Assembly method of membrane electrode assembly

Abstract

The present invention relates to an assembly method for a membrane electrode assembly. First, a first jig maintained at room temperature is used to position a first frame and a catalyst-coated film, and a second jig is used to position a second frame. After pre-bonding the first frame, the catalyst-coated film, and the second frame, the pre-bonded semi-finished product is then sent into a hot press for a high-temperature pressing step. Since the catalyst-coated film is first pre-bonded on the first jig maintained at room temperature to achieve a temporary fixing effect, it is possible to avoid deformation of the catalyst-coated film directly in the high-temperature process, resulting in low fitting alignment accuracy. Moreover, by separating the low-temperature and high-temperature processes, the hot press can be maintained at a high temperature without cooling, effectively shortening the process time and energy consumption.

Description

Technical Field

[0001] The present invention relates to a method for assembling a membrane electrode assembly, particularly to a method for assembling a membrane electrode assembly for a proton exchange membrane fuel cell. Background Art

[0002] A proton exchange membrane fuel cell (PEMFC) achieves the function of power generation through the electrochemical reaction generated by proton exchange in its membrane electrode assembly (MEA). The MEA is generally assembled from a proton exchange membrane (PEM), an anode / cathode catalyst layer, a gas diffusion layer (GDL), and a frame. The catalyst layer is coated on the PEM to form a catalyst coated membrane (CCM).

[0003] In recent years, in order to reduce the internal resistance of the CCM, the thickness of the PEM has been gradually thinned. Although the efficiency of proton exchange can be improved, the CCM is prone to deformation due to changes in temperature and humidity in the environment. Moreover, in the assembly process, since the PEM is getting thinner, although the efficiency of proton exchange can be improved, the mechanical strength of the PEM decreases, and in the high-temperature and high-pressure assembly process, problems such as deformation, breakage, and perforation of the CCM are likely to occur.

[0004] In the prior art, for the combination of the CCM and the frame, the central part is the CCM active area, and the surrounding is the frame gluing area. The junction of the two areas is the structure of frame / CCM / frame, and the layers are adhered to each other with an adhesive. Since the CCM is the main active material of the PEMFC, in order to avoid contamination and consider uniformity, a frame substrate with a uniform glue coating (the glue surface has no viscosity or low viscosity at room temperature) is usually used. The gluing of the CCM and the frame is a high-temperature and high-pressure process. If the curing temperature is directly applied, the viscosity of the adhesive will rapidly increase, and a high-level flatness and flatness pressing equipment and fixtures are required to ensure that all parts of the upper and lower frames come into contact and cure at the same time. Once the accuracy of the equipment and fixtures is insufficient, it is easy to cause premature adhesion at local positions, resulting in problems such as frame wrinkles, air bubbles not being discharged, and deviation of the bonding position, leading to a reduction in the yield. Moreover, the adhesive has been cured, and it is difficult to recycle and rework the materials.

[0005] As described above, since the CCM is sensitive to environmental temperature and humidity, prone to deformation, and the adhesive starts to change its properties when heated, most of the existing technologies stack the CCM and the frame at room temperature, then send them into a press. First, pressure is applied to make the materials contact each other, then the temperature is raised. After reaching the curing temperature of the adhesive, it is maintained for a period of time to make them bond. After cooling down to near room temperature, the press can finally be opened to take out the finished product. In the manufacturing process of the existing technology, more than half of the time is consumed in heating and cooling, which not only reduces the equipment utilization rate, prolongs the manufacturing process time, but also consumes a lot of energy. Summary of the Invention

[0006] In view of this, the present invention improves the assembly process of the membrane electrode assembly in order to solve the problems of equipment utilization rate, manufacturing process time, and energy consumption in the existing technology.

