Membrane electrode processing device

Abstract

The application discloses a membrane electrode processing device. The membrane electrode processing device comprises a supporting component, a shielding component and a scanning mechanism, the scanning mechanism comprises a laser working area and a laser scanning head arranged opposite to the laser working area, the supporting component is arranged in the laser working area to support a membrane electrode, and the shielding component has a hollow area and is arranged between the membrane electrode and the laser scanning head to shield positions of ridges on a surface of the membrane electrode to be processed for matching flow channels of a bipolar plate and to leak out positions of grooves on the surface of the membrane electrode to be processed for matching the flow channels of the bipolar plate. The application can realize cooling of high-temperature air and humidification of dry air without additional humidification devices and intercooling devices.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a membrane electrode processing device. Background Technology

[0002] Proton exchange membrane fuel cells (PEMFCs), also known as polymer electrolyte fuel cells, offer advantages such as cleanliness, high efficiency, low noise, and rapid cold start at low temperatures. They have broad application prospects in automotive engines, ships, distributed power generation, portable power supplies, drones, and two-wheeled vehicles. PEMFCs mainly consist of core components such as a proton exchange membrane (electrolyte), catalyst layer, gas diffusion layer, and bipolar plates. In traditional technologies, the gas diffusion layer (GDL), catalyst layer, and proton exchange membrane are typically fabricated into a membrane electrode assembly (MEA) using a hot-pressing process. The proton exchange membrane, located in the middle, acts as a conductor of protons (H+). + The membrane electrode assembly (MEA) plays multiple roles, including preventing electron transfer and isolating the anode and cathode reactions. The catalyst layers on both sides are the site of the electrochemical reaction between the fuel and oxidant. The main functions of the GDL are to support the catalyst layer, stabilize the electrode structure, provide gas transport channels, and improve water management. The main functions of the bipolar plates are to separate the reactant gases, guide them into the fuel cell through a flow field, collect and conduct current, support the membrane electrode assembly, and handle heat dissipation and drainage for the entire fuel cell. GDL is a crucial material in the MEA assembly. It is typically made of hydrophobic treated carbon paper or carbon cloth with a microporous layer, possessing advantages such as high conductivity, high strength, high permeability, and corrosion resistance. It is widely used in fuel cells, water electrolysis, and other fields, serving as a vital component connecting the catalyst layer and the bipolar plates, playing a crucial role in guiding gas transport, draining reaction product water, conducting current, and transferring heat.

[0003] Depending on the cooling method, fuel cells are classified into liquid-cooled fuel cells and air-cooled fuel cells. In liquid-cooled fuel cells, the development trend is towards low-humidity or no-humidification operating conditions. Air humidification requires a system configuration with humidification devices (such as membrane humidifiers or spray humidification systems). Furthermore, before entering the fuel cell, air is typically compressed and pressurized by an air compressor, resulting in a higher temperature, sometimes exceeding 100°C. This air generally needs to be cooled by an intercooler before entering the fuel cell to participate in the reaction. All of these factors increase system complexity and cost, reducing the competitive advantage and commercial viability of fuel cells. In air-cooled fuel cells, especially when the temperature rises and the ambient air humidity decreases, a large amount of air flowing through the cathode carries away a significant amount of moisture. However, commercially available gas-cooled polymers (GDLs) in traditional technologies are mostly hydrophobic, which is insufficient to meet these requirements.

[0004] Traditional techniques involve hydrophilic treatment of carbon paper. This method immerses the carbon paper in an alcoholic solution of tetrabutyl titanate or ethyl silicate, then soaks it under vacuum for a certain period. Following this, the carbon paper is hydrolyzed in deionized water, rinsed with deionized water, and dried. While this method significantly improves hydrophilicity, the entire carbon paper remains hydrophilic, which can hinder the removal of water generated in the catalyst layer. It also easily forms a water film on the catalyst layer surface, blocking the entry of reactant gases and affecting fuel cell performance. Furthermore, tetrabutyl titanate is not a conductive material, which affects the conductivity of the material, thus impacting fuel cell performance. In addition, this process is relatively complex and difficult to use on a large scale. Utility Model Content

[0005] Therefore, it is necessary to provide a membrane electrode preparation method that can both cool high-temperature air and humidify dry air without the need for additional humidification and intercooling devices.

[0006] One embodiment of this application provides a method for preparing a membrane electrode.

