membrane-electrode assemblies [MEA]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • H01M2008/1095—Fuel cells with polymeric electrolytes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present invention relates to a gas diffusion electrode body, a manufacturing method thereof, a membrane electrode assembly for a fuel cell using the same, and a fuel cell.
  • a fuel cell is a clean power generation system in which the product of an electrode reaction is water in principle and has almost no adverse effect on the global environment.
  • a polymer electrolyte fuel cell (PEFC) is expected as a power source for electric vehicles because it operates at a relatively low temperature.
  • the polymer electrolyte fuel cell has a structure in which a plurality of single cells that exhibit a power generation function are stacked.
  • This single cell includes a polymer-electrolyte membrane, a membrane-electrode assembly (MEA) having a pair of catalyst layers and a pair of gas diffusion layers (GDL) that are sequentially formed on both sides of the membrane. And MEA which each single cell has is electrically connected with MEA of an adjacent single cell through a separator.
  • MEA which each single cell has is electrically connected with MEA of an adjacent single cell through a separator.
  • a fuel cell stack is comprised by laminating
  • the fuel cell stack functions as power generation means that can be used for various applications.
  • an electrolyte membrane in which a polymer solid electrolyte resin is contained in a porous pore portion of expanded porous polytetrafluoroethylene (ePTFE), and an electrode in which a gap between ePTFE is filled with an electrode catalyst and a polymer solid electrolyte
  • ePTFE expanded porous polytetrafluoroethylene
  • Patent Document 1 An MEA having the above is disclosed (for example, Patent Document 1). According to the above configuration, it is described that the electrolyte membrane is thinned, and the generated ions in the catalyst layer are rapidly moved, the gas diffusibility is good, and the reactivity and strength can be improved.
  • ePTFE has a problem that the distance between micronodules is short and the pore diameter is small, so that the material transportability is poor and the power generation performance is insufficient.
  • the present invention has been made in view of the above circumstances, and an object thereof is to provide a gas diffusion electrode body having excellent material transportability.
  • the present inventors have found that the above-mentioned problems can be solved by including a polymer electrolyte and an electrode catalyst in a non-conductive nonwoven fabric or woven fabric.
  • FIG. 1 is a polymer electrolyte fuel cell (PEFC); 2 is a solid polymer electrolyte membrane; 3a is an anode gas diffusion electrode body; 3c is a cathode gas diffusion electrode body; 8a is an anode separator; 8c is a cathode separator; 9a is an anode gas flow path; 9c is a cathode gas flow path; 10 is an MEA; and 11 is a refrigerant flow path.
  • PEFC polymer electrolyte fuel cell
  • 2 is a solid polymer electrolyte membrane
  • 3a is an anode gas diffusion electrode body
  • 3c is a cathode gas diffusion electrode body
  • 8a is an anode separator
  • 8c is a cathode separator
  • 9a is an anode gas flow path
  • 9c is a cathode gas flow path
  • 10 is an MEA
  • 11 is a refrigerant flow path.
  • the gas diffusion electrode body of the present invention is characterized in that a polymer electrolyte and an electrode catalyst are held in a nonconductive nonwoven fabric or woven fabric. Since the non-conductive nonwoven fabric or woven fabric is a continuous porous structure in which pores are continuously present, the ratio of the pores is higher than the conventional one. For this reason, the gas diffusion electrode body which uses a nonelectroconductive nonwoven fabric or a textile fabric can improve substance transportability (for example, gas diffusion property). The pores of the non-conductive nonwoven fabric or woven fabric have a size that can pass through the polymer electrolyte and the electrode catalyst.
  • the gas diffusion electrode body can ensure sufficient conductivity. Therefore, the fuel cell using the gas diffusion electrode body is excellent in power generation performance.
  • the non-woven fabric or the woven fabric is non-conductive, the range of materials that can be used is widened.
  • the gas diffusion electrode body also functions as a catalyst layer. Therefore, the gas diffusion electrode body of the present invention can fulfill both functions of the catalyst layer and the gas diffusion layer in one layer. For this reason, size reduction of a fuel cell can also be achieved by using the gas diffusion electrode body of the present invention.
  • the present invention also provides a fuel cell membrane electrode assembly having the gas diffusion electrode assembly of the present invention and a fuel cell including the fuel cell membrane electrode assembly.
  • the membrane electrode assembly for a fuel cell of the present invention can ensure sufficient material transportability by using a non-conductive nonwoven fabric or woven fabric that can ensure a pore diameter as a base material of a gas diffusion electrode body. For this reason, the fuel cell using a gas diffusion electrode body is excellent in power generation performance.
  • the membrane electrode assembly is generally produced by a direct coating method or a transfer method.
  • MEA is produced by applying catalyst ink directly to a polymer electrolyte membrane and then drying.
  • this method has a problem that the solvent derived from the catalyst ink penetrates into the electrolyte membrane and the dimensional stability deteriorates.
  • the polymer electrolyte and the electrode catalyst are previously held on a non-conductive nonwoven fabric or woven fabric.
  • the MEA can be easily produced by pressing the gas diffusion electrode body on the electrolyte membrane, and the catalyst ink is not brought into contact with the electrolyte membrane, so that the dimensional stability of the electrolyte membrane (and hence MEA) can be improved.
  • an MEA is produced by hot pressing after sandwiching a polymer electrolyte membrane between two sheets of a catalyst ink coated and dried on a transfer substrate.
  • this method has problems such as a decrease in yield due to transfer failure during transfer processing, and generation of a transfer substrate as a discarded material.
  • the polymer electrolyte and the electrode catalyst are held in advance in a non-conductive nonwoven fabric or woven fabric.
  • a gas diffusion electrode body can be produced simply by immersing and drying a non-conductive nonwoven fabric or woven fabric in a solution containing a low-viscosity polymer electrolyte and an electrode catalyst. For this reason, the viscosity control of a solution and the thickener for raising a viscosity are unnecessary, and the special stirrer for making it high viscosity is also unnecessary.
  • the drying condition and the solvent type are limited.
  • the gas diffusion electrode body is manufactured and then pressure-bonded to the electrolyte membrane, the range of drying conditions and solvent selection is widened.
  • X to Y indicating a range means “X or more and Y or less”, “weight” and “mass”, “weight%” and “mass%”, “part by weight” and “weight part”. “Part by mass” is treated as a synonym. Unless otherwise specified, measurement of operation and physical properties is performed under conditions of room temperature (20 to 25 ° C.) / Relative humidity 40 to 50%.
  • FIG. 1 is a schematic diagram showing a basic configuration of a polymer electrolyte fuel cell (PEFC) 1 according to a first embodiment of the present invention.
  • the PEFC 1 first has a polymer electrolyte membrane 2 and a pair of gas diffusion electrode bodies (anode gas diffusion electrode body 3a and cathode gas diffusion electrode body 3c) sandwiching the polymer electrolyte membrane 2.
  • the polymer electrolyte membrane 2 and the pair of gas diffusion electrode bodies (3a, 3c) constitute a membrane electrode assembly (MEA) 10 in a stacked state.
  • MEA membrane electrode assembly
  • MEA 10 is further sandwiched between a pair of separators (anode separator 8a and cathode separator 8c).
  • the separators (8 a, 8 c) are illustrated so as to be positioned at both ends of the illustrated MEA 10.
  • the separator is generally used as a separator for an adjacent PEFC (not shown).
  • the MEAs are sequentially stacked via the separator to form a stack.
