TW202127719A - Sealing structure for membrane electrode assembly of fuel cell and manufacturing method thereof - Google Patents

Abstract

Provided are a sealing structure for a membrane electrode assembly (MEA) of a fuel cell and a manufacturing method thereof. The sealing structure includes a membrane electrode assembly, a first gas diffusion layer, a second gas diffusion layer, an adhesive layer and at least two gaskets. The membrane electrode assembly includes a membrane and a first and second catalytic layers coated on the two opposite surfaces of the membrane. The first gas diffusion layer is disposed on the first catalytic layer and in contact with a portion thereof, and the second gas diffusion layer is disposed on the second catalytic layer. The adhesive layer is disposed on a portion of the first catalytic layer, and a portion of the adhesive layer penetrates into the first catalystic layer. The sealing structure for a membrane electrode assembly of a fuel cell provided by the present invention can achieve excellent sealing effect using existing membrane electrode assembly under low cost.

Description

Sealing structure of membrane electrode group for fuel cell and manufacturing method thereof

The present invention relates to a sealing structure and a manufacturing method thereof, in particular to a sealing structure and a manufacturing method of a membrane electrode assembly used in a fuel cell.

Please refer to Figure 1. FIG. 1 is an exploded schematic diagram of a three-dimensional structure of a conventional hydrogen fuel cell (PEM FUEL CELL, proton exchange membrane fuel cell). Generally speaking, a sub-gasket 4'(Sub-gasket) is formed around the membrane electrode assembly 1'(MEA) of the hydrogen fuel cell structure of the prior art to provide sealing and fixing to the membrane electrode assembly 1' This component is combined with the frame 5'(Gasket, also known as gasket) of the battery pack. For example, as shown in FIG. 1, the hydrogen fuel cell includes an anode end plate 8'(anode end plate) and a cathode end plate 9'(cathode end plate) on the outside, and a current collecting plate 7'(current collector plate 7'(current collector), graphite plate 6'(graphite plate), frame 5'(gaskets), gas diffusion layers 2', 3'(gas diffusion layers), and sub-gaskets 4'(sub-gaskets). It can be seen from Fig. 1 that the sub-frame 4'is used to clamp and fix the membrane electrode assembly 1'.

In the above structure, the sub-frame 4'can be used to enhance the strength of the membrane electrode assembly 1'to prevent the membrane electrode assembly 1'from being damaged and leaking during the assembly of the hydrogen fuel cell. In addition, the use of the sub-frame 4'can reduce the size of the Nafion film (Nafion membrane) in the membrane electrode assembly 1'that needs to be used. And reduce the amount of Nafion membrane used to reduce costs.

However, for the aforementioned hydrogen fuel cell structure including the sub-frame 4', in order to match the design of the sub-frame 4', the catalyst layer on the Nafion membrane of the membrane electrode assembly 1'will have a smaller coating range on one side than the other side. This is to reserve a blank space for the attachment of the sub-frame 4', so as to avoid micro short circuits during subsequent cutting. In this way, for the membrane electrode assembly 1'that has been manufactured, it may be necessary to adjust the coating range of the catalyst layer on the membrane electrode assembly through additional processing procedures, so that it can be applied to the fixing method of the sub-frame 4'in the prior art. .

In addition, in the procedure of combining the membrane electrode group 1'with the sub-frame 4', since the Nafion membrane is made of a polytetrafluoroethylene perfluorinated main chain ionomer, its chemical structure contains four Fluorine atoms are difficult to combine with general plastic materials or rubber materials, and the selection of adhesives is relatively difficult. Furthermore, in the process of combining the membrane electrode assembly 1'and the sub-frame 4', there is also a disadvantage that bubbles are generated during the bonding process and the airtightness is not as expected.

Accordingly, in the prior art, there is still a need to provide a sealing structure and related manufacturing method for the membrane electrode assembly of a fuel cell to solve the aforementioned technical problems.

In order to solve the above technical problems, the present invention provides a sealing structure for a membrane electrode assembly of a fuel cell and a manufacturing method thereof. The sealing structure of the membrane electrode assembly for the fuel cell of the present invention can achieve excellent sealing performance without changing the structure of the existing membrane electrode assembly.

