JP2009064592A - Method and device for forming electrode member of fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and device for forming an electrode member of a fuel cell, which reduces the manufacturing cost of a catalyst layer and a gas diffusion layer as an electrode member without requiring preparation of ink and solvent. <P>SOLUTION: The method relates to forming an electrode member 51 of a thin layer used to constitute an electrode of a film electrode junction body for fuel cell, and forms an electrode member by supplying conductive particles 62 and resin-dispersed liquid 63 onto a substrate 61 via systems 111 and 112 independent of each other. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for forming an electrode member for a fuel cell and a forming apparatus.

  In recent years, fuel cells have attracted attention as vehicle drive sources and stationary power sources. Fuel cells are classified into various types depending on the type of electrolyte and electrode, and representative types include alkali type, phosphoric acid type, molten carbonate type, solid electrolyte type, and solid polymer type. Among these, a polymer electrolyte fuel cell (PEFC) operable at a low temperature (usually 100 ° C. or less) attracts attention, and development / practical use as a low-pollution power source for automobiles is proceeding (see Patent Document 1). .

  The PEFC generally has a structure in which a membrane electrode assembly (hereinafter also referred to as “MEA”) is sandwiched between separators. The MEA has a structure in which a solid polymer electrolyte membrane is sandwiched between a pair of electrodes, that is, a fuel electrode and an air electrode. Each electrode is configured using a thin layer electrode member. The thin layer electrode member includes a catalyst layer and a gas diffusion layer (hereinafter also referred to as “GDL”). One side of the catalyst layer is in contact with the solid polymer electrolyte membrane. The catalyst layer includes catalyst particles, a conductive carrier such as carbon particles supporting the catalyst particles, and a solid polymer electrolyte. The gas diffusion layer is disposed between the catalyst layer and the separator and is a gas permeable layer.

  The catalyst layer is applied to a base material such as a solid polymer film or a polytetrafluoroethylene (PTFE) sheet using a coating device such as a spray, a screen printer or a die coater. It is formed by drying. The catalyst ink is mainly composed of catalyst-supported carbon, a resin dispersion (ionomer), alcohol, and pure water. Since it is necessary to control the physical properties of the catalyst ink such as viscosity according to the characteristics of the coating apparatus, a solvent such as alcohol is used.

GDL is a carbon particle layer (Micro carbon layer; hereinafter referred to as “MIL”) composed of an aggregate of carbon particles containing a water repellent agent on a substrate such as carbon paper or sheet to improve water repellency. ). This type of GDL is formed by applying the prepared MIL ink onto a substrate using an application device such as a spray, a screen printer, or a die coater, and drying it with a heater or the like. The MIL ink is mainly composed of carbon, a water repellency imparting resin dispersion (PTFE or the like), and alcohol (or surfactant + pure water). Since it is necessary to control the physical properties of the MIL ink such as viscosity according to the characteristics of the coating apparatus, a solvent such as alcohol (or surfactant + pure water) is used.
JP-A-6-20710

  However, a large amount of a solvent such as alcohol is necessary for the preparation of the catalyst ink, and a large amount of a solvent such as alcohol or water containing a surfactant is also necessary for the preparation of the MIL ink. These large amounts of solvent are wasted because they are finally vaporized. Therefore, the manufacturing cost of the catalyst layer and the gas diffusion layer is increased and the facilities are increased. As a result, there is a problem that the electrode member for the fuel cell cannot be manufactured at a low cost.

  An object of the present invention is to provide a method and an apparatus for forming an electrode member for a fuel cell, which do not require ink preparation or a solvent, and can reduce the manufacturing cost of a catalyst layer and a gas diffusion layer as electrode members Is to provide.

In order to achieve the above object, the present invention provides a method for forming a thin layer electrode member used for constituting an electrode of a membrane electrode assembly for a fuel cell.
Forming the electrode member of the fuel cell, wherein the electrode member is formed by supplying the conductive particles and the resin dispersion, which are respectively supplied through a separate and independent system, onto the substrate. Is the method.