  • a gas seal portion is disposed between the separators (8a, 8c) and the polymer electrolyte membrane 2, or between the PEFC 1 and another adjacent PEFC. In 1, these descriptions are omitted.
  • the separators (8a, 8c) are obtained, for example, by forming a concavo-convex shape as shown in FIG. 1 by subjecting a thin plate having a thickness of 0.5 mm or less to a press treatment.
  • the protrusions seen from the MEA side of the separators (8a, 8c) are in contact with the MEA10. Thereby, the electrical connection with MEA10 is ensured.
  • a recess (space between the separator and the MEA generated due to the concavo-convex shape of the separator) viewed from the MEA side of the separator (8a, 8c) is a gas for circulating gas during operation of the PEFC 1 Functions as a flow path. Specifically, fuel gas (for example, hydrogen) is circulated through the gas flow path 9a of the anode separator 8a, and oxidant gas (for example, air) is circulated through the gas flow path 9c of the cathode separator 8c.
  • fuel gas for example, hydrogen
  • the recess viewed from the side opposite to the MEA side of the separators (8a, 8c) serves as a refrigerant flow path 11 for circulating a refrigerant (for example, water) for cooling the PEFC during operation of the PEFC 1.
  • the separator is usually provided with a manifold (not shown). This manifold functions as a connection means for connecting cells when a stack is formed. With such a configuration, the mechanical strength of the fuel cell stack can be ensured.
  • the separators (8a, 8c) are formed in an uneven shape.
  • the separator is not limited to such a concavo-convex shape, and may be any form such as a flat plate shape and a partially concavo-convex shape as long as the functions of the gas flow path and the refrigerant flow path can be exhibited. Also good.
  • the gas diffusion electrode bodies (3a, 3c) function as both a catalyst layer and a gas diffusion layer. For this reason, a gas diffusion layer (GDL) (gas diffusion layer, fine porous layer) is not necessarily required separately. However, if necessary, the PEFC 1 has a gas diffusion layer (GDL) (gas diffusion substrate, fine porous layer) between the gas diffusion electrode bodies (3a, 3c) and the separators (8a, 8c). (MPL)) may be included separately.
  • GDL gas diffusion layer, fine porous layer
  • the gas diffusion electrode bodies (anode gas diffusion electrode body 3a and cathode gas diffusion electrode body 3c) of the present invention are arranged on both the cathode and anode sides.
  • the present invention is not limited to the above form. That is, the gas diffusion electrode body of the present invention may be disposed on at least one side of the cathode and the anode. Preferably, the gas diffusion electrode body of the present invention is disposed at least on the cathode side, and more preferably disposed on both the cathode and anode sides.
  • the gas diffusion electrode bodies are layers in which the battery reaction actually proceeds. Specifically, the oxidation reaction of hydrogen proceeds in the anode catalyst layer 3a, and the reduction reaction of oxygen proceeds in the cathode catalyst layer 3c. For this reason, ePTFE as described in the said patent document 1 is not included in the nonwoven fabric of this invention.
  • the gas diffusion electrode body has a structure in which a polymer electrolyte and an electrode catalyst are held in a non-conductive nonwoven fabric or woven fabric.
  • the gas diffusion electrode body has a structure in which a polymer electrolyte and an electrode catalyst are held by a non-conductive nonwoven fabric.
  • nonwoven fabric means a laminate of fibers.
  • the material constituting the nonconductive nonwoven fabric or woven fabric is not particularly limited as long as it is nonconductive.
  • glass, polymer resin fiber, cellulose and the like can be mentioned. Of these, glass and polymer resin fibers are preferred. Although it does not restrict
  • the said material may be used individually by 1 type, or may be used with the form of 2 or more types of mixtures. That is, the nonconductive nonwoven fabric or woven fabric is preferably formed from at least one selected from the group consisting of glass, polymer resin fibers, and cellulose.
  • the thickness of the non-conductive nonwoven fabric or woven fabric is not particularly limited. Specifically, the thickness of the non-conductive nonwoven fabric or woven fabric (when loaded with 19.6 kPa) is preferably 5 to 500 ⁇ m, more preferably 25 to 250 ⁇ m.
  • the size of the fibers constituting the nonconductive nonwoven fabric or woven fabric is not particularly limited. Specifically, the thickness (diameter) of the fiber is preferably 0.01 to 100 ⁇ m, more preferably 0.1 to 25 ⁇ m. If it is such a magnitude
  • the method for producing the nonconductive nonwoven fabric or woven fabric is not particularly limited.
  • the nonconductive nonwoven fabric can be produced by a dry method, a wet papermaking method, a spunbond method, or the like.
  • a nonelectroconductive textile fabric can be produced with a well-known weaving method.
  • the production conditions of the non-conductive nonwoven fabric or woven fabric are not particularly limited, but for example, the basis weight is preferably 1 to 50 g / m 2 , and more preferably 5 to 25 g / m 2 .
  • the density of the nonconductive nonwoven fabric or woven fabric is preferably 0.05 to 1.0 g / cm 3 , more preferably 0.1 to 0.4 g / cm 3 .
  • the non-conductive nonwoven fabric or woven fabric can obtain an appropriate porosity (for example, 60 to 97.5%).
  • porosity of a nonelectroconductive nonwoven fabric or a woven fabric is the said range, gas diffusibility and electroconductivity can be improved, ensuring intensity
  • the non-conductive nonwoven fabric or woven fabric preferably has pores of a size that can pass through the polymer electrolyte or the electrode catalyst, preferably the electrode catalyst.
  • an electrode catalyst especially conductive support
  • the size of the pores of the non-conductive non-woven fabric or woven fabric is not particularly limited as long as it can pass through the electrode catalyst.
  • the pore diameter of the non-conductive nonwoven fabric or woven fabric is preferably 1.2 to 100 times, more preferably 1.5 to 20 times, particularly preferably 2 to 5 times the average particle diameter of the electrode catalyst. is there. If the pores have such a size, a sufficient amount of electrode catalyst can be continuously arranged in the pores (in contact with each other), so that the gas diffusion electrode body has sufficient conductivity and catalytic activity. Can demonstrate.
  • the “particle size of the electrode catalyst” means the average secondary particle size of the electrode catalyst.
  • a value calculated as the median value of the particle diameter of the electrode catalyst observed with a laser diffraction / scattering particle size distribution analyzer is adopted.
  • the pore diameter of the non-conductive nonwoven fabric or woven fabric is preferably 100 ⁇ m or less, more preferably 1 to 50 ⁇ m, more preferably 5 to 25 ⁇ m, and particularly preferably 5 to 10 ⁇ m. . Within such a range, the strength of the gas diffusion electrode body can be sufficiently secured, and even in a fuel cell stack in which a plurality of MEAs are laminated, no hole is caused by local reverse cell reaction or deterioration.
  • the “pore diameter” of the non-conductive nonwoven fabric or woven fabric is an average pore diameter ( ⁇ m) calculated from the bubble point.
  • a non-conductive non-woven fabric or woven fabric (sample) is dipped in isopropyl alcohol for 10 minutes or more in advance, it is placed horizontally and attached to a test tank, and isopropyl alcohol is placed in the tank up to a height of 15 mm at the upper end of the sample. pour it up.
  • the air pressure inside the sample is gradually increased from zero, bubbles are first generated from the medium, and the air pressure when the bubbles are continuously generated is read with a manometer. Further increase the air flow rate, measure the air flow rate and air pressure, and continue until the rate of change of the air flow rate becomes almost constant.
