JP2008135256A - Method and device for manufacturing membrane electrode assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and device for manufacturing a membrane electrode assembly capable of manufacturing a high quality electrode in high productivity. <P>SOLUTION: An adhesive layer 9 is formed on the surface of an electrolyte membrane 8, and the electrolyte membrane 8 is bonded to the lower surface of an upper electrode plate 1 so that the adhesive layer 9 faces a lower electrode plate 2. While vibrating a sieve 3 with a vibrating device 4, an electric field is generated between the upper electrode plate 1 and the lower electrode plate 2 with power sources 5, 6, an electrode material 7 on the lower electrode plate 2 is charged by the electric field, and moves toward the upper electrode plate 1 by the force from the electric field. At this point, even if the electrode material 7 is aggregated, it is dispersed by passing through the vibrating sieve 3, and uniformly bonded to the adhesive layer 9 of the electrolyte membrane 8 bonded to the lower surface of the upper electrode plate 1. By drying the adhesive layer 9, the electrode material 7 is fixed to the surface of the electrolyte membrane 8, and the membrane electrode assembly is manufactured. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method and apparatus for manufacturing a membrane electrode assembly, and more particularly to a method and apparatus for manufacturing a membrane electrode assembly in which a catalyst electrode is bonded to the surface of a solid polymer electrolyte membrane.

  The polymer electrolyte fuel cell has a structure in which a porous negative electrode and a positive electrode including carbon fine particles supporting a catalyst such as platinum are bonded to both surfaces of a proton-conductive electrolyte membrane, and the temperature ranges from room temperature to 100 ° C. It is known as a fuel cell that operates in a temperature range of ℃ or less, is small and lightweight, and has excellent startability. When hydrogen is supplied to the negative electrode side and oxygen or air is supplied to the positive electrode side, hydrogen becomes protons (hydrogen ions) and electrons on the negative electrode side, and these electrons flow to the positive electrode side through an external circuit. Oxygen that has received electrons on the side becomes oxygen ions. Protons generated on the negative electrode side move to the positive electrode side in the electrolyte membrane and react with oxygen ions to become water.

  Conventionally, as a method for producing an electrode of such a polymer electrolyte fuel cell, there has been a method in which an ink comprising catalyst-supported carbon fine particles, an electrolyte, and a solvent is directly applied to the surface of the electrolyte membrane and dried. In addition, there is a problem that cracks are likely to occur due to expansion and contraction of the solvent during drying.

  Thus, for example, Patent Document 1 proposes a method of manufacturing an electrode by electrostatically attaching an electrode material to the surface of the electrolyte membrane and thermally joining the attached electrode material and the electrolyte membrane.

JP-A-11-288728

However, in the method disclosed in Patent Document 1, when the electrode material is directly attached to the electrolyte membrane, a membrane electrode assembly in which the electrode material is embedded in the electrolyte membrane is formed. There was a risk of damage. In addition, simply attaching an electrode material such as catalyst-supported carbon particles using static electricity does not provide sufficient bonding strength between the formed electrode and the electrolyte membrane, resulting in a decrease in electrode quality and desired characteristics. There was a risk that the fuel cell could not be obtained.
The present invention has been made to solve such problems, and an object of the present invention is to provide a method and apparatus for manufacturing a membrane electrode assembly that can obtain high-quality electrodes with excellent productivity.

  The method for producing a membrane electrode assembly according to the present invention is a method for producing a membrane electrode assembly in which a catalyst electrode is joined to the surface of a solid polymer electrolyte membrane, wherein an adhesive layer is formed on the surface of the electrolyte membrane, and a powder The electrode material is fixed to the surface of the electrolyte membrane by adhering the electrode material to the adhesive layer and drying the adhesive layer.

The adhesion of the electrode material to the adhesive layer can be performed by charging and dispersing the electrode material and forming an electric field between the accommodating means for accommodating the electrode material and the surface of the electrolyte membrane.
In addition, the electrode material is dispersed by passing the electrode material that travels to the surface of the electrolyte membrane by receiving a force from an electric field through a vibration fluid, or by bringing the charged electrode material into a fluidized state. Can do.
The electrode material can be charged by an electric field formed between the containing means and the surface of the electrolyte membrane, or a net having a friction charging film formed on the surface is brought into contact with the fluidized electrode material. It can also be performed by vibrating.
In addition, the electrode material can be simultaneously charged and dispersed by placing the electrode material on the friction charging film and vibrating the friction charging film. At this time, the pulverization medium may be placed on the frictional charging film together with the electrode material.

