A process for improving fuel cell CCM spraying efficiency

Abstract

The present invention discloses a process for improving the spraying efficiency of fuel cell CCM, including the following steps: S1, cutting the proton exchange membrane, the breathable membrane and the film into the required size; S2, placing the proton exchange membrane on the spraying machine for spraying; S3, placing the breathable membrane on the adsorption platform, and then placing the proton exchange membrane and attaching the film; S4, transferring the three-layer combined proton exchange membrane to the spraying machine for spraying. The present invention forms a "sandwich" structure with the proton membrane through the combination of the breathable membrane and the release membrane. The structure fixes the proton membrane and solves the problem of thermal expansion and contraction of the proton membrane. At the same time, there is a proton membrane that is not sprayed around, and the air tightness is better when it is fitted; the problem of the proton membrane base is solved, and the production volume can be quickly increased; the method is simple to operate, and the spraying personnel can assemble the structure when spraying the cathode, and then spray the anode, which can achieve seamless connection.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cell CCM spraying, and in particular to a process for improving the fuel cell CCM spraying efficiency. Background Art

[0002] With the gradual advancement of hydrogen energy development in recent years, fuel cells have also ushered in rapid development. Fuel cell membrane electrode (MEA) is the core component of hydrogen fuel cells, accounting for 60% of the cost of hydrogen fuel cells. It consists of a proton exchange membrane (PEM), a catalytic layer electrode (CL), a gas diffusion layer (GDL), and a bipolar plate to form a fuel cell stack. In order to reduce costs, it is an inevitable development trend to achieve domestic substitution of key components and expand production scale. Domestic membrane electrode technology started relatively late compared to foreign countries, but in recent years, technological progress has been significant. The shipments of domestic membrane electrode manufacturers have increased year by year, and the market share of imported membrane electrodes has decreased year by year. The realization of large-scale production mainly lies in improving membrane electrode technology. The second-generation CCM membrane electrode is the most commercialized technology at present. It improves the utilization rate of catalysts by directly coating or spraying the catalyst on both sides of the proton exchange membrane. The main factors affecting the production capacity of membrane electrodes prepared by the spraying method are two points: 1. Since the proton exchange membrane is very thin, only 8-15 microns, it is difficult for operators to flatten and adsorb it on the heating platform after tearing off the protective substrate of the membrane, which affects production efficiency. 2. During the spraying process, the membrane will swell, causing wrinkles in the membrane, resulting in membrane electrode leakage when the frame is synthesized.

[0003] 1. In the traditional spraying method, there are some technical and cost challenges in the preparation of membrane electrodes, which directly affect the performance and commercialization process of fuel cells. However, this technology has caused several problems:

[0004] Low production efficiency: When spraying the cathode, the proton membrane itself has a protective film on the anode, which can support the membrane electrode, so it is easy for operators to lay it flat for spraying. But when spraying the anode, because the proton membrane is very thin, it is difficult for operators to lay the membrane flat after the base is torn off, and the heating platform has a temperature of 75-85℃, which makes the operation more difficult and affects the efficiency of spraying.

[0005] Thermal expansion and contraction: When spraying the anode, the thermal expansion and contraction of the membrane at high temperature will cause the effective area to deviate or the slurry to be wasted. After high temperature, due to the swelling problem, the proton membrane will become very wrinkled, which will cause appearance problems such as wrinkles when the frame is fitted, and small creases may penetrate the sealing area of ​​the frame, causing airtightness problems.

[0006] Problem of decreased adhesion: Since the traditional spraying method has already sprayed a catalyst on the surface of the film, the surface adhesion is reduced. When the frame is attached, the frame and CCM will not be firmly adhered, resulting in airtightness problems.

[0007] 2. The latest technology is to use an auxiliary frame to solve the problem of spraying. The specific method is to cut a cold-paste frame, cut it in half, fit the proton membrane to the half-cut frame, then spray, and finally cut off the auxiliary frame. The auxiliary frame solves the problems of swelling, anode tearing the base, and decreased adhesion. However, this technology has created several new problems:

[0008] Waste problem: The auxiliary frame is a disposable consumable and cannot be reused, which causes waste of materials and increased production costs.

[0009] Labor and time issues: The preparation process of the auxiliary frame is complicated, requiring 2-3 people to cut, punch, fit, spray and then punch, which greatly increases labor, equipment costs and time costs. Although the spraying time is reduced, other time is greatly increased, which in turn affects the production capacity of membrane electrode.

