JP5321181B2 - Method for producing assembly of catalyst layer and electrolyte membrane of fuel cell member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a porous and arbitrary shaped catalyst layer with homogeneously and uniformly dispersed catalyst, and a catalyst layer contact face to the electrolytic membrane for the fuel cell of which is in good adhesive state, in order to provide an MEA, junction structure of a catalyst layer with an electrolytic film with high power output and durability, and to provide a manufacturing method and a device for a junction structure MEA (Membrane Electrode Assembly) for the electrolyte membrane of the fuel cell by the R to R method with high productivity. <P>SOLUTION: The manufacturing method includes a step of applying catalyst solution on a transfer film 3 and forming an arbitrary shaped catalyst layer 2 with homogeneously and uniformly dispersed catalyst, a drying step of evaporating a solvent in the catalyst layer on the transfer film 3 into a porous state, a step of making the junction structure MEA of the electrolytic film 1 and the catalyst layer 2 by transferring the catalyst layer 2 on the electrolytic layer 1 with a transfer roll 9 by heating with pressure in an arbitrary temperature, velocity and pressure, and a step of peeling off the transfer film 3 from the junction structure of the catalyst layer 2 and the electrolytic film 1 with an arbitrary velocity. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a method of manufacturing a MEA of a catalyst layer and an electrolyte membrane in a fuel cell and an apparatus therefor.

A fuel cell is a chemical cell that can extract electric power by supplying a fuel such as hydrogen and an oxidant such as oxygen.
Various fuels are used for fuel cells, and hydrogen is used as the fuel. In many cases, power is extracted by 2H ₂ + O ₂ → 2H ₂ O, which is the reverse reaction of water electrolysis. Fuel cells are classified according to the electrochemical reaction used and the type of electrolyte. In particular, the polymer electrolyte fuel cell can be operated at room temperature and can be reduced in size and weight, and is expected to be applied to portable devices, fuel cell vehicles, and the like.

  Among fuel cell members is a membrane / electrode assembly MEA that forms catalyst layers on both sides of an electrolyte membrane. In order to improve power generation efficiency by MEA, a catalyst layer having a uniform film thickness in which the catalyst is uniformly and uniformly dispersed is formed, and the catalyst layer is porous so that the fuel is easily diffused into the catalyst layer. It is demanded.

  As a conventional manufacturing method, there is a hot press method as in Patent Document 1. In this method, it is possible to uniformly transfer the catalyst layer to the electrolyte membrane, but there is a problem that the production efficiency is low such as a long time for pressing and an intermittent operation.

  As a method for increasing the production efficiency instead of the hot press method, there is a bonding method using a heating roll. With this method, RtoR production is possible, and production efficiency is greatly increased. As shown in Patent Document 3, there is a technique in which a catalyst layer formed on a transfer film is heated and pressed with a heat roll on an electrolyte film, transferred, and the transfer film is peeled off. In this manufacturing method, the transfer speed depends on the line speed. However, the optimal transfer speed and the optimal speed are often different, and it is difficult to find the optimal process conditions for this transfer peeling. is there. In general, the lower the temperature, the better the releasability. In this process, however, peeling is performed with a hot roll, so that the transfer to the transfer sheet and the rough surface condition of the peeled surface are quality. , Likely to adversely affect performance.

  As a method for separating the transfer and peeling processes, Patent Document 3 can be cited. However, this method can lower the peeling temperature, but the problem remains that the transfer and peeling speed are the same.

JP 2006-278073 A (Nissan) JP 2003-331863 A (Toyota) JP 2006-185762 A (Dainippon)

  The present invention relates to the joining of a catalyst layer and a fuel cell electrolyte membrane in which the joint surface of the catalyst layer of any shape on the porous material in which the catalyst is uniformly and homogeneously dispersed and the fuel cell electrolyte membrane has good interface adhesion It is an object of the present invention to provide a method and an apparatus for manufacturing a body (MEA: Membrane Electrode Assembly) in an RtoR system with high productivity. This manufacturing apparatus can provide a MEA having high output and durability.