Further, the present invention provides an apparatus for forming a thin-layer electrode member used for constituting an electrode of a membrane electrode assembly for a fuel cell.
A first system for supplying conductive particles onto a substrate;
And a second system that is provided separately and independently from the first system and supplies a resin dispersion onto the substrate.

  According to the present invention, the conductive particles and the resin dispersion are separately supplied to form the electrode member on the base material, so that the catalyst layer as the electrode member is not required without preparing ink or solvent. In addition, the manufacturing cost of the gas diffusion layer can be reduced.

  Embodiments of the present invention will be described below with reference to the drawings. For easy understanding, each component is exaggerated in the drawings.

  FIG. 1 is a cross-sectional view of an essential part schematically showing a membrane electrode assembly for a fuel cell according to an embodiment of the present invention.

  Referring to FIG. 1, the MEA 10 generally includes a solid polymer electrolyte membrane 20, a fuel electrode 30, and an air electrode 40, and the solid polymer electrolyte membrane 20 includes a pair of these electrodes 30, 40. It is pinched by. Each of the electrodes 30 and 40 is configured using a thin layer electrode member. The thin layer electrode member includes catalyst layers 31 and 41 and GDLs 32 and 42. One side of the catalyst layers 31 and 41 is in contact with the solid polymer electrolyte membrane 20.

  The catalyst layers 31 and 41 of the electrodes 30 and 40 include catalyst particles, a conductive carrier such as carbon particles supporting the catalyst particles, and a solid polymer electrolyte.

  As the catalyst particles, any conventionally known particles can be used without particular limitation as long as they have a catalytic action with respect to the oxidation reaction of hydrogen and / or the reduction reaction of oxygen. For example, selected from the group consisting of metals such as platinum, ruthenium, iridium, rhodium, palladium, osmium, tungsten, lead, iron, chromium, cobalt, nickel, manganese, vanadium, molybdenum, gallium, aluminum, and alloys thereof. At least one of them. The catalyst particles may be used alone, but may be an alloy containing platinum as a main component in order to increase the stability and activity of the catalyst particles.

  Any conductive carrier may be used as long as it has a 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. Is preferred. Specific examples include carbon particles made of carbon black, activated carbon, coke, natural graphite, artificial graphite and the like. “The main component is carbon” means that the main component contains carbon atoms, and is a concept that includes both carbon atoms and substantially carbon atoms. In some cases, elements other than carbon atoms may be included in order to improve the characteristics of the fuel cell. In addition, being substantially composed of carbon atoms means that mixing of impurities of about 2 to 3% by mass or less is allowed. The size of the conductive carrier is not particularly limited, but from the viewpoint of easy loading, catalyst utilization, and catalyst layer thickness control within an appropriate range, the average particle size is 5 to 200 nm, preferably 10 It is good to be about ~ 100 nm.

  The solid polymer electrolyte covering the surfaces of the catalyst particles and the conductive carrier is not particularly limited as long as it is generally used in the catalyst layers 31 and 41. Specifically, a perfluorocarbon polymer having a sulfonic acid group such as Nafion (registered trademark of DuPont), a hydrocarbon polymer compound doped with an inorganic acid such as phosphoric acid, a part of which is proton-conductive Examples thereof include organic / inorganic hybrid polymers substituted with functional groups, and solid polymer electrolytes such as proton conductors in which a polymer matrix is impregnated with a phosphoric acid solution or a sulfuric acid solution.

  A method of forming the catalyst layers 31 and 41 as electrode members will be described later.

  As the GDLs 32 and 42, conventionally known ones can be used without particular limitation. Examples thereof include those based on a sheet-like material having electrical conductivity and porosity, such as carbon woven fabric, paper-like paper body, felt, and nonwoven fabric. More specifically, carbon paper, carbon cloth, carbon nonwoven fabric and the like are preferable. The thickness of the substrate may be appropriately determined in consideration of the characteristics of the obtained gas diffusion layer, but may be about 30 to 500 μm. GDL preferably contains a water repellent in the substrate for the purpose of further improving water repellency and preventing flooding. Although it does not specifically limit as said water repellent, PTFE, polyvinylidene fluoride (PVDF), etc. are mentioned.