Also, the electrode material is charged by friction with the carrier by mixing a carrier made of a magnetic material in the housing means, and an electromagnetic brush is formed on the magnet roller by the carrier to which the electrode material adheres, and the housing means and the electrolyte membrane The electrode material can also be detached from the carrier by an electric field formed between the surface and attached to the adhesive layer of the electrolyte membrane.
Preferably, an electrode material obtained by atomizing ink containing platinum-supporting carbon, an electrolyte, and a solvent by a spray drying method is used.

  An apparatus for manufacturing a membrane electrode assembly according to the present invention is an apparatus for manufacturing a membrane electrode assembly in which a catalyst electrode is bonded to the surface of a solid polymer electrolyte membrane. The charging means for charging the material, the dispersing means for dispersing the electrode material, and the electrode material charged by forming an electric field between the surface of the electrolyte membrane on which the adhesive layer is formed and the accommodating means And an electric field forming means for attaching to the adhesive layer. The electrode material is fixed on the surface of the electrolyte membrane by drying the adhesive layer of the electrolyte membrane.

Note that an electric field forming electrode on which an electrode material is placed can be provided in the housing means, and the electric field forming means can be configured to form an electric field between the surface of the electrolyte membrane and the electric field forming electrode.
Furthermore, the electric field forming means may also serve as the charging means. In this case, as the dispersing means, a vibration fluid disposed between the surface of the electrolyte membrane and the electric field forming electrode, or a fluidizing device for bringing the electrode material into a fluid state on the electric field forming electrode can be used.
Further, as a charging means and a dispersion means, a friction charging film formed on the surface of the electric field forming electrode and a vibration device for vibrating the electric field forming electrode are provided, and the electrode material is vibrated on the friction charging film. Thus, charging and dispersion can be performed. In this case, the grinding medium may be placed on the electric field forming electrode together with the electrode material. Further, a carrier made of a magnetic material can be used as a grinding medium, and a magnet can be disposed on the back side of the electric field forming electrode.

Further, as a dispersion means, a fluidizing device that makes the electrode material in a fluid state on the electric field forming electrode is used. You may use the net-like body in which this was formed, and the vibration apparatus which vibrates this net-like body.
Further, the charging means and the dispersion means include a magnet roller housed in the housing means and driven to rotate, and a carrier made of a magnetic material housed in the housing means together with the electrode material, and the electrode material is caused by friction with the carrier. It is also possible to form an electromagnetic brush on the magnet roller with a carrier charged and to which the electrode material is attached, and to receive the force from the electric field formed by the electric field forming means so that the electrode material is detached from the carrier.

  According to this invention, the adhesive layer is formed on the surface of the electrolyte membrane, and the powdered electrode material is attached to the adhesive layer, so that the adhesive layer functions like a buffer layer when attaching the electrode material. In addition, the electrode is bonded to the electrolyte membrane with sufficient strength without impairing the characteristics of the electrolyte membrane, and a high-quality electrode can be obtained with excellent productivity.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
Embodiment 1
FIG. 1 shows the configuration of a membrane electrode assembly manufacturing apparatus according to Embodiment 1 of the present invention. An upper electrode plate 1 and a lower electrode plate 2 for forming an electric field are arranged opposite to each other in parallel with a space therebetween. Between the upper electrode plate 1 and the lower electrode plate 2, a metal sieve 3 is disposed in parallel with the upper electrode plate 1 and the lower electrode plate 2, and the vibration device 4 is connected to the sieve 3. A power source 5 for forming an electric field between them is connected to the upper electrode plate 1 and the fluid 3, and an electric field in the same direction as the electric field by the power source 5 is formed between the fluid electrode 3 and the lower electrode plate 2. A power source 6 is connected.

Electric field forming means for forming an electric field between the upper electrode plate 1 and the lower electrode plate 2 is constituted by the upper electrode plate 1, the lower electrode plate 2, and the power sources 5 and 6. The upper electrode plate 1 and the lower electrode plate 2 can be formed of a conductive material such as aluminum.
Further, the lower electrode plate 2 also functions as a storage unit that stores the electrode material 7.
Further, the fluid 3 and the vibration device 4 constitute a vibration fluid as a dispersing means for dispersing the electrode material 7. Note that the vibration device 4 applies vibration to the fluid 3, and is formed of a vibrator or an ultrasonic vibrator.