As a means for solving the above problems, the invention according to claim 1 is directed to an electrolyte component / catalyst layer assembly for a polymer electrolyte fuel cell in which a catalyst layer is formed on both surfaces of an electrolyte membrane. An application step of applying a catalyst solution containing an organic solvent and a catalyst metal-supported powder to the surface of the transfer film; a drying step of drying the applied catalyst solution to form a porous catalyst layer; and the catalyst on the transfer film a transfer step of transferring the layer to the electrolyte membrane surface, the transfer film, have a, a peeling step of peeling from the catalyst layer transferred to the electrolyte membrane surface, in the coating step, the transfer on the suction table The film is transported, and the application of the catalyst solution to the transfer film is performed by temporarily stopping the transport and holding the transfer film on an adsorption table, and then applying the catalyst solution onto the stopped transfer film. In the transfer step, the electrolyte film and the transfer film on which the catalyst layer is formed are transported on an adsorption plate and transferred to the surface of the electrolyte film. The transfer of the catalyst layer is performed by temporarily stopping the conveyance and moving the transfer roll on the adsorption plate while pressing the transfer film against the electrolyte membrane by the transfer roll on the adsorption plate. In the peeling step, the transfer film is peeled off by adsorbing the peeling roll that changes the direction of the transfer film conveyance path in a direction away from the electrolyte film conveyance path in a state in which the conveyance in the transfer process is continuously stopped. It is made by moving on a plate, It is a manufacturing method of the electrolyte membrane and catalyst layer assembly characterized by the above-mentioned.
In other words, the invention according to claim 1 is a catalyst having four steps: application of a catalyst layer, drying, transfer of the catalyst layer to the surface of the electrolyte membrane, and peeling of the transfer film from the joined body of the catalyst layer and the electrolyte membrane. It is a manufacturing method of the joined body of a layer and an electrolyte membrane.

In other words, the invention according to claim 1 forms a catalyst layer having an arbitrary film thickness and shape at an optimum speed for coating by stopping film transport in the coating process and moving the coating head. It is.

In other words, the invention described in claim 1 performs transfer by laminating the catalyst layer on the transfer film facing the electrolyte membrane with a certain gap as shown in FIG. 2 by heating lamination with a transfer roll as shown in FIG. The transfer is performed under optimum temperature, speed, and pressure conditions, and the porous shape of the catalyst layer is not destroyed, and the adhesion of the joint surface between the catalyst layer and the electrolyte membrane is improved.

In other words, the invention described in claim 1 includes the peeling roll 1 and the peeling roll 2 that support the transfer film as shown in FIG. 5 after the catalyst layer is transferred to the electrolyte membrane as shown in FIG. By moving in the horizontal direction, peeling can be performed at a constant speed, peeling angle, and peeling force. More thereto, stripping the remaining to the transfer sheet, roughness can prevent the catalyst layer surface shape after peeling, a method for producing a joined body of the catalyst layer and the electrolyte membrane.

  Therefore, in the present invention, coating, drying, transfer, and peeling are on the same line of RtoR. However, since it is the contents of the invention described above, the surface of the electrolyte membrane can be applied to the surface of the electrolyte membrane at the optimum speed for each process regardless of the line speed. It is an apparatus for manufacturing a joined body of a catalyst layer and an electrolyte membrane that can form a catalyst layer.

  According to the present invention, an electrolyte membrane-catalyst assembly MEA having a uniform and homogeneous porous catalyst layer can be produced, whereby fuel (hydrogen, oxygen) can be efficiently supplied to the catalyst. Therefore, the output of the fuel cell can be improved. Compared to conventional techniques, the interface adhesion and surface shape of the joint can be improved, so durability is also expected to improve.

Schematic diagram of manufacturing device for fuel cell catalyst layer and electrolyte membrane assembly Illustration of catalyst layer transfer process Illustration of catalyst layer transfer process Illustration of catalyst layer transfer process Protective film peeling process illustration Protective film peeling process illustration Schematic diagram of manufacturing apparatus for catalyst layer assembly on both sides of electrolyte membrane

  Hereinafter, a method and an apparatus for producing a joined body MEA of a catalyst layer and an electrolyte membrane of a fuel cell member of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic view of an apparatus for manufacturing a joined body according to an embodiment of the present invention. The joined body manufacturing apparatus of the embodiment includes an application part for applying a catalyst coating liquid on the surface of the transfer film 3, a drying part for the catalyst layer 2, a transfer part for transferring the catalyst layer 2 to the surface of the electrolyte membrane 1, and a transfer film from the joined body. It consists of the peeling part which peels. Details of each part will be described later.

