JP6307960B2 - Method for producing electrolyte membrane with catalyst layer for polymer electrolyte fuel cell, polymer electrolyte fuel cell, and electrolyte membrane with catalyst layer - Google Patents

Description

  The present invention relates to a method for producing an electrolyte membrane with a catalyst layer used in a polymer electrolyte fuel cell.

A fuel cell is a power generation system that converts a chemical energy of a fuel into electric energy and extracts it by electrochemically reacting a fuel such as hydrogen with an oxidant such as air. This power generation system has high power generation efficiency, excellent quietness, nitrogen oxides (NO _x ) and sulfur oxides (SOx) that cause air pollution, and carbon dioxide (CO ₂ ) that causes global warming. There are advantages such as low emissions. Because of these advantages, fuel cells are expected as new energy. Examples of application fields of fuel cells include long-time power supply for portable electric devices, stationary generation hot water supply machines for cogeneration, fuel cell vehicles, etc., and their uses and scales are diverse.

Fuel cell types are classified into solid polymer type, phosphoric acid type, molten carbonate type, solid oxide type, alkaline type, etc., depending on the electrolyte used. The fields are also different.
Among the various fuel cells described above, a polymer electrolyte fuel cell having many advantages is known. This polymer electrolyte fuel cell uses a cation exchange membrane as an electrolyte. Advantages include (1) the fact that the fuel cell operates at a relatively low temperature, so it can be used near room temperature, and (2) the internal resistance can be reduced by reducing the thickness of the electrolyte membrane, enabling high output and compactness. Attention is paid to this point. Therefore, the polymer electrolyte fuel cell is considered promising for use in an in-vehicle power source or a home stationary power source, and various research and development have been conducted in recent years.

  In a polymer electrolyte fuel cell, a pair of gas diffusion layers are arranged on a membrane in which a pair of electrode catalyst layers are formed on both sides of a polymer electrolyte, and a membrane electrode assembly (Membrane Electrode Assembly) as a central member is provided. MEA) is configured. A gasket is disposed on the peripheral edge of the electrode catalyst layer. And the battery is comprised by pinching the membrane electrode assembly which is a center member with a pair of separator plate. In this polymer electrolyte fuel cell, each gas flow path is formed in order to supply a fuel gas containing hydrogen to one electrode and an oxidant gas containing oxygen to the other electrode. In addition, the film | membrane in which a pair of electrode catalyst layer was formed on both surfaces of the polymer electrolyte is also called an electrolyte membrane with a catalyst layer (Catalyst Coated Membrane: CCM). A battery sandwiched between a pair of separator plates is called a single battery cell.

  A polymer electrolyte fuel cell is used by stacking a plurality of unit cells for the purpose of increasing the power density and making the entire fuel cell compact. The number of stacks varies depending on the required power, from several to about 10 for a portable power source of a general portable electric device, about 60 to 90 for a stationary electric and hot water supply machine for cogeneration, and 250 to about a car application. About 400 sheets. In order to increase the output, it is necessary to increase the number of stacks, and the cost (expense) of the unit cell greatly affects the cost of the entire fuel cell. From the viewpoint of process cost, an inexpensive and simple method for producing an electrolyte membrane with a catalyst layer and a membrane electrode assembly is desired.

  In the production of an electrolyte membrane with a catalyst layer, as a method of forming an electrode catalyst layer having a desired shape on a solid polymer electrolyte layer, a method using a covering member has been studied (Patent Documents 1 and 2). For example, (1) a frame-shaped covering member is bonded to a solid polymer electrolyte membrane, and a coating liquid containing a catalyst is applied to the solid polymer electrolyte membrane in the opening in the frame, thereby making the catalyst layer a solid polymer. A method of forming on an electrolyte membrane, (2) applying a coating solution containing a catalyst on a separately prepared base film, laminating it with a solid polymer electrolyte membrane having a frame-shaped covering member bonded thereto, and hot pressing Thus, a method of transferring the catalyst layer onto the solid polymer electrolyte membrane only at the opening in the frame is known.

  In addition, as a method for producing an electrolyte membrane with a catalyst layer easily and inexpensively, a first electrode catalyst layer is produced on a substrate, then a polymer electrolyte layer 8 is produced, and finally a second electrode catalyst layer is produced. There has been proposed a method by sequential lamination for manufacturing (Patent Document 3). In this sequential lamination method, the tact time is short and the production efficiency is high, so that the manufacturing cost is low.

JP 2007-294183 A JP 2008-77984 A Japanese Patent No. 4696462

However, in the method for producing an electrolyte membrane with a catalyst layer disclosed in Patent Literature 1 and Patent Literature 2, a catalyst layer having a desired shape can be formed on the solid polymer electrolyte membrane, but it is formed on the covering member. The catalyst layer is lost. In the catalyst layer, a noble metal typified by platinum is present as a catalyst. Therefore, there is a problem that the loss of the catalyst layer leads to an increase in cost.
Moreover, in the manufacturing method of the electrolyte membrane with a catalyst layer disclosed in Patent Document 3 and Patent Document 4, the manufacturing cost is low because it does not include a hot pressing process, but the shape of the catalyst layer depends on the method of application. There is a problem that a catalyst layer having a desired shape cannot be obtained.

Furthermore, when a catalyst ink is applied to a polymer electrolyte membrane to form a catalyst layer, only the interface between the membrane and the catalyst layer is bonded, and the catalyst layer is easily dried from the exposed cross section. There is a problem that the power generation performance is lowered under low humidification conditions such as only generated water.
The present invention has been accomplished in consideration of the above problems, and (1) there is little loss of catalyst ink, (2) a catalyst layer can be formed in a desired shape with high accuracy, and (3) ionic resistance is small. (4) It aims at providing the manufacturing method of the electrolyte membrane with a catalyst layer which has high power generation performance on low humidification conditions, and the electrolyte membrane with the catalyst layer.

