KR20210158510A - A method of manufacturing a membrane-electrode assembly using a novel evaluation method for heat treatment - Google Patents

Abstract

The present invention relates to a method for manufacturing a membrane-electrode assembly using a novel evaluation method for heat treatment. More specifically, the present invention can provide a method capable of evaluating the quality and effectiveness of heat treatment through a hot press device by providing a pigment material that changes a state according to temperature to a sub-gasket or the surface of the sub-gasket.

Description

A method of manufacturing a membrane-electrode assembly using a novel evaluation method for heat treatment

The present invention relates to a method for manufacturing a membrane-electrode assembly to which a novel evaluation method for heat treatment is applied, and more particularly, the present invention relates to a sub-gasket or a surface of a sub-gasket by providing a pigment material that changes state according to temperature to the surface of the sub-gasket. It is characterized by providing a method for evaluating the quality and effectiveness of heat treatment through the device.

Polymer electrolyte fuel cell (PEMFC, Proton Exchange Membrane Fuel Cell) is a fuel cell that uses a polymer membrane with hydrogen ion exchange function as an electrolyte. It has the advantages of high power density, short starting time, and fast response characteristics to load changes, so it is used in fuel cells for hydrogen electric vehicles.

A stack for a polymer electrolyte fuel cell is generally composed of hundreds of unit cells, wherein the unit cell includes an electrolyte membrane and a 3-layer membrane-electrode assembly including electrode layers formed on both sides of the electrolyte membrane, In the three-layer membrane-electrode assembly, a sub-gasket bonded to both sides of the electrolyte membrane is included.

In general, the sub-gasket is first attached to the 3-layer membrane-electrode assembly through an adhesive, and then heat-treated through a hot press device. However, in general, it is impossible to confirm whether the heat treatment has been performed properly during the process, and it can be confirmed only by manufacturing a cell and performing a performance test on the cell. That is, there is a problem in that there is no way to detect or control a heat treatment failure occurring during the process of manufacturing the membrane-electrode assembly.

Until now, there is no way to know whether the heat treatment has proceeded smoothly by a non-destructive method that does not disassemble the cell, and many studies are being made on this.

Korean Patent Application Laid-Open No. 10-2015-0045071 relates to an apparatus for manufacturing a membrane electrode assembly, and discloses a configuration in which Zion pigment is applied to a polymer electrolyte membrane in order to check whether the temperature control of the transfer roll is abnormal. However, the above patent only controls the transfer process of the electrolyte membrane and the electrode layer forming the 3-layer membrane-electrode assembly, but only controls the quality of the heat treatment state of the 3-layer membrane-electrode assembly and the subgasket fixed inside the subgasket. none.

Korean Patent Publication No. 10-2015-0045071

According to the present invention, an object of the present invention is to provide a method capable of confirming the quality and presence or absence of heat treatment during a process of manufacturing a membrane-electrode assembly.

According to the present invention, it is an object of the present invention to provide a method capable of confirming in real time a poor heat treatment state when manufacturing a membrane-electrode assembly.

According to the present invention, it is an object of the present invention to provide a method capable of evaluating the heat treatment quality by a simple non-destructive test, even if the performance is not evaluated by manufacturing a cell.

The object of the present invention is not limited to the object mentioned above. The object of the present invention will become clearer from the following description, and will be realized by means and combinations thereof described in the claims.

According to the present invention, a three-layer membrane-preparing electrode assembly comprising an electrolyte membrane and electrode layers provided on both sides of the electrolyte membrane; preparing a sub-gasket including an opening; obtaining a 5-layer membrane-electrode assembly by attaching sub-gaskets to both sides of the 3-layer membrane-electrode assembly while exposing the electrode layer through the opening; and bonding the three-layer membrane-electrode assembly to the sub-gasket by heat-treating the 5-layer membrane-electrode assembly with a hot press apparatus. It provides a method for manufacturing a membrane-electrode assembly, comprising: the sub-gasket or a pigment material whose state changes according to temperature on the surface of the sub-gasket.

The sub-gasket may include a coating layer on at least one surface, and the pigment material may be included in the coating layer.