[0007] A membrane electrode processing apparatus includes a support component, a shielding component, and a scanning mechanism. The scanning mechanism includes a laser working area and a laser scanning head disposed opposite to the laser working area. The support component is disposed in the laser working area to support the membrane electrode. The shielding component has a hollow area and is disposed between the membrane electrode and the laser scanning head to shield the ridge position of the membrane electrode on the surface to be processed for matching bipolar plate channels, while exposing the groove position of the membrane electrode on the surface to be processed for matching bipolar plate channels.

[0008] In some embodiments, the support component includes a positioning plate with a plurality of positioning holes, the positioning plate being positioned in the laser working area through the plurality of positioning holes.

[0009] In some embodiments, the positioning plate is arranged horizontally, and the laser scanning head is located above the positioning plate and is configured to scan downwards.

[0010] In some embodiments, the shielding component has multiple hollow areas that are sequentially and spaced apart along the same direction.

[0011] In some embodiments, the shape and size of the hollowed-out area are respectively matched with the shape and size of the groove in the bipolar plate flow channel.

[0012] In some embodiments, the spacing between adjacent cutout areas matches the spacing between adjacent slots in the bipolar plate channel.

[0013] In some embodiments, the number of the cutout areas matches the number of slots in the bipolar plate flow channel.

[0014] In some embodiments, the hollowed-out area is a long, narrow channel.

[0015] In some embodiments, the size of the shielding member is larger than the size of the membrane electrode, so that the shielding member can fully cover the membrane electrode.

[0016] In some embodiments, the scanning mechanism further includes a driving component connected to the laser scanning head to drive the laser scanning head to move in a preset direction.

[0017] In some embodiments, the shielding component is made of one or both of aluminum alloy and copper.

[0018] An embodiment of this application also provides a method for preparing a membrane electrode.

[0019] A method for preparing a membrane electrode, using the membrane electrode processing apparatus described in any of the above embodiments, includes the following steps:

[0020] The membrane electrode is placed on the support component in the laser working area, and the surface of the membrane electrode to be processed is controlled to face the laser scanning head.

[0021] The shielding component is provided on one side of the surface to be treated of the membrane electrode, and the hollow area of ​​the shielding component is controlled to correspond to the position of the groove on the surface to be treated of the membrane electrode for matching the bipolar plate flow channel, and the non-hollow area of ​​the shielding component is controlled to shield the position of the ridge on the surface to be treated of the membrane electrode for matching the bipolar plate flow channel.

[0022] In addition, the focus of the laser scanning head is controlled to the gas diffusion layer of the membrane electrode, and the position of the exposed hollow area on the surface of the membrane electrode to be processed is laser scanned.

[0023] In some embodiments, the laser scanning head has a power of 1W to 20W in the membrane electrode fabrication method.

[0024] In some embodiments, the power of the laser scanning head is controlled to be 5W~15W in the membrane electrode fabrication method.

[0025] In some embodiments, the filling density of the laser scanning head is controlled to be 0.01 mm to 0.1 mm in the membrane electrode fabrication method.

[0026] In some embodiments, the processing speed of the laser scanning head is controlled to be 100 mm / s to 10000 mm / s in the membrane electrode fabrication method.

[0027] In some embodiments, the membrane electrode fabrication method further includes the following steps:

[0028] The laser working area, the support component, the membrane electrode, the shielding component, and the laser scanning head are arranged in a vertical direction from bottom to top, and the surface of the membrane electrode to be processed is controlled to face the laser scanning head above it.

[0029] One embodiment of this application also provides a membrane electrode.

[0030] A membrane electrode is prepared using the membrane electrode preparation method described in any of the above embodiments.

