JP2012074315A - Membrane electrode assembly of solid polymer fuel cell, and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a membrane electrode assembly in a solid polymer fuel cell having a high sealing property, and a manufacturing method of the same.SOLUTION: A cathode catalyst layer (3) and an anode catalyst layer (2) are disposed on both surfaces of an electrolyte membrane (1), and gas diffusion layers (4, 5) are disposed on surfaces opposite to the surfaces of both catalyst layers (2, 3) contacting with the electrolyte membrane (1). The electrolyte membrane (1) has an area larger than that of both catalyst layers (2, 3) and the gas diffusion layers (4, 5). A gasket layer is disposed around both catalyst layers and both surfaces of the electrolyte membrane. The gasket layer is made by integrating first gasket layers (21, 31) made from a cured material of liquid resin such as an adhesive material or a bonding material, and formed on the electrolyte membrane by pattern printing; second gasket layers (22, 32) made from two parts disposed on the first gasket layer; and third gasket layers (23, 33) disposed between the two parts of the second gasket layers.

Description

  The present invention relates to a membrane electrode assembly for a polymer electrolyte fuel cell and a method for producing the same.

A fuel cell is a power generation method in which chemical energy of fuel is converted into electric energy and extracted by causing an electrochemical reaction between a fuel such as hydrogen and an oxidant such as air.
Fuel cells are expected as new energy because of their advantages such as high power generation efficiency, excellent quietness, NOx and SOx that cause air pollution, and low CO2 emissions that cause global warming. .

Examples of its application include a variety of uses and scales, such as long-term power supply for portable electrical devices, stationary generation hot water supply machines for cogeneration, and fuel cell vehicles.
The types of fuel cells are classified into solid polymer type, phosphoric acid type, molten carbonate type, solid oxide type, alkaline type, etc., depending on the electrolyte used. In addition, the operating temperature varies greatly depending on the type, and accordingly, the power generation scale and the field of use also differ.

A polymer electrolyte fuel cell using a cation exchange membrane as an electrolyte can operate at a relatively low temperature. Moreover, since the internal resistance can be reduced by reducing the thickness of the electrolyte membrane, high output and compactness are possible.
A fuel cell has a membrane electrode assembly (hereinafter referred to as MEA) in which an anode catalyst layer, a gas diffusion layer, and a gasket layer are provided on one surface of an electrolyte membrane, and a cathode catalyst layer, a gas diffusion layer, and a gasket layer are provided on the other surface. A single battery cell having separators disposed on both sides thereof, or a structure in which a plurality of single battery cells are stacked.

  FIG. 3 is a cross-sectional view of a conventional membrane electrode assembly in which electrode catalyst layers are formed on both surfaces of an electrolyte membrane. A conventional unit cell of a polymer electrolyte fuel cell (PEFC) has a polymer electrolyte membrane 81 (perfluorocarbon sulfonic acid membrane), a carbon black particle and a catalyst substance (mainly platinum (Pt) or platinum group metal (Ru). , Rh, Pd, Os, Ir)) are held between the anode catalyst layer 82 and the cathode catalyst layer 83.

  Then, the anode catalyst layer 82 and the cathode catalyst layer 83 are sandwiched between the anode side gas diffusion layer 84 and the cathode side gas diffusion layer 85 to form an anode 86 and a cathode 87, respectively. The membrane electrode assembly 92 is configured by these configurations, the anode side gasket 88 having a gas sealing function, and the cathode side gasket 89. A single cell is configured by sandwiching the membrane electrode assembly 92 between a pair of separators 90.

  As the battery structure, for the purpose of increasing the output density and making the entire fuel cell compact, a structure in which a plurality of single battery cells each having a membrane electrode assembly 92 sandwiched between separators 90 is stacked is used. . Depending on the power required, the number of stacks varies. Generally, several to about 10 portable power sources for portable electric devices, about 60 to 90 for stationary electric and hot water supply machines for cogeneration, and 250 for automotive applications. It is said that it is about 400 or more. In order to increase the output, the number of stacks must be increased. Therefore, the cost of a single cell greatly affects the price of the fuel cell body.

