WO2005074061A1

WO2005074061A1 - Solid polymer membrane fuel cell manufacturing method

Info

Publication number: WO2005074061A1
Application number: PCT/JP2004/019845
Authority: WO
Inventors: Akira Fujiki; Yukihiro Maekawa; Takeshi Shimizu; Takayuki Hirao; Masanori Iwamoto; Sadao Miki; Haruhiko Suzuki; Hiroshi Saitou
Original assignee: Nissan Motor Co., Ltd.
Priority date: 2004-01-28
Filing date: 2004-12-28
Publication date: 2005-08-11
Also published as: KR100737660B1; CN1906787A; JP2005216598A; KR20070001104A; DE112004002695T5

Abstract

A method for manufacturing a solid polymer membrane fuel cell in which a first gas-diffusing layer (6A) and a first separator (7A) are formed on one side of a membrane electrode composite body (9) and a second gas-diffusing layer (6B) and a second separator (7B) are formed on the other. An adhesive is applied to the contact surfaces of the first separator (7A) and the first gas-diffusing layer (6A), and an adhesive is applied to the contact surfaces of the second separator (7B) and the second gas-diffusing layer (6B). The first separator (7A), the first gas-diffusing layer (6A), the membrane electrode composite body (9), the second gas-diffusing layer (6B), and the second separator (7B) are stacked in order of mention between a pair of pressing jigs (113, 123). While the first and second separators (7A, 7B) are being compressed by means of the pressing jigs (113, 123), they are heated, thus manufacturing a one-piece fuel cell.

Description

Specification

TECHNICAL FIELD The present invention relates to a method for manufacturing a solid polymer membrane fuel cell. BACKGROUND OF THE INVENTION JP2001-236971A, published by the Japan Patent Office in 2001, discloses a method for manufacturing a solid polymer membrane fuel cell.

According to this manufacturing method, first, a catalyst is applied to both sides of a solid polymer membrane and dried to obtain a membrane electrode assembly (MEA). On the other hand, an electrolyte solution is applied to two gas diffusion layers (GDLs) prepared in advance, and the membrane electrode assembly is sandwiched between the two GDLs so that the applied surfaces are in contact with the MEA and integrated with a hot roll. I do. This is called the first unit

On the other hand, two second units are formed by bonding the cell frames to the two separations and adding the holes.

Finally, the first unit is sandwiched between two second units, and a hot roll is added to complete the solid polymer membrane fuel cell. DISCLOSURE OF THE INVENTION According to the prior art, a process for obtaining a first unit by integrating a gas diffusion layer into a membrane electrode assembly, and a solid polymer membrane fuel by integrating a first unit and a second unit. Battery ^ Process is performed sequentially, so the manufacturing process becomes longer.

An object of the present invention is therefore to shorten the manufacturing process of a polymer electrolyte fuel cell.

In order to achieve the above object, the present invention provides a solid polymer film, a first gas diffusion layer and a first separator over one surface of a solid polymer film, Provided is a method for manufacturing a solid polymer membrane fuel cell in which a second gas diffusion layer and a second separator are laminated on one surface.

The manufacturing method includes applying an adhesive to a contact surface of the first separator with the first gas diffusion layer, and applying an adhesive to a contact surface of the second separator with the second gas diffusion layer. The first separation layer, the first gas diffusion layer, the solid polymer film, the second gas diffusion layer, and the second separation layer are arranged between the pair of holding jigs in the stated order, An integrated fuel cell is obtained by heating the first and second separators while compressing them with a holding jig.

The details of the invention, as well as other features and advantages, are set forth in the accompanying description as well as set forth in the following description of the specification. '' Brief description of the drawings

FIG. 1 is a schematic configuration diagram of a manufacturing apparatus illustrating a manufacturing process of a polymer electrolyte membrane fuel cell according to the present invention.

FIG. 2 is a schematic plan view of a supply mechanism for explaining a supply structure of a separator to a production apparatus.

FIG. 3 is a schematic configuration diagram of a manufacturing apparatus for explaining a hot pressing step according to the present invention.

FIG. Is an exploded vertical sectional view of the polymer electrolyte membrane fuel cell and the holding jig.