[0007] To achieve the above invention purpose, the technical means adopted by the present invention is to provide an assembly method for a membrane electrode assembly, comprising the following steps:

[0008] a. Provide a first jig and a second jig, wherein the first jig is maintained at room temperature;

[0009] b. Provide a first frame and a second frame, wherein the first frame is positioned on the first jig, the second frame is positioned on the second jig, and at least one surface of the first frame and the second frame is provided with a colloid;

[0010] c. Provide a catalyst-coated film, which is positioned on the first jig and contacts the colloid on the first frame;

[0011] d. Invert the second jig together with the second frame onto the first jig, so that the second frame is butted against the first frame, and pre-bond the first frame, the catalyst-coated film, and the second frame to obtain a semi-finished membrane electrode assembly;

[0012] e. Remove the second jig to separate the second jig from the second frame;

[0013] f. Use a hot press jig at a high temperature pressing temperature to perform high temperature pressing on the semi-finished membrane electrode assembly to cure the colloid and obtain a finished membrane electrode assembly;

[0014] g. Take out the finished membrane electrode assembly.

[0015] The advantages of the present invention are as follows. A first jig maintained at room temperature is used to carry the catalyst-coated film, so as to prevent the catalyst-coated film from deforming due to temperature before lamination. Before entering the high-temperature lamination step, pre-lamination of the first frame, the catalyst-coated film, and the second frame is carried out first to temporarily position their relative positions. Then, there is no need to worry about displacement during the subsequent high-temperature lamination step. Moreover, since the pre-lamination step and the high-temperature lamination step are carried out separately, the hot press can continuously operate at a high temperature without cooling, thus effectively reducing the time required for cooling, so as to achieve the purpose of energy conservation and time saving.

[0016] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments, but it is not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a flowchart of the present invention;

[0018] Figure 2 is a flowchart of the low-temperature assembly step of the present invention;

[0019] Figure 3 is a three-dimensional external view of the first jig and the second jig used in the present invention;

[0020] Figure 4 and 5 is a schematic diagram of the implementation state of step S12 of the present invention;

[0021] Figure 6 is a schematic diagram of the implementation state of step S13 of the present invention;

[0022] Figure 7 is a three-dimensional external view of the CCM jig used in the present invention;

[0023] Figure 8 is a schematic diagram of the implementation state of the CCM jig carrying the CCM of the present invention;

[0024] Figure 9 is a schematic diagram of the implementation state of step S14 of the present invention;

[0025] Figures 10 to 12 is a plan view of each component of the carrier jig of the present invention;

[0026] Figure 13 is a side sectional view of the carrier jig of the present invention;

[0027] Figure 14 and 15 is a schematic diagram of the implementation state of one implementation mode of step S16 of the present invention;

[0028] Figure 16 is a flowchart of the high-temperature lamination step of the present invention;

[0029] Figure 17 It is a schematic diagram of the implementation state of step S21 of the present invention;

[0030] Figure 18 It is a schematic diagram of the implementation state of step S22 of the present invention;

[0031] Figure 19 It is a side sectional view of the membrane electrode assembly product prepared by the present invention.

[0032] Among them, reference numerals:

[0033] 10: First jig 11: First frame fixing area

[0034] 12: CCM fixing area 20: Second jig

[0035] 21: Second frame fixing area 22: CCM docking area

[0036] 30: Rotating shaft assembly 40: First frame

[0037] 41: Colloid 50: Second frame

[0038] 51: Colloid 60: CCM

[0039] 600: MMEA semi-finished product 601: Viscous colloid

[0040] 602: MEA finished product 603: Cured colloid

[0041] 70: CCM jig 71: Vacuum suction area

[0042] 80: Body 81: Soft pad

[0043] 82: Positioning frame 801: CCM fixing area

[0044] 90: Release film 91: Hot pressing jig Detailed implementation manners

[0045] The following further elaborates on the technical means adopted by the present invention to achieve the predetermined invention purpose in conjunction with the drawings and the embodiments of the present invention.

[0046] Please refer to Figure 1 As shown, the assembly method of the membrane electrode assembly of the present invention includes the following steps: a low-temperature assembly step (S1) and a high-temperature pressing step (S2).