The three-layer membrane-electrode assembly and the sub-gasket are adhered through the coating layer,

The coating layer may include one selected from the group consisting of a binder, a pigment material, and a combination thereof.

The sub-gasket may include a color-changing part formed to have a predetermined width along the circumference of the opening, and the pigment material may be included in the color-changing part.

The pigment material may include any one of a color change material whose color changes according to temperature and a color change material whose turbidity changes with temperature.

The hot press apparatus may heat-treat all or a part of the sub-gasket.

The hot press apparatus may include a pressing part having a width capable of heat-treating both the electrode layer and the sub-gasket.

The pressing unit of the hot press device may include a central protruding main pressing unit and a sub pressing unit having a height difference from the main pressing unit.

The main pressing unit may correspond to the electrode layer, and the sub pressing unit may correspond to the sub gasket so that a hot press device is positioned on the five-layer membrane-electrode assembly.

The step of evaluating the heat treatment state of the three-layer membrane-electrode assembly and the sub-gasket may be further included.

The evaluating may include a heat treatment evaluation step; heat treatment temperature evaluation step; And heat treatment position evaluation step; may include at least one of

In the heat treatment evaluation step, the heat treatment state may be evaluated through the presence or absence of a change in the state of the pigment material.

If there is no state transformation of the pigment material, the heat treatment may be defective.

In the heat treatment temperature evaluation step, the heat treatment state may be evaluated by measuring a state transformation degree of the pigment material.

In the heat treatment position evaluation step, the heat treatment state may be evaluated by measuring the effective rate of the pigment material whose state is deformed.

According to the present invention, a 3-layer membrane-electrode assembly comprising an electrolyte membrane and electrode layers provided on both sides of the electrolyte membrane; and a sub-gasket provided on both sides of the three-layer membrane-electrode assembly and bonded thereto. It includes, and provides a membrane-electrode assembly comprising a pigment material whose state changes according to temperature on the sub-gasket or the surface of the sub-gasket.

The sub-gasket may include a coating layer on at least one surface, and the pigment material may be included in the coating layer.

The three-layer membrane-electrode assembly and the sub-gasket are adhered through the coating layer, and the coating layer may include one selected from the group consisting of a binder, a pigment material, and a combination thereof.

According to the present invention, it is possible to provide a method for checking the quality and presence or absence of heat treatment during the process of manufacturing a membrane-electrode assembly.

According to the present invention, it is possible to provide a method for checking in real time a poor heat treatment state when manufacturing a membrane-electrode assembly.

According to the present invention, it is possible to provide a method capable of evaluating the heat treatment quality by a simple non-destructive test, even if the performance is not evaluated by manufacturing a cell.

The effects of the present invention are not limited to the above-mentioned effects. It should be understood that the effects of the present invention include all effects that can be inferred from the following description.

1 is a flowchart showing a method for manufacturing a membrane-electrode assembly of the present invention.
2 is a plan view of a sub-gasket including a discoloration part.
3 shows a plan view and a cross-sectional view of a five-layer membrane-electrode assembly.
4 shows a pressing part and a 5-layer membrane-electrode assembly of the hot press apparatus.
5 shows embodiments of a hot press apparatus.
6 shows an example for heat treatment temperature evaluation.
7 shows an embodiment for the evaluation of the heat treatment position.

The above objects, other objects, features and advantages of the present invention will be easily understood through the following preferred embodiments in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed subject matter may be thorough and complete, and that the spirit of the present invention may be sufficiently conveyed to those skilled in the art.

In describing each figure, like reference numerals have been used for like elements. In the accompanying drawings, the dimensions of the structures are enlarged than the actual size for clarity of the present invention. Terms such as first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component. The singular expression includes the plural expression unless the context clearly dictates otherwise.

In this specification, terms such as "comprise" or "have" are intended to designate that a feature, number, step, operation, component, part, or a combination thereof described in the specification exists, but one or more other features It is to be understood that it does not preclude the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof. Also, when a part of a layer, film, region, plate, etc. is said to be “on” another part, it includes not only the case where the other part is “directly on” but also the case where there is another part in between. Conversely, when a part, such as a layer, film, region, plate, etc., is "under" another part, this includes not only cases where it is "directly under" another part, but also a case where another part is in the middle.

