Single-frame membrane electrode packaging structure

Abstract

The utility model discloses a single-frame membrane electrode packaging structure, which belongs to the technical field of fuel cells and comprises a catalyst coating film, a first gas diffusion layer, a membrane electrode frame and a second gas diffusion layer. An adhesive film is arranged between the catalyst coating film and the membrane electrode frame, and the adhesive film and the membrane electrode frame are bonded through a second adhesive layer and a second gas diffusion layer. The membrane electrode packaging structure provided by the utility model is a single frame, the material cost of the membrane electrode frame and the adhesive is at least saved by 50%, the use cost is effectively reduced, meanwhile, the single frame structure is adopted, the process of oppositely pasting two layers of frames is avoided, the generation of bubbles is reduced, the problem of frame alignment does not exist, and the production efficiency and the yield are greatly improved.

Description

Technical Field

[0001] The utility model relates to the technical field of fuel cells, and particularly relates to a single-frame membrane electrode encapsulation structure. Background Art

[0002] At present, the mainstream membrane electrode in the market is a double-frame membrane electrode, and its assembly method is mainly as follows: a cathode catalyst layer and an anode catalyst layer are respectively coated on both sides of a proton membrane to form a catalyst-coated membrane with a three-layer structure, usually referred to as CCM; then, the edges of the catalyst layers on both sides of the CCM are bonded to the cathode and anode frames through an adhesive to form a membrane electrode assembly with a five-layer structure; finally, the cathode and anode gas diffusion layers on both sides are bonded to the frames of the five-layer membrane electrode assembly through an adhesive to form a double-frame membrane electrode with a seven-layer structure.

[0003] Although the production of double-frame membrane electrodes has been mass-produced and the sealing performance can basically meet the requirements, it still has the following disadvantages: (1) High cost: The use environment of fuel cells involves harsh conditions such as high and low temperature cycles, high and low humidity cycles, and chemical corrosion resistance (free radicals, strong acids), so the frame materials and adhesives used must pass these tests, and the R & D and production costs are very high, and the price is more expensive than ordinary materials; the frame materials of the membrane electrode need to be cut into the area of the product size in advance, and then cut and formed according to the requirements of the drawing and assembled, so for double-frame membrane electrode products, a large amount of frame materials and adhesives are required, resulting in high costs. (2) Easy to generate bubbles: When preparing the five-layer membrane electrode assembly, the bonding process (thermal bonding, pressure bonding, etc.) of the frames on both sides to the CCM is very likely to cause bubbles due to uneven pressure. The bubble part, as a defect point, will degrade preferentially during operation, easily leading to air leakage and failure of the membrane electrode. Therefore, it is necessary to add processes to eliminate bubbles, such as pre-pressing treatment, pre-vacuuming treatment, etc. The addition of the defoaming process will reduce the efficiency of mass-producing membrane electrodes and increase the production cost; moreover, the current defoaming process cannot completely eliminate bubbles, resulting in a decrease in the yield of products. (3) Difficult to align: The two frames of the double-frame membrane electrode need to be accurately aligned, but it is very easy to deform and misalign during the bonding process, making it difficult to accurately align and affecting the production efficiency.

[0004] In the existing single-frame membrane electrode, although the bonding methods of the double-sided gas diffusion layers are different, there is a problem that the gas diffusion layer is prone to peeling off. The reason is that the double-sided gas diffusion layer needs to be hot-pressed to bond with the CCM and the membrane electrode frame. Generally, the gas diffusion layer is composed of a carbon fiber substrate and an MPL carbon microporous layer, and the bonded areas are all MPL carbon microporous layers. The bonding force between the microporous layer structures is relatively poor, or the compatibility between the used adhesive and the surface of the microporous layer is low, and the bonding is not firm, so it is easy to peel off. Since the surface materials and structures of different gas diffusion layers are different, whether it is liquid glue bonding or solid glue film bonding, the combination of the gas diffusion layer and the liquid glue or solid glue film generally has selectivity, and the application range of the bonding method of pure liquid glue or pure glue film is limited.

[0005] In view of this, this application is proposed. Utility Model Content

[0006] The purpose of the present utility model is to overcome the deficiencies of the existing technology and provide a single-frame membrane electrode packaging structure. The membrane electrode packaging structure of the present utility model is a single frame, and the material cost of the membrane electrode frame and the adhesive is saved by at least 50%, effectively reducing the use cost. At the same time, the single-frame structure eliminates the process of pasting two layers of frames, reduces the generation of bubbles, and there is no frame alignment problem, greatly improving the production efficiency and the yield rate.