  Further, the gasket constituting a part of the membrane electrode assembly is required to support the electrolyte membrane and contribute to the suppression of oxygen and hydrogen leakage and the maintenance of the humidity of the electrolyte membrane. Further, from the viewpoint of process cost, a membrane electrode assembly structure with a small number of parts and easy assembly is desired, and a membrane electrode assembly structure capable of a lamination process is advantageous in manufacturing. In particular, a process including a lamination process by printing is desirable in terms of mass production and continuous production.

  As described in Patent Document 1, the conventional fuel cell gasket performs gas sealing while making contact between the separator plate and the electrode, so that high dimensional accuracy, sufficient elasticity, and sufficient tightening allowance are provided. It is necessary to have. For this reason, a sheet-like gasket made of resin or rubber, an O-ring made of rubber, or the like is used. However, the gasket is usually in the shape of a frame, and when a sheet material is used, it is formed by a method such as punching, and therefore there is a problem that the inner member becomes a material loss. Further, when an O-ring is used, there is a problem that handling during assembly is difficult because the material is not rigid.

  In Patent Document 2, as a membrane electrode assembly structure with a small number of parts and easy assembly, a protective layer of a thermoplastic resin is disposed on the catalyst layer and the electrolyte membrane, and a reinforcing frame of the thermosetting resin is disposed thereon. A laminated membrane electrode assembly structure is employed. By disposing a thermosetting resin having a high elastic modulus on the reinforcing frame on a plane, the stress applied to the gasket can be dispersed to suppress the distortion of the electrolyte membrane, and the sealing performance can be improved. The protective layer is for reducing alteration of the electrolyte membrane at a high temperature during thermosetting due to components (main agent and curing agent) of the thermosetting resin that is a reinforcing frame, and a thermoplastic resin is used.

JP 2006-66160 A JP 2007-109576 A

  However, when a solid such as a thermoplastic resin is laminated on the electrolyte membrane, there is a problem that gaps are likely to occur due to accuracy problems. As the fuel cell repeats power generation and non-power generation, the electrolyte membrane repeats a wet state and a dry state. At this time, since expansion and contraction are repeated, if there is a gap between the catalyst layer and the gasket layer, stress concentrates in the gap and damage due to fatigue of the electrolyte membrane occurs. As a result, a gas leak from a damaged part and a decrease in humidity occur.

Further, in constructing a membrane electrode assembly, a heat treatment process (particularly a heat treatment required for curing a thermosetting resin) causes damage or peeling of each member due to a difference in thermal expansion coefficient of each member including an electrolyte membrane. Because there is a fear, it is desirable to suppress as much as possible.
The object of the present invention is to solve the problem of improving the sealing performance in consideration of the problems in the background art described above, and is based on the damage of the electrolyte membrane due to expansion and contraction and the heat treatment process during the manufacturing process. An object of the present invention is to provide a membrane electrode assembly in a polymer electrolyte fuel cell that suppresses breakage and peeling of each member and has high sealing performance, and a method for producing the same.

  As a result of intensive studies to solve the above problems, the present inventors have, for example, a first gasket layer that is a cured product of a liquid resin, and a second gasket layer disposed on the first gasket layer. By using the third gasket layer disposed between the end portions of the second gasket layer as an integrated membrane electrode assembly of a solid polymer fuel cell, the polymer electrolyte fuel cell having excellent sealing performance The present inventors have found that a membrane electrode assembly can be provided for use in the present invention.