[0047] Please refer to Figure 2As shown, the aforementioned low-temperature assembly step (S1) includes providing a first fixture and a second fixture (S11), providing a first frame and a second frame (S12), placing a catalyst coated membrane (CCM) on the first frame (S13), pre-bonding the first frame, the CCM and the second frame (S14), removing the second fixture (S15), and taking out the membrane electrode assembly (Membrane Electrode Assembly, MEA) semi-finished product (S16). The following is a detailed description of each step:

[0048] Provide a first fixture and a second fixture (S11): Please refer to Figure 3 As shown, the first fixture 10 is not given additional heating, so that it is at room temperature. In one embodiment, since the first fixture 10 will inevitably contact the second fixture 20 in the subsequent process, and heat transfer will occur, resulting in a temperature rise, the first fixture 10 can be maintained at room temperature by water cooling or air cooling. The first fixture 10 has a first frame fixing area 11 and a CCM fixing area 12, and the first frame fixing area 11 is surrounded by the CCM fixing area 12. The second fixture 20 has a second frame fixing area 21 and a CCM docking area 22, and the second frame fixing area 21 is surrounded by the CCM docking area 22. The position of the second frame fixing area 21 corresponds to the first frame fixing area 11, and the position of the CCM fixing area 12 of the first fixture 10 corresponds to the position of the CCM docking area 22 of the second fixture 20. In one embodiment, assuming that the sum of the thickness of the first frame 40 and the second frame 50 is S1, and the sum of the thickness of the colloids 41 and 51 is S2, the CCM fixing area 12 slightly protrudes from the surrounding first frame fixing area 11 by a height T1 and is not flush, so that the first frame 40 is easy to align, but it cannot affect the effect of vacuum adsorption of CCM60 on the CCM fixing area 12; the height difference between the CCM docking area 22 and the surrounding second frame fixing area 21 is T2, T2 can be greater than zero or less than zero and not flush, and T1+T2 should be less than S1-S2 to ensure that the colloids 41 and 51 are fitted. In one embodiment, the first fixture 10 and the second fixture 20 are respectively connected to a rotating shaft assembly 30, so that the second fixture 20 can pivot relative to the first fixture 10 and cover the first fixture 10. In another embodiment (not shown in the figure), the first fixture 10 and the second fixture 20 are independent structures and are not connected. In one embodiment, the first frame fixing area 11 of the first fixture 10 is a soft interface to compensate for the thickness error caused by the assembly of the material and the fixture body, while the second fixture 20 is a hard interface to maintain the flatness of the fit. By combining soft and hard interfaces, the high-precision requirements on materials or assembly when using double hard interfaces can be avoided while taking into account the flatness of the fit.

[0049] Provide a first frame and a second frame (S12): Please refer to Figure 4 and Figure 5 as shown, place the first frame 40 on the first frame fixing area 11 of the first jig 10. The surface of the first frame 40 is coated with a colloid 41. Place the second frame 50 on the second frame fixing area 21 of the second jig 20. The surface of the second frame 50 is coated with a colloid 51. The colloids 41 and 51 are high molecular adhesion materials, such as thermosetting rubber, hot melt adhesive film (commonly thermoplastic elastomer or EVA that does not have adhesiveness at normal temperature), acrylic ester, polyester, polyacetal, etc. Their general properties will gradually generate adhesiveness as the temperature or pressure rises. At this time, the attached articles are adhered to each other through the colloids that generate adhesiveness. When the temperature continues to rise and exceeds its crosslinking temperature, it will cure and solidify and cannot return. In an embodiment, the first frame 40 and the second frame 50 can be positioned on the first and second frame fixing areas 11 and 21 of the first jig 10 and the second jig 20 through vacuum adsorption, positioning pins, limiting mechanisms, electrostatic adsorption, clamping, or attachment, etc.