  In order to solve the above problems, a method for producing an electrolyte membrane with a catalyst layer according to an aspect of the present invention includes a pattern formation step, a cathode catalyst layer formation step, a polymer electrolyte membrane formation step, and a pattern formation step. And an anode catalyst layer forming step, a hot pressing step, and a peeling step. The electrolyte membrane with a catalyst layer includes a polymer electrolyte membrane, an anode catalyst layer provided on one surface of the polymer electrolyte membrane, and a cathode catalyst layer provided on the other surface of the polymer electrolyte membrane. .

  In the pattern formation step, an affinity area having affinity for the catalyst ink containing the catalyst-carrying particles, the polymer electrolyte, and the solvent and a non-affinity area having no affinity for the catalyst ink are patterned on the release substrate. . In the cathode catalyst layer forming step, the catalyst ink is applied to the affinity area to form a coating film, the solvent in the formed coating film is removed, and the cathode catalyst layer is formed. In the polymer electrolyte membrane forming step, an electrolyte ink containing a polymer electrolyte and a solvent is applied onto the cathode catalyst layer to form a coating film, and the solvent in the formed coating film is removed, and the polymer electrolyte membrane is removed. Form. In the pattern forming step, an affinity area having affinity for the catalyst ink containing catalyst-carrying particles, a polymer electrolyte, and a solvent and a non-affinity area having no affinity for the catalyst ink are patterned on the transfer substrate. . In the anode catalyst layer forming step, the catalyst ink is applied to the affinity area to form a coating film, the solvent in the formed coating film is removed, and the anode catalyst layer is formed. In the hot pressing step, the anode catalyst layer produced on the transfer substrate is laminated on the polymer electrolyte membrane on the back surface on which the cathode catalyst layer is formed, and the anode catalyst layer is transferred to the polymer electrolyte membrane by hot pressing. In the peeling step, the peeling substrate and the transfer substrate are peeled and removed.

  According to the present invention, (1) loss of catalyst ink is small, (2) a catalyst layer can be formed in a desired shape with high accuracy, (3) ion resistance is low, and (4) power generation is high under low humidification conditions. The manufacturing method of the electrolyte membrane with a catalyst layer which has performance, and the electrolyte membrane with a catalyst layer can be provided.

It is a schematic diagram for demonstrating the manufacturing method of the electrolyte membrane with a catalyst layer which concerns on embodiment of this invention to process order. It is sectional drawing which shows the ideal structure of the electrolyte membrane with a catalyst layer which concerns on embodiment of this invention. It is sectional drawing which shows the structure of the electrolyte membrane with a catalyst layer different from the ideal of embodiment of this invention. It is sectional drawing which shows the structure of the membrane electrode assembly which concerns on embodiment of this invention. It is a flowchart for demonstrating the manufacturing method of the electrolyte membrane with a catalyst layer which concerns on embodiment of this invention to process order.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic diagram for explaining the method for producing an electrolyte membrane with a catalyst layer according to this embodiment in the order of steps.
The outline of the manufacturing method of the electrolyte membrane with a catalyst layer according to the present embodiment is as follows.
The method for producing an electrolyte membrane with a catalyst layer according to the present embodiment includes (1) a step of forming an electrolyte membrane with a cathode catalyst layer in which a cathode catalyst layer 7b and a solid polymer electrolyte membrane 8 are formed on a release substrate 1a; (2) A step of forming an anode catalyst layer in which the anode catalyst layer 7c is formed on the transfer substrate 1b on the transfer substrate, and (3) a step of transferring the anode catalyst layer to the electrolyte membrane with the cathode catalyst layer. It consists of two steps.

(1) Formation Step of Electrode Membrane with Cathode Catalyst Layer First, pattern the affinity area 5 having affinity with the catalyst ink 7a and the non-affinity area 6 having no affinity with the catalyst ink 7a on the peeling substrate 1a. The step of forming (FIG. 1 (1b)) is performed. Next, the catalyst ink 7a is applied to the affinity area 5 having affinity with the catalyst ink 7a on the release substrate 1 to form a coating film, and the solvent in the formed coating film is removed to remove the cathode catalyst layer 7b. The step of forming (FIG. 1 (1c)) is performed. Next, on the cathode catalyst layer 7b, an electrolyte ink containing at least a polymer electrolyte and a solvent is formed to form a coating film, and the solvent in the formed coating film is removed to form the polymer electrolyte membrane 8. (FIG. 1 (1e)) is executed. As a result, an electrolyte membrane with a cathode catalyst layer in which the cathode catalyst layer is formed on one side of the solid polymer electrolyte membrane is formed.

(2) Anode catalyst layer forming step First, the step of patterning the affinity area 5 having affinity with the catalyst ink 7a and the non-affinity area 6 having no affinity with the catalyst ink 7a on the transfer substrate 1b. (FIG. 1 (2b)) is executed. Next, the catalyst ink 7a is applied to the affinity area 5 having affinity with the catalyst ink 7a on the transfer substrate 1 to form a coating film, the solvent in the formed coating film is removed, and the anode catalyst layer The step of forming 7c (FIG. 1 (2c)) is executed.