  The present invention is in contact with the cathode catalyst layer disposed on one surface of the electrolyte membrane, the anode catalyst layer disposed on the other surface of the electrolyte membrane, and the electrolyte membrane of the cathode catalyst layer and the anode catalyst layer. A membrane electrode assembly of a polymer electrolyte fuel cell having a gas diffusion layer and a gasket layer disposed on a surface opposite to the surface, wherein the electrolyte membrane includes the cathode catalyst layer, the anode catalyst And a cured product of a liquid resin disposed on both sides of each of the cathode catalyst layer and the anode catalyst layer and on both sides of the electrolyte membrane. A first gasket layer, a second gasket layer comprising two portions disposed on the first gasket layer, and the two portions of the second gasket layer. A third gasket layer disposed proposes a membrane electrode assembly of the polymer electrolyte fuel cell, wherein a are integral.

Further, the thickness of the cathode catalyst layer is equal to the thickness of the first gasket layer disposed around the cathode catalyst layer, and the thickness of the anode catalyst layer is disposed around the anode catalyst layer. The thickness of the first gasket layer may be equal.
Further, a part of the first gasket layer may be in contact with a part of the gas diffusion layer and bonded thereto.
The first gasket layer may be made of an adhesive material or an adhesive material, and may be formed on the electrolyte membrane by pattern printing.

Further, the second gasket layer may be produced by punching a polygonal thermoplastic resin film drawn in a strip shape or a single stroke.
The third gasket layer may be produced by welding with the second gasket layer.
Further, the second gasket layer and the third gasket layer are prepared by laminating on the first gasket layer after welding and planarizing while applying pressure from the outside. May be.

  The present invention also provides a cathode catalyst layer disposed on one surface of the electrolyte membrane, an anode catalyst layer disposed on the other surface of the electrolyte membrane, and the electrolyte membrane of the cathode catalyst layer and the anode catalyst layer. A gas diffusion layer disposed on a surface opposite to the surface in contact with the gasket, and a gasket layer, wherein the electrolyte membrane has a larger area than the cathode catalyst layer, the anode catalyst layer, and the gas diffusion layer The gasket layer includes a first gasket layer that is a cured product of a liquid resin disposed around each of the cathode catalyst layer and the anode catalyst layer and on both surfaces of the electrolyte membrane; A second gasket layer composed of two portions disposed on one gasket layer, and a third gasket layer disposed between the two portions of the second gasket layer. A method for producing a membrane electrode assembly of a solid polymer fuel cell formed into a solid body, wherein the first gasket layer is formed on the electrolyte membrane by pattern printing A method of manufacturing a membrane electrode assembly for a fuel cell is proposed.

In addition, the second gasket layer may be formed by punching a polygonal thermoplastic resin film drawn in a strip shape or a single stroke.
Further, the third gasket layer may be welded to the second gasket layer.
Further, the second gasket layer and the third gasket layer may be planarized by welding while applying pressure from the outside, and then laminated on the first gasket layer. .

  According to the present invention, by using a cured product of a liquid resin such as an adhesive or an adhesive for the first gasket layer, the gap between the catalyst layer and the gasket layer can be filled, so that the electrolyte membrane is prevented from being damaged. Can do. In addition, by dividing the gasket layer into three parts, for example, if a thermoplastic resin is used for the second gasket layer, the heat treatment temperature and time during curing can be suppressed compared to the case where all gasket layers are made of adhesive or adhesive. it can. By these, the membrane electrode assembly with high sealing performance can be provided.

It is sectional drawing of the membrane electrode assembly of the polymer electrolyte fuel cell concerning embodiment of this invention. It is sectional drawing of the membrane electrode assembly of the polymer electrolyte fuel cell produced by the manufacturing method concerning embodiment of this invention. It is sectional drawing of the conventional membrane electrode assembly which formed the electrode catalyst layer, the gas diffusion layer, and the gasket layer on both surfaces of the conventional electrolyte membrane.

Below, the membrane electrode assembly in the polymer electrolyte fuel cell concerning embodiment of this invention and its manufacturing method are demonstrated.
FIG. 1 is a schematic cross-sectional view of a membrane electrode assembly 12 in a polymer electrolyte fuel cell according to an embodiment of the present invention. As shown in FIG. 1, the membrane electrode assembly 12 includes an electrolyte membrane 1, an anode catalyst layer 2 disposed on one surface side of the electrolyte membrane 1, and a cathode catalyst layer 3 disposed on the other surface side. It consists of.