Unless otherwise specified, all numbers, values, and/or expressions expressing quantities of ingredients, reaction conditions, polymer compositions and formulations used herein, contain all numbers, values and/or expressions in which such numbers essentially occur in obtaining such values, among others. Since they are approximations reflecting various uncertainties in the measurement, it should be understood as being modified by the term "about" in all cases. Also, where the disclosure discloses numerical ranges, such ranges are continuous and inclusive of all values from the minimum to the maximum inclusive of the range, unless otherwise indicated. Furthermore, when such ranges refer to integers, all integers inclusive from the minimum to the maximum inclusive are included, unless otherwise indicated.

In this specification, when a range is described for a variable, the variable will be understood to include all values within the stated range including the stated endpoints of the range. For example, a range of “5 to 10” includes the values of 5, 6, 7, 8, 9, and 10, as well as any subranges such as 6 to 10, 7 to 10, 6 to 9, 7 to 9, etc. It will be understood to include any value between integers that are appropriate for the scope of the recited range, such as 5.5, 6.5, 7.5, 5.5 to 8.5 and 6.5 to 9, and the like. Also for example, ranges from "10% to 30%" include values of 10%, 11%, 12%, 13%, etc. and all integers up to and including 30%, as well as 10% to 15%, 12% to It will be understood to include any subranges such as 18%, 20% to 30%, etc., as well as any value between reasonable integers within the scope of the recited ranges, such as 10.5%, 15.5%, 25.5%, and the like.

The present invention relates to a method for manufacturing a membrane-electrode assembly to which a novel evaluation method for heat treatment is applied. More specifically, the present invention is characterized by providing a method for evaluating the quality of heat treatment even without directly driving the cell by applying a pigment material that changes state according to temperature.

A method for manufacturing a membrane-electrode assembly to which a novel evaluation method for heat treatment is applied includes the steps of preparing a three-layer membrane-electrode assembly including an electrolyte membrane and electrode layers provided on both sides of the electrolyte membrane, a sub-gasket including an opening preparing, applying subgaskets to both sides of the 3-layer membrane-electrode assembly while exposing the electrode layer through the opening to obtain a 5-layer membrane-electrode assembly, and preparing the 5-layer membrane-electrode assembly and bonding the three-layer membrane-electrode assembly to the sub-gasket by heat treatment using a hot press apparatus.

1 shows a flowchart of a method for manufacturing a membrane-electrode assembly according to the present invention, and each step will be described with reference to this.

Three-layer membrane-electrode assembly preparation steps

This is a step of preparing a 3-layer membrane-electrode assembly including an electrolyte membrane and electrode layers provided on both sides of the electrolyte membrane.

The electrolyte membrane of the present invention may be used without particular limitation as long as it is commonly applied in the field of fuel cell technology. In addition, the electrode layers provided on both sides of the electrolyte membrane _{include a catalyst capable of reacting with hydrogen (H 2} ) gas or oxygen (O ₂ ) gas introduced from the outside, and the catalyst used in this case is not particularly limited.

Subgasket preparation steps

This is a step of preparing a sub-gasket including an opening.

The subgasket of the present invention includes an opening including an opening in the center.

The sub-gasket is attached to the prepared 3-layer membrane-electrode assembly to be used for fixing and protecting the 3-layer membrane-electrode assembly.

The sub-gasket of the present invention is characterized in that it contains a pigment material whose state changes depending on the temperature on the inside or on the surface. The pigment material is used as a means for evaluating the quality of heat treatment in the manufacturing process of the membrane-electrode assembly of the present invention.

The pigment material preferably includes any one of a color change material whose color changes according to temperature and a color change material whose turbidity changes with temperature.

The color-changing material is a material capable of changing color by reacting with external temperature.

The turbidity material, unlike the discoloration material, is a material that reacts with external temperature and changes the degree of turbidity.

The pigment material of the present invention is not particularly limited and can be applied as long as it is a material that does not destroy or impair performance even at a temperature higher than the heat treatment temperature of the present invention.

The material of the subgasket of the present invention may be selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, polyimide, and polypropylene.