  Each material will be described. The transfer film 3 is made of a PET or PP film with a silicon coating or a film having excellent releasability such as a fluororesin film.

  As the electrolyte membrane 1, a thin film having a thickness of about 10 to 300 μm such as a fluorine ion exchange resin (such as “Nafion” manufactured by DuPont) is used.

  As the catalyst coating liquid, a mixture of a platinum or other metal catalyst, powdered carbon, a fluorine-based ion exchange resin, and an organic solvent (IPA or the like) is used.

  In the coating unit, as shown in FIG. 1, the transfer film 3 is temporarily stopped, the unwound transfer film 3 is held by the suction table 7, and the catalyst coating liquid is intermittently applied by the coating head 6. A catalyst layer having a thickness of 5 to 50 μm is formed thereon. At this time, since the conveyance of the film 3 is stopped, the coating can be performed at a coating speed optimum for coating. Therefore, a catalyst layer having a uniform film thickness, a uniformly dispersed catalyst, and a good surface shape can be formed. The coating method is described using a die coating method, but the coating method is not limited to this, and a known coating method such as a screen printing method, spray coating, or an applicator method can be used.

  In the drying section, the coated catalyst layer is transported into the drying furnace 8 in FIG. 1, and the organic solvent and water in the catalyst coating solution are evaporated to form a porous catalyst layer.

  The transfer is performed as shown in FIGS. As shown in FIG. 2, the catalyst layer 2 is transported to the transfer portion, the transport of the transfer film 3 and the electrolyte membrane 1 is temporarily stopped, and the electrolyte membrane 1 is held on the adsorption plate 14. Thereafter, the catalyst layer 2 is pressed against the electrolyte membrane 1 by the transfer roll 9 as shown in FIG. The transfer roll 9 has heat resistance and strength that can withstand heat and pressure. Heat transfer lamination is performed by moving the transfer roll 9 in the horizontal direction while being pressed. In this case, the transfer roll 9 may move while rotating. In this method, lamination can be performed at any optimum temperature, pressure, and speed. Thereby, sufficient adhesion between the catalyst layer and the electrolyte membrane can be obtained without breaking the porous shape.

  Peeling is performed by moving the peeling rolls 10 and 17 in the horizontal direction as shown in FIG. 5 in a state where the transfer of the transfer film 3 and the electrolyte membrane 1 is continuously stopped in the transfer step after the transfer is completed. That is, the peeling rolls 10 and 17 that change the direction of the transfer path of the transfer film 3 in the direction away from the transfer path of the electrolyte membrane 1 are moved on the suction plate 14. Stripping can be performed at an optimum speed. Therefore, the remaining peeling on the transfer film 3 and surface roughness due to excessive peeling are reduced.

  After the catalyst layer 2 is formed on the electrolyte membrane 1, the treated surface is protected by the protective film 16 and wound up.

  With the above manufacturing method and apparatus, each process can be made into an MEA under optimum conditions.

The catalyst layer 2 can be formed on one surface of the electrolyte membrane 1 by the above method and manufacturing apparatus. In the fuel cell MEA, it is necessary to form the catalyst layer 2 on both surfaces of the electrolyte membrane 1.
In order to form the catalyst layer 2 on both surfaces of the electrolyte membrane 1, the above-described coating step, drying step, transfer step, and peeling step are performed on both sides of the electrolyte membrane, and are formed on both sides of the electrolyte membrane before the transfer step. The catalyst layers may be aligned.
That is, as one method for performing MEA with this apparatus, after forming the catalyst layer 2 on one side, the catalyst layer 2 is formed on the back side using this apparatus again. As another method, as shown in the figure, the catalyst layers 2 are formed on both sides in one manufacturing apparatus. The latter will be described below.