  The GDL of the present embodiment has a MIL composed of an aggregate of carbon particles containing a water repellent on the above-described base material in order to further improve water repellency. The MIL carbon particles are not particularly limited, and may be conventional ones such as carbon black, graphite, and expanded graphite. The particle size of the carbon particles is preferably about 10 to 100 nm. Examples of the water repellent include those similar to the above-described water repellent used for the substrate.

  A method for forming the GDLs 32 and 42 as electrode members will be described later.

  The solid polymer electrolyte membrane 20 is not particularly limited, and examples thereof include a membrane made of a proton conductive electrolyte similar to that used for the catalyst layers 31 and 41. In addition, perfluorosulfonic acid membranes represented by various Nafion (registered trademark) and Flemion (registered trademark) manufactured by DuPont, ion exchange resins, ethylene-tetrafluoroethylene copolymer resin membranes manufactured by Dow Chemical Company, Fluoropolymer electrolytes such as resin membranes based on trifluorostyrene, and hydrocarbon polymer resin membranes having sulfonic acid groups, such as commercially available solid polymer electrolyte membranes and polymer microporous materials A membrane in which a membrane is impregnated with a liquid electrolyte, a membrane in which a porous body is filled with a polymer electrolyte, or the like may be used.

  Next, a method for forming catalyst layers 31 and 41 and GDLs 32 and 42 as electrode members and a forming apparatus will be described. For convenience of explanation, the catalyst layers 31 and 41 and the GDLs 32 and 42 are collectively referred to as an electrode member 51.

  In the method for forming the electrode member for a fuel cell of the present invention, the electrode member 51 is formed by supplying the conductive particles and the resin dispersion, which are supplied respectively, via a separate and independent system onto the substrate. To do. An apparatus for forming an electrode member for a fuel cell according to the present invention that embodies such a forming method can be summarized as follows: a first system for supplying conductive particles onto a substrate, and a first system independently of the first system. And a second system for supplying the resin dispersion onto the substrate. Specifically, the electrode member 51 is formed by the following first and second forming methods.

  FIG. 2 is a schematic view schematically showing a first method for forming the electrode member 51.

  Referring to FIG. 2A, a forming apparatus 101 is provided with a first system 111 for supplying conductive particles 62 onto a substrate 61 and a first system 111 separately from the first system 111. And a second system 112 for supplying 63 onto the substrate 61.

  The base material 61 has a rectangular sheet shape. The base material 61 is held by a holder 60 incorporating heating means such as a heater. The base material 61 is arranged so that the surface 61a is along the vertical direction.

  A coating device 70 including a spray nozzle 71 and a liquid storage container 72 is disposed so as to face the surface 61a of the substrate 61 and face each other. A resin dispersion 63 is accommodated in the liquid container 72, and the resin dispersion 63 is sprayed from the spray nozzle 71. The spray nozzle 71 is provided so that the resin dispersion 63 can be sprayed while being moved vertically and horizontally. In order to reduce the movement range of the spray nozzle 71, a plurality of spray nozzles 71 may be arranged in the coating apparatus 70.

  A particle supply unit 80 is disposed above the base 61 and the injection nozzle 71. The particle groups of the conductive particles 62 are uniformly dropped from the particle supply means 80 along the surface 61a of the base member 61 and dispersed.

  Immediately below the particle supply means 80, a collection container 81 having an open top is disposed to receive the conductive particles 62 that fall without being accompanied by the sprayed resin dispersion 63. What is blown off by the sprayed resin dispersion 63 slightly below the particle supply means 80 and just below the substrate is the conductive particles 62 and the resin dispersion 63 that fall without reaching the surface 61 a of the substrate 61. In order to receive the mixture 62a (see FIG. 2 (b)), a collection container 82 having an open top is disposed.