An embodiment of the present invention provides a sealing structure for a membrane electrode assembly of a fuel cell, which includes a membrane electrode assembly, a first gas diffusion layer, a second gas diffusion layer, an adhesive layer, and at least two frames. The membrane electrode group includes a thin film and two A first catalytic layer and a second catalytic layer on two opposite surfaces, the first gas diffusion layer is disposed on the first catalytic layer of the membrane electrode group and is in contact with a part of the first catalytic layer, The second gas diffusion layer is disposed on the second catalytic layer of the membrane electrode group and is in contact with the second catalytic layer. The adhesive layer is disposed on another part of the membrane electrode assembly where the first catalytic layer and the first gas diffusion layer are not in contact with each other, and a part of the adhesive layer is formed by infiltrating into the first catalytic layer An impregnation layer. Each frame has a main body part and at least one holding part, wherein one side of the main body part is connected to the adhesive layer, the impregnated layer, the film, the second catalytic layer and the second gas The sides of the diffusion layer are in contact with each other, and the two mutually perpendicular sides of the holding portion are in contact with the first gas diffusion layer and a surface of the adhesive layer away from the first catalytic layer, respectively.

In a preferred embodiment, the adhesive layer has a ring structure.

In a preferred embodiment, the areas of the first catalytic layer and the second catalytic layer coated on the two surfaces of the thin film of the membrane electrode assembly are substantially the same.

In a preferred embodiment, the adhesive layer is made of EPDM, pressure sensitive adhesive, acrylic adhesive or thermosetting adhesive.

In a preferred embodiment, the adhesive layer and the impregnated layer together form a composite layer, and a chemical reaction occurs at the interface between the composite layer and the film.

Another embodiment of the present invention provides a method for manufacturing a sealing structure of a membrane electrode assembly for a fuel cell, which includes: providing a membrane electrode assembly, which includes a membrane and is coated on two surfaces of the membrane, respectively A first catalytic layer and a second catalytic layer; a first gas diffusion layer and a second gas diffusion layer are respectively provided on the first catalytic layer and the second catalytic layer of the membrane electrode assembly, Wherein, the first gas diffusion layer is disposed on the membrane electrode group The first catalytic layer is in contact with a part of the first catalytic layer, and the second gas diffusion layer is disposed on the second catalytic layer of the membrane electrode group and interacts with the second catalytic layer. The layers are in contact with each other; an adhesive material is arranged on the other part of the first catalytic layer of the membrane electrode assembly that is not in contact with the first gas diffusion layer; the membrane electrode assembly is sandwiched by at least two frames , The first gas diffusion layer, the second gas diffusion layer and the adhesive material; and performing a hot pressing process, so that the adhesive material penetrates into the first catalytic layer to form an impregnated layer, and An adhesive layer is formed on the first catalytic layer. Each frame has a main body portion and at least one pinching portion, and one side of the main body portion is connected to the adhesive layer, the first catalytic layer, the film, the second catalytic layer, and the second gas The sides of the diffusion layer are in contact with each other, and the two mutually perpendicular sides of the holding portion are in contact with a surface of the first gas diffusion layer and the adhesive layer relative to the first catalytic layer, respectively.

In a preferred embodiment, the hot pressing procedure is performed at a temperature of 70°C to 130°C and a pressure of 300 to 1000 kgf.

In a preferred embodiment, the areas of the first catalytic layer and the second catalytic layer coated on the two surfaces of the thin film of the membrane electrode assembly are substantially the same.

In a preferred embodiment, the adhesive layer is made of EPDM, pressure sensitive adhesive, acrylic adhesive or thermosetting adhesive.

In a preferred embodiment, the adhesive layer and the impregnated layer together form a composite layer, and a chemical reaction occurs at the interface between the composite layer and the film.

The main technical means of the present invention is that the sealing structure and manufacturing method of the membrane electrode assembly for fuel cells provided by the embodiments of the present invention are through the use of "an adhesive layer, which is set On another part of the membrane electrode assembly where the first catalytic layer and the first gas diffusion layer are not in contact with each other, and a part of the adhesion layer penetrates into the first catalytic layer to form an impregnated layer "The technical characteristics of the membrane electrode assembly used in the fuel cell membrane electrode assembly has an excellent sealing effect and prevent the occurrence of micro-short circuit.