  • the non-conductive nonwoven fabric or woven fabric may be a commercially available product.
  • a porous glass manufactured by Nippon Sheet Glass Co., Ltd., trade name: TGP-015A
  • a polymer nonwoven fabric manufactured by Sanki, trade name: Delpore P1001-20B
  • the like can be used.
  • the electrode catalyst is composed of a catalyst component and a conductive carrier (catalyst carrier) carrying the catalyst component.
  • the catalyst component used in the anode gas diffusion electrode body is not particularly limited as long as it has a catalytic action in the oxidation reaction of hydrogen, and a known catalyst can be used in the same manner.
  • the catalyst component used in the cathode gas diffusion electrode body is not particularly limited as long as it has a catalytic action for the oxygen reduction reaction, and a known catalyst can be used in the same manner. Specifically, it may be selected from metals such as platinum, ruthenium, iridium, rhodium, palladium, osmium, tungsten, lead, iron, chromium, cobalt, nickel, manganese, vanadium, molybdenum, gallium, aluminum, and alloys thereof. .
  • those containing at least platinum are preferably used in order to improve catalytic activity, poisoning resistance to carbon monoxide, heat resistance, and the like.
  • the composition of the alloy depends on the type of metal to be alloyed, the content of platinum is preferably 30 to 90 atomic%, and the content of the metal to be alloyed with platinum is preferably 10 to 70 atomic%.
  • an alloy is a generic term for a metal element having one or more metal elements or non-metal elements added and having metallic properties.
  • the alloy structure consists of a eutectic alloy, which is a mixture of the component elements as separate crystals, a component element completely melted into a solid solution, and a component element composed of an intermetallic compound or a compound of a metal and a nonmetal.
  • the catalyst component used for the anode gas diffusion electrode body and the catalyst component used for the cathode gas diffusion electrode body can be appropriately selected from the above.
  • the descriptions of the catalyst components for the anode gas diffusion electrode body and the cathode gas diffusion electrode body have the same definition for both. Therefore, they are collectively referred to as “catalyst components”.
  • the catalyst components of the anode gas diffusion electrode body and the cathode gas diffusion electrode body do not have to be the same, and can be appropriately selected so as to exhibit the desired action as described above.
  • the shape and size of the catalyst component are not particularly limited, and the same shape and size as known catalyst components can be adopted.
  • the catalyst component may be granular, scale-like, or layered, but is preferably granular.
  • the average particle diameter of the catalyst particles is preferably 1 to 30 nm, more preferably 1 to 10 nm, still more preferably 1 to 5 nm, and particularly preferably 2 to 4 nm. When the average particle diameter of the catalyst particles is within such a range, the balance between the catalyst utilization rate related to the effective electrode area where the electrochemical reaction proceeds and the ease of loading can be appropriately controlled.
  • the “average particle diameter of the catalyst particles” in the present invention is the crystallite diameter determined from the half-value width of the diffraction peak of the catalyst component in X-ray diffraction, or the particle diameter of the catalyst component determined by a transmission electron microscope (TEM). It can be measured as an average value of.
  • the catalyst component described above is included in the catalyst ink as an electrode catalyst supported on a conductive carrier.
  • the conductive carrier functions as a carrier for supporting the above-described catalyst component and an electron conduction path involved in the transfer of electrons between the catalyst component and another member.
  • the conductive carrier may have any specific surface area for supporting the catalyst particles in a desired dispersed state and has sufficient electronic conductivity as a current collector.
  • the main component is carbon. Preferably there is.
  • “the main component is carbon” refers to containing a carbon atom as a main component, and is a concept including both a carbon atom only and a substantially carbon atom.
  • elements other than carbon atoms may be included in order to improve the characteristics of the fuel cell. Incidentally, being substantially composed of carbon atoms means that contamination of impurities of about 2 to 3% by weight or less is allowed.
  • conventionally known materials such as carbon black, graphite (including granular graphite), and expanded graphite can be appropriately employed.
  • carbon black such as oil furnace black, channel black, lamp black, thermal black, acetylene black and the like can be preferably used because of excellent conductivity and a large specific surface area.
  • carbon particles commercially available products can be used, such as Vulcan XC-72, Vulcan P, Black Pearls 880, Black Pearls 1100, Black Pearls 1300, Black Pearls 2000, Regal 400, Lion Corporation Black EC, Oil Furnace Black such as # 3150 and # 3250 manufactured by Mitsubishi Chemical Corporation; Denka Black manufactured by Denki Kagaku Kogyo Co., and acetylene black such as acetylene black AB-6 manufactured by Denki Kagaku Kogyo Co., Ltd.
  • artificial graphite or carbon obtained from an organic compound such as activated carbon, natural graphite, pitch, coke, polyacrylonitrile, phenol resin, or furan resin may be used.
  • the conductive carrier may be used alone or in the form of a mixture of two or more.
  • the particle size of the conductive carrier is not particularly limited. Considering the relationship with the pore size of the non-conductive nonwoven fabric or woven fabric, the particle size (average primary particle size) of the conductive carrier is preferably 5 to 200 nm, and more preferably 10 to 100 nm. If it is such a range, an electroconductive support
  • the shape of the conductive carrier is not particularly limited, and may have any structure such as a spherical shape, a rod shape, a needle shape, a plate shape, a column shape, an indefinite shape, a flake shape, and a spindle shape, but a granular shape is preferable.
  • the size of the conductive carrier can be measured by a known method. In this specification, unless otherwise specified, a statistically significant number of fields of view (for example, several to several tens of fields of view) using observation means such as a scanning electron microscope (SEM) or a transmission electron microscope (TEM) is used. ) The value calculated as the average value of the particle diameters (diameters) of the particles observed in the above is adopted.
  • the “particle diameter” means the maximum distance among the distances between any two points on the particle outline.
  • the BET specific surface area of the conductive carrier may be a specific surface area sufficient to support the catalyst component in a highly dispersed state, but is preferably 20 to 1600 m 2 / g, more preferably 80 to 1200 m 2 / g. Is good. When the specific surface area is in the above range, the catalyst component and the polymer electrolyte are sufficiently dispersed on the conductive support to obtain sufficient power generation performance, and the catalyst component and the polymer electrolyte can be sufficiently effectively used. .
  • the supported amount of the catalyst component is preferably 10 to 80% by weight, more preferably 30 to 70% by weight, based on the total amount of the electrode catalyst. Good.
  • the supported amount of the catalyst component is within such a range, the balance between the degree of dispersion of the catalyst component on the catalyst support and the catalyst performance can be appropriately controlled.
  • the amount of the catalyst component supported can be examined by inductively coupled plasma emission spectroscopy (ICP).
  • ICP inductively coupled plasma emission spectroscopy
  • the catalyst component can be supported on the conductive support by a known method.
  • a commercially available electrode catalyst may be used.
  • a platinum catalyst for example, trade name: TEC10E40E, TEC10E50E, TEC10E60TPM, TEC10E70TPM, TEC10V30E, TEC10V40E, TEC10V50E, etc.
  • a catalyst for example, trade names: TEC66E50, TEC61E54, TEC62E58, etc.
  • TEC66E50, TEC61E54, TEC62E58, etc. can be used.
  • the content (mg / cm 2 ) of the electrode catalyst per unit catalyst application area is not particularly limited, but in view of sufficient dispersibility of the catalyst on the carrier, power generation performance, etc., 0.01 to 1. 0 mg / cm 2 .