[0031] The membrane electrode prepared by the above-described method can both cool high-temperature air and humidify dry air without the need for additional humidification and cooling devices. The gas diffusion layer (GDL) mainly consists of two parts: a substrate layer and a microporous layer. The substrate layer is the most important part of the gas diffusion layer, and its main material is carbon fiber. The substrate layer is first treated with hydrophobic polytetrafluoroethylene (PTFE), and then a microporous layer is prepared on one side of the substrate layer. This microporous layer is generally prepared by mixing carbon black powder and PTFE, etc. When the substrate layer is in contact with the bipolar plate, the microporous layer on the substrate layer is in contact with the catalyst layer. The main function of the gas diffusion layer is to distribute gas and moisture. This application employs a laser scanning process to treat the substrate layer of the gas diffusion layer, specifically by laser-treating the surface of the substrate layer in contact with the bipolar plates. The laser-treated area reduces the contact angle of the gas diffusion layer surface of the membrane electrode, increasing its hydrophilicity and facilitating the formation of a thin water film on the gas diffusion layer surface. When the high-temperature, dry air entering the fuel cell passes through the flow field channel formed by the flow field and the membrane electrode, it exchanges heat with the water film on the gas diffusion layer surface of the membrane electrode. The water changes from a liquid to a gaseous state and mixes with the dry air, humidifying the dry air and improving fuel cell performance. Simultaneously, the high-temperature, dry air is effectively cooled, reducing the fuel cell system's reliance on intercooling. Furthermore, the increased porosity of the gas diffusion layer facilitates gas transport, reduces concentration polarization, and further enhances fuel cell performance. This method is particularly suitable for fuel cells operating under relatively dry conditions, reducing the requirements for system humidification and intercooling, and simplifying the fuel cell system.

[0032] In summary, compared with traditional technologies, the membrane electrode fabrication apparatus and method of this application produce membrane electrodes with the following advantages:

[0033] (1) The flow channel of the bipolar plate is composed of multiple grooves, and the area between adjacent grooves forms a ridge. In the membrane electrode prepared in this application, when the membrane electrode is matched with the bipolar plate, the membrane electrode gas diffusion layer area corresponding to the ridge of the flow channel is hydrophobic, and the membrane electrode gas diffusion layer area corresponding to the groove of the flow channel is hydrophilic. This is beneficial to form a thin water film on the surface of the gas diffusion layer corresponding to the groove of the flow channel. When the high temperature dry air entering the fuel cell flows through the groove of the flow channel, it undergoes hydrothermal exchange with the water film. The high temperature dry air is humidified on the one hand and cooled on the other hand. The low temperature humid air passes through the gas diffusion layer to reach the surface of the catalyst layer to participate in the reaction. This is beneficial to improve the performance of the fuel cell and is particularly suitable for fuel cell systems without external humidification and intercooler.

[0034] (2) After the membrane electrode of this application is laser-treated, the hydrophilicity of the gas diffusion layer surface is improved, while the catalyst layer on the surface of the proton exchange membrane retains its original hydrophobic properties. The gas diffusion layer is hydrophilic, which will facilitate the discharge of water generated by the reaction from the surface of the catalyst layer.

[0035] (3) A thin water film is easily formed on the surface of the gas diffusion layer of the membrane electrode after laser treatment. When the high-temperature dry air entering the fuel cell passes through the flow field channel formed by the flow channel and the membrane electrode, the high-temperature dry air is effectively cooled, improving the durability of the fuel cell. At the same time, it reduces the requirements of the fuel cell system for air cooling and simplifies the fuel cell system.

[0036] (4) The porosity of the gas diffusion layer of the membrane electrode in this application increases after laser treatment, which is beneficial to gas transport and improves the performance of the fuel cell.

[0037] (5) This application can reduce the requirements for system humidification and intercooling, simplify the fuel cell system, and make the fuel cell system structure simpler, lighter, and cheaper.

[0038] (6) The carbon fiber on the surface of the gas diffusion layer of the membrane electrode of this application was not damaged after laser treatment, and the contact resistance of the gas diffusion layer did not change significantly.

[0039] (7) This application can control the degree of PTFE removal from the substrate by changing the laser process parameters.

[0040] (8) The membrane electrode preparation method of this application is simple, low cost, and can be promoted and applied on a large scale. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0042] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings. In the following description, the same reference numerals denote the same parts.

[0043] Figure 1 This is a schematic diagram of a membrane electrode fabrication apparatus according to an embodiment of this application;

[0044] Figure 2 This is a schematic diagram of the positioning plate of the membrane electrode fabrication apparatus according to an embodiment of this application;

[0045] Figure 3 This is a schematic diagram of the positioning plate and the membrane electrode of the membrane electrode preparation apparatus described in one embodiment of this application.

[0046] Figure 4 This is a schematic diagram showing the positioning plate, membrane electrode, and shielding component of the membrane electrode fabrication apparatus according to an embodiment of this application.