The electrolyte membrane 1 is slightly larger than the catalyst layers 2 and 3 and the gas diffusion layers 4 and 5. Further, the catalyst layers 2 and 3 are disposed on both surfaces of the electrolyte membrane 1, respectively. Further, gas diffusion layers 4 and 5 are disposed on the surfaces of the catalyst layers 2 and 3 opposite to the surfaces in contact with the electrolyte membrane 1, respectively. The gas diffusion layers 4 and 5 are larger in area than the catalyst layers 2 and 3.
Further, first gasket layers 21 and 31 are disposed around the ends of the catalyst layers 2 and 3, respectively. Second gasket layers 22 and 32 are disposed around the ends of the gas diffusion layers 4 and 5, respectively. In addition, the 2nd gasket layer 22 is comprised from two site | parts 22a and 22b. The second gasket layer 32 includes two portions 32a and 32b. The third gasket layers 23 and 33 serve to connect the ends of the two portions 22a and 22b of the second gasket layers 22 and 32 and the ends of the portions 32a and 32b, respectively.

Moreover, the 1st gasket layer 21, the 2nd gasket layer 22, and the 3rd gasket layer 23 are integrated. The first gasket layer 31, the second gasket layer 32, and the third gasket layer 33 are integrated.
That is, in the membrane electrode assembly 12 according to the present embodiment, the gasket layer is divided into the first gasket layers 21 and 31 and the second gasket layers 22 and 32, so that the gap between the catalyst layer and the gasket layer, and The gap between the gas diffusion layer and the gasket layer can be suppressed, and the sealing performance can be improved.

The electrolyte membrane 1 used in the present embodiment may be one generally used for solid polymer fuel cells. For example, a fluorine-based electrolyte membrane or a hydrocarbon electrolyte membrane can be suitably used, and a fluorine-based electrolyte membrane is particularly desirable.
Similarly, the catalyst layers 2 and 3 may be those generally used for polymer electrolyte fuel cells. For example, a conductive material such as carbon black in which fine particles of platinum or an alloy of platinum and other metal (for example, Ru, Rh, Mo, Cr, Co, Fe, etc.) (average particle size is preferably 10 nm or less) is supported on the surface. Made of an ink in which a fine carbon particle (average particle size: about 20 nm to about 100 nm or less) and a polymer solution such as a perfluorosulfonic acid resin solution are uniformly mixed in an appropriate solvent (ethanol or the like). Can be used.

  The gas diffusion layers 4 and 5 only need to have at least gas permeability (breathability) and conductivity. For example, woven fabrics, non-woven fabrics (felts obtained by entanglement of carbon fibers, etc.), papers (carbon papers, etc.) made of carbon materials are widely used. Further, the gas diffusion layers 4 and 5 have an area larger than that of the catalyst layers 2 and 3. As a result, a catalyst layer containing an expensive platinum catalyst or the like can be used up to the end.

  The first gasket layers 21 and 31 are made of an adhesive or an adhesive. As the pressure-sensitive adhesive or adhesive, those having a main chain skeleton such as a polysiloxane skeleton, a polyether skeleton, a fluoroether skeleton, and a polyolefin skeleton can be used. Moreover, the material loss which becomes a problem with the gasket using a resin film can be avoided by applying a pattern by a method such as screen printing. That is, since processing such as punching a frame-shaped gasket is not performed, useless material loss can be reduced, and an inexpensive membrane electrode assembly and a manufacturing method thereof can be provided. Further, since it is disposed on the electrolyte membrane, it is desirable that the solventless system be used in order to avoid swelling of the electrolyte membrane due to the solvent of the adhesive or adhesive.