Next, a method for producing a membrane electrode assembly using this production apparatus will be described. First, an adhesive is applied on the surface of the solid polymer electrolyte membrane 8 to form an adhesive layer 9, and the electrolyte membrane 9 is directed downward, that is, facing the lower electrode plate 2. 8 is attached to the lower surface of the upper electrode plate 1.
On the other hand, an electrode material 7 is placed on the lower electrode plate 2. Here, as the electrode material 7, it is possible to use an ink made of platinum-supported carbon, an electrolyte, and a solvent, which is granulated by a spray drying method.

  Then, an electric field is formed between the upper electrode plate 1 and the lower electrode plate 2 by the power sources 5 and 6 in a state where the fluid 3 is vibrated by the vibration device 4. The electrode material 7 on the lower electrode plate 2 is charged by this electric field, receives a force from the electric field, and proceeds toward the upper electrode plate 1 as indicated by an arrow in FIG. At this time, since the fluid 3 is present between the upper electrode plate 1 and the lower electrode plate 2, the electrode material 7 directed to the upper electrode plate 1 passes through the fluid 3. The vibration is given by. For this reason, even if the electrode material 7 is aggregated, the electrode material 7 is effectively dispersed by passing through the vibrating sieve 3 and the aggregation is eliminated. As a result, the electrode material 7 uniformly adheres to the adhesive layer 9 of the electrolyte membrane 8 attached to the lower surface of the upper electrode plate 1.

In this way, by drying the adhesive layer 9 to which the electrode material 7 is adhered, the electrode material 7 is fixed on the surface of the electrolyte membrane 8, and a catalyst electrode is formed.
Similarly, an adhesive layer 9 is formed on the other surface of the electrolyte membrane 8, and a catalyst electrode is formed by adhering the electrode material 7, thereby forming a membrane electrode in which the catalyst electrode is bonded to both surfaces of the electrolyte membrane 8. A joined body is manufactured.

  Examples of the adhesive layer 9 include a mixture obtained by mixing a platinum-carrying carbon and a dispersion of a proton conductive resin to a thickness of 10 to 100 μm. As the platinum-supported carbon, for example, TEC10E60E (platinum support concentration 55% by weight) manufactured by Tanaka Kikinzoku Co., Ltd. can be used.

  Here, a suitable proton conductive resin applied to the present invention will be described. In the present invention, either a proton conductive resin having an acidic group or a proton conductive resin having a basic group can be applied.

Proton conductive resin having an acidic group, for _{example, -SO 3 H, -COOH, -PO} (OH) 2, -POH (OH), - SO 2 NHSO 2 -, - Ph (OH) (Ph represents a phenyl group Having an ion exchange group such as Among them, as the acidic group, sulfonic acid group _(-SO 3 H) or phosphonic acid groups (-PO _{(OH) 2)} is more preferable.

As a representative example of such proton conductive resin, for example,
(A) Proton conductive resin in which a sulfonic acid group and / or a phosphonic acid group are introduced into a polymer whose main chain is an aliphatic hydrocarbon:
(B) A proton conductive resin in which a sulfonic acid group and / or a phosphonic acid group are introduced into a polymer in which all or part of the hydrogen atoms of an aliphatic hydrocarbon are substituted with fluorine atoms:
(C) Proton conductive resin in which a sulfonic acid group and / or a phosphonic acid group are introduced into a polymer having a main chain having an aromatic ring:
(D) Proton conductive resin in which a sulfonic acid group and / or a phosphonic acid group is introduced into a polymer such as polysiloxane or polyphosphazene substantially free of carbon atoms in the main chain:
(E) A sulfonic acid group is added to a copolymer composed of any two or more repeating units selected from repeating units constituting the sulfonic acid group and / or phosphonic acid group polymer before introduction of (A) to (D). And / or proton conductive resin into which phosphonic acid groups are introduced:
(F) The proton conductive resin etc. which contained the basic nitrogen atom in the principal chain or the side chain, and introduce | transduced acidic compounds, such as a sulfuric acid and phosphoric acid, by the ionic bond, etc. are mentioned.

  Examples of the proton conductive resin (A) include an ethylene-vinylsulfonic acid copolymer, a resin obtained by introducing a sulfonic acid group into a polyethylene or poly (α-methylstyrene) with a sulfonating agent, and the like. . Here, in the case of an ethylene-vinyl sulfonic acid copolymer, the ion exchange capacity can be controlled by the copolymerization ratio of ethylene and vinyl sulfonic acid used as a monomer. Moreover, the resin which introduce | transduced the sulfonic acid group into the polyethylene or poly ((alpha) -methylstyrene) with the sulfonating agent can control an ion exchange capacity with the usage-amount of a sulfonating agent.