  • the platinum content per unit catalyst coating area is preferably 0.5 mg / cm 2 or less.
  • the use of expensive noble metal catalysts typified by platinum (Pt) and platinum alloys has become a high cost factor for fuel cells. Therefore, it is preferable to reduce the amount of expensive platinum used (platinum content) to the above range and reduce the cost.
  • the lower limit is not particularly limited as long as power generation performance is obtained, and is, for example, 0.01 mg / cm 2 or more.
  • the platinum content is 0.05 to 0.30 mg / cm 2 .
  • inductively coupled plasma emission spectroscopy is used for measurement (confirmation) of “catalyst (platinum) content per unit catalyst application area (mg / cm 2 )”.
  • a person skilled in the art can easily carry out a method of making the desired “catalyst (platinum) content per unit catalyst coating area (mg / cm 2 )”, and control the ink composition (catalyst concentration) and coating amount. You can adjust the amount.
  • the content of the electrode catalyst is not particularly limited.
  • the content of the electrode catalyst is preferably 2.5 to 40% by volume, more preferably 5 to 25% by volume with respect to the gas diffusion electrode body. With such an electrode catalyst content, a sufficient conductive path can be formed, and good material diffusibility is ensured, so that excellent performance can be exhibited.
  • the gas diffusion electrode body includes an ion conductive polymer electrolyte in addition to the electrode catalyst.
  • the polymer electrolyte is not particularly limited, and conventionally known knowledge can be referred to as appropriate.
  • the ion exchange resin which comprises the catalyst layer mentioned above can be used conveniently as a polymer electrolyte.
  • the polymer electrolyte held in the non-conductive nonwoven fabric or woven fabric together with the electrode catalyst is not particularly limited, and conventionally known knowledge can be referred to as appropriate.
  • Polymer electrolytes are roughly classified into fluorine-based polymer electrolytes and hydrocarbon-based polymer electrolytes depending on the type of ion exchange resin that is a constituent material.
  • the fluoropolymer electrolyte include perfluorocarbon sulfonic acid polymers such as Nafion (registered trademark, manufactured by DuPont), Aciplex (registered trademark, manufactured by Asahi Kasei Co., Ltd.), and Flemion (registered trademark, manufactured by Asahi Glass Co., Ltd.).
  • Perfluorocarbon phosphonic acid polymer trifluorostyrene sulfonic acid polymer, ethylene tetrafluoroethylene-g-styrene sulfonic acid polymer, ethylene-tetrafluoroethylene copolymer, polyvinylidene fluoride-perfluorocarbon sulfonic acid polymer, etc. Is mentioned.
  • hydrocarbon electrolytes include sulfonated polyethersulfone (S-PES), sulfonated polyaryletherketone, sulfonated polybenzimidazole alkyl, phosphonated polybenzimidazole alkyl, sulfonated polystyrene, sulfone.
  • the polymer electrolyte preferably contains a fluorine atom because it is excellent in heat resistance, chemical stability, and the like.
  • fluorine-based electrolytes such as Nafion (registered trademark, manufactured by DuPont), Aciplex (registered trademark, manufactured by Asahi Kasei Co., Ltd.), Flemion (registered trademark, manufactured by Asahi Glass Co., Ltd.), and the like.
  • the said polymer electrolyte only 1 type may be used independently and 2 or more types may be used together. Moreover, it is not restricted only to the material mentioned above, Other materials may be used.
  • the content of the polymer electrolyte is not particularly limited.
  • the content of the polymer electrolyte is preferably 1.0 to 30% by volume, more preferably 2.5 to 20% by volume with respect to the gas diffusion electrode body. With such an amount, the gas diffusion electrode body can exhibit sufficient ion conductivity and conductivity.
  • the mixing ratio of the polymer electrolyte and the electrode catalyst is not particularly limited.
  • the polymer electrolyte is arranged (blended) so as to be an electrode catalyst, preferably in a proportion of 0.1 to 2 parts by mass, more preferably 0.3 to 1.4 parts by mass with respect to 100 parts by weight of the electrode catalyst. To do. With such an amount, the gas diffusion electrode body can exhibit sufficient ion conductivity, conductivity and catalytic activity.
  • the gas diffusion electrode body is formed by holding a conductive carrier on a non-conductive nonwoven fabric or woven fabric, but may further contain other additives.
  • the additive is not particularly limited, and examples thereof include a dispersant, a dispersion aid, a water repellent, and a binding binder. These additives may be used alone or in combination of two or more.
  • the gas diffusion electrode body preferably contains a water repellent for the purpose of further improving water repellency and preventing flooding.
  • the water repellent is not particularly limited, but fluorine-based high repellents such as polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), polyhexafluoropropylene, and tetrafluoroethylene-hexafluoropropylene copolymer (FEP).
  • PTFE polytetrafluoroethylene
  • PVdF polyvinylidene fluoride
  • FEP tetrafluoroethylene-hexafluoropropylene copolymer
  • Molecular materials; thermoplastic resins such as polyethylene and polypropylene are listed.
  • fluorine-based polymer materials are preferably used because of their excellent water repellency and corrosion resistance during electrode reaction.
  • the polymer electrolyte is a fluorine electrolyte
  • the polymer electrolyte can also act as a water repellent.
  • the content (addition amount) of the water repellent is not particularly limited.
  • other additives are preferably mixed in an amount of about 1 to 10 parts by weight with respect to 100 parts by weight of the conductive carrier. With such an amount, the gas diffusion electrode body satisfies both conductivity and water repellency.
  • the gas diffusion electrode body may further contain conductive carbon (no catalyst component supported).
  • conductive carbon no catalyst component supported.
  • the conductivity of the gas diffusion electrode body can be improved. For this reason, when the amount of the electrode catalyst is small, it is preferable to use conductive carbon for the purpose of ensuring conductivity.
  • the conductive carbon is not particularly limited, and conventionally known materials such as carbon black, graphite (including granular graphite), and expanded graphite can be appropriately employed.
  • carbon black such as oil furnace black, channel black, lamp black, thermal black, acetylene black and the like can be preferably used because of excellent conductivity and a large specific surface area.
  • carbon particles commercially available products can be used, such as Vulcan XC-72, Vulcan P, Black Pearls 880, Black Pearls 1100, Black Pearls 1300, Black Pearls 2000, Regal 400, Lion Corporation Black EC, Oil Furnace Black such as # 3150 and # 3250 manufactured by Mitsubishi Chemical Corporation; Denka Black manufactured by Denki Kagaku Kogyo Co., and acetylene black such as acetylene black AB-6 manufactured by Denki Kagaku Kogyo Co., Ltd.
  • artificial graphite or carbon obtained from organic compounds such as natural graphite, pitch, coke, polyacrylonitrile, phenol resin, furan resin may be used.
  • the conductive carbon may be used alone or in the form of a mixture of two or more.
  • the size of the conductive carbon is not particularly limited, but is preferably a size that can pass through the pores of the non-conductive nonwoven fabric or woven fabric.
  • the conductive carbon is continuously arranged (in contact with each other) in the pores of the non-conductive nonwoven fabric or woven fabric to form a conductive path, thereby further improving the conductivity of the gas diffusion electrode body. it can.
  • the particle size (average primary particle size) of the conductive carbon is preferably 2 to 250 nm, and more preferably 10 to 100 nm.
  • the conductive carbon can be efficiently and continuously disposed in the pores of the non-conductive nonwoven fabric or woven fabric to ensure sufficient conductivity.