  In addition, the first gasket layers 21 and 31 are gasses in portions (region A portion shown in FIG. 1) that are not in contact with the catalyst layers 2 and 3 on the contact surface side of the gas diffusion layers 4 and 5 with the catalyst layers 2 and 3. It arrange | positions so that the diffusion layers 4 and 5 may be contact | connected. Thereby, the gas diffusion layers 4 and 5 can be integrated as the membrane electrode assembly 12. If the region A is too narrow, adhesion to the gas diffusion layers 4 and 5 becomes insufficient, and if it is too wide, the gas diffusion layers 4 and 5 are wasted. Good.

The second gasket layers 22 and 32 are made of a thermoplastic resin. For example, PET (polyethylene terephthalate), PEN (polyethylene nanaphthalate), SPS (syndiotactic polystyrene), PTFE (polytetrafluoroethylene), PI (polyimide) and the like can be used. In particular, a thermoplastic resin having a high elastic modulus is desirable, and a fiber reinforced one may be used.
It is desirable that the second gasket layers 22 and 32 be sufficiently thicker than the first gasket layers 21 and 31. Desirably, the thickness is about 4 to 15 times. Thereby, the stress to the first gasket layers 21 and 31 after the cell assembly is received by the second gasket layers 22 and 32, respectively, and the stress is dispersed, so that the distortion of the electrolyte membrane 1 due to the stress can be reduced.

  For the third gasket layers 23 and 33, it is necessary to select a material capable of welding between the end portions of the second gasket layers 22 and 32 each having a strip shape or a shape that can be drawn with a single stroke. A thermoplastic resin that can be welded using heat or ultrasonic waves is preferred. For example, as with the first gasket layers 21 and 22, the main chain skeleton is a pressure-sensitive adhesive or adhesive material such as a polysiloxane skeleton, a polyether skeleton, a fluoroether skeleton, or a polyolefin skeleton, and rubber or a thermoplastic elastomer. However, these are examples. Here, it is possible to reduce the material loss of the second gasket layers 22 and 32 by making the second gasket layers 22 and 32 into a strip shape or a shape that can be drawn with a single stroke.

Next, the manufacturing method of the membrane electrode assembly in the polymer electrolyte fuel cell according to the embodiment of the present invention will be described with reference to FIG.
As shown in FIG. 2A, first, catalyst layers 2 and 3 are formed on both surfaces of the electrolyte membrane 1, respectively. In forming the catalyst layers 2 and 3, an ink including a polymer electrolyte, a catalyst material, a carbon carrier supporting the catalyst, and a dispersion medium is prepared. The prepared catalyst ink is applied onto the electrolyte membrane 1 by using a coating method such as a doctor blade method, a dipping method, a screen printing method, a roll coating method, or a spray method, or a spraying method to form the catalyst layers 2 and 3. . Also, using a transfer substrate, a catalyst ink is applied on the transfer substrate, catalyst layers 2 and 3 are once formed on the transfer substrate, and then catalyst layers 2 and 3 are formed on the electrolyte membrane 1 by a transfer method. You may do it.

Next, the first gasket layer 21 is formed on the electrolyte membrane 1 (region B portion) around the formed catalyst layer 2. In forming the first gasket layer 21, an adhesive or an adhesive is applied by a method capable of pattern formation such as screen printing to form the first gasket layer 21.
The thickness of the first gasket layer 21 is desirably the same as that of the catalyst layer 2. If the thickness of the first gasket layer 21 is different from the thickness of the catalyst layer 2, a gap is generated when the gas diffusion layer 4 or the second gasket layer 22 is laminated, resulting in a decrease in sealing performance.

  Moreover, you may provide about 0.1 mm or more and 1 mm or less of the gap | interval of the catalyst layer 2 and the 1st gasket layer 21 from a precision problem. In that case, it is applied slightly thicker than the thickness of the catalyst layer 2, and after the second gasket layer 22 and the third gasket layer 23 are laminated, the thickness of the catalyst layer 2 and the first gasket layer 21 is made uniform by pressing. The gap between the catalyst layer 2 and the first gasket layer 21 can be filled. As a result, damage due to fatigue of the electrolyte membrane 1 caused by the gap between the catalyst layer 2 and the first gasket layer 21 can be suppressed.