  Examples of the proton conductive resin (B) include Naponion (registered trademark) manufactured by Dupont, Aciplex (registered trademark) manufactured by Asahi Kasei Kogyo Co., Ltd., and Flemion (registered trademark) manufactured by Asahi Glass Co., Ltd. . Further, a sulfone composed of a main chain made by copolymerization of a fluorocarbon vinyl monomer and a hydrocarbon vinyl monomer described in JP-A-9-102322 and a hydrocarbon side chain having a sulfonic acid group. Acid-type polystyrene-graft-ethylene-tetrafluoroethylene copolymer (ETFE) and fluorocarbon vinyl monomers and hydrocarbons described in US Pat. No. 4,012,303 or US Pat. No. 4,605,685 A sulfonic acid type poly (trifluorostyrene) made by copolymerization with α, β, β-trifluorostyrene grafted onto a vinyl monomer, and then introducing a sulfonic acid group into the proton conductive resin. -Graft-ETFE etc. are also mentioned.

  The proton conductive resin (C) may be one in which the main chain is interrupted by a hetero atom such as an oxygen atom. For example, polyether ether ketone, polysulfone, polyether sulfone, poly (arylene)・ Sulphonic acid groups are introduced into each unit polymer such as ether), polyimide, poly ((4-phenoxybenzoyl) -1,4-phenylene), polyphenylene sulfide, polyphenylquinoxalene, etc. using a sulfonating agent. Sulfoarylated polybenzimidazole, sulfoalkylated polybenzimidazole, phosphoalkylated polybenzimidazole (JP-A-9-110882), phosphonated poly (phenylene ether) (J. Appl. Polym. Sci. , 18, 1969 (1974)) etc. It is.

Examples of the proton conductive resin (D) include those obtained by introducing a sulfonic acid group into polyphosphazene.
These resins exemplified as (C) or (D) can also control the ion exchange capacity by the amount of the sulfonating agent used in the same manner as described above.

  As the proton conductive resin (E) described above, a sulfonic acid group and / or a phosphonic acid group are introduced into an alternating copolymer even if a random copolymer is introduced with a sulfonic acid group and / or a phosphonic acid group. The sulfonic acid group and / or the phosphonic acid group may be introduced into the block copolymer. Examples of the sulfonic acid group introduced into the random copolymer include a sulfonated polyethersulfone / dihydroxybiphenyl copolymer described in JP-A No. 11-116679. The ion exchange capacity can be controlled by the amount of the agent used.

Specific examples of the block copolymer having a sulfonic acid group and / or a phosphonic acid group in the proton conductive resin (E) described above include, for example, a sulfonic acid group described in JP-A No. 2001-250567. A block copolymer comprising a segment having hydrophilicity (hydrophilic segment) and a segment having substantially no ion exchange group (hydrophobic segment) is disclosed, and such block copolymer is disclosed as the hydrophilic segment. The ion exchange capacity can be controlled by the composition ratio between the hydrophobic segment and the hydrophobic segment.
In addition, examples of the proton conductive resin (F) include polybenzimidazole containing phosphoric acid described in JP-A-11-503262, which is the amount of phosphoric acid to be contained. The ion exchange capacity can be controlled.

  Examples of the dispersion of the proton conductive resin include a solution obtained by using a good solvent of the above proton conductive resin, and a solution emulsified in a poor solvent. For example, a 5% Nafion solution (5% alcohol aqueous solution: Aldrich) is used. Chemical Company). The solvent of the dispersion is preferably one that does not dissolve the solid polymer electrolyte membrane.

The mixing ratio of the platinum-supported carbon and the proton conductive resin dispersion may be a ratio that leads to the degree that both protons and electrons can be conducted when the dry film is formed. About 0.1 to 2 is preferable. The solid content concentration of the dispersion is not particularly limited as long as it has a viscosity to which the electrode material 7 is easily attached, but is preferably about 0.1 to 10% by weight. If the concentration is lower than this, it is difficult to produce sufficient bonding strength. If the concentration is higher than this, the viscosity is increased and the mutual contact between the powdered electrode materials 7 tends to be impaired.
In Embodiment 1, after the adhesive layer 9 is formed on the surface of the electrolyte membrane 8, the electrolyte membrane 8 is pasted on the lower surface of the upper electrode plate 1. However, the present invention is not limited to this. The adhesive film 9 may be formed by applying the electrolyte membrane 8 to the lower surface of the plate 1 and then applying an adhesive on the surface of the electrolyte membrane 8.
As the lower electrode plate 2, a conductive material coated with an insulating material may be used without using the conductive material as it is.