[0050] Place a CCM on the first frame (S13): Please refer to Figure 6 as shown, place a CCM 60 on the first frame 40. The CCM 60 is relatively located on the CCM fixing area 12 of the first jig 10. The CCM 60 can be positioned on the CCM fixing area 12 through vacuum adsorption, positioning pins, limiting mechanisms, electrostatic adsorption, clamping, or attachment, etc. The periphery of the CCM 60 is in contact with the colloid 41 on the first frame 40. In an embodiment, the CCM fixing area 12 adopts the vacuum adsorption method, while the first frame fixing area 11 adopts different fixing methods to meet different process and precision requirements. Since the CCM 60 is placed on the first jig 10 and the first jig 10 is maintained at room temperature, the CCM 60 is also maintained at room temperature before the subsequent process starts, and deformation before assembly can be avoided. In an embodiment, please further refer to Figure 7 and Figure 8 as shown, first adsorb the CCM 60 with a CCM jig 70. The CCM jig 70 has a vacuum suction area 71 to adsorb the CCM 60, and then invert the CCM jig 70 on the first jig 10, release the vacuum suction of the CCM jig 70 and place the CCM 60 on the first frame 40.

[0051] Pre-bond the first frame, the CCM and the second frame (S14): Please refer to Figure 9As shown, the second jig 20 is inverted on the first jig 10, such that the second frame 50 on the second jig 20 is butted against the first frame 40 on the first jig 10, and the colloid 51 on the second frame 50 is brought into contact with the colloid 41 and the CCM 60 on the first frame 40, causing the colloids 41 and 51 to exhibit a pre-bonding phenomenon, thereby positioning the relative positions of the first frame 40, the CCM 60, and the second frame 50, and forming a semi-finished MEA. In one embodiment, the second jig 20 is pivoted and then inverted on the first jig 10. In one embodiment, the second jig 20 is heated to a temperature slightly higher than room temperature, and the second jig 20 is maintained at 40 to 90 °C, causing the colloids 41 and 51 to enter a molten state and exhibit a viscous phenomenon, enabling pre-bonding. In another embodiment, the second jig 20 is pressurized to cause the colloids 41 and 51 to exhibit a pre-bonding phenomenon.

[0052] Remove the second jig (S15): Next, the second jig 20 is removed. In one embodiment, the positioning force of the second jig 20 on the second frame 50 is released, and then the second jig 20 is removed.

[0053] Take out the semi-finished MEA (S16): After removing the second jig 20, the semi-finished MEA is immediately moved to the next high-temperature pressing step (S2). In one embodiment, the first jig 10 together with the semi-finished MEA is moved to the next high-temperature pressing step (S2); in another embodiment, the positioning force of the first jig 10 on the semi-finished MEA is released, and the semi-finished MEA can be removed from the first jig 10 and moved to a carrier jig. Please refer to Figures 10 to 13 As shown, the carrier jig includes a body 80, a soft pad 81, and a positioning frame 82. The center of the body 80 has a CCM fixing area 801. In one embodiment, the soft pad 81 is sleeved outside the CCM fixing area 801, and the positioning frame 82 is sleeved outside the CCM fixing area 801 as a limiting mechanism. Please refer further to Figure 14 and 15 As shown, after the semi-finished MEA 600 is removed from the first jig, it is moved onto the carrier jig. The first frame 40 and the second frame 50 are placed opposite each other on the soft pad 81, and then the CCM 60 is located relative to the CCM fixing area 801; in another embodiment (not shown in the figure), the soft pad is laid flat on the CCM fixing area. After the semi-finished MEA 600 is removed from the first jig, it is moved onto the carrier jig and placed flat on the soft pad as a whole. The frame of the semi-finished MEA 600 and the CCM fixing area 801 can be positioned on the CCM fixing area 801 through methods such as vacuum adsorption, positioning pins, limiting mechanisms, electrostatic adsorption, clamping, or adhesion. After the semi-finished MEA 600 is positioned, the positioning frame 82 is removed.

[0054] Please refer to Figure 16 As shown, the aforementioned high-temperature pressing step (S2) includes the following steps: providing a release film (S21), pressing and laminating the MEA semi-finished product (S22), and taking out the MEA finished product (S23). The following is a detailed description of each step:

[0055] Providing a release film (S21): Please refer to Figure 17 As shown, a release film 90 is placed on the MEA semi-finished product 600. The release film 90 can be PTFE (polytetrafluoroethylene), but is not limited thereto, and is mainly used to block the MEA semi-finished product 600 from the surface of the subsequent hot press.