  Next, the second gasket layer 22 and the third gasket layer 23 are integrated. For example, the third gasket layer 23 is placed on an easily peelable film between the portion 22a and the portion 22b of the second gasket layer 22 processed by a method such as punching into a strip shape or a shape that can be drawn with one stroke. After placement, the film is further hot-pressed with an easily peelable film. Then, the integrated 2nd gasket layer 22 and the 3rd gasket layer 23 excellent in surface precision can be produced by peeling an easily peelable film.

  Here, the third gasket layer 23 can be formed by a method capable of forming a pattern such as dispensing or screen printing. In order to further improve the surface accuracy, the material of the third gasket layer 23 may be printed in a frame shape on an easily peelable film. Moreover, although the method of integrating using an easily peelable film was illustrated above, it is also possible to mold in a mold without using a film.

On the first gasket layer 21, the integrated second gasket layer 22, third gasket layer 23, and gas diffusion layer 4 are laminated. In forming the integrated second gasket layer 22, the third gasket layer 23, and the gas diffusion layer 4, they can be bonded together with a bonding apparatus or the like.
As described above, the gas diffusion layer and the gasket layer can be formed on one surface of the electrolyte membrane 1 (FIG. 2A). Here, the second gasket layer 22, the third gasket layer 23, and the gas diffusion layer 4 may be formed in addition to the method of forming the gas diffusion layer 4 after the second gasket layer 22 and the third gasket layer 23 are integrated. It is also possible to use a method of bonding.

Subsequently, as shown in FIG. 2B, the first gasket layer 31 is turned upside down and applied onto the electrolyte membrane 1 by a method capable of forming a pattern such as screen printing. The region to be applied is only the region B ′ (around the catalyst layer 3) or the region B ′ and the region C (around the first gasket layer 21).
After forming the first gasket layer 31, as shown in FIG. 2C, the second gasket layer 32, the third gasket layer 33, and the gas diffusion layer 5, which are manufactured and integrated by the above-described method, are laminated. To do. Here, in addition to the method in which the gas diffusion layer 5 is laminated after the second gasket layer 32 and the third gasket layer 33 are integrated, the second gasket layer 32, the third gasket layer 33, and the gas diffusion layer 5 are respectively formed. It is also possible to use a method of bonding.

Further, the first gasket layer 31 may also be applied to the region D (the outer periphery of the first gasket layer 31 formed around the electrolyte membrane 1 and around the catalyst layer 3) shown in FIG. . As a result, the end of the electrolyte membrane 1 can also be sealed, which can contribute to maintaining the humidity of the electrolyte membrane 1.
Finally, pressing and heat treatment are performed to integrate the membrane electrode assembly 12 (FIG. 2C). The method of integrating the membrane electrode assembly 12 is preferably a hot pressing method or a thermal laminating method, but is not limited thereto. Thus, the membrane electrode assembly 12 of the present invention can be produced. In the present embodiment, the method of forming the anode side first is exemplified, but the method of forming the cathode side first is also possible.

Hereinafter, specific examples will be shown, and the membrane electrode assembly of the polymer electrolyte fuel cell according to the present embodiment and the manufacturing method thereof will be further described. In addition, the Example mentioned later is an example and this invention is not limited only to this Example.
Moreover, in the Example described below, unlike the manufacturing method mentioned above, it formed previously from the cathode side.
A platinum-supported carbon catalyst having a platinum loading of 60% and Nafion (registered trademark, manufactured by DuPont), which is a 20% by mass polymer electrolyte solution, were mixed with a water / ethanol mixed solvent having a mixing ratio of 1: 2. Subsequently, a dispersion treatment was performed with a planetary ball mill to prepare a catalyst ink.