  Referring to FIG. 2B, the first forming method is briefly described as a step of arranging the surface 61 a of the base material 61 along the vertical direction, and a conductive particle along the surface 61 a of the base material 61. And spraying the resin dispersion 63 toward the surface 61a of the substrate 61 so as to cross the conductive particles 62 that fall. Then, the electrode member 51 is formed by applying the falling conductive particles 62 and the sprayed resin dispersion 63 together to the substrate 61.

  More specifically, the particle groups of the conductive particles 62 are uniformly dropped from the particle supply means 80 along the surface 61a of the base member 61 and dispersed. The resin dispersion 63 is sprayed toward the surface 61 a of the base 61 from the spray nozzle 71 of the coating device 70 through the particle group of the conductive particles 62 that fall. The conductive particles 62 are used as a powder as a solid, and the resin dispersion 63 does not contain a solvent such as alcohol.

  Then, when the resin dispersion 63 sprayed from the injection nozzle 71 passes through the particle group of the conductive particles 62, the conductive particles 62 and the resin dispersion 63 are mixed and stacked while being laminated. It will adhere on the material 61. In order to uniformly laminate the mixture of the conductive particles 62 and the resin dispersion 63 on the entire surface 61a of the substrate 61, the resin dispersion 63 is sprayed while the spray nozzle 71 of the coating device 70 is moved vertically and horizontally.

  After the application is completed, when the heater on the holder 60 is energized to dry the deposit on the substrate 61, the formation of the electrode member 51 is completed.

  The conductive particles 62 that have fallen without coming into contact with the resin dispersion 63 sprayed from the spray nozzle 71 are collected in a collection container 81 disposed immediately below the particle supply means 80. Since the conductive particles 62 collected in the collection container 81 are not in contact with the resin dispersion 63, they can be reused as they are. In addition, the mixture 62a that has come into contact with the resin dispersion 63 sprayed from the spray nozzle 71 but has not reached the substrate 61 is a collection container that is disposed on the substrate side from the position directly below the particle supply means 80. It falls into 82 and is collected. The mixture 62 a recovered in the recovery container 82 is in contact with the resin dispersion 63. When the catalyst layers 31 and 41 are formed, the catalyst particles are separated from the mixture 62a and reused. When the GDLs 32 and 42 are formed, the mixture 62a is discarded.

  As described above, according to the first forming method and forming apparatus, the conductive particles 62 are used as a powder as a solid, and the resin dispersion 63 does not contain a solvent such as alcohol. The manufacturing cost of the catalyst layers 31 and 41 and the GDLs 32 and 42 as the electrode member 51 can be reduced. As a result, the MEA 10 can be manufactured at a low cost.

  Furthermore, since the conductive particles 62 and the resin dispersion 63 are applied while being uniformly mixed, the formed electrode member 51 is made uniform. As a result, the performance of the catalyst layers 31 and 41 and the GDLs 32 and 42 as the electrode member 51 can be improved.

  The catalyst ink and the MIL ink are generally prepared through a mixing process, a pulverizing process, a collecting process, a washing process, and the like, and many facilities and man-hours are required for preparing the ink. Since there is a stirring operation, a defoaming process is also required. In the present embodiment, it is possible to reduce the number of man-hours for ink preparation as ink preparation becomes unnecessary. Since the number of steps can be reduced and no ink preparation facility is required, the manufacturing cost of the electrode member 51 can be reduced also from this viewpoint.

  In the case of using ink, generally, there are many container transfer operations from preparation to the end of coating, and the ink recovery rate is low. In this embodiment, since there are few container transfer operations, the constituent materials are not wasted. Since the utilization factor of the constituent material of the electrode member 51 is improved, the manufacturing cost of the electrode member 51 can be reduced also from this viewpoint.

  In the ink adjusted by the pulverizing / dispersing device, the carbon particle size distribution is determined by the ink adjusting conditions and the like, and therefore it is difficult to arbitrarily control the carbon particle size distribution. In the present embodiment, since the ink adjustment process is not performed, arbitrary control of the particle size distribution of the conductive particles 62 and / or the resin dispersion 63 is easy. Since the holes of the electrode member 51 are made uniform, the performance of the catalyst layers 31 and 41 and the GDLs 32 and 42 as the electrode member 51 can be improved.