Embodiment 2
FIG. 2 shows the configuration of a membrane / electrode assembly manufacturing apparatus according to Embodiment 2 of the present invention. The second embodiment uses the porous lower electrode plate 10 instead of the lower electrode plate 2 in the manufacturing apparatus of the first embodiment described above, and forms a chamber 11 below the lower electrode plate 10. A fluidizing device is formed by connecting a compressed gas source (not shown) to the lower electrode plate 10, the chamber 11, and a compressed gas source.

When compressed air or compressed nitrogen is supplied from the compressed gas source to the chamber 11, the compressed air or compressed nitrogen is blown upward from the upper surface of the lower electrode plate 10 through the porous lower electrode plate 10. As a result, the electrode material 7 placed on the lower electrode plate 10 is in a fluid state. The electrode material 7 is dispersed by the fluidization, is charged by the electric field, and proceeds toward the upper electrode plate 1. The electrode material 7 is further dispersed by the vibrating sieve 3 and attached to the adhesive layer 9 of the electrolyte membrane 8. By drying the adhesive layer 9 to which the electrode material 7 is attached in this manner, the electrode material 7 is fixed on the surface of the electrolyte membrane 8, and a membrane electrode assembly is formed.
In addition, when the electrode material 7 is sufficiently dispersed only by fluidization, the fluid 3 and the vibration device 4 may be omitted.

Embodiment 3
FIG. 3 shows the configuration of a membrane electrode assembly manufacturing apparatus according to Embodiment 3 of the present invention. In Embodiment 3, the frictional coating 12 is formed on the upper surface of the lower electrode plate 2 in place of the fluid 3, the vibration device 4, and the power sources 5 and 6 in the manufacturing apparatus of Embodiment 1 described above. A vibration device 13 for vibrating the lower electrode plate 2 is disposed on the lower surface side of the electrode plate 2, and a power source 14 is connected to the upper electrode plate 1 and the lower electrode plate 2.
For example, Teflon (registered trademark) is used as the friction charging film 12, and a vibrator or an ultrasonic vibrator can be used as the vibration device 13.

  The electrode material 7 is placed on the friction charging film 12 of the lower electrode plate 2. When the lower electrode plate 2 is vibrated by the vibration device 13 in this state, the electrode material 7 is charged and dispersed by friction with the friction charging film 12. Therefore, the electrode material 7 receives the force from the electric field formed between the upper electrode plate 1 and the lower electrode plate 2 by the power source 14 and proceeds toward the upper electrode plate 1, and the adhesive layer of the electrolyte membrane 8. 9 uniformly adheres. By drying the adhesive layer 9 to which the electrode material 7 is attached in this manner, the electrode material 7 is fixed on the surface of the electrolyte membrane 8, and a membrane electrode assembly is formed.

Embodiment 4
FIG. 4 shows the configuration of a membrane electrode assembly manufacturing apparatus according to Embodiment 4 of the present invention. In the fourth embodiment, the grinding medium 15 is placed on the friction charging film 12 together with the electrode material 7 in the manufacturing apparatus of the third embodiment described above.

  The grinding medium 15 is made of, for example, ceramics and has a larger diameter than the electrode material 7. When the lower electrode plate 2 is vibrated by the vibration device 13, the vibration is transmitted to the grinding medium 15 together with the electrode material 7, and the grinding material 15 moves relative to the electrode material 7, so that the electrode material 7 is aggregated. Even so, it is dispersed by the grinding medium 15 and aggregation is eliminated. For this reason, the electrode material 7 is more effectively dispersed, and the electrode material 7 uniformly adheres to the adhesive layer 9 of the electrolyte membrane 8. By drying the adhesive layer 9 to which the electrode material 7 is attached in this manner, the electrode material 7 is fixed on the surface of the electrolyte membrane 8, and a membrane electrode assembly is formed.

Embodiment 5
FIG. 5 shows the configuration of a membrane electrode assembly manufacturing apparatus according to Embodiment 5 of the present invention. In the fifth embodiment, in the manufacturing apparatus of the second embodiment described above, instead of the fluid 3, the vibration device 4, and the power sources 5 and 6, a mesh body 16 is disposed on the upper part of the fluidizing device and the mesh body 16 is arranged. The vibration device 17 is connected to the upper electrode plate 1 and the lower electrode plate 2 to which the power source 14 is connected. A frictional charging film made of Teflon (registered trademark) or the like is formed on the surface of the net 16. As the vibration device 17, a vibrator or an ultrasonic transducer can be used.