1. 1’‧‧‧Membrane electrode group

11‧‧‧Film

12‧‧‧First catalytic layer

13‧‧‧Second catalytic layer

14‧‧‧Impregnated layer

2‧‧‧The first gas diffusion layer

2’、3’‧‧‧Gas diffusion layer

3‧‧‧Second gas diffusion layer

4‧‧‧Adhesive layer

4’‧‧‧ secondary border

5. 5’‧‧‧Frame

51S, 52S, 52S’‧‧‧side

6’‧‧‧Graphite plate

7’‧‧‧Current Collecting Board

8’‧‧‧Anode plate

9’‧‧‧Cathode plate

FIG. 1 is an exploded schematic diagram of a three-dimensional structure of a conventional hydrogen fuel cell (PEM FUEL CELL);

2 is a schematic partial cross-sectional view in one of the states of the manufacturing method of the sealing structure for the membrane electrode assembly of the fuel cell provided by the embodiment of the present invention; and

3 is a schematic partial cross-sectional view of a sealing structure of a membrane electrode assembly for a fuel cell provided by an embodiment of the present invention.

The following are specific examples to illustrate the implementation of the "sealing structure of membrane electrode assembly for fuel cell and its manufacturing method" disclosed in the present invention. Those skilled in the art can understand the present invention from the content disclosed in this specification. The advantages and effects. The present invention can be implemented or applied through other different specific embodiments, and various details in this specification can also be based on different viewpoints and applications, and various modifications and changes can be made without departing from the spirit of the present invention. In addition, the drawings of the present invention are merely schematic illustrations, and are not drawn according to actual size, and are described first. The following embodiments will further describe the related technical content of the present invention in detail, but the disclosed content is not intended to limit the technical scope of the present invention.

First, please refer to Figure 2 and Figure 3. 2 is a schematic partial cross-sectional view in one of the states of the manufacturing method of the sealing structure for the membrane electrode assembly of the fuel cell provided by the embodiment of the present invention. 3 is a schematic partial cross-sectional view of a sealing structure of a membrane electrode assembly for a fuel cell provided by an embodiment of the present invention.

First of all, it is worth noting that the partial cross-sectional schematic diagram shown in FIG. 2 is the state of the sealing structure for the membrane electrode assembly of the fuel cell provided by the embodiment of the present invention before the hot pressing process, and the partial cross-sectional view shown in FIG. 3 The schematic cross-sectional view shows the state of the sealing structure for the membrane electrode assembly of the fuel cell provided by the embodiment of the present invention after the hot pressing process. Therefore, for the structural description of the sealing structure of the membrane electrode assembly for the fuel cell provided by the embodiment of the present invention, please refer to FIG. 3.

As shown in FIG. 3, the sealing structure of the membrane electrode assembly for the fuel cell includes the membrane electrode assembly 1. The membrane electrode assembly 1 includes a thin film 11 and a first catalytic layer 12 and a second catalytic layer 13 respectively coated on two opposite surfaces of the thin film 11. In the embodiment of the present invention, the membrane electrode assembly 1 may be any membrane electrode assembly suitable for fuel cells in the prior art. For example, the thin film 11 may be a Nafion membrane, and both surfaces of the Nafion membrane have been coated with a catalytic layer.

Please cooperate as shown in Figure 1. FIG. 1 is an exploded schematic diagram of the three-dimensional structure of a conventional hydrogen fuel cell (PEM FUEL CELL). In the three-dimensional structure of the hydrogen fuel cell shown in Fig. 1, the membrane electrode assembly 1'also includes a thin film as a substrate and a catalytic layer (also called a catalyst layer) coated on the thin film. However, it can be seen from FIG. 1 that one of the catalytic layers coated on the film is not completely coated on the entire surface of the film, but a blank position is left for the sub-gasket 4'(sub-gasket) for bonding. In the prior art, in order to enable the secondary frame 4'to perform the function of fixing the membrane electrode assembly, a common method is to leave the surface of the membrane in the existing membrane electrode assembly 1'blank.