The material of the sub-gasket may further include a pigment material. The pigment material may be directly included in the material of the sub-gasket as described above, but may also be included in one surface of the sub-gasket if necessary.

The subgasket of the present invention may include a coating layer on at least one surface, and the coating layer includes one selected from the group consisting of a binder, a pigment material, and combinations thereof.

When the material of the sub-gasket of the present invention does not contain a pigment material, preferably, the coating layer essentially contains the pigment material. In addition, when the coating layer does not contain a pigment material, preferably, the material of the sub-gasket must include the pigment material.

When the coating layer is provided on the surface of the sub-gasket in a direction facing the 3-layer membrane-electrode assembly, the 3-layer membrane-electrode assembly and the sub-gasket are adhered through the coating layer.

When the pigment material of the present invention is included on the surface of the sub-gasket, in the present invention, a region where the pigment material is distributed is defined as a discoloration part.

2 shows the range of the discoloration part including the pigment material on the surface of the sub-gasket. Referring to this, the discoloration portion may be the entire surface of the sub-gasket, or may be formed to have a predetermined width along the periphery of the opening. This can be adjusted as needed, but in common, it is preferable that the discoloration part includes all edges forming the opening of the subgasket.

Attachment step

This is a step of manufacturing a 5-layer membrane-electrode assembly by attaching sub-gaskets to both sides of the 3-layer membrane-electrode assembly. At this time, the electrode layer of the 3-layer membrane-electrode assembly is exposed through the opening of the sub-gasket.

Preferably, in the present invention, a coating layer is provided at a portion where the electrolyte membrane and the sub-gasket of the three-layer membrane-electrode assembly contact each other.

3 shows a 5-layer membrane-electrode assembly in which a sub-gasket is attached to the 3-layer membrane-electrode assembly and a coating layer is formed.

In FIG. 3A , a coating layer is formed between the sub-gasket and the electrolyte membrane. On the contrary, it can be seen that the coating layer is formed on the surface exposed to the outside from the sub-gasket in FIG. 3(B). In addition, a discoloration part containing the pigment material is formed on the entire surface of the sub-gasket. It can be seen from FIG. 3(C) that the coating layer is formed on the surface exposed to the outside of the sub-gasket. However, it can be seen that the discoloration part is formed only by a certain distance away from the opening, not the entire area of the surface of the sub-gasket.

bonding step

In this step, the 5-layer membrane-electrode assembly is heat-treated with a hot press device to bond the attached 3-layer membrane-electrode assembly to the sub-gasket.

The hot press apparatus of the present invention includes a pressing unit that transfers heat, and the pressing unit is characterized in that the area of the opening is larger than that of the electrode layer and the sub-gasket to be heat-treated.

The pressurizing unit may simultaneously transmit heat and pressure, if necessary.

The hot press apparatus heat-treats all or a part of the sub-gasket, and the state of the pigment material is changed through the heat treatment. In this case, the heat treatment temperature may be performed at a temperature of 200° C. or less, and the heat treatment is preferably performed at 120° C. to 200° C.

The pigment material of the present invention should be capable of being deformed in the above heat treatment temperature range.

4 shows a hot press apparatus and a 5-layer membrane-electrode assembly of the present invention. Referring to this, the pressing unit includes a main pressing unit in the center and a sub pressing unit located at an edge of the main pressing unit.

The pressing part has a width capable of heat-treating both the electrode layer and the sub-gasket.

The main pressing part is provided at a position corresponding to the electrode layer, and is equal to or smaller than an area of the electrode layer. The main pressing part has a shape that protrudes compared to the sub pressing part, and a step is formed between the sub pressing part and the main pressing part.

The sub-pressurizing part is formed to have a step lower than that of the main-pressing part, and is continuous to the main pressing part and is located at a position corresponding to the sub-gasket.