[0056] Pressing and laminating the MEA semi-finished product (S22): Please refer to Figure 18 As shown, the MEA semi-finished product 600 is fed into the hot press. Since step S22 is carried out in the hot press, the first jig or the carrying jig for carrying the MEA semi-finished product 600 must also inevitably enter the hot press. To prevent the temperature of the first jig and the carrying jig from rising due to the working temperature in the hot press, the substrate below it should be at room temperature or have a water-cooling design. Only the hot pressing jig 91 that has reached the high-temperature pressing temperature is used to press down the MEA semi-finished product 600. Therefore, the hot pressing jig 91 does not need to be cooled again and will not cause deformation of the CCM 60. In an embodiment, the temperature state of the hot pressing jig 91 is 90 to 150 °C, but is not limited thereto. At this time, the temperature causes the viscous colloid 601 in the MEA semi-finished product 600 to cure and produce a permanent fixing effect.

[0057] Taking out the MEA finished product (S23): The MEA finished product 602 is taken out of the hot press, and the MEA finished product 602 is removed from the first jig or the carrying jig. Please refer to Figure 19 As shown, the first frame 40, the CCM 60, and the second frame 50 of the MEA finished product 602 are firmly bonded by the cured colloid 603.

[0058] In the present invention, a first jig 10 maintained at room temperature is used to carry the CCM 60 for a low-temperature assembly step (S1), and only a hot pressing jig 91 is used for a high-temperature pressing step (S2). Therefore, the time for the CCM 60 to contact high temperature is shortened to avoid deformation of the CCM 60. Furthermore, since the first frame 40, the second frame 50 and the CCM 60 are pre-fitted by using the low-temperature assembly step (S1), when fed into the hot press, the structures in the MEA semi-finished product 600 are already in the correct fitting positions and are located on a substrate with a normal temperature or water-cooled design. Therefore, there is no need to worry about displacement problems that may be caused by direct high-temperature pressing. At the same time, since the low-temperature assembly step and the high-temperature pressing step are carried out separately, the temperature of the hot press can be continuously maintained at a high temperature without cooling, so as to greatly reduce the time required for temperature rise and fall, and make the overall process more energy-saving and time-saving.

[0059] Furthermore, for those using the vacuum adsorption method for positioning, a highly porous material (such as porous ceramics, porous graphite, porous aluminum alloy, etc.), a multi-hole elastic pad (silicone, rubber, etc.) or a pegboard can be used as the vacuum interface to adjust the interface and the vacuum force state and ensure that the material can be flatly fixed on the jig. However, in the high-temperature pressing step, in order to maintain a uniform and flat pressing surface, a pressing plane with high flatness and low roughness can be used for hot pressing.

[0060] The above are only examples of the present invention and do not impose any formal restrictions on the present invention. Although the present invention has been disclosed as above by way of examples, it is not intended to limit the present invention. Any person with ordinary knowledge in the technical field can make some changes or modifications to the above-disclosed technical content to form equivalent embodiments within the scope of the technical solution of the present invention. However, as long as the content does not depart from the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

[0061] Of course, the present invention can also have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes and deformations should all fall within the protection scope of the claims of the present invention.

Claims

1. A method for assembling a membrane electrode assembly, characterized in that, The following steps are included: a. Provide a first jig and a second jig, wherein the first jig is maintained at room temperature; b. Provide a first frame and a second frame, wherein the first frame is positioned on the first jig, the second frame is positioned on the second jig, and at least one surface of the first frame and the second frame is provided with a colloid; c. Provide a catalyst-coated film, which is positioned on the first jig and contacts the surface on the first frame; d. Invert the second jig together with the second frame onto the first jig, so that the second frame is docked with the first frame, and preliminarily bond the first frame, the catalyst-coated film, and the second frame to obtain a semi-finished membrane electrode assembly, wherein the second jig is maintained at a temperature slightly higher than room temperature, so that the colloid enters a molten state to produce a preliminary bonding effect, and the temperature slightly higher than room temperature is between 40 and 90 °C; e. Remove the second jig to separate the second jig from the second frame; f. Use a hot press jig at a high temperature pressing temperature to perform high temperature pressing on the semi-finished membrane electrode assembly to cure the colloid and obtain a finished membrane electrode assembly; g. Take out the finished membrane electrode assembly.