FIG. 5 is similar to FIG. 4, but shows another embodiment of the holding jig. Kasumiga 19845

-3-

FIG. 6 is similar to FIG. 6, but shows yet another embodiment of a holding jig. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 3 of the drawings, a polymer electrolyte membrane fuel cell includes a membrane electrode assembly (MEA) 9, a first gas diffusion layer (GDL) 6A, and a second gas diffusion layer (MED). GDL) 6B, and the first separator 7A and the second separator 7B are integrated by using a pair of holding jigs 113 and 123. The MEA 9, the gas diffusion layers 6A and 6B, and the separators 7A and 7B all have a rectangular planar shape.

MEA 9 has a structure in which a first catalyst layer 8A and a second catalyst layer 8B are formed at regular intervals on both surfaces of a solid polymer film 5 made of a perfluoroethylene sulfonic acid resin film. The catalyst layers 8A and 8B are formed by applying an electrolyte solution containing platinum as a catalyst to the solid polymer film 5 in advance.

One of the catalyst layers 8A and 8B constitutes the anode of the fuel cell, and the other constitutes the cathode of the fuel cell. The first catalyst layer 8A, the first GDL 6A, and the first separator 7A are disposed below the solid polymer film 5, and the second catalyst layer 8B, the second GDL 6B, and the second The separator 7B is disposed below the solid polymer film 5. The holding jig 123 contacts the first separator 7A from below, and the holding jig 113 contacts the second separator 7B from above.

As shown in FIG. 1, MEA 9 is supplied as roll 100. To protect the catalyst layers 8A, 8B, the MEA 9 is wound on a roll with its surface covered with a protective film.

GDL 6A and 6B are made of carbon cloth and carbon paper with water repellent treatment. The role of dispersing the anode gas and power source gas supplied from Separators 7A and 7B while diffusing them into the catalyst layers 8A and 8B. have. The GDLs 6A and 6B are supplied in a state where they are mounted in advance inside a frame 6C made of an electrically insulating material. 2004/019845

-4-The first separator 7A has a grooved gas passage 7C on one side facing the first GDL 6A. In order to prevent gas from leaking from the gas passage 7C, a sealing groove 7E for filling a sealing gasket 10 is formed along the outer periphery of the first separator 7A. Further, a groove-shaped coolant passage 7D and a seal groove 7E for filling a gasket 10 for sealing are formed on the other surface of the first separator 7A.

The second separator 7B has a groove-shaped gas passage 7C on one side facing the second GDL 6B. In order to prevent gas from leaking from the gas passage 7C, a seal groove 7E for filling a gasket 10 for sealing is formed along the outer periphery of the second separator 7A. The other side of the second Separation 7B is flat.

The coolant passage 7D of the first separator 7A does not necessarily have to be formed, depending on the specifications of the fuel cell to be manufactured. In that case, the first separation 7B may be the same as the separation 7A and the second separation 7B. Depending on the specifications of the fuel cell, instead of the coolant passage 7D, it is possible to form a gas passage for another adjacent fuel cell at the time of stacking.

Separators 7A and 7B are formed by mixing graphite powder and plastic powder and compression-molding them with a heated press using a mold. Alternatively, it can be formed by press forming an expanded graphite sheet. Further, it can be formed using a metal. The desired characteristics of Separators 7A and 7B are low electrical resistance and low gas permeability. Furthermore, in order to reduce the thickness of Separators 7A and 7B, it is desirable that they have excellent mechanical strength. Metal separators can meet these requirements.However, since separators 7A and 7B are exposed to both oxidizing and reducing atmospheres, it is necessary to use a corrosion-resistant metal or perform surface treatment with metal plating. preferable.

Referring to FIG. 1, the present invention uses MEA 1, GDL 6A, 6E and Separation 7A, 7B configured as described above by using press machine 101 provided with holding jigs 113 and 123. Braid Stand up.

The MEA 9 is sent from the roll 100 to the press 101 in a substantially horizontal direction by a transport mechanism including a transport roller 102, a belt conveyor 103, and a discharge roller 104. Preferably, transport holes are formed at regular intervals on both sides of the MEA 9, and projections engaging with the transport holes are formed on the transport roller 102 and the discharge roller 104 at equal angular intervals. With such a configuration, it is possible to prevent the MEA 9 from being loosened during transportation, and to supply the MEA 9 to the press 101 with a certain length according to the interval at which the catalyst layer 8 is formed. It is also preferable to attach marks corresponding to the positions of the catalyst layers 8A and 8B to the MEA 9, and to arrange a sensor for reading the marks on the press 101. By feeding the MEA 9 based on the mark read by the sensor, the catalyst layers 8A and 8B can be accurately arranged at predetermined working positions in the press 101.