(3) Step of transferring the anode catalyst layer to the cathode catalyst layer-attached electrolyte membrane First, the back surface side of the cathode catalyst layer-forming electrolyte membrane with the cathode catalyst layer is in contact with the anode catalyst layer on the transfer substrate on which the anode catalyst layer is formed. And a hot press process (FIG. 1 (3f)) is performed. Next, the release substrate and the transfer substrate are sequentially peeled and removed to form an electrolyte membrane with a catalyst layer in which a cathode catalyst layer and an anode catalyst layer are formed on both sides of the solid polymer electrolyte.

  More specifically, in the method for producing an electrolyte membrane with a catalyst layer according to the present embodiment, first, the affinity area 5 having an affinity for the catalyst ink 7a and the affinity for the release substrate 1a and the transfer substrate 1b are non-affected. The affinity area 6 is patterned. The pattern forming step includes a first step (silane coupling agent forming step), a second step (silane coupling agent limited removal step), and a third step (residual silane coupling agent removal step).

As a first step of pattern formation (silane coupling agent forming step), a silane coupling agent 2 is formed on the peeling substrate 1a and the transfer substrate 1b (FIG. 1 (1a), FIG. 1 (2a)). Then, the release substrate 1 a and the transfer substrate 1 b on which the silane coupling agent 2 is formed are subjected to a water repellency treatment with the low surface energy functional group of the silane coupling agent 2.
The type of the silane coupling agent 2 is not particularly limited as long as it has no affinity with the catalyst ink 7a and can be removed by the vacuum ultraviolet light 3, but it has a low surface energy functional group. A fluoroalkylsilane having a bond and being easily decomposed by vacuum ultraviolet light 3 is desirable. Moreover, the formation method of the silane coupling agent 2 includes spray coating, spin coating, chemical vapor deposition, immersion, and the like, and is not particularly limited.

Next, as a second pattern formation process (silane coupling agent limited removal process), the photomask 4 having a predetermined shape is limited only to the catalyst layer formation area of the silane coupling agent 2 formed in the first process. 1 is irradiated with vacuum ultraviolet light 3 (FIG. 1 (1b), FIG. 1 (2b)). And the silane coupling agent 2 of the area irradiated with the vacuum ultraviolet light 3 is decomposed | disassembled, and only the peeling base material 1a and the transfer base material 1b of the area irradiated with the vacuum ultraviolet light 3 are hydrophilized.
The wavelength of the vacuum ultraviolet light 3 is not particularly limited as long as the Si—C bond of the silane coupling agent 2 can be cut, but is 172 nm because the Si—C bond is easily cut. It is desirable.

  Next, as a step of forming the cathode catalyst layer 7b on the peeling substrate 1a and the anode catalyst layer 7c on the transfer substrate 1b, a second catalyst ink 7a containing catalyst-carrying particles, a polymer electrolyte, and a solvent is used. A catalyst ink 7a is dropped onto the prepared and patterned release substrate 1a and affinity area 5 on the transfer substrate 1b to form a cathode catalyst layer 7b and an anode catalyst layer 7c (FIG. 1 (1c), FIG. 1 (2c)). The catalyst ink 7a used in this embodiment includes fine particles of platinum or an alloy of platinum and other metals (for example, Ru, Rh, Mo, Cr, Co, Fe, etc.) (the average particle size is preferably 10 nm or less). Is a solvent in which conductive carbon fine particles such as carbon black (average particle diameter: about 20 to 100 nm) and a polymer solution such as perfluorosulfonic acid resin solution are not compatible with the silane coupling agent 2 What is manufactured using the ink mixed uniformly in (water etc.) can be used.

In the electrolyte membrane with a catalyst layer according to this embodiment, the amount of platinum supported by the cathode catalyst layer 7b is equal to or greater than the amount of platinum supported by the anode catalyst layer 7c.
Next, as a third step of pattern formation (residual silane coupling agent removal step), vacuum ultraviolet light 3 is applied to the release substrate 1a and the transfer substrate 1b on which the cathode catalyst layer 7b and the anode catalyst layer 7c are formed. Irradiation is performed to decompose and remove the silane coupling agent 2 in the area 6 formed by the silane coupling agent 2 having no affinity with the catalyst ink 7a (FIG. 1 (1d), FIG. 1 (2d)).

Next, an electrolyte solution containing a polymer electrolyte and a solvent is prepared, and the electrolyte solution is applied onto the cathode catalyst layer 7b to form a polymer electrolyte membrane 8 (FIG. 1 (1e)).
Next, the anode catalyst layer is formed by stacking the anode catalyst layer-formed electrolyte membrane with the cathode catalyst layer so that the cathode catalyst layer-forming back side is in contact with the anode catalyst layer and then performing hot pressing. Transferred to the solid polymer electrolyte membrane (FIG. 1 (3f)).

Finally, the catalyst membrane-attached electrolyte membrane composed of the cathode catalyst layer 7b, the polymer electrolyte layer 8, and the anode catalyst layer 7c is peeled from the release substrate 1a and the transfer substrate 1b, whereby the catalyst of the present embodiment. A layered electrolyte membrane is produced.
FIG. 2 is a cross-sectional view showing an ideal configuration of the electrolyte membrane with a catalyst layer according to the present embodiment. Thus, in the electrolyte membrane with a catalyst layer manufactured by the manufacturing method according to the present embodiment, the mixed layer 7d of the catalyst layer and the polymer electrolyte membrane is provided between the cathode catalyst layer 7b and the electrolyte membrane 8. Yes.