  The mesh body 16 is installed at a height such that the mesh body 16 is brought into contact with the electrode material 7 that has been brought into a fluid state by the fluidizing device. 16 is charged by friction with 16 and receives a force from the electric field formed between the upper electrode plate 1 and the lower electrode plate 2 by the power source 14 and travels toward the upper electrode plate 1. The electrode material 7 is dispersed by fluidization, but is further dispersed by passing through the mesh 16 and is uniformly attached to the adhesive layer 9 of the electrolyte membrane 8. By drying the adhesive layer 9 to which the electrode material 7 is attached in this manner, the electrode material 7 is fixed on the surface of the electrolyte membrane 8, and a membrane electrode assembly is formed.

Embodiment 6
FIG. 6 shows the configuration of a membrane electrode assembly manufacturing apparatus according to Embodiment 6 of the present invention. In this sixth embodiment, in the manufacturing apparatus of the fourth embodiment described above, a carrier 18 made of a magnetic material is used as a grinding medium instead of the grinding medium 15 made of ceramics, and a magnet 19 is provided on the lower surface side of the lower electrode plate 2. The wire mesh 20 is disposed between the upper electrode plate 1 and the lower electrode plate 2, the power source 5 is connected to the upper electrode plate 1 and the wire mesh 20 instead of the power source 14, and the power source 6 is connected to the metal mesh 20 and the lower electrode plate 2. Are connected.

  When the lower electrode plate 2 is vibrated by the vibration device 13, the electrode material 7 is charged by friction with the friction charging film 12 and friction with the carrier 18, and vibration is also transmitted to the carrier 18, and When the carrier 18 moves relatively, even if the electrode material 7 is aggregated, it is dispersed by the carrier 18 and the aggregation is eliminated. Further, the carrier 18 is connected by the magnetic force from the magnet 19 to form an electromagnetic brush between the lower electrode plate 2 and the wire mesh 20, and the charged electrode material 7 adheres to the carrier 18. The electromagnetic brush is vibrated by the vibration device 13 and the electrode material 7 receives a force from the electric field formed between the wire mesh 20 and the lower electrode plate 2, and the electrode material 7 is detached from the carrier 18 forming the electromagnetic brush. . The electrode material 7 that has passed through the wire mesh 20 further receives a force from the electric field formed between the upper electrode plate 1 and the wire mesh 20, travels toward the upper electrode plate 1, and the adhesive layer 9 of the electrolyte membrane 8. It adheres evenly. By drying the adhesive layer 9 to which the electrode material 7 is attached in this manner, the electrode material 7 is fixed on the surface of the electrolyte membrane 8, and a membrane electrode assembly is formed.

  Note that the vibration device 13 may be omitted and the magnet 19 may be rotated. The carrier 18 forming the electromagnetic brush moves by the rotation of the magnet 19, and the electrode material 7 is charged by the friction with the carrier 18 or by the electric field and adheres to the carrier 18. The electromagnetic brush is moved by the rotation of the magnet 19 and the electrode material 7 receives a force from the electric field formed between the wire mesh 20 and the lower electrode plate 2, so that the electrode material 7 is detached from the carrier 18, It adheres to the adhesive layer 9.

Embodiment 7
FIG. 7 shows the configuration of a membrane electrode assembly manufacturing apparatus according to Embodiment 7 of the present invention. A hopper 22 is installed on the top of the container 21 and an opening 23 is formed at one end of the container 21. A mixing drum 24 is rotatably provided in the container 21, and a rotary shell 25 is rotatably disposed near the opening 23. A magnet 26 is fixed inside the rotary shell 25, and the rotary shell 25 and the magnet 26 constitute a magnet roller. A doctor blade 27 is fixed in the container 21 in the vicinity of the outer peripheral surface of the rotary shell 25. A predetermined amount of carrier 28 made of a magnetic material is accommodated in the container 21. An electrode plate 29 for forming an electric field is disposed in front of the opening 23 of the container 21, and a power source 30 for forming an electric field is connected between the electrode plate 29 and the rotating shell 25.