2. The method for assembling a membrane electrode assembly according to claim 1, characterized in that, When performing step d, the second jig is pressurized to make the colloid produce a preliminary bonding effect.

3. The method for assembling a membrane electrode assembly according to claim 1 or 2, characterized in that, Before performing step f, first perform the following steps: e11. Move the first jig together with the semi-finished membrane electrode assembly thereon into a hot press.

4. The method for assembling a membrane electrode assembly according to claim 1 or 2, characterized in that, Before performing step f, first perform the following steps: e21. Remove the semi-finished membrane electrode assembly from the first jig; e22. Position the semi-finished membrane electrode assembly on a carrier jig; e23. Move the carrier jig together with the semi-finished membrane electrode assembly thereon into a hot press.

5. The method for assembling a membrane electrode assembly according to claim 4, characterized in that, The carrier jig includes a body and a soft pad. The center of the body has a catalyst-coated film fixing area. The soft pad is arranged on the body. In step e22, the first frame and the second frame of the semi-finished membrane electrode assembly are placed relative to the soft pad, and the catalyst-coated film of the semi-finished membrane electrode assembly is relatively positioned on the catalyst-coated film fixing area.

6. The method for assembling a membrane electrode assembly according to claim 5, characterized in that, The soft pad is sleeved outside the catalyst-coated film fixing area or the soft pad is laid flat on the catalyst-coated film fixing area.

7. The method for assembling a membrane electrode assembly according to claim 1 or 2, characterized in that, The first jig includes a first frame fixing area and a catalyst-coated film fixing area. The first frame fixing area surrounds the outside of the catalyst-coated film fixing area. In step b, the first frame is positioned on the first frame fixing area. In step c, the catalyst-coated film is positioned on the catalyst-coated film fixing area.

8. The method for assembling a membrane electrode assembly according to claim 1 or 2, characterized in that, The second jig includes a second frame fixing area and a catalyst-coated film docking area. The second frame fixing area surrounds the outside of the catalyst-coated film docking area. In step b, the second frame is positioned on the second frame fixing area.

9. The method for assembling a membrane electrode assembly according to claim 7, characterized in that, The second jig includes a second frame fixing area and a catalyst coating film docking area. The second frame fixing area surrounds the outside of the catalyst coating film docking area. The position of the second frame fixing area corresponds to that of the first frame fixing area. The position of the catalyst coating film fixing area of the first jig corresponds to that of the catalyst coating film docking area of the second jig. In step b, the second frame is positioned on the second frame fixing area.

10. The method for assembling a membrane electrode assembly according to claim 9, characterized in that, The catalyst coating film fixing area protrudes from the first frame fixing area.

11. The method for assembling a membrane electrode assembly according to claim 1 or 2, characterized in that, The first jig and the second jig are respectively connected to a rotating shaft assembly. The second jig can pivot relative to the first jig by means of the rotating shaft assembly.

12. The method for assembling a membrane electrode assembly according to claim 1 or 2, characterized in that, In step c, first pick up the catalyst coating film with a catalyst coating film jig, and then invert the catalyst coating film jig on the first jig to position the catalyst coating film on the first jig.

13. The method for assembling a membrane electrode assembly according to claim 1, characterized in that, Before performing step f, first perform the following steps: f0. Provide a release film and place the release film on the membrane electrode assembly semi-finished product.

14. The assembly method of the membrane electrode assembly according to claim 1, characterized in that In step f, the high temperature is between 90 and 150 °C.

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