  • the shape of the conductive carbon is not particularly limited, and may be any structure such as a spherical shape, a rod shape, a needle shape, a plate shape, a column shape, an indefinite shape, a flake shape, or a spindle shape, but a granular shape is preferable.
  • the size of the conductive carbon can be measured by a known method.
  • a statistically significant number of fields of view (for example, several to several tens of fields of view) using observation means such as a scanning electron microscope (SEM) or a transmission electron microscope (TEM) is used.
  • SEM scanning electron microscope
  • TEM transmission electron microscope
  • the value calculated as the average value of the particle diameters (diameters) of the particles observed in the above is adopted.
  • the “particle diameter” means the maximum distance among the distances between any two points on the particle outline.
  • the ratio of the average particle diameter of the conductive carbon to the pore diameter of the non-conductive nonwoven fabric or woven fabric is 1 / 2 to 1/100 times, more preferably 1/2 to 1/20 times, even more preferably 1/3 to 1/10 times, and particularly preferably 1/3 to 1/5 times. It is. With holes of such a size, a sufficient amount of conductive carbon can be arranged continuously (in contact with each other) in the holes. For this reason, since the continuous arrangement of the conductive carbon forms a conductive path, the conductivity of the gas diffusion electrode body can be further improved.
  • particle diameter of conductive carbon means the average secondary particle diameter of conductive carbon.
  • a value calculated as the median value of the particle diameter of the particles observed with a laser diffraction / scattering particle size distribution measuring apparatus is adopted.
  • the content of conductive carbon when the gas diffusion electrode body contains conductive carbon (non-supported catalyst component) is not particularly limited. Considering improvement in conductivity, the total content of the electrode catalyst and the conductive carbon is preferably 2.5 to 40% by volume, more preferably 5 to 30% by volume with respect to the gas diffusion electrode body. .
  • the content of the electrode catalyst is in the above range, a sufficient conductive path can be formed and good material diffusibility is ensured, so that excellent performance can be exhibited.
  • the amount of the electrode catalyst is excessive, which is not preferable from the viewpoint of cost. Even in such a case, the conductive carbon can act so as to complement the provision of conductivity by the electrode catalyst. For this reason, especially when there are few compounding quantities of an electrode catalyst, it is especially preferable from a viewpoint of electroconductivity provision to further arrange
  • the thickness of the gas diffusion electrode body is not particularly limited, but is preferably 5 to 500 ⁇ m, and more preferably 25 to 250 ⁇ m. If it is such thickness, since sufficient amount of a polymer electrolyte and an electrode catalyst can be hold
  • the gas diffusion electrode body may be provided on at least one of the cathode side and the anode side of the MEA, but it is preferably provided on both the cathode and the anode.
  • the method for producing the gas diffusion electrode body is not particularly limited as long as the polymer electrolyte and the electrode catalyst can be held on the non-conductive nonwoven fabric or woven fabric.
  • a method of applying a slurry containing a polymer electrolyte, an electrode catalyst and a solvent to a non-conductive nonwoven fabric or woven fabric and then drying; impregnating and drying the non-conductive nonwoven fabric or woven fabric in a catalyst ink containing an electrode catalyst and a solvent A method of impregnating and drying (heat treatment) an electrolyte ink containing a polymer electrolyte and a solvent after heat treatment; After impregnating and drying (heat treatment) a non-conductive nonwoven fabric or fabric in an electrolyte ink containing a polymer electrolyte and a solvent
  • a method of impregnating and drying (heat treatment) a catalyst ink containing an electrode catalyst and a solvent a method of impregnating and drying (heat treatment) a catalyst
  • the manufacturing method of the gas diffusion electrode body when the gas diffusion electrode body contains conductive carbon is not particularly limited.
  • a method in which an ink (slurry) containing a polymer electrolyte, an electrode catalyst, conductive carbon and a solvent is applied to a non-conductive nonwoven fabric or woven fabric and then dried (heat treatment); a polymer electrolyte, an electrode catalyst, a conductive carbon
  • the application method is not particularly limited, and known methods such as spray coating (spraying method), dip coating (dipping method), spin coating, bar coating, roll coating, and screen printing are similarly modified or appropriately modified. Can be applied. Preferably, an immersion method is applied.
  • the drying conditions are not particularly limited as long as the conductive carbon can be held in the non-conductive nonwoven fabric or woven fabric, but are preferably 200 ° C. or less from the viewpoint of time, energy cost, and mass production. That is, the present invention also includes dipping a non-conductive nonwoven fabric or woven fabric in a slurry containing a polymer electrolyte, an electrode catalyst and a solvent; and heat-treating the non-conductive nonwoven fabric or woven fabric after the immersion at a temperature of 200 ° C.
  • the manufacturing method of the gas diffusion electrode body of this invention which has is also provided.
  • the preferable form of the manufacturing method of the gas diffusion electrode body of this invention is demonstrated.
  • the present invention is not limited to the following form.
  • the form in which the gas diffusion electrode body contains conductive carbon will be described.
  • the catalyst ink containing an electrode catalyst and a solvent, and the electrolyte ink containing a polymer electrolyte and a solvent are collectively referred to as “ink”.
  • the solvent is not particularly limited and is appropriately selected depending on the type of polymer electrolyte, electrode catalyst, and conductive carbon.
  • the solvent include water, perfluorobenzene, dichloropentafluoropropane, methanol, ethanol, propanol, 2-propanol, cyclohexanol, and other petroleum solvents such as toluene.
  • the concentration of the polymer electrolyte in the electrolyte ink is not particularly limited. Specifically, the concentration (solid content concentration) of the polymer electrolyte in the ink is preferably 0.1 to 20% by weight, more preferably 0.5 to 10% by weight.
  • the concentration (solid content concentration) of the electrode catalyst in the catalyst ink is not particularly limited. Specifically, the concentration of the electrode catalyst in the ink is preferably 0.1 to 25% by weight, more preferably 0.25 to 10% by weight. If it is such a density
  • the conductive carbon concentration (solid content concentration) in the carbon ink is not particularly limited. Specifically, the concentration of conductive carbon in the ink is preferably 5 to 25% by weight, more preferably 10 to 20% by weight. If it is such a density
  • the ink may contain other additives in addition to at least one of a polymer electrolyte, an electrode catalyst and conductive carbon, and a solvent.
  • the additive is not particularly limited, and examples thereof include a dispersion aid, a dispersant, a water repellent, and a binder binder.
  • the addition amount of the additive is not particularly limited, and is appropriately selected in consideration of a desired effect (for example, dispersibility and water repellency of conductive carbon).
  • the additive is preferably added in an amount of about 1 to 10% by weight with respect to the total amount of polymer electrolyte, electrode catalyst, and conductive carbon contained in the same ink.
  • the ink may be dispersed while being subjected to ultrasonic treatment (ultrasonic dispersion treatment). Since the viscosity of the ink is lowered by such treatment, each component (polymer electrolyte, electrode catalyst, or conductive carbon) is not contained in the nonconductive nonwoven fabric or woven fabric when the nonconductive nonwoven fabric or woven fabric is immersed in the next step. It can penetrate more efficiently into the pores.
  • ultrasonic treatment ultrasonic dispersion treatment
  • the ink may contain a thickener.
  • the thickener that can be used in this case is not particularly limited, and a known thickener can be used. Examples thereof include glycerin, ethylene glycol (EG), polyvinyl alcohol (PVA), and propylene glycol (PG). Of these, propylene glycol (PG) is preferably used.