  The conductive particles 62 can be easily recovered. In particular, since the conductive particles 62 recovered in the recovery container 81 are not in contact with the resin dispersion 63, the conductive particles 62 can be reused as they are, and the cost for reuse is reduced. Can be reduced.

  Since it is easy to arbitrarily control the particle size distribution of the conductive particles 62 and / or the resin dispersion 63, the conductive particles 62 having a particle size different from the particle size of the conductive particles 62 supplied onto the substrate 61 are used as the substrate 61. You may supply further above. That is, the particle supply means 80 containing the conductive particles 62 having different particle sizes is prepared, and the particle groups of the conductive particles 62 having different particle sizes are dropped from the particle supply means 80 and dispersed. Instead of varying the particle size of the conductive particles 62, or in addition to varying the particle size of the conductive particles 62, a resin dispersion having a particle size different from the particle size of the resin dispersion 63 supplied onto the substrate 61. 63 may be further supplied onto the substrate 61. That is, a coating device 70 containing resin dispersions 63 having different particle sizes is prepared, and the resin dispersions 63 having different particle sizes are sprayed from the coating device 70. In forming one electrode member 51, by varying the particle size of the conductive particles 62 and / or the resin dispersion 63, it becomes possible to control the pores along the thickness direction of the electrode member 51. The performance of the catalyst layers 31 and 41 and the GDLs 32 and 42 as the member 51 can be further improved.

  FIG. 3 is a schematic view schematically showing a second method for forming the electrode member 51.

  Referring to FIG. 3A, similarly to the forming apparatus 101, the forming apparatus 102 is independent of the first system 121 that supplies the conductive particles 62 onto the base material 61 and the first system 121. And a second system 122 that supplies the resin dispersion 63 onto the substrate 61.

  The base material 61 has a rectangular sheet shape. The base material 61 is held by a holder 60 incorporating heating means such as a heater. The base material 61 is disposed so that the surface 61a thereof is along the horizontal direction. A rectangular frame-shaped mask 90 is applied to the periphery of the surface 61 a of the base material 61.

  A coating device 70 including a spray nozzle 71 and a liquid storage container 72 is disposed obliquely above the substrate 61. The spray nozzle 71 faces downward so as to face the surface 61a of the base member 61. A resin dispersion 63 is accommodated in the liquid container 72, and the resin dispersion 63 is sprayed downward from the spray nozzle 71. The spray nozzle 71 is provided so that the resin dispersion 63 can be sprayed while being moved back and forth and left and right. In order to reduce the movement range of the spray nozzle 71, a plurality of spray nozzles 71 may be arranged in the coating apparatus 70.

  Between the base material 61 and the injection nozzle 71, a particle supply means 80 that is movable in the horizontal direction is disposed. When the particle supply means 80 is located immediately above the base material 61, the particle groups of the conductive particles 62 are uniformly dropped and dispersed.

  Referring to FIG. 3B, the second forming method, in brief, is a step of arranging the surface 61 a of the substrate 61 along the horizontal direction, and conductive particles toward the surface 61 a of the substrate 61. In addition to the step of dropping and spraying 62, and the step of spraying the conductive particles 62, a step of spraying the resin dispersion 63 toward the surface 61 a of the substrate 61 is included. Then, the electrode member 51 is formed by alternately performing the step of spraying the conductive particles 62 and the step of spraying the resin dispersion 63.

  More specifically, a step of uniformly dropping a small amount of particles of the conductive particles 62 onto the surface 61a of the substrate 61 from the particle supply means 80 (see FIG. 3B), and a spray nozzle of the coating device 70 The step of spraying a small amount of the resin dispersion 63 on the surface 61a of the base 61 from 71 (see FIG. 3C) is performed alternately. The conductive particles 62 are used as a powder as a solid, and the resin dispersion 63 does not contain a solvent such as alcohol.