However, please refer to Figure 2. In the present invention, the membrane 11 of the membrane electrode assembly 1 used in the sealing structure of the membrane electrode assembly of the fuel cell is actually coated on both sides with catalytic layers (the first catalytic layer 12 and the second catalytic layer 13) , And the areas of the first catalytic layer 12 and the second catalytic layer 13 coated on the two surfaces of the thin film 11 of the membrane electrode assembly 1 are substantially the same. In other words, in the embodiment of the present invention, it is not necessary to adjust the size of the coating area of the membrane electrode group in advance in order to provide subsequent adhesion of the sub-frame.

Please refer to Figure 3. The sealing structure for the membrane electrode assembly of the fuel cell provided by the embodiment of the present invention includes a membrane electrode assembly 1, a first gas diffusion layer 2, a second gas diffusion layer 3, an adhesion layer 4 and at least two frames 5. As shown in FIGS. 2 and 3, the membrane electrode assembly 1 includes a thin film 11 and a first catalytic layer 12 and a second catalytic layer 13 respectively coated on two opposite surfaces of the thin film 11. As mentioned above, the areas of the first catalytic layer 12 and the second catalytic layer 13 coated on the two surfaces of the thin film 11 of the membrane electrode assembly 1 are substantially the same.

Continuing from the above, the first gas diffusion layer 2 is arranged on the first catalytic layer 12 of the membrane electrode assembly 1 and is in contact with a part of the first catalytic layer 12; and the second gas diffusion layer 3 is arranged on the membrane electrode assembly 1 The second catalytic layer 13 is on and in contact with the second catalytic layer 13. It can be seen from FIGS. 2 and 3 that the width of the first gas diffusion layer 2 and the width of the second gas diffusion layer 3 are different. In the embodiment of the present invention, the width of the first gas diffusion layer 2 can be adjusted according to the size of the frame 5 (gaskets) selected later.

Next, please refer to Figure 3 in particular. The adhesive layer 4 is disposed on another part of the first catalytic layer 12 of the membrane electrode assembly 1 that is not in contact with the first gas diffusion layer 2, and a part of the adhesive layer 4 penetrates into the first catalytic layer 12 to form the impregnated layer 14 . In fact, the adhesive layer 4 can be a ring structure, which is formed around the first catalytic layer 12 on the membrane electrode assembly 1, and the material of the adhesive layer 4 is permeated. The impregnated layer 14 formed by being inserted into the first catalytic layer 12 may also have a ring structure.

Please refer to Figure 2 and Figure 3. In the embodiment of the present invention, the adhesive layer 4 may be made of an adhesive material M. The adhesive material can be Ethylene Propylene Diene Monomer (EPDM), pressure sensitive adhesive, acrylic adhesive or thermosetting adhesive. For example, the adhesive material M may be coated on the surface of the first catalytic layer 12 exposed to the first gas diffusion layer 2, and the adhesive material M may be subjected to, for example, the pressure and temperature of the frame 5 through a hot pressing process Affected and penetrated into the voids of the material of the first catalytic layer 12, the part of the adhesive layer 4 penetrating into the first catalytic layer 12 chemically reacts with a part of the first catalytic layer 12 to form the impregnated layer 14. The formation of the adhesion layer 4 and the impregnation layer 14 will be further described in the description of the sealing structure of the membrane electrode assembly and the manufacturing method thereof for the fuel cell later.

Please also refer to Figure 2 and Figure 3. The sealing structure further includes at least two frames 5. As shown in the figure, each frame 5 has a main body 51 and at least one clamping portion 52. In fact, in the embodiment of the present invention, the frame 5 has a main body 51 and two clamping parts 52. However, in order to make the drawings concise, the set of (two) frames 5 shown in FIG. 2 and FIG. 3 only depict a single clamping portion 52. In detail, the side 51S of the main body portion 51 of the frame 5 is in contact with the sides of the adhesive layer 4, the impregnated layer 14, the film 11, the second catalytic layer 13, and the second gas diffusion layer 3. The two mutually perpendicular sides 52S, 52S' of the holding portion 52 of the frame 5 are in contact with the surfaces of the first gas diffusion layer 2 and the adhesive layer 4 away from the first catalytic layer 12, respectively. In other words, as shown in FIG. 3, the frame 5 can be formed by the adhesive layer 4 and a part of the first catalytic layer 12 and a part of the adhesive layer 4 through the cooperation of the main body 51 and the clamping part 52. The impregnated layer 14 stably provides support for the membrane electrode group 1.