  • PG propylene glycol
  • the boiling point of the ink increases and the solvent evaporation rate decreases. For this reason, for example, the solvent evaporation rate in the applied ink is suppressed, and the occurrence of cracks (cracks) in the gas diffusion electrode body after the drying process can be suppressed / prevented.
  • the concentration of mechanical stress on the gas diffusion electrode body is relaxed, and as a result, the durability of the MEA can be improved.
  • the amount of the thickener added when the thickener is used is not particularly limited as long as it does not interfere with the above effect of the present invention, but is preferably 5 to 20 weight with respect to the total weight of the ink. %.
  • the dipping condition is a condition in which a sufficient amount of electrolyte and electrode catalyst and, if necessary, conductive carbon can be held in a non-conductive nonwoven fabric or woven fabric within a range that avoids volatilization and solidification of the solvent used and an increase in viscosity.
  • the immersion temperature is preferably 10 to 80 ° C., more preferably 20 to 40 ° C.
  • the immersion time is preferably 5 seconds to 15 minutes, more preferably 10 seconds to 5 minutes. In addition, you may repeat the said immersion process as needed.
  • the nonconductive nonwoven fabric or woven fabric is dried (heat treated).
  • the drying condition is such that the solvent is removed from the non-conductive nonwoven fabric or woven fabric and the conductive carbon is held on the surface and in the pores, so that a high temperature for baking (firing) is required as in the past. And not.
  • the drying temperature should just be the temperature which can remove a solvent, and changes with kinds of solvent to be used.
  • the drying temperature is 200 ° C. or less from the viewpoint of time and energy cost.
  • the drying temperature is preferably 60 to 200 ° C., more preferably 80 to 150 ° C.
  • the drying time is preferably 5 to 20 minutes, more preferably 2 to 10 minutes.
  • the above conditions can be particularly suitably applied when a low boiling point solvent such as water or ethanol is selected as the solvent. In consideration of mass production, it is preferable to select a low boiling point solvent such as water or ethanol as the solvent.
  • an air flow may be introduced into the drying furnace. By performing such an operation, it is possible to further shorten the drying time.
  • the gas diffusion electrode body can be produced at a low temperature and in a short time, which is very preferable from an industrial viewpoint.
  • you may repeat the said drying (heat processing) process as needed. By performing such an operation, more polymer electrolyte and electrode catalyst and, if necessary, conductive carbon can be held in the non-conductive nonwoven fabric or woven fabric.
  • the nonconductive nonwoven fabric or woven fabric after the immersion may be subjected to a water repellent treatment.
  • the water repellent treatment method is not particularly limited, but is preferably immersed in a solution containing the water repellent as described above from the viewpoint of ease of operation.
  • the solvent that can be used to prepare the water repellent solution is not particularly limited as long as it can dissolve the water repellent, and can be appropriately selected depending on the type of the water repellent. Examples thereof include water, alcohols such as perfluorobenzene, dichloropentafluoropropane, methanol and ethanol, and petroleum solvents such as toluene.
  • the concentration of the water repellent is not particularly limited. Specifically, the concentration (solid content concentration) of the water repellent in the water repellent solution is preferably 0.1 to 25% by weight, more preferably 1 to 5% by weight. With such a concentration, sufficient water repellency can be imparted to the gas diffusion electrode body.
  • the immersion conditions in the water repellent solution are not particularly limited as long as a sufficient amount of water repellency can be imparted to the gas diffusion electrode body, but in order to prevent volatilization of the solvent used for immersion, It is preferably performed at a temperature lower than 20 ° C. so that the solution does not thicken or coagulate.
  • the immersion temperature when an alcohol solution of a perfluorosulfonic acid polymer is used is preferably 10 to 60 ° C., more preferably 20 to 40 ° C.
  • the immersion time is preferably 2 seconds to 15 minutes, more preferably 5 seconds to 10 minutes.
  • an ultrasonic treatment in order to remove the bubble inside a gas diffusion electrode body, it is preferable to perform an ultrasonic treatment.
  • the gas diffusion electrode body is dried (heat treatment). That is, after immersion and before heat treatment, the nonconductive nonwoven fabric or woven fabric after immersion may be subjected to water repellent treatment. Thereby, a gas diffusion electrode body with further improved water repellency can be obtained.
  • drying conditions should just remove a solvent, and change with kinds of solvent to be used.
  • the drying temperature is 200 ° C. or less, preferably 40 to 200 ° C., more preferably 80 to 150 ° C.
  • the drying time is preferably 30 seconds to 20 minutes, more preferably 3 minutes to 15 minutes.
  • the gas diffusion layer can be produced at a low temperature and in a short time, which is very preferable from an industrial viewpoint.
  • the polymer electrolyte membrane 2 has a function of selectively transmitting protons generated on the anode side (anode gas diffusion electrode body) during operation of the PEFC 1 to the cathode side (cathode gas diffusion electrode body) along the film thickness direction. Have.
  • the solid polymer electrolyte membrane 2 also has a function as a partition wall for preventing the fuel gas supplied to the anode side and the oxidant gas supplied to the cathode side from being mixed.
  • the polymer electrolyte membrane 2 is roughly classified into a fluorine-based polymer electrolyte membrane and a hydrocarbon-based polymer electrolyte membrane depending on the type of ion exchange resin that is a constituent material.
  • a fluorine-based polymer electrolyte membrane is preferably used, and particularly preferably a fluorine-based polymer electrolyte composed of a perfluorocarbon sulfonic acid-based polymer.
  • a molecular electrolyte membrane is used.
  • the hydrocarbon-based polymer electrolyte membrane has advantages in manufacturing such that the raw material is inexpensive, the manufacturing process is simple, and the material selectivity is high.
  • ion exchange resin As for the ion exchange resin mentioned above, only 1 type may be used independently and 2 or more types may be used together. Moreover, it is not restricted only to the material mentioned above, Other materials may be used.
  • the thickness of the polymer electrolyte membrane may be appropriately determined in consideration of the characteristics of the obtained fuel cell, and is not particularly limited.
  • the thickness of the electrolyte layer is usually about 5 to 300 ⁇ m. When the thickness of the electrolyte layer is within such a range, the balance of strength during film formation, durability during use, and output characteristics during use can be appropriately controlled.
  • the membrane electrode assembly (MEA) may have a microporous layer (MPL) between the gas diffusion electrode body and the separator, if necessary.
  • MPL microporous layer
  • the microporous layer (MPL) is not particularly limited, but preferably has a large gas diffusion coefficient. By using such a microporous layer (MPL), the gas permeability can be further improved, and the power generation performance under dry and wet conditions can be more effectively achieved.
  • Such a microporous layer (MPL) is not particularly limited, but can be an aggregate of carbon particles containing a water repellent if necessary.
  • the carbon particles are not particularly limited, and conventionally known materials such as carbon black, graphite (including granular graphite), expanded graphite and the like can be appropriately employed.
  • carbon black such as oil furnace black, channel black, lamp black, thermal black, acetylene black and the like can be preferably used because of excellent electron conductivity and a large specific surface area.
  • carbon particles commercially available products can be used, such as Vulcan XC-72, Vulcan P, Black Pearls 880, Black Pearls 1100, Black Pearls 1300, Black Pearls 2000, Regal 400, Lion Corporation Examples include black EC, oil furnace black such as # 3150 and # 3250 manufactured by Mitsubishi Chemical Corporation, and acetylene black such as Denka Black manufactured by Denki Kagaku Kogyo.