[0007] To achieve the above purpose, the technical solution adopted by the present utility model is as follows:

[0008] A single-frame membrane electrode packaging structure includes a catalyst coated membrane, a first gas diffusion layer, a membrane electrode frame, and a second gas diffusion layer. The catalyst coated membrane bonds the first gas diffusion layer through a first adhesive layer. A glue film is provided between the catalyst coated membrane and the membrane electrode frame, and the glue film and the membrane electrode frame bond with the second gas diffusion layer through a second adhesive layer.

[0009] Preferably, the thickness of the glue film is 5 - 30 μm.

[0010] Preferably, the catalyst coated membrane includes an anode catalyst layer, a proton exchange membrane, and a cathode catalyst layer, and the proton exchange membrane is located between the anode catalyst layer and the cathode catalyst layer.

[0011] Preferably, the size of the proton exchange membrane is larger than the size of the catalyst coated membrane.

[0012] Preferably, the outer peripheral size of the glue film is larger than the inner peripheral size of the membrane electrode frame, the outer peripheral size of the glue film is smaller than the outer peripheral size of the membrane electrode frame, and the inner peripheral size of the glue film is smaller than the inner peripheral size of the membrane electrode frame.

[0013] Preferably, the first adhesive layer corresponds to the size of the proton exchange membrane.

[0014] Preferably, the thickness of the first adhesive layer is 3-10 μm.

[0015] Preferably, the second adhesive layer has a thickness of 3 to 10 μm.

[0016] Preferably, the first gas diffusion layer is one of carbon fiber paper, carbon fiber non-woven fabric or carbon black paper having a microporous structure on the surface;

[0017] The second gas diffusion layer is one of carbon fiber paper, carbon fiber non-woven fabric or carbon black paper having a microporous structure on the surface.

[0018] Preferably, the material of the first adhesive layer is one of a heat-curing adhesive, a pressure-sensitive adhesive, a light-curing adhesive, a thermosetting adhesive film or a pressure-sensitive adhesive film;

[0019] The material of the second adhesive layer is one of a heat-curing adhesive, a pressure-sensitive adhesive, a light-curing adhesive, a thermosetting adhesive film or a pressure-sensitive adhesive film.

[0020] The beneficial effects of the present invention are as follows: (1) The membrane electrode packaging structure described in the present invention is a single-frame structure, which saves at least 50% of the material cost of the membrane electrode frame and adhesive, effectively reducing the cost of use. At the same time, the single-frame structure does not require the process of two-layer frame bonding, which reduces the generation of bubbles and does not cause frame alignment problems, greatly improving production efficiency and yield rate. (2) The catalyst coating membrane of the present invention is bonded to the first gas diffusion layer through the first adhesive layer, and can be bonded without the need for a hot pressing process. The catalyst coating membrane will not shrink or wrinkle due to heat, further increasing the yield rate, improving production efficiency, and facilitating the mass production of membrane electrodes. (3) The first adhesive layer and the second adhesive layer of the present invention, in combination with the proton exchange membrane and the adhesive film, not only solve the glue overflow problem of the simple liquid glue process, but also solve the compatibility problem of the simple adhesive film process, increase the adhesion of the first gas diffusion layer and the second gas diffusion layer, avoid the gas diffusion layer from falling off, and greatly improve the yield rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the single-frame film electrode packaging structure of the present invention.

[0022] Figure 2 This is a schematic diagram of the assembly of the component 1 of the present invention.

[0023] Figure 3 This is a schematic diagram of the assembly of component 2 of the present invention.

[0024] Figure 4 This is an assembly schematic diagram of Component 3 of the present utility model.

[0025] Figure 5 This is an assembly schematic diagram of the single-frame membrane electrode encapsulation structure of the present utility model. Detailed implementation manners

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0027] In the present application, regarding numerical ranges, unless otherwise specified, the above numerical ranges are considered continuous, including the minimum and maximum values of the range, as well as each value between such minimum and maximum values. Further, when the range refers to integers, it includes each integer between the minimum and maximum values of the range. In addition, when multiple ranges are provided to describe features or characteristics, these ranges can be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all sub-ranges subsumed therein.

[0028] Unless otherwise specified, the component raw materials used in each embodiment and comparative example of the present utility model are all commercially available raw materials, and the component raw materials used in each parallel experiment are the same.