Next, the embodiment of the present invention also provides a method of manufacturing a sealing structure for a membrane electrode assembly of a fuel cell. Please refer to Figure 2 and Figure 3. The system provided by the embodiment of the present invention The manufacturing method includes: providing a membrane electrode assembly, which includes a thin film and a first catalytic layer and a second catalytic layer respectively coated on the two surfaces of the membrane; respectively on the first catalytic layer and the second catalytic layer of the membrane electrode assembly A first gas diffusion layer and a second gas diffusion layer are arranged, wherein the first gas diffusion layer is arranged on the first catalytic layer of the membrane electrode group and is in contact with a part of the first catalytic layer, and the second gas diffusion layer is arranged On the second catalytic layer of the membrane electrode group and in contact with the second catalytic layer; set the adhesive material on the other part of the first catalytic layer of the membrane electrode group that is not in contact with the first gas diffusion layer; The frame clamps the membrane electrode group, the first gas diffusion layer, the second gas diffusion layer, and the adhesion layer; and performs a hot pressing process so that the adhesion material penetrates into the first catalytic layer, and an adhesion layer is formed on the first catalytic layer .

In the manufacturing method provided by the embodiment of the present invention, the described steps are not necessarily performed in the order described. In fact, the aforementioned manufacturing method is used to manufacture the aforementioned sealing structure for the membrane electrode assembly of the fuel cell. Therefore, the details of each component in the sealing structure will not be described again here.

It can be seen from the manufacturing method provided by the embodiment of the present invention that the present invention heats the adhesive material M disposed on the first catalytic layer 12 of the membrane electrode assembly 1, so that a part of the adhesive material M is filled in the membrane electrode assembly 1, the first catalytic layer 12 An adhesive layer is formed between a gas diffusion layer 2 and the frame 5, and another part of the adhesive material M penetrates under the surface of the first catalytic layer 12 not covered by the first gas diffusion layer 2 to form an impregnated layer. Specifically, the adhesive material M chemically reacts with a part of the material of the first catalytic layer 12, so that the adhesive material M is filled between the materials of the first catalytic layer 12, and the adhesive material M downwardly contacts the membrane electrode assembly 1 The contact of the film 11 causes a chemical reaction on the surface of the film 11 to enhance the support and adhesion formed by the adhesive layer 4 and the impregnated layer 14.

In the embodiment of the present invention, the hot pressing procedure is at a temperature of 70°C to 130°C and It is carried out under a pressure of 300 to 1000 kgf. Within the aforementioned temperature and pressure range, the formed adhesive layer 4 and the impregnated layer 14 have better adhesive strength.

[Feasible effects of the embodiment]

In summary, the beneficial effect of the present invention is that the sealing structure and manufacturing method of the membrane electrode assembly for fuel cells provided by the embodiments of the present invention are achieved by selecting an appropriate adhesive material M and by hot pressing. The adhesive material M is made to form an adhesive layer 4 on the membrane electrode assembly 1, and a part of the adhesive material M penetrates into the first catalytic layer 12 of the membrane electrode assembly 1 to form an impregnated layer, so that the formed sealing structure has excellent adhesive strength.

In detail, the sealing structure of the membrane electrode assembly for fuel cells and the manufacturing method thereof provided by the present invention do not need to add special procedures to modify the coating position of the catalytic layer in the existing membrane electrode assembly. In other words, there is no need to leave a position for the subsequent placement of the sub-frame on the film 11 in the membrane electrode assembly 1, but the adhesive material M provided on the membrane electrode assembly 1 and the hot pressing procedure are used to directly press the membrane The electrode group 1 is combined with the frame 5. In this way, not only the cost of processing the existing membrane electrode assembly 1 can be saved, but because the secondary frame is omitted at the same time, the frame 5 and the adhesive material M are used to clamp and fix the membrane electrode assembly 1 directly, which can effectively achieve The technical effect of blocking micro-short circuit.

Although the embodiments of the present invention are disclosed in the above-mentioned more detailed manner, those with ordinary knowledge in the technical field can understand that various modifications of the present invention can be made without departing from the scope of the present invention defined in the appended patent application. . Therefore, further modifications of the examples of the present invention will not deviate from the technology of the present invention.