  In the electrolyte membrane with a catalyst layer manufactured by the manufacturing method according to this embodiment, the cathode catalyst layer 7b and the surface of the polymer electrolyte layer 8 are formed on the same plane on the release substrate 1. That is, the electrolyte membrane with a catalyst layer includes a polymer electrolyte membrane 8, an anode catalyst layer 7c provided on one surface of the polymer electrolyte membrane 8, and a cathode catalyst layer 7b provided on the other surface of the polymer electrolyte membrane 8. The surface of the cathode catalyst layer 7b and the surface of the polymer electrolyte membrane 8 provided with the cathode catalyst layer 7b are on substantially the same plane.

FIG. 3 is a cross-sectional view showing a configuration of an electrolyte membrane with a catalyst layer different from the ideal of the present embodiment. 3A shows a configuration in which the cathode catalyst layer 7b is convex, and FIG. 3B shows a configuration in which the cathode catalyst layer 7b is completely surrounded by the polymer electrolyte membrane 8 and is not exposed to the outside. Is shown.
When the cathode catalyst layer 7b is convex, the cathode catalyst layer 7b is not covered with the polymer electrolyte membrane 8, so that the moisture retention of the cathode catalyst layer 7b is reduced (FIG. 3A). ). On the other hand, when the polymer electrolyte membrane 8 enters the interface between the cathode catalyst layer 7b and the release substrate 1, that is, the cathode catalyst layer 7b is completely surrounded by the polymer electrolyte membrane 8 and is not exposed to the outside. As conductivity decreases, gas diffusibility of the cathode catalyst layer 7b decreases (FIG. 3B). A configuration in which the cross section of the cathode catalyst layer 7b is completely covered with the polymer electrolyte membrane 8 and the surface of the cathode catalyst layer 7b and the surface of the polymer electrolyte membrane 8 are completely coincident is more desirable.

  FIG. 4 is a cross-sectional view showing a configuration of a membrane electrode assembly in which a gas diffusion layer and a gasket layer are provided on the electrolyte membrane with a catalyst layer of the present embodiment. Gas diffusion layers (cathode side gas diffusion layer 11b, anode side gas diffusion layer 11c) are exposed on the exposed surfaces of the catalyst layers (cathode catalyst layer 7b, anode catalyst layer 7c) on the front and back sides of the electrolyte membrane with a catalyst layer. Gasket layers (cathode side gasket layer 12b, anode side gasket layer 12c) are provided.

  Since the surfaces of the cathode catalyst layer 7b and the polymer electrolyte membrane 8 of the electrolyte membrane with catalyst layer according to the present embodiment are completely coincident with each other, the cathode side gas diffusion layer 11b and the cathode side gasket layer 12b have the same thickness. It is desirable to adjust the gasket thickness so that

  Since the surfaces of the anode catalyst layer 7c and the polymer electrolyte membrane 8 do not completely match and the anode catalyst layer is convex downward, more strictly, the thickness of the anode side gasket layer 12c is Although it is desirable to adjust so that it may become the sum of the thickness of the side gas diffusion layer 11c and the thickness of the anode catalyst layer 7c, since the anode catalyst layer 7c is a thin layer of 5 micrometers or less, the thickness of the anode side gasket layer 12c is Even if it is the same as the thickness of the anode side gas diffusion layer 11c, it can be used suitably.

  By controlling the thickness of the gas diffusion layer and gasket layer, the pressure applied to the catalyst layer forming part and the catalyst layer peripheral part can be made uniform when the membrane electrode assembly is stacked, thereby suppressing deterioration of the fuel cell. be able to.

  The formation method of a gas diffusion layer and a gasket layer is not specifically limited. A method of forming a gasket layer after the gas diffusion layer is bonded to the catalyst layer forming portions on the front and back of the electrolyte membrane with a catalyst layer, and the gas diffusion layer with a gasket in which the gas diffusion layer and the gasket layer are integrated in advance. The formation method by bonding to the attached electrolyte membrane can be suitably used.

According to the manufacturing method of the electrolyte membrane with a catalyst layer according to the present embodiment, the loss of the catalyst ink 7a can be eliminated. The reason is that when the cathode catalyst layer 7b and the anode catalyst layer 7c are formed, the catalyst layer is formed only in the affinity area 5 having affinity with the catalyst ink 7a. As a result, the manufacturing cost can be reduced.
According to the manufacturing method of the electrolyte membrane with a catalyst layer according to the present embodiment, the ionic resistance can be reduced. The reason is that the polymer electrolyte layer 8 is applied directly on the cathode catalyst layer 7b, whereby a cathode catalyst layer-polymer electrolyte membrane mixed layer is formed, and the contact between the cathode catalyst layer 7b and the polymer electrolyte membrane 8 is prevented. It is because it improves. As a result, better power generation performance can be obtained.

The electrolyte membrane with a catalyst layer according to this embodiment can improve power generation performance under low humidification conditions. The reason is that the cathode catalyst layer 7b is covered with the polymer electrolyte layer 8 on all sides including the cross section, so that the catalyst layer is moisturized even under low humidification conditions, and the membrane electrode assembly (high proton conductivity) ( This is because the MEA can be formed.
The amount of platinum supported on the catalyst layer of the electrolyte membrane with a catalyst layer is such that the amount of platinum supported on the cathode catalyst layer 7b is greater than or equal to the amount of platinum supported on the anode catalyst layer 7c. That is, platinum content of the cathode catalyst layer 7b is, 0.20~0.40mg / cm ^2, amount of platinum supported anode catalyst layer 7c is 0.05~0.10mg / cm ² is desirable.