  Then, the conductive particles 62 and the resin dispersion liquid 63 are mixed and adhered to the masked surface 61a of the base material 61 while being laminated.

  After the application is completed, when the heater on the holder 60 is energized to dry the deposit on the substrate 61, the formation of the electrode member 51 is completed.

  Any of the step of spraying the conductive particles 62 and the step of spraying the resin dispersion 63 may be performed first. To form the electrode member 51 uniformly, the conductive particles 62 are sprayed. It is preferable that the spraying of the resin dispersion 63 is alternately performed in small amounts. The electrode member 51 having a desired thickness can be formed according to the number of executions of the step of spraying the conductive particles 62 and the step of spraying the resin dispersion 63.

  As described above, according to the second forming method and forming apparatus, similarly to the first forming method and forming apparatus, the conductive particles 62 are used as a powder as a solid, and the resin dispersion 63 is a solvent such as alcohol. Therefore, a large amount of solvent is not required as in the prior art, and the manufacturing cost of the catalyst layers 31 and 41 and the GDLs 32 and 42 as the electrode member 51 can be reduced. As a result, the MEA 10 can be manufactured at a low cost.

  Furthermore, since the conductive particles 62 and the resin dispersion 63 are applied while being uniformly mixed, the formed electrode member 51 is made uniform. As a result, the performance of the catalyst layers 31 and 41 and the GDLs 32 and 42 as the electrode member 51 can be improved.

  Similar to the first forming method and the forming apparatus, it is possible to reduce the number of man-hours for ink preparation as ink preparation becomes unnecessary. Since the number of steps can be reduced and no ink preparation facility is required, the manufacturing cost of the electrode member 51 can be reduced also from this viewpoint.

  Moreover, since there are few container transfer operations, a constituent material is not consumed wastefully. Since the utilization factor of the constituent material of the electrode member 51 is improved, the manufacturing cost of the electrode member 51 can be reduced also from this viewpoint.

  Further, since the ink adjustment process is not performed, it is easy to arbitrarily control the particle size distribution of the conductive particles 62 and / or the resin dispersion 63. Since the holes of the electrode member 51 are made uniform, the performance of the catalyst layers 31 and 41 and the GDLs 32 and 42 as the electrode member 51 can be improved.

  In the first and second forming methods, when the electrode member 51 is the catalyst layers 31 and 41, the substrate 61 is a solid polymer film, a sheet material that can be peeled off from the catalyst layer, or a gas diffusion layer. be able to. That is, it can be formed directly on a solid polymer film or GDL, or can be formed on a sheet material that can be peeled off to be separately bonded to the solid polymer film or GDL. As the peelable sheet material, a PTFE sheet can be used. In addition to GDLs 32 and 42 formed by the first and second forming methods, GDL made of only a base material such as carbon paper, excluding MIL, can also be used as GDL. It is preferable to use carbon particles supporting catalyst particles as the conductive particles 62 and use ionomers as the resin dispersion 63. The ionomer preferably has the same components as the solid polymer electrolyte forming the solid polymer electrolyte membrane 20. This is because it is difficult to form an interface between the solid polymer electrolyte membrane 20 and the catalyst layers 31 and 41, so that the conduction of the generated protons is not hindered.

  When the electrode member 51 is GDL 32 or 42, a sheet-like material having at least a porous property can be used as the substrate 61. The substrate 61 preferably further has conductivity, and carbon paper, a carbon sheet, or the like can be used. It is preferable to use carbon particles as the conductive particles 62 and use a resin dispersion imparted with water repellency as the resin dispersion 63.

  The catalyst layers 31 and 41 and the GDLs 32 and 42 may be continuously stacked by the first and second forming methods. That is, the MIL layer may be formed on the GDL substrate by the first or second forming method, and the catalyst layer may be formed on the MIL layer by the first or second forming method.

  In the MEA 10 of this embodiment, the solid polymer electrolyte membrane 20 and the electrodes 30 and 40 including the catalyst layers 31 and 41 and the gas diffusion layers 32 and 42 are stacked in the order shown in FIG. Bonding is performed by performing a hot press for a predetermined time.