  • black EC oil furnace black such as # 3150 and # 3250 manufactured by Mitsubishi Chemical Corporation
  • acetylene black such as Denka Black manufactured by Denki Kagaku Kogyo.
  • artificial graphite or carbon obtained from organic compounds such as natural graphite, pitch, coke, polyacrylonitrile, phenol resin, furan resin may be used.
  • the above materials may be used alone or in the form of a mixture of two or more.
  • the particle size of the carbon particles is preferably about 10 to 100 nm.
  • the shape of the carbon particles is not particularly limited, and may take any structure such as a spherical shape, a rod shape, a needle shape, a plate shape, a column shape, an indefinite shape, a flake shape, and a spindle shape.
  • the “particle diameter of the carbon particles” is an average secondary particle diameter of the carbon particles.
  • the measurement of the average secondary particle diameter of the carbon particles is performed by using observation means such as a scanning electron microscope (SEM) or a transmission electron microscope (TEM). The value calculated as the average value of the diameters shall be adopted.
  • the fine porous layer (MPL) preferably contains a water repellent for the purpose of further improving water repellency and preventing flooding.
  • the water repellent is not particularly limited, but fluorine-based high repellents such as polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), polyhexafluoropropylene, and tetrafluoroethylene-hexafluoropropylene copolymer (FEP). Examples thereof include molecular materials, thermoplastic resins such as polyethylene and polypropylene. Of these, fluorine-based polymer materials are preferably used because of their excellent water repellency and corrosion resistance during electrode reaction.
  • the mixing ratio of the carbon particles to the water repellent may not be as good as the water repellent as expected when there are too many carbon particles. Conductivity may not be obtained. Considering these, the mixing ratio of the carbon particles and the water repellent in the microporous layer (MPL) is preferably about 90:10 to 40:60 in terms of weight ratio.
  • carbon particles may be bound by a binder.
  • the binder that can be used here include fluorine-based polymer materials such as polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyhexafluoropropylene, and tetrafluoroethylene-hexafluoropropylene copolymer (FEP).
  • PTFE polytetrafluoroethylene
  • PVDF polyvinylidene fluoride
  • FEP tetrafluoroethylene-hexafluoropropylene copolymer
  • thermosetting resins such as phenol resin, melamine resin and polyamide resin
  • thermoplastic resins such as polypropylene and polyethylene. Note that the above-described water repellent and binder partially overlap. Therefore, a binder having water repellency is preferably used.
  • fluorine-based polymer materials are preferably used because of their excellent water repellency and corrosion resistance during electrode reaction, and polytetrafluoroethylene (PTFE) is particularly preferable.
  • PTFE polytetrafluoroethylene
  • these binders may be used individually by 1 type, or may be used together 2 or more types.
  • polymers other than these may be used.
  • the binder content is preferably 5 to 60% by weight, more preferably 10 to 50% by weight, and still more preferably 12 to 40% by weight with respect to the total weight of the microporous layer (MPL). A range is preferred. If the blending ratio of the binder is 5% by weight or more, the particles can be bonded well, and if it is 60% by weight or less, an increase in the electrical resistance of the microporous layer (MPL) can be prevented.
  • the thickness of the microporous layer (MPL) is not particularly limited, and may be appropriately determined in consideration of the characteristics of the gas diffusion electrode body.
  • the thickness of the microporous layer (MPL) is preferably 3 to 500 ⁇ m, more preferably 5 to 300 ⁇ m, still more preferably 10 to 150 ⁇ m, and particularly preferably 20 to 100 ⁇ m. Within such a range, the balance between mechanical strength and permeability such as gas and water can be appropriately controlled.
  • the membrane electrode assembly may have a gas diffusion layer base material between the gas diffusion electrode body and the separator, if necessary.
  • a gas diffusion layer base material and a microporous layer (MPL) are arrange
  • a gas diffusion layer base material is disposed on the separator side, and a microporous layer (MPL) is disposed on the gas diffusion electrode body side.
  • the gas diffusion layer base material is not particularly limited, and known materials can be used in the same manner.
  • carbon paper, carbon cloth such as carbon paper, carbon-made woven fabric, paper-like paper body, felt, non-woven sheet-like material having conductivity and porosity; and metal mesh, expanded metal, etching The thing which uses a plate as a base material etc. are mentioned.
  • the thickness of the substrate is not particularly limited and may be appropriately determined in consideration of desired characteristics, but may be about 30 to 500 ⁇ m. With such a thickness, sufficient mechanical strength and permeability such as gas and water can be secured.
  • the gas diffusion layer base material may contain a water repellent for the purpose of further improving water repellency and preventing a flooding phenomenon or the like.
  • the water repellent is not particularly limited, but fluorine-based such as polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), polyhexafluoropropylene, and tetrafluoroethylene-hexafluoropropylene copolymer (FEP). Examples thereof include polymer materials, polypropylene, and polyethylene.
  • the water repellent treatment method is not particularly limited, and a general water repellent treatment method may be used. For example, after immersing the gas diffusion layer base material in a water repellent dispersion, a method of heating and drying in an oven or the like can be used.
  • a sheet body in which a porous body of polytetrafluoroethylene (PTFE) is impregnated with carbon particles and sintered can be used.
  • PTFE polytetrafluoroethylene
  • the manufacturing process is simplified, and handling and assembly when the members of the fuel cell are stacked are facilitated.
  • the gas diffusion layer substrate may not be subjected to water repellent treatment or may be subjected to hydrophilic treatment.
  • the method for forming the fine porous layer on the gas diffusion layer substrate is not particularly limited.
  • the ink is prepared by dispersing carbon particles, a water repellent, and the like in a solvent such as water, alcohol solvents such as perfluorobenzene, dichloropentafluoropropane, methanol, and ethanol.
  • the ink may be applied on a gas diffusion layer substrate and dried, or the ink may be dried and pulverized to form a powder, which is then applied onto the gas diffusion layer.
  • heat treatment is preferably performed at about 250 to 400 ° C. using a muffle furnace or a firing furnace. Or you may use the commercial item by which the fine porous layer was previously formed on the gas diffusion layer base material.
  • a method for producing the membrane electrode assembly is not particularly limited, and a conventionally known method can be used. For example, a method in which two gas diffusion electrode bodies are arranged on an electrolyte membrane and bonded can be used.
  • the joining conditions are not particularly limited, and may be appropriately adjusted depending on the type of electrolyte (perfluorosulfonic acid type or hydrocarbon type) in the electrolyte membrane or the gas diffusion electrode.
  • the separator has a function of electrically connecting cells in series when a plurality of single cells of a fuel cell such as a polymer electrolyte fuel cell are connected in series to form a fuel cell stack.
  • the separator also functions as a partition that separates the fuel gas, the oxidant gas, and the coolant from each other.
  • each of the separators is preferably provided with a gas flow path and a cooling flow path.
  • a material constituting the separator conventionally known materials such as dense carbon graphite, carbon such as a carbon plate, and metal such as stainless steel can be appropriately employed without limitation.
  • the thickness and size of the separator and the shape and size of each flow path provided are not particularly limited, and can be appropriately determined in consideration of the desired output characteristics of the obtained fuel cell.
  • the type of the fuel cell is not particularly limited.
  • the polymer electrolyte fuel cell (PEFC) has been described as an example.
  • an alkaline fuel cell a direct methanol fuel is used.
  • Examples include batteries and micro fuel cells.
  • a polymer electrolyte fuel cell is preferable because it is small in size, and can achieve high density and high output.