In the configuration of the electrolyte membrane with a catalyst layer of this embodiment, the surfaces of the cathode catalyst layer 7b and the polymer electrolyte layer 8 are substantially on the same plane, and the cross section of the catalyst layer is also covered with the polymer electrolyte. Therefore, particularly under low humidification conditions, the electrode catalyst layer has high moisture retention and high proton conductivity, so that power generation performance can be improved.
As described above, according to the electrolyte membrane with a catalyst layer and the manufacturing method thereof according to the present embodiment, an electrolyte membrane with a catalyst layer that is inexpensive and has sufficient power generation performance can be provided.

[Example]
Hereinafter, the manufacturing method of the membrane electrode assembly according to the present embodiment will be described with reference to FIG. In addition, the Example mentioned later is one Example of this invention, and this invention is not limited only to this Example. Moreover, the electrolyte membrane with a catalyst layer according to this example is used for a polymer electrolyte fuel cell.
[Process order of manufacturing method of electrolyte membrane with catalyst layer]
FIG. 5 is a flowchart for explaining the method of manufacturing the catalyst layer-attached electrolyte membrane according to this embodiment in the order of steps.

As shown to Fig.5 (a), the manufacturing method of the electrolyte membrane with a catalyst layer is divided into the process on a peeling base material, the process on a transfer base material, and a common process.
The steps on the release substrate include a silane coupling agent forming step (S110) on the release substrate, a silane coupling agent limited removal step (S120) on the release substrate, and a cathode catalyst layer forming step (S125). And a residual silane coupling agent removal step (S130) on the release substrate and a polymer electrolyte membrane formation step (S135).

The steps on the transfer substrate include a silane coupling agent formation step (S210) on the transfer substrate, a silane coupling agent limited removal step (S220) on the transfer substrate, and an anode catalyst layer formation step (S225). And a residual silane coupling agent removal step (S130) on the transfer substrate.
The common process includes a transfer process of the anode catalyst layer to the polymer electrolyte membrane (S305), a peeling substrate and a peeling removal process of the transfer substrate (S315).

  As shown in FIG.5 (b), when paying attention only to the pattern formation process (S1000) in the manufacturing method of the electrolyte membrane with a catalyst layer which concerns on this embodiment, the silane coupling agent formation process (S110) as a 1st process ( S210), the silane coupling agent limited removal step (S120) (S220) as the second step, and the residual silane coupling agent removal step (S130) (S230) as the third step. it can. That is, the pattern forming step (S1000) includes the silane coupling agent forming step (S110) (S210) for forming the silane coupling agent 2 in all areas on the peeling substrate 1a and the transfer substrate 1b, and the affinity area 5 The catalyst layers 7b and 7c are formed by the silane coupling agent limited removal step (S120) (S220) in which only the silane coupling agent 2 formed above is removed and the catalyst layer formation step (S125) (S225). After that, the residual silane coupling agent removing step (S130) (S230) for removing the residual silane coupling agent 2 in the non-affinity area 6 is included.

In the pattern formation step (S1000) described above, the affinity area 5 utilizes hydrophilicity and the non-affinity area 6 utilizes water repellency to form a pattern.
(1) Silane coupling agent forming step (S110) (S210)
The silane coupling agent 2 is formed in all areas on the peeling substrate 1a and the transfer substrate 1b.
Here, as shown in FIGS. 1 (1a) and (2a), a glass substrate (hereinafter referred to as glass substrate 1a) is used as the peeling substrate 1a, and a polyethylene terephthalate film (hereinafter referred to as PET film 1b) is used as the transfer substrate 1b. Used. The glass substrate 1a and the PET film 1b were irradiated with vacuum ultraviolet light 3 having a wavelength of 172 nm to form hydroxyl groups on the surfaces of the glass substrate 1a and the PET film 1b. Subsequently, the hydroxyl group on the glass substrate 1a and the PET film 1b is reacted with the hydrolyzed silane coupling agent 2. Here, fluoromethoxysilane (trade name: KBM-7103, manufactured by Shin-Etsu Chemical Co., Ltd.), which is a fluoroalkyl silane coupling agent 2, and the glass substrate 1 on which the hydroxyl group is formed are heated to 160 ° C. To do. Then, a silane coupling agent 2 was formed on the glass substrate 1 by a chemical vapor deposition method (Chemical Vapor Deposition method: CVD method).

(2) Silane coupling agent limited removal step (S120) (S220)
By irradiating the vacuum ultraviolet light 3 only on the affinity area 5 having affinity through the photomask 4, only the catalyst ink 7a and the silane coupling agent 2 formed on the affinity area 5 are removed.
Here, as shown in FIGS. 1 (1b) and (2b), a glass substrate on which a silane coupling agent 2 is formed by applying vacuum ultraviolet light 3 having a wavelength of 172 nm through a photomask 4 having an opening of 50 mm square, Irradiate on PET film. Then, an affinity area 5 having affinity with the catalyst ink 7a obtained by decomposing the silane coupling agent 2 and a non-affinity area 6 having no affinity with the catalyst ink 7a in which the silane coupling agent 2 remains are formed in a pattern. did.

  In addition, according to the manufacturing method of the electrolyte membrane with a catalyst layer which concerns on this embodiment, a catalyst layer can be formed in a desired shape with high precision. The reason is that the accuracy of the photomask 4 used in the silane coupling agent limited removal step (S120) (S220) is reflected in the shapes of the cathode catalyst layer 7b and the anode catalyst layer 7c. Accordingly, by using the photomask 4 having a desired accuracy and shape, a catalyst layer having a desired shape can be formed with high accuracy.