[0010] The problem of thermal expansion and contraction during spraying: Since the auxiliary frame is a cold-stick adhesive made of PEN, it will deform on a heating platform at 75-85°C, causing the film to become concave and convex, and uneven adsorption on the heating platform, affecting the spraying quality.

[0011] In view of the shortcomings of the above-mentioned existing production technologies, we propose a process for improving the spraying efficiency of fuel cell CCM. Summary of the invention

[0012] The object of the present invention is to provide a process for improving the spraying efficiency of fuel cell CCM to solve the problems in the prior art.

[0013] To achieve the above object, the present invention provides the following technical solution: A process for improving the spraying efficiency of fuel cell CCM, comprising the following steps:

[0014] S1. Cutting the proton exchange membrane, the breathable membrane and the film into required sizes;

[0015] S2, placing the proton exchange membrane on a spraying machine for spraying;

[0016] S3, place the breathable membrane on the adsorption platform, then place the proton exchange membrane and attach the film;

[0017] S4. Transfer the three-layer combined proton exchange membrane to a spraying machine for spraying.

[0018] Preferably, the film is a release film.

[0019] Preferably, in S1, the selected proton exchange membrane is cut into the shape required by the drawing by a cutter; the breathable membrane is cut by a cutter to a size slightly larger than the proton membrane; the film is cut by a cutter to a size larger than the proton exchange membrane and smaller than or equal to the breathable membrane.

[0020] Preferably, the S2 is to spray the cathode onto the proton exchange membrane.

[0021] Preferably, the S3 adopts an unheated adsorption platform.

[0022] Preferably, the specific operation of S3 is: placing the breathable membrane on top, placing the proton exchange membrane sprayed with the catalytic layer on one side on the breathable membrane; turning on the adsorption, the proton exchange membrane is firmly fixed under the action of suction, and then the substrate of the proton exchange membrane is torn off; the adsorption is not turned off, and the film is placed on the proton exchange membrane with the substrate removed. Since the adsorption platform will suck out the gas in the breathable membrane, and since the pores of the breathable membrane are small and the film is not breathable, under the action of pressure, the breathable membrane will be combined with the proton exchange membrane and the film to form a "sandwich" structure.

[0023] Preferably, the specific operation of S4 is: placing the three-layer combined proton exchange membrane on a sprayer, removing the film after adsorption, and directly spraying.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. Through the combination of the breathable membrane and the release membrane, a "sandwich" structure is formed with the proton membrane. The structure fixes the proton membrane and solves the problem of thermal expansion and contraction of the proton membrane. At the same time, unsprayed proton membrane is left around, which has better air tightness when fitted; the problem of the proton membrane base is solved, and the production volume can be quickly increased; the method is simple to operate, and the spraying personnel can assemble the structure when spraying the cathode, and then carry out anode spraying, which can achieve seamless connection. At the same time, the breathable membrane and the release membrane can be reused to reduce material costs.

[0026] 2. Solved the waste problem: The auxiliary frame is a disposable consumable and cannot be reused, which causes waste of materials and increased production costs, while the release film and breathable film can be reused.

[0027] 3. Solved the labor and time problems: The preparation process of the auxiliary frame is complicated, and requires 2-3 people to cut, punch, and fit. Although the process of punching after spraying reduces the time of spraying, other time is greatly increased; the present application only needs one person to assemble, and the anode and cathode spraying can achieve seamless connection.

[0028] 4. Solved the problem of thermal expansion and contraction: Since the auxiliary frame is cold-adhesive and made of PEN, it will deform on a heating platform at 75-85°C, causing the membrane to become concave and convex, and uneven adsorption on the heating platform, affecting the spraying quality; this application is not affected by high temperature and will not cause the proton membrane to deform. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0030] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention.

[0032] See also Figure 1 In an embodiment of the present invention, a process for improving the spraying efficiency of a fuel cell CCM includes the following steps:

[0033] S1. Cut the proton exchange membrane, the breathable membrane and the thin film into required sizes; any thin film can be used as long as it is airtight and does not stick to the catalyst layer and the proton membrane; and the thin film is preferably a release film;

[0034] S2, placing the proton exchange membrane on a sprayer for spraying; spraying the cathode onto the proton exchange membrane;

[0035] S3, place the breathable membrane on the adsorption platform, then place the proton exchange membrane and attach the film;

[0036] S4. Transfer the three-layer combined proton exchange membrane to a spraying machine for spraying.