[0029] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present utility model, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0030] Please refer to Figure 1 , the present utility model provides a single-frame membrane electrode encapsulation structure, including a catalyst coated membrane, a first gas diffusion layer 100, a membrane electrode frame 500, and a second gas diffusion layer 200. The catalyst coated membrane bonds the first gas diffusion layer through a first adhesive layer 600. A glue film 400 is provided between the catalyst coated membrane and the membrane electrode frame, and the glue film and the membrane electrode frame are bonded to the second gas diffusion layer through a second adhesive layer.

[0031] The membrane electrode packaging structure described in the present utility model is a single border. The material cost of the membrane electrode border and the adhesive is saved by at least 50%, effectively reducing the usage cost. At the same time, the single border structure eliminates the process of pasting two layers of borders, reducing the generation of bubbles and avoiding the problem of border alignment, greatly improving the production efficiency and the yield rate.

[0032] The catalyst coated membrane of the present utility model is bonded to the first gas diffusion layer through the first adhesive layer, and the lamination can be achieved without the hot pressing process. The catalyst coated membrane will not have defects such as dimensional shrinkage and wrinkles due to heat, further increasing the yield rate, improving the production efficiency, and facilitating the batch production of membrane electrodes.

[0033] The first adhesive layer and the second adhesive layer of the present utility model, in combination with the proton exchange membrane and the adhesive film, solve both the problem of adhesive overflow in the pure liquid glue process and the compatibility problem in the pure adhesive film process, increase the adhesiveness of the first gas diffusion layer and the second gas diffusion layer, prevent the gas diffusion layer from falling off, and greatly improve the yield rate.

[0034] Preferably, the thickness of the adhesive film is 5 - 30 μm.

[0035] Preferably, the catalyst coated membrane includes a catalyst coated membrane 300 and a proton exchange membrane surrounding the catalyst coated membrane.

[0036] Preferably, the catalyst coated membrane includes an anode catalyst layer, a proton exchange membrane, and a cathode catalyst layer, and the proton exchange membrane is located between the anode catalyst layer and the cathode catalyst layer.

[0037] The proton exchange membrane is arranged on the outside of the catalyst coated membrane, and in combination with the adhesive film, it can effectively solve the problem of adhesive overflow, increase the adhesiveness of the upper and lower gas diffusion layers, prevent the gas diffusion layer from falling off, and greatly improve the yield rate.

[0038] There is almost no adhesiveness between the first gas diffusion layer and the second gas diffusion layer and the proton exchange membrane described in the present utility model, and the gas diffusion layer falls off 100%. Through the structural arrangement of the present utility model, the first gas diffusion layer, the second gas diffusion layer, the proton exchange membrane, and the catalyst coated membrane do not fall off, improving the compatibility of the adhesive process of the gas diffusion layer, enabling the single border membrane electrode structure to be used with different gas diffusion layer materials to meet different design requirements.

[0039] Preferably, the size of the proton exchange membrane is larger than the size of the catalyst coated membrane.

[0040] Preferably, the outer peripheral dimension of the adhesive film is larger than the inner peripheral dimension of the membrane electrode frame, the outer peripheral dimension of the adhesive film is smaller than the outer peripheral dimension of the membrane electrode frame, and the inner peripheral dimension of the adhesive film is smaller than the inner peripheral dimension of the membrane electrode frame.

[0041] Preferably, the size of the first adhesive layer corresponds to that of the proton exchange membrane.

[0042] Preferably, the thickness of the first adhesive layer is 3 - 10 μm.

[0043] Preferably, the thickness of the second adhesive layer is 3 - 10 μm.

[0044] Preferably, the first gas diffusion layer is one of carbon fiber paper, carbon fiber non-woven fabric or carbon black paper with a microporous structure on the surface;

[0045] The second gas diffusion layer is one of carbon fiber paper, carbon fiber non-woven fabric or carbon black paper with a microporous structure on the surface.

[0046] Preferably, the material of the first adhesive layer is one of thermosetting adhesives, pressure-sensitive adhesives, photocuring adhesives, thermosetting adhesive films or pressure-sensitive adhesive films;

[0047] The material of the second adhesive layer is one of thermosetting adhesives, pressure-sensitive adhesives, photocuring adhesives, thermosetting adhesive films or pressure-sensitive adhesive films.