The transfer sheet was fixed on the plate, and the catalyst ink was applied onto the transfer sheet with a doctor blade. The transfer sheet on which the coating film made of catalyst ink is formed is placed in an oven (hot air circulating thermostatic dryer 41-S5H / Satake Chemical Machinery Co., Ltd.), and the oven temperature is set to 50 ° C. and dried for 5 minutes. Catalyst layers 2 and 3 were produced on the sheet. At this time, the platinum loading was adjusted so that the cathode catalyst layer 3 was about 0.5 mg / cm ² and the anode catalyst layer 2 was about 0.3 mg / cm ² .

^Two transfer sheets on which the catalyst layers 2 and 3 were formed were cut out at 25 cm ² and arranged on both surfaces of the electrolyte membrane 1 so that the catalyst layers 2 and 3 face each other. As the electrolyte membrane 1, Nafion 211 (manufactured by DuPont) was used. Subsequently, hot pressing was performed under conditions of 130 ° C. and 6 MPa, and only the transfer substrate was peeled off.
Next, a fluoroether adhesive is applied in a frame shape on a 50 μm-thick PTFE sheet by screen printing so as to have a thickness of 25 μm, and then a strip-like PEN film having a thickness of 150 μm is applied to the printed portion. It was placed on top and its ends were coated with the same material using a dispenser.

After that, a sheet coated with a fluoroether adhesive in a frame shape by screen printing so as to have a thickness of 25 μm is placed on a PTFE sheet having a thickness of 50 μm, and after PTFE sheet is heated and post-baked at 150 ° C. The second gasket layer 32 and the third gasket layer 33 which were integrated were obtained.
A fluoroether adhesive was applied to the end of the cathode catalyst layer 3 by screen printing to a thickness of 35 μm to form a first gasket layer 31. Subsequently, after MPL-treated carbon paper (manufactured by Toray Industries, Inc.) is bonded onto the cathode catalyst layer 3, the cathode-side gas diffusion layer 5 is formed, and is integrated with the end of the formed gas diffusion layer 5. A gasket layer 32 and a third gasket layer 33 were formed.

  The first gasket layer 21 was formed by turning upside down and applying a fluoroether-type adhesive to the end of the anode catalyst layer 2 by screen printing to a thickness of 35 μm. At this time, an adhesive was also applied to the cathode-side second gasket layer 32 previously formed. Subsequently, similarly to the cathode side, the gas diffusion layer 4 and the integrated second gasket layer 22 and third gasket layer 23 were formed.

The membrane / electrode assembly 12 obtained as described above was pressed, placed in an oven, and integrated by heat treatment at 150 ° C. for 1 hour. Thereby, the desired membrane electrode assembly 12 was able to be obtained.
Further, after the heat treatment, the membrane electrode assembly 12 was punched out with a blade shape. When the gap between the catalyst layers 2 and 3 and the first gasket layers 21 and 31 was observed, it was confirmed that the gap was filled with the first gasket layers 21 and 31. It was also confirmed that the end of the electrolyte membrane 1 was sealed with a gasket.

  The membrane electrode assembly according to the present invention can be suitably used for a polymer electrolyte fuel cell single cell or a stack in a polymer electrolyte fuel cell, particularly a fuel cell automobile or a household fuel cell.

DESCRIPTION OF SYMBOLS 1 ... Electrolyte membrane 2 ... Anode catalyst layer 3 ... Cathode catalyst layer 4 ... Anode side gas diffusion layer 5 ... Cathode side gas diffusion layer 12 ... Membrane electrode assembly 21 ... Anode side first gasket layer 22 ... Anode side second gasket layer 23 ... Anode side third gasket layer 31 ... Cathode side first gasket layer 32 ... Cathode side second gasket layer 33 ... Cathode side third gasket layer 81 ... solid polymer electrolyte membrane 82 ... anode catalyst layer 83 ... cathode catalyst layer 84 ... anode side gas diffusion layer 85 ... cathode side gas diffusion layer 86 ...・ Anode 87 ... Cathode 88 ... Anode side gasket 89 ... Cathode side gasket 90 ... Separator 92 ... Membrane electrode assembly