[0037] In said S1, the selected proton exchange membrane is cut into the shape required by the drawing by a cutter; the breathable membrane is cut into a size slightly larger than the proton membrane by a cutter; the film is cut into a size larger than the proton exchange membrane and smaller than or equal to the breathable membrane by a cutter.

[0038] The S3 uses an unheated adsorption platform (a heated adsorption platform will cause the material on the proton membrane to be removed when it is torn, affecting the membrane electrode performance); the specific operation of the S3 is: placing the breathable membrane on top, and placing the proton exchange membrane sprayed with a catalytic layer on the breathable membrane; turning on the adsorption, the proton exchange membrane is firmly fixed under the action of suction, and then the base of the proton exchange membrane is torn off; the adsorption is not turned off, and the film is placed on the proton exchange membrane with the base removed. Since the adsorption platform will suck out the gas in the breathable membrane, and since the pores of the breathable membrane are small and the film is not breathable, under the action of pressure, the breathable membrane will be combined with the proton exchange membrane and the film to form a "sandwich" structure.

[0039] The specific operation of S4 is: putting the three-layer combined proton exchange membrane on the sprayer, removing the film after adsorption, and directly spraying.

[0040] The working principle of the present invention is as follows: a selected proton exchange membrane is cut into a shape required by a drawing by a cutter; a breathable membrane is cut by a cutter to a size slightly larger than the proton membrane; a thin film is cut by a cutter to a size larger than the proton exchange membrane and smaller than or equal to the breathable membrane; a cathode is sprayed onto the proton exchange membrane; the breathable membrane is placed on the top, and the proton exchange membrane sprayed with a catalytic layer on one side is placed on the breathable membrane; adsorption is turned on, and the proton exchange membrane is firmly fixed under the action of suction, and the substrate of the proton exchange membrane is torn off at this time; adsorption is not turned off, and the thin film is placed on the proton exchange membrane with the substrate removed, because the adsorption platform will suck out the gas in the breathable membrane, and because the pores of the breathable membrane are small and the thin film is not breathable, under the action of pressure, the breathable membrane will be combined with the proton exchange membrane and the thin film to form a "sandwich" structure; the three-layer combined proton exchange membrane is placed on the sprayer, and the thin film is removed after adsorption, and spraying is directly performed.

[0041] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A process for improving the spraying efficiency of fuel cell CCM, characterized in that: The following steps are involved: S1. Cutting the proton exchange membrane, the breathable membrane and the film into required sizes; S2, placing the proton exchange membrane on a spraying machine for spraying; S3, place the breathable membrane on the adsorption platform, then place the proton exchange membrane and attach the film; S4. Transfer the three-layer combined proton exchange membrane to a spraying machine for spraying.

2. A process for improving fuel cell CCM spraying efficiency according to claim 1, characterized in that: The film is a release film.

3. A process for improving fuel cell CCM spraying efficiency according to claim 2, characterized in that: In said S1, the selected proton exchange membrane is cut into the shape required by the drawing by a cutter; the breathable membrane is cut into a size slightly larger than the proton membrane by a cutter; the film is cut into a size larger than the proton exchange membrane and smaller than or equal to the breathable membrane by a cutter.

4. A process for improving fuel cell CCM spraying efficiency according to claim 1, characterized in that: The S2 is to spray the cathode onto the proton exchange membrane.

5. A process for improving fuel cell CCM spraying efficiency according to claim 1, characterized in that: The S3 uses an unheated adsorption platform.

6. A process for improving fuel cell CCM spraying efficiency according to claim 1 or 5, characterized in that: The specific operation of S3 is: placing the breathable membrane on top, placing the proton exchange membrane sprayed with the catalytic layer on one side on the breathable membrane; turning on the adsorption, the proton exchange membrane is firmly fixed under the action of suction, and then the base of the proton exchange membrane is torn off; the adsorption is not turned off, and the film is placed on the proton exchange membrane with the base removed. Since the adsorption platform will suck out the gas in the breathable membrane, and since the pores of the breathable membrane are small and the film is not breathable, under the action of pressure, the breathable membrane will be combined with the proton exchange membrane and the film to form a "sandwich" structure.

7. A process for improving fuel cell CCM spraying efficiency according to claim 6, characterized in that: The specific operation of S4 is: putting the three-layer combined proton exchange membrane on the sprayer, removing the film after adsorption, and directly spraying.

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