[0047] Figure 5 This is a schematic diagram of the membrane electrode fabrication method according to an embodiment of this application;

[0048] Figure 6 This is a schematic diagram of the membrane electrode and bipolar plate according to an embodiment of this application;

[0049] Figure 7 This is a schematic diagram showing the contact angle of the membrane electrode before and after laser treatment in the membrane electrode fabrication method described in an embodiment of this application;

[0050] Figure 8 , Figure 9 , Figure 10 , Figure 11 The images shown are SEM images of the gas diffusion layer surface of the membrane electrode before and after laser treatment in the membrane electrode fabrication method described in an embodiment of this application.

[0051] Figure 12 This is a comparison diagram of the polarization performance and internal resistance of the membrane electrode before and after laser treatment in a fuel cell, as described in an embodiment of this application.

[0052] Explanation of reference numerals in the attached figures

[0053] 10. Membrane electrode preparation apparatus; 100. Positioning plate; 101. Positioning hole; 200. Shielding component; 201. Hollowed-out area; 310. Laser working area; 320. Laser scanning head; 20. Membrane electrode; 21. Gas diffusion layer; 30. Bipolar plate. Detailed Implementation

[0054] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0055] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0056] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0057] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0058] In the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0059] In this document, "optionally," "optionally," and "optional" mean that something is optional, that is, it is selected from either "with" or "without." If multiple "options" appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "option" is independent. In this application, descriptions such as "optionally contains" and "optionally includes" indicate "contains or does not contain."

[0060] In this document, unless otherwise stated, the reaction steps may be performed in the order described herein or not. For example, other steps may be included between reaction steps, and the order of reaction steps may be appropriately interchanged. This is something that those skilled in the art can determine based on conventional knowledge and experience. Preferably, the reaction methods described herein are performed sequentially.

[0061] In this application, when numerical intervals (i.e., numerical ranges) are mentioned, unless otherwise specified, the distribution of selectable numerical values ​​within the numerical interval is considered continuous, and includes the two endpoints of the numerical interval (i.e., the minimum and maximum values), as well as every numerical value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that numerical interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints, which is equivalent to directly listing every integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed in this application should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical interval" can be broadly included to include percentage intervals, ratio intervals, proportion intervals, etc.

[0062] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0063] This application provides a membrane electrode preparation apparatus and a membrane electrode preparation method to solve at least one of the following technical problems in conventional fuel cells: (1) In liquid-cooled fuel cells, air humidification requires a system configuration of humidification devices (such as membrane humidifiers or water spray humidification systems). Before air enters the fuel cell, it is generally compressed and pressurized by an air compressor and then cooled by an intercooler before it can enter the fuel cell to participate in the reaction. This increases the complexity and cost of the system, reducing the competitive advantage and commercial promotion of fuel cells. (2) In air-cooled fuel cells, especially when the temperature rises and the ambient air humidity decreases, a large amount of air flows through the cathode and carries away a large amount of moisture. However, the gas diffusion layers in conventional technologies are mostly hydrophobic, which is difficult to meet the usage requirements. (3) The hydrophilic treatment method in conventional technologies, which involves immersing carbon paper in an alcohol solution of tetrabutyl titanate or tetraethyl orthosilicate and then soaking it under vacuum for a certain period of time, has the problems of affecting the discharge of water generated in the catalyst layer, easily forming a water film on the surface of the catalyst layer, blocking the entry of reactant gases, affecting the performance of the fuel cell, and having a relatively complex process that is difficult to use on a large scale. The following description, in conjunction with the accompanying drawings, will explain the membrane electrode preparation apparatus and the membrane electrode preparation method.

[0064] The membrane electrode fabrication apparatus 10 provided in this application embodiment is exemplary; please refer to [link to example]. Figure 1 As shown, Figure 1 This is a schematic diagram of the membrane electrode fabrication apparatus 10 provided in an embodiment of this application. The membrane electrode fabrication method of this application can be used to prepare a membrane electrode 20, which has good dry operating performance, and the fabrication method is simple and low in cost.

[0065] To more clearly illustrate the structure of the membrane electrode fabrication apparatus 10, the membrane electrode fabrication apparatus 10 will be described below in conjunction with the accompanying drawings.

[0066] For example, please refer to Figure 1 As shown, a membrane electrode 20 processing apparatus includes a support member, a shielding member 200, and a scanning mechanism. The scanning mechanism includes a laser working area 310 and a laser scanning head 320 disposed opposite to the laser working area 310. The support member is disposed in the laser working area 310 to support the membrane electrode 20, and the shielding member 200 has a hollow area 201. The shielding member 200 is disposed between the membrane electrode 20 and the laser scanning head 320 to shield the ridge positions on the surface of the membrane electrode 20 to be processed for matching bipolar plate 30 channels, while exposing the groove positions on the surface of the membrane electrode 20 to be processed for matching bipolar plate 30 channels.