(3) Catalyst layer forming step (S125) (S225)
The catalyst ink 7a is applied to the affinity area 5 on the release substrate 1a and the transfer substrate 1b to form a coating film, and the solvent in the formed coating film is removed, and the cathode catalyst layer 7b and the anode catalyst layer 7c. Form.
Here, as shown in FIGS. 1 (1c) and (2c), a platinum-supported carbon catalyst (trade name: TEC10E50E, manufactured by Tanaka Kikinzoku Kogyo Co., Ltd.) having a platinum support amount of 50% and a 20% by mass polymer electrolyte solution. Nafion (registered trademark, manufactured by DuPont) was mixed with water as a solvent. Subsequently, dispersion treatment was performed with a planetary ball mill to prepare catalyst ink 7a. Then, on the patterned glass substrate and PET film, the adjusted catalyst ink 7a is applied to the affinity area 5 having affinity with the catalyst ink 7a, and the platinum loadings are 0.30 mg / cm ² and 0.10 mg, respectively. / Cm ² was added dropwise. The coating film formed by the dropped catalyst ink 7a was dried to form the cathode catalyst layer 7b and the anode catalyst layer 7c.

(4) Residual silane coupling agent removal step (S130) (S230)
After the formation of the cathode catalyst layer 71b and the anode catalyst layer 7c, the residual silane coupling agent 2 in the non-affinity area 6 having no affinity with the catalyst ink 7a is removed.
Here, as shown in FIGS. 1 (1d) and (2d), a vacuum ultraviolet light 3 having a wavelength of 172 nm is irradiated onto a glass substrate on which the cathode catalyst layer 7b is formed and a PET film on which the anode catalyst layer 7c is formed. The silane coupling agent 2 in the non-affinity area 6 having no affinity for the catalyst ink 7a at the peripheral portions of the cathode catalyst layer 7a and the anode catalyst layer 7b was decomposed and removed.

(5) Polymer electrolyte membrane forming step (S135)
On the cathode catalyst layer 7b, an electrolyte ink containing at least a polymer electrolyte and a solvent is applied to form a coating film, and the solvent in the formed coating film is removed to form the polymer electrolyte membrane 8.
Here, as shown in FIG. 1 (1e), Nafion (registered trademark, manufactured by DuPont), which is a 20% by mass polymer electrolyte solution, is placed on the cathode catalyst layer 7a so that the film thickness becomes 20 μm. The polymer electrolyte membrane 8 was formed by applying and drying the coating film.

(6) Step of transferring anode catalyst layer to polymer electrolyte membrane (S305)
On the transfer base material on which the anode catalyst layer is formed, the electrolyte membrane with the cathode catalyst layer is laminated so that the back side of the cathode catalyst layer formation is in contact with the anode catalyst layer, a hot press process is performed, and the anode catalyst layer 7c is polymer electrolyte. Transfer to film 8.
Here, as shown in FIG. 1 (3 f), the cathode catalyst layer-forming back surface side of the electrolyte membrane with a cathode catalyst layer is laminated on the transfer substrate on which the anode catalyst layer 7 c is formed, so that the anode catalyst layer is in contact with the anode catalyst layer. Hot pressing was performed at a temperature of 6.0 × 10 ⁶ Pa and the anode catalyst layer 7 c was transferred to the polymer electrolyte membrane 8.

(7) Peeling / removing step of peeling substrate and transfer substrate (S315)
The peeling base material 1a and the transfer base material 1b are peeled from the electrolyte membrane with a catalyst layer comprising the cathode catalyst layer 7b, the polymer electrolyte layer 8, and the anode catalyst layer 7c.
Here, the cathode catalyst layer 7b, the polymer electrolyte membrane 8, and the anode catalyst layer 7c were peeled from the glass substrate 1a and the PET film 1b to form an electrolyte membrane with a catalyst layer.

[Comparative example]
(A) Cathode catalyst layer forming step (S125)
A platinum-supported carbon catalyst (trade name: TEC10E50E, manufactured by Tanaka Kikinzoku Kogyo Co., Ltd.) with a platinum-supported amount of 50%, Nafion (registered trademark, manufactured by DuPont), which is a 20% by mass polymer electrolyte solution, and water as a solvent, Mixed. Subsequently, a dispersion treatment was performed with a planetary ball mill to prepare a catalyst ink 70. And the adjusted catalyst ink 7a was apply | coated on the transfer base material with which the mask material which has a 50 mm square opening part was bonded on PET film. The catalyst ink 7a is applied by a doctor blade method so that the amount of platinum supported is 0.30 mg / cm ² . After being applied, the coating film is dried to form the cathode catalyst layer 7b.

(B) Anode catalyst layer forming step (S225)
The catalyst ink 70 was applied by a doctor blade method on a transfer substrate in which a mask material having an opening of 50 mm square on a PET film was bonded so that the platinum carrying amount was 0.10 mg / cm ^2. The coating film was dried to form the anode catalyst layer 72.
(C) Polymer electrolyte membrane forming step (S135)
A 20 mass% polymer electrolyte solution Nafion (registered trademark, manufactured by DuPont) was applied onto a glass substrate by a doctor blade method so that the film thickness was 20 μm, the coating film was dried, and polymer electrolyte membrane 8 Formed. After forming the polymer electrolyte membrane 8, the glass substrate was peeled off.

(D) Hot press process (S305)
Both electrode catalyst layers manufactured on the PET sheet are arranged so as to face both surfaces of the polymer electrolyte membrane 8 manufactured from the polymer electrolyte solution, and hot pressing is performed at 130 ° C. and 6.0 × 10 ⁶ Pa. Then, an electrolyte membrane with a catalyst layer was produced.