5 shows a comparison between the conventional hot press apparatus and the hot press apparatus of the present invention. FIG. 5(A) is a conventionally used hot press apparatus, and it can be seen that the pressing part corresponds only to the electrode layer so that only the electrode layer can be heat-treated in the 5-layer membrane-electrode assembly. Meanwhile, it can be seen that FIG. 5(B) is a hot press device of the present invention, and the pressurizing part corresponds to the entire surface of the 5-layer membrane-electrode assembly so that not only the electrode layer but also the entire sub-gasket can be heat-treated. 5(C), it can be seen that the sub-pressurizing part corresponds only to a part of the sub-gasket. This is to increase the efficiency by reducing the length of the sub-pressurizing part so that only the discolored part containing the pigment material whose state changes through heat treatment can be heat-treated.

evaluation stage

The method for manufacturing a membrane-electrode assembly of the present invention further includes the step of evaluating the heat treatment state of the three-layer membrane-electrode assembly and the sub-gasket. That is, it is a step of checking the deformation state of the pigment material during the process to check the quality of the heat treatment.

The evaluating is characterized in that it includes at least one of a heat treatment evaluation step, a heat treatment temperature evaluation step, and a heat treatment position evaluation step. Preferably, the evaluation step of the present invention includes all of the heat treatment evaluation step, the heat treatment temperature evaluation step and the heat treatment position evaluation step. At this time, in the present invention, the order of each step is not important and can be controlled as needed.

However, in the present invention, the means for measuring and evaluating the state are not particularly limited, and it is sufficient if only the state transformation of the pigment material can be measured and the result can be output based on the measurement result.

Hereinafter, each evaluation step will be described separately.

Heat treatment evaluation

It is a step to evaluate the state of heat treatment through the presence or absence of change in the state of the pigment material. That is, the pigment material of the present invention is characterized in that the state is deformed even with little heat, but when heat is not transferred through the hot press device, the state change as described above does not proceed. As such, if the state of the pigment material before and after the heat treatment is the same, the heat treatment is judged to be defective.

Heat treatment temperature evaluation

This is a step of evaluating the state of heat treatment by measuring the degree of state transformation of the pigment material. That is, it is assumed that the state of the pigment material desired by the manufacturer in the pigment material that is deformed according to temperature is 100°C (in this case, the final allowable state range is 98% to 102%), and the pigment material used depends on the temperature. Assuming that a unique color is provided, if the state of the pigment material actually deformed by the heat treatment is out of 98°C to 102°C of the target state, the heat treatment is judged to be defective. The reason for such evaluation is to control the 5-layer membrane-electrode assembly because unpredictable problems occur when the temperature range required for bonding is out of the bonding process.

6 shows a change in the state of the pigment material included in the surface of the sub-gasket. When a higher temperature than necessary is transmitted by heat treatment, the pigment material is transformed from gray to red and a defective product is output. In this case, the red color can be seen as a result of the pigment material exceeding 110°C in the example shown above.

Heat treatment position evaluation

It is a step to evaluate the heat treatment state by measuring the effective rate of the pigment material whose state has been changed. 7 shows a case in which the heat treatment process related thereto is defective, which will be described with reference to this.

The entire surface of the sub-gasket contains a pigment material, and the hot press device is performing heat treatment on the 5-layer membrane-electrode assembly. in case it is defective. When it is said that the pigment material shows green color at an appropriate temperature, there is no problem with the temperature of the heat treatment. However, looking at the area where the color has changed, it can be seen that only a part of the electrode layer and the sub-gasket has undergone heat treatment. In order to obtain a desirable result in the heat treatment position evaluation step of the present invention, all color changes along the interface should be observed in the discoloration part positioned at the interface between the electrode layer and the sub-gasket. As described above, when a color change is observed in the entire discoloration portion positioned at the edge of the electrode layer, at least the electrode layer can be considered to be all heat-treated.

Membrane-electrode assembly

The membrane-electrode assembly of the present invention includes a 3-layer membrane-electrode assembly including an electrolyte membrane and electrode layers provided on both surfaces of the electrolyte membrane, and a sub-gasket provided and joined to both sides of the 3-layer membrane-electrode assembly do.

The membrane-electrode assembly of the present invention is characterized in that the sub-gasket or the surface of the sub-gasket contains a pigment material whose state changes according to temperature.

The sub-gasket may include a coating layer on at least one surface, and the pigment material may be included in the coating layer.

The three-layer membrane-electrode assembly and the sub-gasket are adhered through the coating layer, and the coating layer includes one selected from the group consisting of a binder, a pigment material, and a combination thereof.