[0067] In some of these embodiments, see Figure 2 As shown, Figure 1This is a schematic diagram of a membrane electrode fabrication apparatus 10 according to an embodiment of this application. The supporting component includes a positioning plate 100. The positioning plate 100 is provided with a plurality of positioning holes 101. The positioning plate 100 is positioned in the laser working area 310 through the plurality of positioning holes 101.

[0068] In some embodiments, the positioning plate 100 is arranged horizontally, and the laser scanning head 320 is located above the positioning plate 100 and is configured to scan downwards. See also Figure 3 As shown, Figure 3 This is a schematic diagram of the positioning plate 100 of the membrane electrode preparation apparatus 10 according to an embodiment of the present application when it is engaged with the membrane electrode 20. During processing, the membrane electrode 20 is disposed above the positioning plate 100, and the multiple positioning holes 101 on the positioning plate 100 are used for positioning itself and the membrane electrode 20.

[0069] In some embodiments, the blocking component 200 includes a baffle. The blocking component 200 is capable of moving along a preset path under the action of an external force.

[0070] In some of these embodiments, see Figure 4 As shown, Figure 4 This is a schematic diagram of the positioning plate 100, the membrane electrode 20, and the shielding member 200 of the membrane electrode preparation apparatus 10 according to an embodiment of this application. The shielding member 200 has a plurality of hollow areas 201 that are sequentially and spaced apart along the same direction.

[0071] In some embodiments, the shape and size of the hollowed-out region 201 are respectively matched with the shape and size of the groove of the bipolar plate 30 channel.

[0072] In some embodiments, the spacing between adjacent cutout regions 201 matches the spacing between adjacent slots in the bipolar plate 30 channel.

[0073] In some embodiments, the number of cutout regions 201 matches the number of slots in the bipolar plate 30 channel.

[0074] In some of these embodiments, see Figure 4 As shown, the hollowed-out area 201 is a long, narrow channel.

[0075] In some embodiments, the size of the shielding member 200 is larger than the size of the membrane electrode 20, so that the shielding member 200 can fully cover the membrane electrode 20. It should be noted that "the size of the shielding member 200 is larger than the size of the membrane electrode 20" means that when the shielding member 200 and the membrane electrode 20 have the same shape, the dimensions of corresponding parameters of the shielding member 200 are larger than the dimensions of corresponding parameters of the membrane electrode 20. For example, the length of the shielding member 200 is greater than the length of the membrane electrode 20, and the width of the shielding member 200 is greater than the width of the membrane electrode 20.

[0076] In some embodiments, the scanning mechanism further includes a driving component. The driving component is connected to the laser scanning head 320 to drive the laser scanning head 320 to move in a preset direction. The driving component is not shown in the accompanying drawings.

[0077] In some embodiments, the shielding component 200 is made of one or both of aluminum alloy and copper.

[0078] An embodiment of this application also provides a method for preparing a membrane electrode.

[0079] A method for preparing a membrane electrode, using the membrane electrode 20 processing apparatus in any of the above embodiments, see [link to documentation]. Figure 5 As shown, Figure 5 This is a schematic flowchart of a membrane electrode fabrication method according to an embodiment of this application, including the following steps:

[0080] S10. Place the membrane electrode 20 on the support component of the laser working area 310, and control the surface of the membrane electrode 20 to be processed to face the laser scanning head 320.

[0081] S20. A shielding member 200 is provided on one side of the surface to be treated of the membrane electrode 20. The hollow area 201 of the shielding member 200 is controlled to correspond to the position of the groove on the surface to be treated of the membrane electrode 20 for matching the flow channel of the bipolar plate 30. The non-hollow area 201 of the shielding member 200 is controlled to shield the position of the ridge on the surface to be treated of the membrane electrode 20 for matching the flow channel of the bipolar plate 30.

[0082] S30: Control the focus of the laser scanning head 320 to the gas diffusion layer 21 of the membrane electrode 20, and perform laser scanning processing on the position of the exposed hollow area 201 on the surface of the membrane electrode 20 to be processed.