[Evaluation results]
As a result of examining the volume of the catalyst ink 7a used in the examples and comparative examples and the respective production methods, it was confirmed that the amount of the catalyst ink 7a used could be reduced by 40% according to the production method of the example.
Moreover, as a result of investigating the power generation characteristic in low humidification about the electrolyte membrane with a catalyst layer manufactured with the Example, the comparative example, and the respective manufacturing methods, it was confirmed that the power generation performance of the example was higher.

[Summary]
In the present embodiment, the following method for producing an electrolyte membrane with a catalyst layer was employed.
The method for producing an electrolyte membrane with a catalyst layer according to this embodiment includes a polymer electrolyte membrane (8), an anode catalyst layer (7c) provided on one surface of the polymer electrolyte membrane (8), and the polymer. The present invention relates to a method for producing an electrolyte membrane with a catalyst layer comprising a cathode catalyst layer (7b) provided on the other surface of the electrolyte membrane (8). This manufacturing method includes a pattern formation step (S1000), a cathode catalyst layer formation step (S125), a polymer electrolyte membrane formation step (S135), a pattern formation step (S1000), and an anode catalyst layer formation step (S225). And a hot pressing step (S305) and a peeling step (S315).

  In the pattern formation step (S1000), the affinity area (5) having an affinity for the catalyst ink (7a) containing the catalyst-supporting particles, the polymer electrolyte, and the solvent, and the catalyst ink (7a) have no affinity for the non-affinity The area (6) is patterned on the release substrate (1a). In the cathode catalyst layer forming step (S125), the catalyst ink (7a) is applied to the affinity area (5) to form a coating film, the solvent in the formed coating film is removed, and the cathode catalyst layer (7b). Form. In the polymer electrolyte membrane formation step (S135), an electrolyte ink containing a polymer electrolyte and a solvent is applied to the cathode catalyst layer (7b) to form a coating film, and the solvent in the formed coating film is removed. Then, the polymer electrolyte membrane (8) is formed. In the pattern formation step (S1000), the affinity area (5) having an affinity for the catalyst ink (7a) containing the catalyst-supporting particles, the polymer electrolyte, and the solvent, and the catalyst ink (7a) have no affinity for the non-affinity The area (6) is patterned on the transfer substrate (1b). In the anode catalyst layer forming step (S225), the catalyst ink (7a) is applied to the affinity area (5) to form a coating film, the solvent in the formed coating film is removed, and the anode catalyst layer (7c). Form. In the hot pressing step (S305), the anode catalyst layer (7c) produced on the transfer substrate (1b) is laminated on the back polymer electrolyte membrane (8) on which the cathode catalyst layer (7b) is formed. The anode catalyst layer is transferred to the polymer electrolyte membrane by pressing. In the peeling step (S315), the peeling substrate (1a) and the transfer substrate (1b) are peeled and removed.

The pattern formation step (S1000) includes a silane coupling agent formation step (S110, S210), a silane coupling agent limited removal step (S120, S220), and a residual silane coupling agent removal step (S130, S230). You may have.
In the silane coupling agent forming step (S110, S210), the silane coupling agent (2) is formed on the entire area of the release substrate (1a) or the transfer substrate (1b). In the silane coupling agent limited removal step (S120, S220), only the silane coupling agent (2) formed on the affinity area (5) is removed. In the residual silane coupling agent removal step (S130, S230), after the catalyst layer (7b, 7c) is formed by the catalyst layer formation step (S125, S225), the residual silane coupling agent in the non-affinity area (6) (2) is removed.

Further, in the silane coupling agent limited removal process (S120, S220), the vacuum ultraviolet light (3) is irradiated only on the affinity area (5) through the photomask (4). good.
In the pattern formation step (S1000), the hydrophilicity may be utilized in the affinity area (5), and the water repellency may be utilized in the non-affinity area (6).

The water contact angle of the affinity area (5) may be 15 degrees or less, and the water contact angle of the non-affinity area (6) may be 100 degrees or more.
The electrolyte membrane with a catalyst layer according to this embodiment includes a polymer electrolyte membrane (8), an anode catalyst layer (7c) provided on one surface of the polymer electrolyte membrane (8), and a polymer electrolyte membrane (8). And a cathode catalyst layer (7b) provided on the other surface of the substrate. The electrolyte membrane with a catalyst layer has a mixed layer (7d) of the catalyst layer and the polymer electrolyte membrane between the cathode catalyst layer (7b) and the polymer electrolyte membrane (8), and the surface of the cathode catalyst layer (7b) The surface of the polymer electrolyte membrane (8) provided with the cathode catalyst layer is substantially on the same plane.

[Effect of this embodiment]
This embodiment has the following effects.
According to this embodiment, (1) there is little loss of catalyst ink, (2) a catalyst layer can be formed in a desired shape with high accuracy, (3) ion resistance is low, and (4) high under low humidification conditions. It is possible to provide a method for producing an electrolyte membrane with a catalyst layer and an electrolyte membrane with a catalyst layer, which have the effect of having power generation performance.

(1) The reason why the loss of the catalyst ink can be reduced is that when the cathode catalyst layer and the anode catalyst layer are formed, the catalyst layer is formed only in the affinity area having affinity with the catalyst ink. As a result, the manufacturing cost can be reduced.
(2) The reason why the catalyst layer can be formed in a desired shape with high accuracy is that the accuracy of the photomask used in the step of removing the silane coupling agent is reflected in the shapes of the cathode catalyst layer and the anode catalyst layer. . Therefore, by using a photomask having a desired accuracy and shape, a catalyst layer having a desired shape can be formed with high accuracy.