First, the adhesive layer 9 is formed on the surface of the electrolyte membrane 8, and the electrolyte membrane 8 is attached to the electrode plate 29 so that the adhesive layer 9 faces the opening 23 of the container 21. The rotating shell 25 is rotated at a predetermined speed, and an electric field is formed between the rotating shell 25 and the electrode plate 29 by the power source 30. In this state, the electrode material 7 is supplied from the hopper 22 into the container 21, and the mixing drum When 24 is driven to rotate, the electrode material 7 is charged and dispersed by friction with the carrier 28. Further, the magnetic force from the magnet 26 causes the carrier 28 to continue on the surface of the rotary shell 25 to form the electromagnetic brush 31, and the charged electrode material 7 adheres to the carrier 28. When the electromagnetic brush 31 formed in this way rotates together with the rotating shell 25 and reaches the opening 23 of the container 21, the electrode material 7 is transferred to the carrier by the electric field formed between the rotating shell 25 and the electrode plate 29. Detach from 28, proceed toward the electrode plate 29, and uniformly adhere to the adhesive layer 9 of the electrolyte membrane 8. By drying the adhesive layer 9 to which the electrode material 7 is attached in this manner, the electrode material 7 is fixed on the surface of the electrolyte membrane 8, and a membrane electrode assembly is formed.
The supply speed of the electrode material 7 can be controlled by adjusting the rotation speed of the rotary shell 25.

As shown in each of the embodiments described above, according to the manufacturing method of the present invention, an electrode in which an electrode material is fixed uniformly and with sufficient bonding strength is formed on the electrolyte membrane without impairing the characteristics of the electrolyte membrane. The A membrane electrode assembly in which such electrodes are formed on both surfaces of the electrolyte membrane efficiently supplies a fuel gas such as hydrogen and an oxidant gas such as air (or oxygen) to the electrodes of the membrane electrode assembly. A fuel cell is formed by combining a gas diffusion layer to be supplied, a separator, and a sealant that prevents gas ejection.
Since the membrane / electrode assembly obtained by the present invention has an electrode that has almost no aggregate in which the electrode material is non-uniformly aggregated, the surface area of platinum per unit area of the electrode material is wider than that of the conventional electrode, and the fuel cell Therefore, it is possible to efficiently advance the electrode reaction according to the above, so that a fuel cell having excellent power generation performance can be obtained.
In addition, the electrode obtained by the manufacturing method of the present invention does not embed the electrode material in the electrolyte membrane unlike the electrode disclosed in Patent Document 1, so that the electrolyte membrane itself is not significantly damaged, The reliability of the said membrane electrode assembly can be improved, and the manufacturing method of the fuel cell excellent in productivity can be provided.

It is sectional drawing which shows the structure of the manufacturing apparatus of the membrane electrode assembly which concerns on Embodiment 1 of this invention. 6 is a cross-sectional view showing a configuration of a manufacturing apparatus for a membrane / electrode assembly according to Embodiment 2. FIG. 6 is a cross-sectional view showing a configuration of a manufacturing apparatus for a membrane / electrode assembly according to Embodiment 3. FIG. 6 is a cross-sectional view showing a configuration of a manufacturing apparatus for a membrane electrode assembly according to Embodiment 4. FIG. FIG. 10 is a cross-sectional view illustrating a configuration of a manufacturing apparatus for a membrane / electrode assembly according to Embodiment 5. FIG. 10 is a cross-sectional view illustrating a configuration of a manufacturing apparatus for a membrane / electrode assembly according to Embodiment 6. FIG. 10 is a cross-sectional view showing a configuration of a manufacturing apparatus for a membrane / electrode assembly according to Embodiment 7.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Upper electrode plate, 2,10 Lower electrode plate, 3 Fluid, 4 Vibration apparatus, 5, 6, 14, 30 Power supply, 7 Electrode material, 8 Electrolyte film, 9 Adhesive layer, 11 Chamber, 12 Friction charging film, 13, 17 Vibration device, 15 Grinding medium, 16 Net body, 18, 28 Carrier, 19, 26 Magnet, 20 Wire mesh, 21 Container, 22 Hopper, 23 Opening, 24 Mixing drum, 25 Rotating shell, 27 Doctor blade, 29 Electrode plate, 31 electromagnetic brush.