[0083] In some embodiments, the power of the laser scanning head 320 in the membrane electrode fabrication method is 1W to 20W. The power of the laser scanning head 320 includes, but is not limited to, 1W, 2W, 5W, 10W, 12W, 15W, 17W, 18W, 20W, or any range between the foregoing.

[0084] In some embodiments, the power of the laser scanning head 320 is controlled to be 5W~15W in the membrane electrode fabrication method.

[0085] In some embodiments, the filling density of the laser scanning head 320 is controlled to be 0.01 mm to 0.1 mm in the membrane electrode fabrication method. The values ​​for the filling density of the laser scanning head 320 include, but are not limited to: 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.1 mm, or any range between the foregoing. It should be noted that the filling density refers to the spacing between adjacent lines after scanning by the laser scanning head 320. A lower filling density results in a smaller spacing between adjacent lines on the scanned pattern obtained by the laser scanning head 320, while a higher filling density results in a larger spacing between adjacent lines on the scanned pattern obtained by the laser scanning head 320.

[0086] In some embodiments, in the membrane electrode fabrication method, the processing speed of the laser scanning head 320 is controlled to be 100 mm / s to 10000 mm / s. The value of the processing speed of the laser scanning head 320 includes, but is not limited to: 100 mm / s, 200 mm / s, 500 mm / s, 800 mm / s, 1000 mm / s, 2000 mm / s, 4000 mm / s, 5000 mm / s, 7000 mm / s, 9000 mm / s, 10000 mm / s, or any range between the foregoing.

[0087] In some embodiments, the membrane electrode fabrication method further includes the following steps:

[0088] The laser working area 310, support component, membrane electrode 20, shielding component 200 and laser scanning head 320 are arranged in a vertical direction from bottom to top, and the surface to be treated of the membrane electrode 20 is controlled to face the laser scanning head 320 above it.

[0089] The membrane electrode 20 prepared by the above-described membrane electrode preparation method can both cool high-temperature air and humidify dry air without the need for additional humidification and cooling devices. The gas diffusion layer 21 (GDL) mainly consists of two parts: a substrate layer and a microporous layer. The substrate layer is the most important part of the gas diffusion layer 21. The material constituting the substrate layer is mainly carbon fiber. The substrate layer is first treated with hydrophobic polytetrafluoroethylene (PTFE), and then a microporous layer is prepared on one side of the substrate layer. This microporous layer is generally prepared by mixing carbon black powder and PTFE, etc. When the substrate layer is in contact with the bipolar plate 30, the microporous layer on the substrate layer is in contact with the catalyst layer. The main function of the gas diffusion layer 21 is to distribute gas and moisture. This application employs a laser scanning process to treat the substrate layer of the gas diffusion layer 21, specifically by laser-treating the surface of the substrate layer in contact with the bipolar plate 30. The laser-treated area reduces the contact angle of the gas diffusion layer 21 surface of the membrane electrode 20, increasing its hydrophilicity and facilitating the formation of a thin water film on the gas diffusion layer 21 surface. When the high-temperature, dry air entering the fuel cell passes through the flow field channel formed by the flow field and the membrane electrode 20, it exchanges heat with the water film on the gas diffusion layer 21 surface, causing the water to transform from a liquid to a gaseous state and mix with the dry air. This humidifies the dry air, improving fuel cell performance. Simultaneously, the high-temperature, dry air is effectively cooled, reducing the fuel cell system's reliance on intercooling. Furthermore, the increased porosity of the gas diffusion layer 21 facilitates gas transport, reduces concentration polarization, and further enhances fuel cell performance. This method is particularly suitable for fuel cells operating under relatively dry conditions, reducing the requirements for system humidification and intercooling, and simplifying the fuel cell system.

[0090] One embodiment of this application also provides a membrane electrode 20.

[0091] A membrane electrode 20 is prepared using the membrane electrode preparation method described in any of the above embodiments.

[0092] Reference Figure 6 As shown, Figure 6 This is a schematic diagram of the membrane electrode 20 and bipolar plate 30 in one embodiment of this application.

[0093] Example 1

[0094] A method for preparing a membrane electrode, using Figure 1 The membrane electrode fabrication apparatus 10 shown includes the following steps:

[0095] S10. Place the membrane electrode 20 on the support component of the laser working area 310, and control the surface of the membrane electrode 20 to be processed to face the laser scanning head 320.