  • the fuel cell is useful as a stationary power source in addition to a power source for a moving body such as a vehicle in which a mounting space is limited.
  • the fuel cell is particularly useful for an automobile application in which system start / stop and output fluctuation frequently occur. It can be particularly preferably used.
  • the manufacturing method of the fuel cell is not particularly limited, and conventionally known knowledge can be appropriately referred to in the field of the fuel cell.
  • the fuel used when operating the fuel cell is not particularly limited.
  • hydrogen, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, secondary butanol, tertiary butanol, dimethyl ether, diethyl ether, ethylene glycol, diethylene glycol and the like can be used.
  • hydrogen and methanol are preferably used in that high output is possible.
  • a fuel cell stack having a structure in which a plurality of membrane electrode assemblies are stacked and connected in series via a separator may be formed so that the fuel cell can exhibit a desired voltage.
  • the shape of the fuel cell is not particularly limited, and may be determined as appropriate so that desired battery characteristics such as voltage can be obtained.
  • the PEFC and membrane electrode assembly described above use a gas diffusion electrode body that is excellent in material transportability (for example, gas diffusibility), catalytic activity, and conductivity. Therefore, the PEFC and the membrane electrode assembly exhibit excellent power generation performance.
  • the carbon ink has a low viscosity, and has properties suitable for the porous body impregnation in the next step.
  • this carbon ink was measured with a laser diffraction / scattering particle size distribution analyzer (Microtrap MT3000), a dispersion having a median value (average secondary particle diameter of conductive carbon) of 2.2 ⁇ m was obtained.
  • platinum-supporting carbon As an electrode catalyst at a weight ratio of 160 to 1, and ultrasonic dispersion was performed for 30 minutes. This was mixed for 5 minutes with a kneading apparatus (trade name: Nertaro, manufactured by Shinky Co., Ltd.) to obtain a mixed dispersion of electrode catalyst / water.
  • a kneading apparatus trade name: Nertaro, manufactured by Shinky Co., Ltd.
  • the contents of the conductive carbon, electrode catalyst and electrolyte in the gas diffusion electrode body thus obtained were 5.68% by volume, 7.40% by volume and 5.29% by volume, respectively.
  • the gas diffusion electrode body contained 0.7 parts by weight of the polymer electrolyte with respect to 100 parts by weight of the electrode catalyst.
  • the thickness of the gas diffusion electrode body was 230 ⁇ m.
  • the MEA (1) thus obtained was subjected to power generation test evaluation under the following conditions. Under the following conditions, the load current density was swept in the range of 0 to 1.9 A / cm 2 , an IV curve was obtained, and the voltage value at 0.5 A / cm 2 was measured. The power generation performance was shown.
  • Comparative Example 1 (Production of catalyst layer) Platinum-supported carbon, water, and NPA (1-propanol) were put in a sand grinder (manufactured by Imex) and pulverized, and an electrolyte solution was further added to prepare a catalyst ink.
  • the obtained catalyst ink had a composition of 4.5% by weight of platinum-supported carbon, 16.5% by weight of electrolyte, 31.5% by weight of water, and 47.5% by weight of NPA (1-propanol).
  • TEC10E50E manufactured by Tanaka Kikinzoku Kogyo Co., Ltd.
  • the obtained catalyst ink was spray-coated on one side of a polytetrafluoroethylene sheet and dried at 130 ° C. for 15 minutes to produce anode and cathode catalyst layers.
  • the coating layer on the polytetrafluoroethylene sheet was adjusted so that the Pt amount was 0.32 mg / cm 2 .
  • Gaskets manufactured by Teijin Dupont, Teonex, thickness: 25 ⁇ m (adhesive layer: 10 ⁇ m) were arranged around both surfaces of the electrolyte membrane.
  • an electrolyte membrane manufactured by DuPont, Nafion (registered trademark) NR211, thickness: 25 ⁇ m
  • the anode catalyst layer (fuel cell electrode) and the cathode catalyst layer (fuel cell electrode) prepared above are formed on the exposed portion of the electrolyte membrane (working area: 25 cm 2 (5.0 cm ⁇ 5.0 cm)).
  • the formed PTFE (polytetrafluoroethylene) sheets were respectively arranged to form a laminate. After applying a pressure of 0.8 MPa to this laminate, the electrolyte membrane and each fuel cell electrode were brought into close contact with each other, heated at 150 ° C. for 10 minutes, and after joining the electrolyte membrane and each fuel cell electrode, The PTFE sheet was peeled to produce a CCM. Using this CCM, a small power generation cell MEA (2) was produced.
  • the cell voltage (Cell voltage) at a current density of 0.3 A / cm 2 under the following conditions: And resistance were measured.
  • the cell voltages of the MEA (1) and (2) are 0.64 V and 0.66 V, respectively, and the MEA (1) of the present invention exhibits power generation performance equivalent to that of the conventional MEA (2). I understood.

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Abstract

La présente invention concerne un corps d'électrode à diffusion gazeuse excellente en termes de transport de substance. Le corps d'électrode à diffusion gazeuse selon la présente invention est conçu en retenant un polyélectrolyte et un catalyseur d'électrode au moyen d'un tissu ou d'un tissu non tissé non conducteur.
PCT/JP2014/058694 2013-04-26 2014-03-26 Corps d'électrode à diffusion gazeuse, son procédé de fabrication, ensemble membrane-électrode pour pile à combustible utilisant celui-ci, et pile à combustible Ceased WO2014174973A1 (fr)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001283865A (ja) * 2000-03-31 2001-10-12 Toray Ind Inc 電極触媒層、膜−電極複合体およびそれらの製造方法並びにそれらを用いた燃料電池
WO2008018410A1 (fr) * 2006-08-07 2008-02-14 Mitsubishi Gas Chemical Company, Inc. électrode POUR PILE À COMBUSTIBLE, SON PROCESSUS DE FABRICATION, ET PILE À COMBUSTIBLE
JP2009518817A (ja) * 2005-12-12 2009-05-07 ビーワイディー カンパニー リミテッド 触媒被覆膜の製造方法
JP2009140927A (ja) * 2007-12-04 2009-06-25 Hanwha Chem Corp 燃料電池用独立電極触媒層及びこれを用いた膜−電極接合体の製造方法
WO2009116630A1 (fr) * 2008-03-21 2009-09-24 旭硝子株式会社 Ensemble membrane-électrode pour pile à combustible à polymère solide, et pile à combustible à polymère solide

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001283865A (ja) * 2000-03-31 2001-10-12 Toray Ind Inc 電極触媒層、膜−電極複合体およびそれらの製造方法並びにそれらを用いた燃料電池
JP2009518817A (ja) * 2005-12-12 2009-05-07 ビーワイディー カンパニー リミテッド 触媒被覆膜の製造方法
WO2008018410A1 (fr) * 2006-08-07 2008-02-14 Mitsubishi Gas Chemical Company, Inc. électrode POUR PILE À COMBUSTIBLE, SON PROCESSUS DE FABRICATION, ET PILE À COMBUSTIBLE
JP2009140927A (ja) * 2007-12-04 2009-06-25 Hanwha Chem Corp 燃料電池用独立電極触媒層及びこれを用いた膜−電極接合体の製造方法
WO2009116630A1 (fr) * 2008-03-21 2009-09-24 旭硝子株式会社 Ensemble membrane-électrode pour pile à combustible à polymère solide, et pile à combustible à polymère solide

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