Claims (20)

In a method for producing a membrane electrode assembly in which a catalyst electrode is joined to the surface of a solid polymer electrolyte membrane,
Forming an adhesive layer on the surface of the electrolyte membrane,
Adhering a powdered electrode material to the adhesive layer;
A method for producing a membrane electrode assembly, comprising drying the adhesive layer to fix the electrode material on the surface of the electrolyte membrane. The adhesion of the electrode material to the adhesive layer is
Charging and dispersing the electrode material;
The method for producing a membrane / electrode assembly according to claim 1, wherein the method is performed by forming an electric field between a storage unit that stores the electrode material and a surface of the electrolyte membrane.   The method for producing a membrane / electrode assembly according to claim 2, wherein the electrode material is dispersed by passing the electrode material that travels to the surface of the electrolyte membrane under a force from an electric field through a vibration fluid.   The manufacturing method of the membrane electrode assembly according to claim 2, wherein dispersion is performed by bringing the charged electrode material into a fluid state.   The manufacturing method of the membrane electrode assembly as described in any one of Claims 2-4 which charges the said electrode material with the electric field formed between the said accommodating means and the surface of the said electrolyte membrane.   5. The method for producing a membrane electrode assembly according to claim 4, wherein the electrode material is charged by bringing a mesh body having a frictional charging film formed on the surface thereof into contact with the fluidized electrode material and vibrating.   3. The method for producing a membrane electrode assembly according to claim 2, wherein the electrode material is placed on the frictional charging film and the electrode material is charged and dispersed by vibrating the frictional charging film.   The manufacturing method of the membrane electrode assembly according to claim 7, wherein a grinding medium is placed on the friction charging film together with an electrode material. Charging the electrode material by friction with the carrier by mixing a carrier made of a magnetic material in a receiving means having a magnet roller;
An electromagnetic brush is formed on the magnet roller by the carrier to which the electrode material is attached,
The method for producing a membrane electrode assembly according to claim 2, wherein the electrode material is separated from the carrier by an electric field formed between the housing means and the surface of the electrolyte membrane.   The said electrode material is a manufacturing method of the membrane electrode assembly as described in any one of Claims 1-9 obtained by granulating the ink containing platinum carrying | support carbon, electrolyte, and a solvent by the spray-drying method. . In an apparatus for manufacturing a membrane electrode assembly in which a catalyst electrode is bonded to the surface of a solid polymer electrolyte membrane,
Storage means for storing powdered electrode material;
Charging means for charging the electrode material;
A dispersing means for dispersing the electrode material;
Electric field forming means for adhering the electrode material charged by forming an electric field between the surface of the electrolyte membrane on which the adhesive layer is formed and the housing means to the adhesive layer of the electrolyte membrane, and An apparatus for manufacturing a membrane electrode assembly, wherein the electrode material is fixed on the surface of the electrolyte membrane by drying the adhesive layer of the electrolyte membrane. The housing means has an electric field forming electrode on which the electrode material is placed,
12. The apparatus for manufacturing a membrane electrode assembly according to claim 11, wherein the electric field forming means forms an electric field between a surface of the electrolyte membrane and the electric field forming electrode.   13. The apparatus for manufacturing a membrane electrode assembly according to claim 12, wherein the electric field forming unit also serves as the charging unit.   The membrane electrode assembly manufacturing apparatus according to claim 13, wherein the dispersing means is a vibrating screen disposed between a surface of the electrolyte membrane and the electric field forming electrode.   14. The apparatus for manufacturing a membrane electrode assembly according to claim 13, wherein the dispersing means comprises a fluidizing device that causes the electrode material to flow on the electric field forming electrode.   The charging means and the dispersing means include a friction charging film formed on the surface of the electric field forming electrode and a vibration device for vibrating the electric field forming electrode, and the electrode material is used as the friction charging film. 13. The apparatus for producing a membrane electrode assembly according to claim 12, wherein charging and dispersion are performed by vibrating above.   The apparatus for manufacturing a membrane electrode assembly according to claim 16, further comprising a grinding medium placed on the electric field forming electrode together with the electrode material. It further includes a magnet disposed on the back side of the electric field forming electrode,
The apparatus for manufacturing a membrane electrode assembly according to claim 17, wherein a carrier made of a magnetic material is used as the grinding medium. The dispersing means comprises a fluidizing device for bringing the electrode material into a fluidized state on the electric field forming electrode,
13. The charging means includes a mesh body that is in contact with the electrode material that has been fluidized by the fluidizing device and has a friction charging film formed on a surface thereof, and a vibration device that vibrates the mesh body. The manufacturing apparatus of the membrane electrode assembly as described in 2. The charging unit and the dispersion unit include a magnet roller housed in the housing unit and driven to rotate, and a carrier made of a magnetic material housed in the housing unit together with the electrode material,
The electrode material is charged by friction with the carrier, an electromagnetic brush is formed on the magnet roller by the carrier to which the electrode material is attached,
12. The apparatus for manufacturing a membrane electrode assembly according to claim 11, wherein the electrode material is detached from the carrier in response to a force from an electric field formed by the electric field forming means.

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