The protective film covering the surface of the MEA 9 is taken up by the protective film take-up roller 105 when the MEA 1 is fed from the roll 100.

The first GDL 6A is supplied to the press 101 via the transport mechanism including the transport roller 106A, the belt conveyor 107, and the discharge roller 108, and passes below the MEA 9 to the press 101. The second GDL 6B is supplied to the press 101 through the MEA 9 by the same transport mechanism.

The initial position of the transport of the first GDL 6A and the second GDL 6fB is a position over the transport roller 106 and the pelt conveyor 107, respectively. Delivery of GDLs 6A and 6B to these two initial positions is performed by the supply mechanism 200 shown in FIG.

Referring to FIG. 2, the supply mechanism 200 is disposed beside the transport roller 106 and the belt conveyor 107. The supply mechanism 200 includes a loading stage 201 and a robot 203. The robot 203 has a rotating robot arm 202. The GDLs 6A and 6B carried into the carry-in stage 201 are gripped by the rotating robot arm 202 and set to the expected position. The The mouth pot 203 has a structure in which GDLs 6A and 6B can be set at both the initial position of the first GDL: 6A of MEA 1 and the initial position of the second GDL 6B.

Referring again to FIG. 1, the first separator 7A is sent out to the press 101 by a transport mechanism including a transport roller 109, a belt conveyor 110, and a discharge roller 111. The second separator 7B is also sent out to the press 101 by another transport mechanism having the same configuration.

The transport mechanism of the first separator 7A is located below the transport mechanism of the first GDL 6A. The transport mechanism of the second separator 7B is located further above the transport mechanism of the second GDL 6B.

The initial positions of transport of the first separator 7A and the second separator 7B are positions that extend over the transport opening 109 and the belt conveyor 110, respectively. The delivery of Separation 7A and 7B to these two initial positions will be carried out by a supply mechanism configured in the same way as the supply mechanism of GDL 6A and 6B. The supply mechanism of Separators 7A and 7B is preferably arranged on the opposite side of the supply mechanism of GDL 6A and 6B so as not to interfere with the supply mechanism of GDL 6A and 6B.

With the above configuration, the press machine 101 is supplied with the first separator 7A, the first GDL 6A, the MEA 9, the second GDL 6B, and the second separator 7B in this order.

Press 101 includes a lifting table 112, the _c lifting table 112 of support 120 which is fixed to the upper first separator Isseki 7A, the first GDL 6A, MEA 9, the second

A holding jig 113 for placing the GDL 6B and the second separator 7B, and a vertical shaft 113A supporting the holding jig 113 are provided. A rack 114 is formed on the shaft 113A. The lifting table 112 further includes a pinion 115 that fits into the rack 114, a servomotor 116 that rotates the pinion 115, and a bearing 117 that guides the shaft 113A up and down. The holding jig 113 has a built-in heater 118. The support 120 includes a holding jig 123 for supporting the fuel cell components pushed up by the lifting table 112 downward. A heater 121 is embedded in the holding jig 123. Regarding the transport direction of the MEA 9, a pair of cuts for cutting the MEA 9 are provided on the front and back of the support 120.

122 is attached.

Next, with reference to FIG. 3, a hot press process by the press machine 101 will be described.

Adhesives containing phenolic or epoxy thermosetting resin are applied to limited surfaces of the two GDLs 6A and 6B facing the MEA 9 in advance. The application of the adhesive is performed in the supply mechanism 200 or in the process of transporting the GDLs 6A and 6B by the transport mechanism.

For the second GDL 6B, set to so applying an adhesive to the lower surface, the application position of the adhesive conveyance roller 102 does not interfere with the belt conveyor 103 and the discharge roller 104, the position _c

Adhesives containing phenolic or epoxy thermosetting resin are applied to the surfaces of the two separators 7A and 7B facing GDL 6A and 6B, respectively. Specifically, in FIG. 3, an adhesive is applied to the partition wall 7F located between the gas passages 7C of the separators 7A and 7B. The adhesive is applied in the supply mechanism of Separators 7A and 7B or during the transport process of Separators 7A and 7B by the transport mechanism. Since adhesive is applied to the lower surface of Separator 7A, the adhesive application position is set so as not to interfere with the transport roller 109, belt conveyor 110, and discharge roller 111.

Hot pressing is a process in which MEA 9, GDL 6A, 6B and separators 7A, 7B are pressed while being heated, and these members are integrated by thermocompression bonding or thermal bonding.