Claims (11)

The cathode catalyst layer disposed on one surface of the electrolyte membrane, the anode catalyst layer disposed on the other surface of the electrolyte membrane, and the surfaces of the cathode catalyst layer and the anode catalyst layer that are in contact with the electrolyte membrane are opposite to each other A membrane electrode assembly of a polymer electrolyte fuel cell having a gas diffusion layer and a gasket layer disposed on each of the surfaces,
The electrolyte membrane has a larger area than the cathode catalyst layer, the anode catalyst layer, and the gas diffusion layer,
The gasket layer includes a first gasket layer that is a cured product of a liquid resin disposed around each of the cathode catalyst layer and the anode catalyst layer and on both surfaces of the electrolyte membrane; and the first gasket layer A second gasket layer composed of two parts disposed above and a third gasket layer disposed between the two parts of the second gasket layer are integrated. A membrane electrode assembly of a polymer electrolyte fuel cell. The thickness of the cathode catalyst layer is equal to the thickness of the first gasket layer disposed around the cathode catalyst layer; and
The membrane electrode joint of the polymer electrolyte fuel cell according to claim 1, wherein the thickness of the anode catalyst layer is equal to the thickness of the first gasket layer disposed around the anode catalyst layer. body.   3. The membrane electrode assembly for a polymer electrolyte fuel cell according to claim 1, wherein a part of the first gasket layer is in contact with a part of the gas diffusion layer.   4. The polymer electrolyte fuel cell according to claim 1, wherein the first gasket layer is made of an adhesive material or an adhesive material, and is formed on the electrolyte membrane by pattern printing. 5. Membrane electrode assembly.   The solid polymer according to any one of claims 1 to 4, wherein the second gasket layer is produced by punching a polygonal thermoplastic resin film drawn in a strip shape or a single stroke. Type fuel cell membrane electrode assembly.   The membrane electrode assembly of a polymer electrolyte fuel cell according to any one of claims 1 to 5, wherein the third gasket layer is produced by welding with the second gasket layer. .   The second gasket layer and the third gasket layer are manufactured by laminating on the first gasket layer after welding and planarizing while applying pressure from the outside. The membrane electrode assembly of the polymer electrolyte fuel cell according to any one of claims 1 to 6. The cathode catalyst layer disposed on one surface of the electrolyte membrane, the anode catalyst layer disposed on the other surface of the electrolyte membrane, and the surfaces of the cathode catalyst layer and the anode catalyst layer that are in contact with the electrolyte membrane are opposite to each other A gas diffusion layer disposed on each of the surfaces of the gas diffusion layer and the gasket layer, and the electrolyte membrane has a larger area than the cathode catalyst layer, the anode catalyst layer, and the gas diffusion layer, and the gasket. A first gasket layer that is a cured product of a liquid resin disposed around each of the cathode catalyst layer and the anode catalyst layer and on both surfaces of the electrolyte membrane; and on the first gasket layer A second gasket layer composed of two portions to be disposed and a third gasket layer disposed between the two portions of the second gasket layer are integrated. A method of manufacturing a membrane electrode assembly body polymer fuel cell,
A method for producing a membrane electrode assembly for a polymer electrolyte fuel cell, wherein the first gasket layer is formed on the electrolyte membrane by pattern printing.   9. The membrane electrode assembly for a polymer electrolyte fuel cell according to claim 8, wherein the second gasket layer is produced by punching a polygonal thermoplastic resin film drawn in a strip shape or a single stroke. Manufacturing method.   The method for producing a membrane electrode assembly for a polymer electrolyte fuel cell according to claim 8 or 9, wherein the third gasket layer is welded to the second gasket layer.   9. The second gasket layer and the third gasket layer are welded and flattened while applying pressure from the outside, and then laminated on the first gasket layer. The method for producing a membrane / electrode assembly of a polymer electrolyte fuel cell according to any one of 10.

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