[0048] The present utility model also provides a method for preparing the single-frame membrane electrode encapsulation structure, comprising the following steps:

[0049] As Figure 2 shown, a cathode catalyst layer and an anode catalyst layer are respectively coated on both sides of the proton exchange membrane, and after drying, a catalyst-coated membrane (abbreviated as CCM) with a three-layer structure is obtained. The catalyst-coated membrane is sheared, and the size of the proton exchange membrane is at least 3 mm - 5 mm larger than that of the active area coating; on one side of the CCM, it is bonded to the first gas diffusion layer through the first adhesive layer, and the bonding area is the same as the area of the proton exchange membrane region reserved more in the CCM. The thickness of the first adhesive layer is set to 3 - 10 μm, and the pressing parameters are as follows: the pressure is set to 20 - 50 KN, and the time is set to 30 - 60 s. The bonding of the CCM and the upper gas diffusion layer can be achieved without a heating pressing process, forming a CCM / gas diffusion layer assembly 1.

[0050] As Figure 3 shown, the membrane electrode frame and the adhesive film are cut into the required sizes according to the drawing, and the adhesive film is pre-bonded to one side of the membrane electrode frame to form a membrane electrode frame / adhesive film assembly 2, as Figure 3As shown, the outer peripheral dimension of the adhesive film is 3 - 5 mm larger than the inner peripheral dimension of the membrane electrode frame and does not exceed the outer peripheral dimension of the frame, and the inner peripheral dimension of the adhesive film is 5 - 10 mm smaller than the inner peripheral dimension of the membrane electrode frame.

[0051] As Figure 4 shown, the other side frame of component 2 is assembled with the second gas diffusion layer. The second gas diffusion layer is bonded to component 2 through the adhesive film exposed inside the inner periphery of the membrane electrode frame. At the same time, a second adhesive layer is also provided in the bonding area between the adhesive film and the second gas diffusion layer. The thickness of the adhesive layer is set to 3 - 10 um, and the lamination parameters are as follows: the hot pressing temperature is set to 120 - 150 °C, the hot pressing pressure is set to 20 - 50 KN, and the hot pressing time is set to 30 - 60 s, obtaining component 3.

[0052] As Figure 5 shown, the other side of the CCM of component 1 is hot-press bonded to the membrane electrode frame side of component 3. The lamination parameters are as follows: the hot pressing temperature is set to 80 - 150 °C, the hot pressing pressure is set to 20 - 50 KN, and the hot pressing time is set to 10 - 60 s, obtaining a single-frame structure membrane electrode.

[0053] The first gas diffusion layer is Toray - 055 from Japan, the second gas diffusion layer is JNTG - JNT20 - A6L, the first adhesive layer and the second adhesive layer use TB 1549B glue from Three Bond, and the adhesive film uses AHMS14H1 adhesive film from PANAC of Japan.

[0054] To better verify the feasibility of the encapsulation structure of the present utility model, peel test samples with different structural compositions were prepared to evaluate the adhesiveness of different bonding methods of the gas diffusion layer. The method for preparing the peel samples is as follows:

[0055] ① Cut gas diffusion layers, 20 - um adhesive film materials, and proton exchange membrane materials with a width of 15 cm * 15 cm respectively for standby;

[0056] ② Spray a layer of liquid adhesive on different types of gas diffusion layers with a thickness of about 5 um, and then perform hot-press lamination with 20 - um adhesive film materials. The hot pressing parameters are set to 120 °C * 40 s * 2T. Samples without applying adhesive are used as comparative samples.

[0057] ③ Spray a layer of liquid adhesive on different types of gas diffusion layers with a thickness of about 5 um, and then perform cold-press lamination with proton exchange membrane materials. The lamination parameters are set to 40 s * 2T. Samples without applying adhesive are used as comparative samples.

[0058] ④ Cut the above samples into specimens with a width of 15 cm * 2 cm, and use a Shanghai Lishi universal testing machine to test the peel force of the specimens. The peel speed is set to 10 mm / min.

[0059] The experimental results are shown in Table 1.

[0060] Table 1

[0061]

[0062] Example 1

[0063] The method for the single - border membrane - electrode encapsulation structure of this example includes the following steps:

[0064] Cathode catalyst layer and anode catalyst layer are respectively coated on both sides of the proton - exchange membrane. After drying, a catalyst - coated membrane with a three - layer structure is obtained. The catalyst - coated membrane is sheared. Except for the active area, a proton - exchange membrane is reserved around the CCM, and the proton - exchange membrane is at least 4 mm larger than the size of the active - area coating. On one side of the CCM, it is bonded to the first gas diffusion layer through the first adhesive layer. The bonding area is the same as the area of the proton - exchange membrane reserved by the CCM. The thickness of the first adhesive layer is set to 3 - 10 um. The pressing parameters are as follows: the pressure is set to 20 KN, the time is set to 40 s, and the bonding of the CCM and the first gas diffusion layer can be achieved without a heating - pressing process, forming the CCM / gas - diffusion - layer component 1.