Each transport mechanism has the first separation 7A, the first GDL 6A, the MEA 9, the second

After laminating the GDL 6B and the second separator 7B in this order on the holding jig 113, the press 101 rotates the pinion 115 by the operation of the servo motor 116 as shown in FIG. And press the holding jig 113 toward the support 120 through the shaft 113A. increase.

Referring to FIG. 4, as the presser jig 113 rises, the second separator 7B located at the top of the laminate comes into contact with the presser jig 123 of the support 120. The holding jig 123 is heated by the heater 121 and the holding jig 113 is heated by the heater 118 in advance in the range of 80 to 150 degrees Celsius, respectively. In the figure, the MEA 9, GDL 6A, 6B and separators 7A, 7B are separated from each other for explanation, but when the holding jig 113 actually rises, these members are stacked. Rise in state.

After the second separation tray 7B abuts on the holding jig 123, the holding jig 113 is vertically moved to MEA 9, GDL 6A, 6B and separation jigs 7A, 7B stacked with the holding jig 123. And apply the specified pressure and heat. As a result, the adhesive applied to GDL 6A, 6B is thermally bonded to MEA 9. Specifically, when the thermosetting agent contained in the adhesive is cured by heating, the MEA 9 and the GDL 6A, 6B are firmly bonded.

The adhesive is applied only to a limited area, not to the entire surface of DGL 6A, 6B as described above. Therefore, in the fuel cell after completion, diffusion and permeation of the gas from the GDLs 6A and 6B to the catalyst layers 8A and 8B are performed without being hindered by the adhesive. The electrolyte constituting the catalyst layers 8A and 8B is thermocompression-bonded to the GDLs 6A and 6B even on the side where no adhesive is applied, and the GDLs 6A and 6B and the catalyst layers 8A and 8B are brought into close contact with each other by the anchor effect.

The adhesive applied to the partition 7F of the separators 7A and 7B also firmly adheres the separators 7A and 7B to the GDLs 6A and 6B by curing the thermosetting agent.

In this way, the first stacked 7A, the first GDL 6A, the MEA 9, the second GDL 6B, and the second stacked 7A are stacked in this order in a single pot pressing process. The fuel cell is completed in a short time.

The fuel cells integrated in the press machine 101 are carried out to a collecting place by a robot 300 having a mouth pot 301 shown in FIGS. 2004/019845

After that, the supply mechanism and the transport mechanism again supply the separator 7A, GDL 6A, MEA 9, GDL 6B and separator 7B to the press machine 101, and integrate these parts by the press machine 101. And the transfer of the integrated fuel cell to the collection location by the robot 300 are repeatedly performed.

As described above, according to the present invention, since the separator 7A, GDL 6A, MEA 9, GDL 6B and separator 7B are integrated in a single hot press step, the manufacturing process of the polymer electrolyte membrane fuel cell is shortened. be able to.

In the above embodiment, MEA 9 in which catalyst layers 8A and 8B are coated at regular intervals on both surfaces of solid polymer membrane 5 is used, but catalyst layers 8A and 8B are formed on the surfaces of GDLs 6A and 6B. It is also possible. In this case, the transport mechanism including the transport roller 102, the belt conveyor 103, and the discharge roller 104 supplies the single solid polymer film 5 to the press 101. On the other hand, the supply mechanism 200 of the GDLs 6A and 6B supplies the catalyst layers 8A and 8B to the surfaces of the GDLs 6A and 6B facing the solid polymer film 5, and then supplies the GDLs 6A and 6B to the initial transport position. In this case, the catalyst layers 8A and 8B are thermocompression-bonded to the solid polymer film 5 by hot pressing in a press 101. It is also possible to apply the catalyst layers 8A and 8B to predetermined positions of the solid polymer film 5 in the process of transporting the solid polymer film 5.

The subject of the method of manufacturing a fuel cell according to the present invention is hot pressing by a press 101, and any method may be used for supplying members to the press 101 and unloading the integrated fuel cell.

Next, with reference to FIG. 5, a second embodiment of the present invention relating to the shape of the holding jig 113 of the press 101 will be described.

This embodiment is characterized by the shape of the upper surface of the holding jig 113. Here, instead of forming the upper surface of the holding member H113 into a flat surface, an upward band-like projection 13 that fits into the groove-shaped coolant passage 7D formed in the first separator 7A is formed. This is the holding jig 1 13 By forming such strip-like projections 13, the separation 7A can be accurately positioned. Further, when forming Separete 7A with graphite, it is difficult for the press 101 to apply a sufficient compressive force to the laminate due to the brittleness of the graphite. As in this embodiment, the band-shaped projections 13 of the holding jig 113 are fitted into the groove-shaped cooling passages 7D of the separator 7A, so that sufficient compressive force is laminated while avoiding concentration of stress. Can be added to the body.