(3) The reason why the ionic resistance can be reduced is that the contact between the polymer electrolyte layer and the cathode catalyst layer is improved. Since the polymer electrolyte layer is coated on the cathode catalyst layer, two mixed layers are formed between the polymer electrolyte layer and the cathode catalyst layer, the adhesion is improved, and good power generation performance results are obtained.
(4) The reason why the power generation performance can be increased under low humidification conditions is that the cathode catalyst layer is covered with the polymer electrolyte layer on all sides including the cross section, so that the catalyst layer is moisturized even under low humidification conditions and is high. This is because a membrane electrode assembly (MEA) having proton conductivity can be formed.

Thus, according to this embodiment, the catalyst layer can be formed in a desired shape without loss of expensive catalyst ink. Furthermore, since a mixed layer is formed between the polymer electrolyte layer and the cathode catalyst layer, the contact between the polymer electrolyte membrane and the cathode catalyst layer is improved, and an electrolyte membrane with a catalyst layer that has an effect of reducing ionic resistance can be provided. .
Further, according to the present embodiment, since the four sides including the cross section are covered with the polymer electrolyte membrane, the catalyst layer is moisturized even under low humidification conditions, and a membrane electrode assembly having high proton conductivity is obtained. It is possible to provide a method for producing an electrolyte membrane with a catalyst layer and an electrolyte membrane with a catalyst layer, which have the effect of high power generation performance under low humidification conditions.

According to the present embodiment, it is possible to provide an electrolyte membrane with a name catalyst layer having a high power generation performance and a method for manufacturing the same, which can form a catalyst layer in a desired shape with little loss and ionic resistance of the catalyst ink. Therefore, it can be suitably used for a single cell or a stack used for a solid polymer fuel cell in a polymer electrolyte fuel cell, particularly a fuel cell vehicle or a household fuel cell.
As mentioned above, although embodiment of this invention was explained in full detail, actually, it is not restricted to said embodiment, Even if there is a change of the range which does not deviate from the summary of this invention, it is included in this invention.

DESCRIPTION OF SYMBOLS 1a ... Release base material 1b ... Transfer base material 2 ... Silane coupling agent 3 ... Vacuum ultraviolet light 4 ... Photomask 5 ... Area with affinity with catalyst ink (affinity) area)
6. Areas with no affinity for catalyst ink (non-affinity areas)
7a ... Catalyst ink 7b ... Cathode catalyst layer 7c ... Anode catalyst layer 7d ... Cathode catalyst layer-polymer electrolyte membrane mixed layer 8 ... Polymer electrolyte membrane 9 ... With cathode catalyst layer Electrolyte membrane 10 ... Hot plate for pressing 11b ... Cathode side gas diffusion layer 11c ... Anode side gas diffusion layer 12b ... Cathode side gasket layer 12c ... Anode side gasket layer

Claims (5)

A method for producing an electrolyte membrane with a catalyst layer, comprising: a polymer electrolyte membrane; an anode catalyst layer provided on one surface of the polymer electrolyte membrane; and a cathode catalyst layer provided on the other surface of the polymer electrolyte membrane. There,
A pattern forming step of patterning on the release substrate an affinity area having affinity for the catalyst ink containing catalyst-supporting particles, a polymer electrolyte, and a solvent, and a non-affinity area having no affinity for the catalyst ink; ,
Forming a coating film by applying the catalyst ink to the affinity area, removing a solvent in the formed coating film, and forming a cathode catalyst layer;
A polymer electrolyte is formed on the cathode catalyst layer by applying an electrolyte ink containing a polymer electrolyte and a solvent to form a coating film, removing the solvent in the formed coating film, and forming the polymer electrolyte membrane. A film forming step;
A pattern forming step of patterning on the transfer substrate an affinity area having affinity for the catalyst ink containing catalyst-carrying particles, a polymer electrolyte and a solvent, and a non-affinity area having no affinity for the catalyst ink; ,
An anode catalyst layer forming step of forming the coating film by applying the catalyst ink to the affinity area, removing the solvent in the formed coating film, and forming the anode catalyst layer;
A hot pressing step of laminating the anode catalyst layer produced on the transfer substrate on the polymer electrolyte membrane on the back surface on which the cathode catalyst layer is formed, and transferring the anode catalyst layer to the polymer electrolyte membrane by hot pressing; ,
A peeling and removing step for peeling and removing the peeling substrate and the transfer substrate;
A method for producing an electrolyte membrane with a catalyst layer, comprising: The pattern forming step includes a silane coupling agent forming step for forming a silane coupling agent on the release substrate or the entire area on the transfer substrate, and a silane coupling agent formed on the affinity area. A silane coupling agent limited removal step for removing only the residual silane coupling agent for removing the residual silane coupling agent in the non-affinity area after the catalyst layer is formed by the catalyst layer forming step;
The method for producing an electrolyte membrane with a catalyst layer according to claim 1, comprising: 3. The production of the electrolyte membrane with a catalyst layer according to claim 2 , wherein, in the silane coupling agent limited removal step, the removal is performed by irradiating only the affinity area with vacuum ultraviolet light through a photomask. Method.   4. The pattern formation step according to claim 1, wherein the affinity area utilizes hydrophilicity and the non-affinity area utilizes water repellency to form a pattern. 5. Of manufacturing an electrolyte membrane with a catalyst layer.   The catalyst according to any one of claims 1 to 4, wherein the water contact angle of the affinity area is 15 degrees or less, and the water contact angle of the non-affinity area is 100 degrees or more. Manufacturing method of electrolyte membrane with layer.

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