[0096] S20. A shielding member 200 is provided on one side of the surface to be treated of the membrane electrode 20. The laser working area 310, the support member, the membrane electrode 20, the shielding member 200, and the laser scanning head 320 are arranged in sequence from bottom to top in the vertical direction, and the surface to be treated of the membrane electrode 20 is controlled to face the laser scanning head 320 above it.

[0097] The cutout area 201 of the control shielding component 200 corresponds to the position of the groove on the surface to be processed of the membrane electrode 20 for matching the flow channel of the bipolar plate 30, and the non-cutout area 201 of the control shielding component 200 shields the position of the ridge on the surface to be processed of the membrane electrode 20 for matching the flow channel of the bipolar plate 30.

[0098] S30. The focal point of the laser scanning head 320 is controlled to be at the gas diffusion layer 21 of the membrane electrode 20, and laser scanning is performed on the position of the exposed hollow area 201 on the surface of the membrane electrode 20 to be processed. The power of the laser scanning head 320 is controlled to be 1W~20W, the power of the laser scanning head 320 is controlled to be 5W~15W, the filling density of the laser scanning head 320 is controlled to be 0.01mm~0.1mm, and the processing speed of the laser scanning head 320 is controlled to be 100mm / s~10000mm / s.

[0099] The contact angle of the membrane electrode 20 prepared in Example 1 was tested, see [reference]. Figure 7 As shown, Figure 7 This is a schematic diagram of the contact angle of the membrane electrode 20 before and after laser treatment in a membrane electrode fabrication method according to an embodiment of this application.

[0100] The membrane electrode 20 prepared in Example 1 was scanned by SEM scanning electron microscopy. See [link to SEM image]. Figure 8 , Figure 9 , Figure 10 , Figure 11 As shown, Figure 8 , Figure 9 , Figure 10 , Figure 11 The images shown are SEM images of the gas diffusion layer 21 surface of the membrane electrode 20 before and after laser treatment, respectively, according to an embodiment of this application.

[0101] Depend on Figures 7-11 It can be seen that after the above preparation method, the carbon fiber outline is clear in the part near the surface of the gas diffusion layer 21, the carbon fiber is not damaged, the PTFE content on the carbon fiber surface and between carbon fibers is reduced, and the porosity is increased.

[0102] A 5cm × 5cm membrane electrode 20 sample prepared in Example 1 was used, and its contact resistance was tested at pressures of 0.6MPa, 1.0MPa, and 1.5MPa. The test results are shown in Table 1. As can be seen from Table 1, the contact resistance of the gas diffusion layer 21 did not change significantly after treatment and did not affect the electronic resistance of the fuel cell.

[0103] Table 1. Contact resistance of 20 membrane electrode samples under pressures of 0.6 MPa, 1.0 MPa, and 1.5 MPa.

[0104]

[0105] The membrane electrode 20 prepared using the method in Example 1 was used to assemble a fuel cell, and the polarization performance and internal resistance of the fuel cell were tested. Specifically, single cells with dimensions of 5cm × 5cm were assembled, and their polarization performance and internal resistance under non-humidification conditions were tested and compared. The test results are shown in [Figure 1]. Figure 12 As shown, Figure 12 This is a comparison of the polarization performance and internal resistance of the membrane electrode before and after laser treatment in a fuel cell, according to an embodiment of the membrane electrode preparation method described in this application. The test results show that the polarization performance of the fuel cell is significantly improved after treatment using the preparation method of Example 1, especially at high current densities. The internal resistance of the battery is also significantly reduced. This is mainly due to the following two aspects: First, the hydrophilicity of the gas diffusion layer 21 is enhanced after laser treatment, and the air can be effectively humidified, thereby increasing the wettability of the proton exchange membrane, reducing the ion resistance, and improving the performance of the fuel cell; Second, the porosity of the gas diffusion layer 21 is increased after treatment, which helps gas transport and improves the performance of the fuel cell.