Next, a third embodiment of the present invention relating to the shape of the holding jig 123 of the press 101 will be described with reference to FIG.

In this embodiment, the coolant passage 7D is formed also on the back surface of the second separator 7B, and the belt-like projection 13 of the second embodiment is formed on the upper surface of the holding jig 113 and the lower surface of the holding jig 123. Form each.

According to this embodiment, since the separators 7A and 7B are in contact with the holding jigs 113 and 123 without any gap, respectively, the support structure of the separators 7A and 7B in the hot press is further stabilized.

The second embodiment and the third embodiment can be applied to a separator having a gas passage instead of the coolant passage 7D.

The contents of Japanese Patent Application No. 2004-019743, filed on January 28, 2004, are incorporated herein by reference.

As described above, the present invention has been described through some specific embodiments. However, the present invention is not limited to the above embodiments. For those skilled in the art, various modifications or changes can be made to these embodiments within the technical scope of the claims. Applicable Industrial Field According to the present invention, the components of the stacked fuel cell can be hot-pressed once. Unite with be able to. Therefore, particularly favorable effects can be obtained by shortening the manufacturing process of the polymer electrolyte fuel cell alone and incorporating the present invention as a part of the manufacturing process of the fuel cell stack using a large number of fuel cells.

The exclusive properties or features encompassed by embodiments of the present invention are claimed as follows.

Claims

The scope of the claims

1. A solid polymer film (5), a first gas diffusion layer (6A) and a first separator (7A) laminated on one side of the solid polymer film (5), On the other side of (5), the second gas diffusion layer (6B)

In the method for manufacturing a solid polymer membrane fuel cell in which the second separator (7B) is laminated, an adhesive is applied to a contact surface of the first separator (7A) with the first gas diffusion layer (6A). Applying an adhesive to the contact surface of the second separator (7B) with the second gas diffusion layer (6B); and applying the first separator (7A) and the first gas diffusion layer (6A) The solid polymer membrane (5), the second gas diffusion layer (6B), and the second separator (7B) are arranged between the pair of holding jigs (113, 123) in the stated order;

The first separator (7A) and the second separator (7B) are compressed and heated by the holding jigs (113, 123) to obtain an integrated fuel cell.

2. The manufacturing method according to claim 1, wherein the first separator (7A) includes a groove-shaped gas passage (7C) facing the first gas diffusion layer (6A); The adhesive applied to the separator (7A) is applied to the partition (7F) that defines the gas passage C), and the second separator (7B) is the groove facing the second gas diffusion layer (6B). An adhesive applied to the second separator (7B) is provided on the partition (7F) that defines the gas passage (7C).

3. The production method according to claim 1 or 2, wherein a first catalyst layer (8A) and a second catalyst layer (8B) are previously coated on both surfaces of the solid polymer membrane (5), The first gas diffusion layer (6A) is converted into the first catalyst layer by the compression force and heat applied by the holding jigs (113, 123) to the first separation layer (7A) and the second separation layer (7B). (8A) is thermocompression bonded, and the second gas diffusion layer (6B) is thermocompression bonded to the second catalyst layer (8B).

4. The manufacturing method according to claim 3, wherein the adhesive is applied only to a part of the first gas diffusion layer (6A) facing the first catalyst layer (8A), The adhesive is applied only to a part of the gas diffusion layer (6B) facing the second catalyst layer (8B), and the holding jigs (113, 123) are attached to the first separator (7A). The first gas diffusion layer (6A) is thermally bonded to the first catalyst layer (8A) by the compression force and heat applied to the second separator (7B), and the second gas diffusion layer (6B) is bonded to the second gas diffusion layer (6B). Is thermally bonded to the catalyst layer (8B).

5. In the manufacturing method according to claim 1, the adhesive includes a thermosetting resin.

6. The manufacturing method according to claim 1, wherein the first separator (7A) has a recess (7D) on a surface facing the holding jig (113), and the holding jig (113) has It has a projection (13) that fits into the depression (7D) of the separator (7A).

7. The manufacturing method according to claim 1, wherein the recess (7D) is a coolant passage (7D) of the fuel cell.