FIG. 7 shows an apparatus for forming the catalyst layer 2 on both surfaces of the electrolyte membrane 1 in one manufacturing apparatus.
Since the transfer unit faces both surfaces of the electrolyte membrane 1, the catalyst layer can be formed on both surfaces by the above-described manufacturing method.

First, the catalyst layer 2 is formed on the lower surface of the electrolyte membrane 1. After that, when the catalyst layer 2 is formed on the upper surface, it is necessary to laminate so that the catalyst layers 2 on both sides are not misaligned. By adding an end point of the catalyst layer 2 or a step of adding an alignment mark at the time of application, the camera 11 can recognize them, and the unit state of unwinding and winding of the electrolyte membrane 1 can be freely moved in the horizontal and rotational directions. It is possible to align the position by using this function.
By performing accurate alignment, an area effective for power generation in which the catalyst layer 2 is formed on both surfaces can be secured.

  The present invention can be used for polymer electrolyte fuel cells for home use, in-vehicle use, and other uses.

DESCRIPTION OF SYMBOLS 1 ... Electrolyte membrane 2 ... Catalyst layer 3 ... Transfer film 4 ... Transfer film unwinding 5 ... Transfer film winding 6 ... Coating head 7 ... Adsorption table 8 ... Drying furnace 9 ... transfer roll 10 ... peeling roll 1
DESCRIPTION OF SYMBOLS 11 ... Alignment camera 12 ... Electrolyte membrane unwinding 13 ... Electrolyte membrane winding 14 ... Adsorption table 15 ... Electrolyte membrane unwinding / winding unit 16 ... Protective film 17 ... Peeling Roll 2

Claims (2)

In the electrolyte membrane / catalyst layer assembly for a polymer electrolyte fuel cell that forms catalyst layers on both sides of the electrolyte membrane,
An application step of applying a catalyst solution containing an electrolyte component, an organic solvent, and a catalyst metal-supported powder to the surface of the transfer film;
A drying step of drying the applied catalyst solution to form a porous catalyst layer;
A transfer step of transferring the catalyst layer on the transfer film to the electrolyte membrane surface;
The transfer film, have a, a peeling step of peeling from the catalyst layer transferred to the electrolyte membrane surface,
In the application step, the transfer film is conveyed on an adsorption table,
Application of the catalyst solution to the transfer film is intermittent application in which the conveyance is temporarily stopped, the transfer film is held on an adsorption table, and the catalyst solution is applied to the stopped transfer film by an application head. Made,
In the transfer step, the electrolyte film and the transfer film on which the catalyst layer is formed are conveyed on an adsorption plate,
The transfer of the catalyst layer to the electrolyte membrane surface temporarily stops the conveyance, and the transfer roll moves on the adsorption plate while pressing the transfer film against the electrolyte membrane by the transfer roll on the adsorption plate. Was made by
In the peeling step, the transfer film is peeled off by changing the direction of the transfer film transport path in a direction away from the electrolyte film transport path in a state where the transport stop in the transfer process is continued. Made by moving on the suction plate,
A method for producing an electrolyte membrane / catalyst layer assembly, wherein: The coating process, the drying process, the transfer process, and the peeling process are performed on both surfaces of the electrolyte membrane,
The coating step includes a first coating step of coating the catalyst solution on the surface of the first transfer film, and a second coating step of coating the catalyst solution on the surface of the second transfer film,
In the drying step, the catalyst solution applied to the first transfer film is dried to form a first catalyst layer, and the catalyst solution applied to the second transfer film is dried. And a second drying step as a second catalyst layer,
The transfer step includes a first transfer step of transferring the first catalyst layer on the first transfer film to one surface of the electrolyte membrane, and the first transfer step transferred to one surface of the electrolyte membrane. An alignment step of aligning the first catalyst layer with the second catalyst layer on the second transfer film; and the second catalyst layer on the second transfer film with the other of the electrolyte membrane A second transfer step for transferring to the surface of
The peeling step includes a first peeling step of peeling the first transfer film from the first catalyst layer transferred to one surface of the electrolyte membrane, and a step of removing the second transfer film from the electrolyte. A second peeling step of peeling from the second catalyst layer transferred to the other surface of the film,
The method for producing an electrolyte membrane / catalyst layer assembly according to claim 1.

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