[0106] In summary, compared with traditional technologies, the membrane electrode preparation apparatus 10 and the membrane electrode preparation method of this application produce the following beneficial effects on the membrane electrode 20:

[0107] (1) The flow channel of the bipolar plate 30 is composed of multiple grooves, wherein the area between adjacent grooves forms a ridge. In the membrane electrode 20 prepared in this application, when the membrane electrode 20 is matched with the bipolar plate, the region of the gas diffusion layer 21 of the membrane electrode 20 corresponding to the ridge of the flow channel of the bipolar plate 30 is hydrophobic, and the region of the gas diffusion layer 21 of the membrane electrode 20 corresponding to the groove of the flow channel is hydrophilic. This is beneficial to forming a thin water film on the surface of the gas diffusion layer 21 corresponding to the groove of the flow channel. When the high-temperature dry air entering the fuel cell flows through the groove of the flow channel, it undergoes hydrothermal exchange with the water film. The high-temperature dry air is humidified on the one hand and cooled on the other hand. The low-temperature humid air passes through the gas diffusion layer 21 to reach the surface of the catalyst layer to participate in the reaction. This is beneficial to improving the performance of the fuel cell, and is particularly suitable for fuel cell systems without external humidification and intercoolers.

[0108] (2) After the membrane electrode 20 of this application is laser-treated, the hydrophilicity of the gas diffusion layer 21 surface is improved, the catalyst layer on the surface of the proton exchange membrane still retains its original hydrophobic properties, and the gas diffusion layer 21 is hydrophilic, which will help the water generated by the reaction to be discharged from the surface of the catalyst layer.

[0109] (3) A thin water film is easily formed on the surface of the gas diffusion layer 21 after the membrane electrode 20 of this application is laser-treated. When the high-temperature dry air entering the fuel cell passes through the flow field channel formed by the flow channel and the membrane electrode 20, the high-temperature dry air is effectively cooled down, improving the durability of the fuel cell. At the same time, it reduces the requirements of the fuel cell system for air cooling and simplifies the fuel cell system.

[0110] (4) The porosity of the gas diffusion layer 21 of the membrane electrode 20 after laser treatment is increased, which is beneficial to gas transport and improves the performance of the fuel cell.

[0111] (5) This application can reduce the requirements for system humidification and intercooling, simplify the fuel cell system, and make the fuel cell system structure simpler, lighter, and cheaper.

[0112] (6) The carbon fiber on the surface of the gas diffusion layer 21 of the membrane electrode 20 after laser treatment was not damaged, and the contact resistance of the gas diffusion layer 21 did not change significantly.

[0113] (7) This application can control the degree of PTFE removal from the substrate by changing the laser process parameters.

[0114] (8) The membrane electrode preparation method of this application is simple, low cost, and can be promoted and applied on a large scale.

[0115] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0116] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0117] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A membrane electrode assembly processing apparatus characterized by comprising: The device includes a support component, a shielding component, and a scanning mechanism. The scanning mechanism includes a laser working area and a laser scanning head disposed opposite to the laser working area. The support component is disposed in the laser working area to support the membrane electrode. The shielding component has a hollowed-out area and is disposed between the membrane electrode and the laser scanning head to shield the ridge position on the surface of the membrane electrode to be processed for matching the bipolar plate flow channel, while exposing the groove position on the surface of the membrane electrode to be processed for matching the bipolar plate flow channel.

2. The membrane electrode assembly according to claim 1, wherein The supporting component includes a positioning plate with a plurality of positioning holes, which are used to position the positioning plate in the laser working area.

3. The membrane electrode assembly of claim 2, wherein, The positioning plate is arranged horizontally, and the laser scanning head is located above the positioning plate and is set to scan downwards.

4. The membrane electrode assembly according to any one of claims 1 to 3, wherein The shielding component has multiple hollow areas that are sequentially distributed and spaced apart along the same direction.

5. The membrane electrode assembly of claim 4, wherein, The shape and size of the hollowed-out area are respectively matched with the shape and size of the groove in the bipolar plate flow channel.

6. The membrane electrode processing apparatus according to claim 4, characterized in that, The spacing between adjacent hollowed-out areas matches the spacing between adjacent slots in the bipolar plate flow channel.

7. The membrane electrode assembly of claim 4, wherein, The number of hollowed-out areas matches the number of slots in the bipolar plate flow channel.

8. The membrane electrode processing apparatus according to claim 4, characterized in that, The hollowed-out area is a long, narrow channel.

9. The membrane electrode assembly according to any one of claims 1 to 3, 5 to 8, wherein The size of the shielding component is larger than the size of the membrane electrode, so that the shielding component can fully cover the membrane electrode.

10. The membrane electrode processing apparatus according to any one of claims 1-3 and 5-8, characterized in that, The scanning mechanism further includes a driving component, which is connected to the laser scanning head to drive the laser scanning head to move in a preset direction.

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