  The polymer electrolyte fuel cell is formed by sandwiching the MEA 10 with a separator (not shown). In the MEA 10 constituting the polymer electrolyte fuel cell, the following electrochemical reaction proceeds. First, hydrogen contained in the fuel gas supplied to the fuel electrode 30 is oxidized by the catalyst particles to become protons and electrons. Next, the generated protons pass through the solid polymer electrolyte contained in the catalyst layer 31 of the fuel electrode 30 and the solid polymer electrolyte membrane 20 in contact with the catalyst layer 31 of the fuel electrode 30 to reach the air electrode 40. The catalyst layer 41 is reached. The electrons generated in the catalyst layer 31 of the fuel electrode 30 pass through the conductive carrier (conductive particles) 62 in the catalyst layer 31 of the fuel electrode 30, the gas diffusion layer 32 of the fuel electrode 30, the separator, and the external circuit. The catalyst layer 41 of the air electrode 40 is reached. The protons and electrons that have reached the catalyst layer 41 of the air electrode 40 react with oxygen contained in the oxidant gas supplied to the air electrode 40 to generate water. Through such an electrochemical reaction, the fuel cell can extract electricity to the outside.

  As described above, according to the present embodiment, the conductive particles 62 and the resin dispersion 63 supplied respectively via the separate and independent systems 111 and 112, 121 and 122 are supplied onto the substrate 61. Thus, since the electrode member 51 is formed, it is possible to reduce the manufacturing cost of the catalyst layers 31 and 41 and the gas diffusion layers 32 and 42 as the electrode member 51 without preparing ink or a solvent. The membrane electrode assembly 10 can be manufactured at low cost. Furthermore, the electrode member 51 can be formed uniformly, and the performance of the electrode member 51 is improved. Along with the fact that ink preparation is not required, the number of steps can be reduced, and ink preparation equipment is not required, so that the manufacturing cost of the electrode member 51 can be further reduced. Moreover, since the utilization factor of the constituent material of the electrode member 51 improves, the manufacturing cost of the electrode member 51 can be reduced also from this viewpoint. Since the ink adjustment process is not performed, it is easy to arbitrarily control the particle size distribution of the conductive particles 62 and / or the resin dispersion 63, uniformize the pores of the electrode member 51, and improve the performance of the electrode member 51. be able to.

  As a first forming method, the step of arranging the surface 61a of the base material 61 along the vertical direction, and dropping and spraying the conductive particles 62 along the surface 61a of the base material 61, and dropping simultaneously with the spraying. Spraying the resin dispersion 63 toward the surface 61a of the substrate 61 so as to cross the conductive particles 62 to be performed. The electrode member 51 is formed by applying the falling conductive particles 62 and the sprayed resin dispersion 63 together to the base member 61. Through this first forming method, the electrode member 51 can be obtained. Further, the conductive particles 62 that have fallen without contacting the resin dispersion 63 can be easily recovered.

  Further, as a second forming method, a step of arranging the surface 61a of the base material 61 along the horizontal direction, a step of dropping and spreading the conductive particles 62 toward the surface 61a of the base material 61, and conductivity A step of spraying the resin dispersion 63 toward the surface 61 a of the substrate 61 is provided separately from the dispersion of the particles 62. The electrode member 51 is formed by alternately performing the step of spraying the conductive particles 62 and the step of spraying the resin dispersion 63. The electrode member 51 can also be obtained by this second forming method.

  The conductive particles 62 having a particle size different from the particle size of the conductive particles 62 supplied onto the substrate 61 are further supplied onto the substrate 61, or the resin particles having a particle size different from the particle size of the resin dispersion 63 supplied onto the substrate 61. By further supplying the dispersion 63 onto the base member 61, the pores can be controlled even in the thickness direction of the electrode member 51, and the performance of the electrode member 51 can be further improved.