1‧‧‧Membrane electrode group

11‧‧‧Film

12‧‧‧First catalytic layer

13‧‧‧Second catalytic layer

14‧‧‧Impregnated layer

4‧‧‧Adhesive layer

51S, 52S, 52S’‧‧‧side

Claims (10)

A sealing structure for a membrane electrode assembly of a fuel cell, which includes: A membrane electrode assembly, which includes a thin film and a first catalytic layer and a second catalytic layer respectively coated on two opposite surfaces of the thin film; A first gas diffusion layer arranged on the first catalytic layer of the membrane electrode group and in contact with a part of the first catalytic layer; A second gas diffusion layer disposed on the second catalytic layer of the membrane electrode group and in contact with the second catalytic layer; An adhesive layer disposed on another part of the membrane electrode assembly where the first catalytic layer and the first gas diffusion layer are not in contact with each other, and a part of the adhesive layer penetrates into the first catalytic layer An impregnated layer is formed inside, and At least two frames, each frame having a main body and at least one holding part, wherein one side of the main body is connected to the adhesive layer, the impregnated layer, the film, the second catalytic layer and the The sides of the second gas diffusion layer are in contact with each other, and the two mutually perpendicular sides of the pinching portion are respectively a surface of the first gas diffusion layer and the adhesive layer away from the first catalytic layer Contact each other. The sealing structure for a membrane electrode assembly of a fuel cell according to claim 1, wherein the adhesive layer has a ring structure. The sealing structure for a membrane electrode assembly of a fuel cell according to claim 1, wherein the first catalytic layer and the The area of the second catalytic layer is substantially the same. The sealing structure for a membrane electrode assembly for a fuel cell according to claim 1, wherein the The adhesive layer is made of EPDM, pressure sensitive adhesive, acrylic adhesive or thermosetting adhesive. The sealing structure for a membrane electrode assembly of a fuel cell according to claim 1, wherein the adhesive layer and the impregnated layer together form a composite layer, and a chemical reaction occurs at the interface between the composite layer and the thin film . A manufacturing method of a sealing structure for a membrane electrode assembly of a fuel cell, which comprises: Provide a membrane electrode assembly, which includes a thin film and a first catalytic layer and a second catalytic layer respectively coated on two surfaces of the thin film; A first gas diffusion layer and a second gas diffusion layer are respectively disposed on the first catalytic layer and the second catalytic layer of the membrane electrode group, wherein the first gas diffusion layer is disposed on the The first catalytic layer of the membrane electrode group is in contact with a part of the first catalytic layer, and the second gas diffusion layer is disposed on the second catalytic layer of the membrane electrode group and is in contact with The second catalytic layers are in contact with each other; Disposing an adhesive material on another part of the first catalytic layer of the membrane electrode assembly that is not in contact with the first gas diffusion layer; Sandwiching the membrane electrode group, the first gas diffusion layer, the second gas diffusion layer, and the adhesive material by at least two frames; and Performing a hot pressing process so that the adhesive material penetrates into the first catalytic layer to form an impregnated layer, and an adhesive layer is formed on the first catalytic layer; Wherein, each frame has a main body portion and at least one pinching portion, and one side of the main body portion is connected to the adhesive layer, the impregnated layer, the film, the second catalytic layer, and the second gas The sides of the diffusion layer are in contact with each other, and the two mutually perpendicular sides of the holding portion The edges are respectively in contact with a surface of the first gas diffusion layer and the adhesive layer opposite to the first catalytic layer. The method of manufacturing a sealing structure for a membrane electrode assembly of a fuel cell according to claim 6, wherein the hot pressing process is performed at a temperature of 70°C to 130°C and a pressure of 300 to 1000 kgf. The method of manufacturing a sealing structure for a membrane electrode assembly of a fuel cell according to claim 6, wherein the first catalytic layer coated on the two surfaces of the thin film of the membrane electrode assembly The area of the second catalytic layer is substantially the same. The manufacturing method of the sealing structure for the membrane electrode assembly of the fuel cell according to claim 6, wherein the adhesive layer is made of EPDM, pressure sensitive adhesive, acrylic adhesive or thermal Made of solid glue. The method for manufacturing a sealing structure for a membrane electrode assembly of a fuel cell according to claim 6, wherein the adhesive layer and the impregnated layer together form a composite layer, and the boundary between the composite layer and the thin film A chemical reaction occurred.

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