[0065] The membrane - electrode frame and the adhesive film are cut into the required sizes according to the drawing. The adhesive film is attached to one side of the membrane - electrode frame through pre - fitting, forming the membrane - electrode - frame / adhesive - film component 2. As Figure 3 shown, the outer - perimeter size of the adhesive film is 4 mm larger than the inner - perimeter size of the membrane - electrode frame and does not exceed the outer - perimeter size of the frame, and the inner - perimeter size of the adhesive film is 8 mm smaller than the inner - perimeter size of the membrane - electrode frame.

[0066] The other - side frame of the component 2 is assembled with the second gas diffusion layer. The second gas diffusion layer is bonded to the component 2 through the adhesive film exposed inside the inner - perimeter of the membrane - electrode frame. At the same time, a second adhesive layer is provided in the bonding area between the adhesive film and the second gas diffusion layer. The thickness of the adhesive layer is set to 3 - 10 um. The pressing parameters are as follows: the hot - pressing temperature is set to 120 °C, the hot - pressing pressure is set to 20 KN, and the hot - pressing time is set to 40 s, obtaining the component 3.

[0067] The other side of the CCM of the component 1 is thermally - pressed and bonded to the membrane - electrode - frame side of the component 3. The pressing parameters are as follows: the hot - pressing temperature is set to 120 °C, the hot - pressing pressure is set to 20 KN, and the hot - pressing time is set to 40 s, obtaining the single - border - structure membrane electrode.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A single - border membrane - electrode encapsulation structure, characterized in that, It includes a catalyst coated membrane, a first gas diffusion layer, a membrane electrode border, and a second gas diffusion layer. The catalyst coated membrane bonds to the first gas diffusion layer through a first adhesive layer. A glue film is provided between the catalyst coated membrane and the membrane electrode border, and the glue film and the membrane electrode border are bonded to the second gas diffusion layer through a second adhesive layer.

2. The single-sided frame membrane electrode encapsulation structure according to claim 1, wherein The thickness of the glue film is 5 - 30 μm.

3. The single-sided frame membrane electrode encapsulation structure according to claim 1, characterized in that The catalyst coated membrane includes an anode catalyst layer, a proton exchange membrane, and a cathode catalyst layer, and the proton exchange membrane is located between the anode catalyst layer and the cathode catalyst layer.

4. The single-sided frame membrane electrode encapsulation structure according to claim 3, characterized in that, The size of the proton exchange membrane is larger than that of the catalyst coated membrane.

5. The single-sideframe membrane electrode assembly packaging structure according to claim 1, wherein, The outer peripheral size of the glue film is larger than the inner peripheral size of the membrane electrode border, and the outer peripheral size of the glue film is smaller than the outer peripheral size of the membrane electrode border.

6. The single-edge frame membrane electrode encapsulation structure according to claim 3, wherein The first adhesive layer corresponds to the size of the proton exchange membrane.

7. The single-edge frame membrane electrode encapsulation structure according to claim 1, wherein The thickness of the first adhesive layer is 3 - 10 μm.

8. The single-sided frame membrane electrode encapsulation structure according to claim 1, wherein The thickness of the second adhesive layer is 3 - 10 μm.

9. The single-sided frame membrane electrode encapsulation structure according to claim 1, characterized in that The first gas diffusion layer is one of carbon fiber paper, carbon fiber non-woven fabric, or carbon black paper with a microporous structure on the surface; The second gas diffusion layer is one of carbon fiber paper, carbon fiber non-woven fabric, or carbon black paper with a microporous structure on the surface.

10. The single-edge frame membrane electrode encapsulation structure according to claim 1, characterized in that, The material of the first adhesive layer is one of thermosetting adhesives, pressure-sensitive adhesives, photocuring adhesives, thermosetting glue films, or pressure-sensitive glue films; The material of the second adhesive layer is one of thermosetting adhesives, pressure-sensitive adhesives, photocuring adhesives, thermosetting glue films, or pressure-sensitive glue films.

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