  When the electrode member 51 is a catalyst layer, the substrate 61 is a solid polymer film, a sheet material that can be peeled off from the catalyst layer, or a gas diffusion layer, and the conductive particles 62 are carbon particles that carry catalyst particles. In addition, the resin dispersion 63 is an ionomer, and the manufacturing cost of the catalyst layers 31 and 41 can be reduced.

  When the electrode member 51 is a gas diffusion layer, the substrate 61 is a sheet-like material having at least porosity, the conductive particles 62 are carbon particles, and the resin dispersion 63 is a water repellency imparting resin dispersion. 63, and the manufacturing cost of the gas diffusion layers 32 and 42 can be reduced.

  The forming apparatuses 101 and 102 embodying the method according to the present embodiment are independent of the first systems 111 and 121 that supply the conductive particles 62 onto the substrate 61 and the first systems 111 and 121. Since the second system 112 and 122 that are provided and supply the resin dispersion 63 onto the substrate 61 are provided, the electrode member 51 can be formed with a reduction in manufacturing cost.

It is principal part sectional drawing which shows typically the membrane electrode assembly for fuel cells which concerns on embodiment of this invention. It is the schematic which shows typically the 1st formation method of the member for electrodes. It is the schematic which shows the 2nd formation method of the member for electrodes typically.

Explanation of symbols

10 MEA (membrane electrode assembly),
20 solid polymer electrolyte membrane,
30 Fuel electrode,
40 air electrode,
31, 41 Catalyst layer (electrode member),
32, 42 Gas diffusion layer (electrode member),
51 Electrode members,
61 substrate,
62 conductive particles,
63 resin dispersion,
70 coating device,
80 particle supply means,
101, 102 forming apparatus,
111, 121 first system,
112, 122 Second system.

Claims (8)

In a method of forming a thin layer electrode member used for constituting an electrode of a fuel cell membrane electrode assembly,
Forming the electrode member of the fuel cell, wherein the electrode member is formed by supplying the conductive particles and the resin dispersion, which are respectively supplied through a separate and independent system, onto the substrate. Method. Arranging the surface of the substrate along the vertical direction;
The conductive particles are dropped and dispersed along the surface of the base material, and at the same time as the spraying, the resin dispersion is sprayed toward the surface of the base material so as to cross the falling conductive particles. And a step of
2. The method for forming an electrode member for a fuel cell according to claim 1, wherein the electrode member is formed by applying the falling conductive particles and the sprayed resin dispersion together to the base material. Arranging the surface of the substrate along the horizontal direction;
Dropping and spreading the conductive particles toward the surface of the substrate;
Spraying the resin dispersion toward the surface of the substrate separately from the dispersion of the conductive particles,
The method for forming an electrode member for a fuel cell according to claim 1, wherein the electrode member is formed by alternately performing a step of spraying the conductive particles and a step of spraying the resin dispersion.   The method for forming a member for an electrode of a fuel cell according to claim 1, wherein the conductive particles having a particle size different from the particle size of the conductive particles supplied onto the base material are further supplied onto the base material.   The method for forming a member for an electrode of a fuel cell according to claim 1, wherein the resin dispersion having a particle size different from the particle size of the resin dispersion supplied onto the substrate is further supplied onto the substrate.   The electrode member is a catalyst layer, the base material is a solid polymer film, a sheet material peelable from the catalyst layer, or a gas diffusion layer, and the conductive particles are carbon particles carrying catalyst particles. The method for forming a member for an electrode of a fuel cell according to any one of claims 1 to 5, wherein the resin dispersion is an ionomer.   The electrode member is a gas diffusion layer, the base material is a sheet-like material having at least porosity, the conductive particles are carbon particles, and the resin dispersion is a water repellency imparting resin dispersion. A method for forming an electrode member for a fuel cell according to any one of claims 1 to 5. In an apparatus for forming a thin layer electrode member used for constituting an electrode of a fuel cell membrane electrode assembly,
A first system for supplying conductive particles onto a substrate;
An apparatus for forming an electrode member for a fuel cell, comprising: a second system that is provided separately and independently from the first system and supplies a resin dispersion onto the substrate.

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