Claims (18)

Preparing a three-layer membrane-electrode assembly comprising an electrolyte membrane and electrode layers provided on both sides of the electrolyte membrane;
preparing a sub-gasket including an opening;
obtaining a 5-layer membrane-electrode assembly by attaching sub-gaskets to both surfaces of the 3-layer membrane-electrode assembly while exposing the electrode layer through the opening; and
bonding the three-layer membrane-electrode assembly to the sub-gasket by heat-treating the 5-layer membrane-electrode assembly with a hot press apparatus; including,
A method for manufacturing a membrane-electrode assembly, characterized in that the sub-gasket or a surface of the sub-gasket contains a pigment material whose state changes according to temperature. The method of claim 1,
The sub gasket includes a coating layer on at least one surface,
The method of manufacturing a membrane-electrode assembly in which the pigment material is included in the coating layer. 3. The method of claim 2,
The three-layer membrane-electrode assembly and the sub-gasket are adhered through the coating layer,
The coating layer comprises one selected from the group consisting of a binder, a pigment material, and a combination thereof - a method of manufacturing a membrane-electrode assembly. According to claim 1,
The sub-gasket includes a discoloration part formed with a predetermined width along the periphery of the opening,
The method of manufacturing a membrane-electrode assembly in which the pigment material is included in the discoloration part. According to claim 1,
The pigment material is a method for producing a membrane-electrode assembly comprising any one of a color-changing material that changes color according to temperature and a color-changing material whose turbidity changes with temperature. According to claim 1,
In the hot press apparatus, all or part of the sub-gasket is heat-treated, the membrane-electrode assembly manufacturing method. The method of claim 1,
The method of manufacturing a membrane-electrode assembly in which the hot press apparatus includes a pressing part having a width capable of heat-treating both the electrode layer and the sub-gasket. 8. The method of claim 7,
The method of manufacturing a membrane-electrode assembly of the pressing unit of the hot press apparatus comprising a central protruding main pressing part and a sub pressing part having a height difference with the main pressing part. 9. The method of claim 8,
The main pressing part corresponds to the electrode layer,
The method of manufacturing a membrane-electrode assembly, wherein the sub-pressing part corresponds to the sub-gasket so that a hot press device is located on the 5-layer membrane-electrode assembly. The method of claim 1,
The method of manufacturing a membrane-electrode assembly further comprising the step of evaluating the heat treatment state of the three-layer membrane-electrode assembly and the sub-gasket. 11. The method of claim 10,
The evaluation step is
heat treatment evaluation step;
heat treatment temperature evaluation step; and
heat treatment position evaluation step; A method for producing a membrane-electrode assembly comprising at least any one of. 12. The method of claim 11,
The heat treatment evaluation step is a method of manufacturing a membrane-electrode assembly to evaluate the heat treatment state through the presence or absence of a change in the state of the pigment material. 13. The method of claim 12,
If there is no change in the state of the pigment material, the heat treatment is poor. Method of manufacturing a membrane-electrode assembly. 12. The method of claim 11,
The heat treatment temperature evaluation step is a method of manufacturing a membrane-electrode assembly to evaluate the heat treatment state by measuring the state transformation degree (degree) of the pigment material. 12. The method of claim 11,
The heat treatment position evaluation step is a method of manufacturing a membrane-electrode assembly to evaluate the heat treatment state by measuring the effective rate of the pigment material whose state is modified. A 3-layer membrane-electrode assembly comprising an electrolyte membrane and electrode layers provided on both sides of the electrolyte membrane; and
a sub-gasket provided on both sides of the three-layer membrane-electrode assembly to be bonded; including,
A membrane-electrode assembly comprising a pigment material whose state changes according to temperature on the sub-gasket or a surface of the sub-gasket. 17. The method of claim 16,
The sub gasket includes a coating layer on at least one surface,
The membrane-electrode assembly in which the pigment material is included in the coating layer. 18. The method of claim 17,
The three-layer membrane-electrode assembly and the sub-gasket are adhered through the coating layer,
The coating layer is a membrane-electrode assembly comprising one selected from the group consisting of a binder, a pigment material, and combinations thereof.

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