A fuel cell membrane electrode spraying device, a spraying method, an electrode and a fuel cell

Abstract

The application discloses a fuel cell membrane electrode spraying device, which comprises a heating system, a spraying system, a driving system and a carrier gas system, the heating system is used for heating and fixing a membrane layer of ionomer; the spraying system comprises a spraying device and a liquid control system, the liquid control system is communicated with the spraying device; the spraying device is internally provided with a vibrating device capable of driving the spraying device to vibrate, the minimum vibration frequency of the spraying device is 1000 times / s, and the spraying end of the spraying device is uniformly provided with a plurality of openings with a diameter of 5-20 mm; the liquid control system is used for guiding a catalyst liquid into the spraying device; the driving system is used for driving the spraying system to move; and the carrier gas system is communicated with the spraying device of the spraying system and is used for providing air into the spraying device. The fuel cell membrane electrode spraying device has the advantages of simple structure, low production cost, uniform spraying thickness, high spraying precision and no waste in small-area spraying.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and specifically to an automated spraying apparatus and method for fuel cell membrane electrode assembly, as well as an alkaline ionomer membrane electrode assembly and a fuel cell. Background Technology

[0002] With the development of the energy industry, green, low-carbon, energy-saving, and environmentally friendly practices have become one of the main goals of industrial development. Fuel cells, which directly convert chemical energy into electrical energy through electrochemical reactions, are a type of highly efficient and clean power source, not limited by the Carnot cycle. Low-temperature fuel cells, in particular, have advantages such as low operating temperature and fast response speed, and have broad application prospects in the transportation sector. The core component of a low-temperature fuel cell is the membrane electrode assembly (MEA). It mainly consists of a proton exchange membrane (anion exchange membrane), a catalyst layer, and a gas diffusion layer. In the cell, the MEA not only isolates the anode and cathode but also provides microchannels for multiphase mass transfer and electrochemical reaction sites. Currently, the mainstream method for preparing MEAs is to spray catalyst slurry onto the membrane surface (CCM). However, during the CCM spraying process, the membrane is prone to wrinkling and deformation, and uneven spraying occurs. Although existing spraying equipment on the market can solve this problem, it is expensive, requires a large spray volume, cannot control the spraying area during the process, and results in significant errors and waste after spraying.

[0003] Chinese Patent 110694827A discloses a pneumatic automatic spraying device for preparing fuel cell membrane electrode assemblies (MEAs). The device includes a housing, an XYZ triaxial sliding shaft, a pneumatic spray gun, a vacuum adsorption heating stage, a diaphragm vacuum pump, an air compressor, electrodes, an air filter, and a position sensor. The spray gun is mounted on one of the three axes of the sliding shaft and connected to the air compressor. A vacuum adsorption heating stage is located below the sliding shaft and connected to the vacuum pump. Catalyst liquid enters the spray gun after ultrasonic vibration. The spray gun is positioned by the triaxial sliding shaft and, under the action of the vacuum pump, sprays the catalyst liquid onto an alkaline ionomer membrane layer. However, this pneumatic automatic spraying device suffers from several drawbacks during the spraying process of alkaline ionomer membrane layers. The membrane layer is prone to deformation and shrinkage, the spray volume is large, the membrane thickness is uneven and difficult to control, resulting in significant spraying errors. It is unsuitable for small-area spraying and has high manufacturing costs. Summary of the Invention

[0004] To address the problems in existing fuel cell alkaline ionomer membrane electrode preparation processes, such as wrinkling and deformation of the alkaline ionomer membrane layer, uneven coating thickness, high preparation cost, and large coating errors, this paper provides an automated fuel cell membrane electrode spraying device and method that features a simple and compact structure, low production cost, uniform coating thickness, prevention of wrinkling and deformation of the alkaline ionomer membrane layer, high coating precision, and ease of operation.

[0005] The technical solution adopted by this invention to solve its technical problem is as follows: it includes a heating system, a spraying system, a driving system, and a carrier gas system. The heating system is used to heat and adsorb and fix the alkaline ionomer film layer. The spraying system includes a spraying device and a liquid control system, which is connected to the spraying device. The spraying device is equipped with a vibration device that can drive the spraying device to vibrate. The minimum vibration frequency of the spraying device is 1000 times / second. Multiple openings are uniformly arranged on the spraying end of the spraying device, and the diameter of the openings ranges from 5 to 20 mm. The liquid control system is used to introduce the catalyst liquid into the spraying device. The driving system is used to drive the spraying system to move. The carrier gas system is connected to the spraying device of the spraying system and is used to supply air to the spraying device.

[0006] Furthermore, the heating system includes a power supply device, a heating plate, a sintering plate, multiple connecting pipes, and a vacuum device; the heating plate and the power supply device are electrically connected, the sintering plate is fixed above the heating plate, the sintering plate is connected to the vacuum device, the multiple connecting pipes are connected to each other, the multiple connecting pipes are connected to form a closed loop structure, the multiple connecting pipes are arranged along the outer contour of the heating plate, and are arranged around the outer periphery of the sintering plate.

[0007] Furthermore, the heating plate is made of metal and has a thermal conductivity of 100–160 W / mC.

[0008] Furthermore, the sintering plate is provided with multiple suction cups, and the suction cups are provided with multiple through holes, the diameter of which ranges from 0.2 to 0.8 micrometers.

[0009] Furthermore, a sealing strip is provided on the outer periphery of the sintered plate.

[0010] Furthermore, the vacuum device is externally connected to a filter, and the vacuum level of the vacuum device ranges from 0.01 to 0.09 MPa.

[0011] Furthermore, the spraying device of the spraying system includes a main body and an inlet device. The inlet device is fixed on the main body at one end away from the hole. A gas inlet is provided on the side of the main body and is connected to the carrier gas system.

[0012] Furthermore, a filter screen is installed at one end of the main body that has multiple openings.

[0013] Furthermore, the liquid control device includes a moving shaft, a fixed device, a transmission device, a power device, and an injection device. The power device is electrically connected to the transmission device. One side of the transmission device is connected to the moving shaft, which is movably mounted on the fixed device. The other end of the moving shaft is fixedly connected to the injection device. The power device can drive the transmission device to move the moving shaft and the injection device in a linear reciprocating motion along the extension direction of the moving shaft.

[0014] Furthermore, the drive system includes a spraying track and a control device; the spraying track includes a first guide rail and a second guide rail, the first guide rail is movably mounted on the second guide rail, the installation direction of the first guide rail is perpendicular to the installation direction of the second guide rail, the second guide rail is vertically mounted on the heating system, the control system is electrically connected to the spraying system, and the control system is used to control the movement of the spraying device on the first guide rail.

[0015] Furthermore, the carrier gas system includes a gas cylinder and a flow controller. The outlet of the gas cylinder is connected to the flow controller, which is also connected to the spraying device.

[0016] This invention also discloses a method for spraying an alkaline ionomer membrane electrode for a fuel cell, comprising:

[0017] Step 1: Mix Pt / C catalyst, deionized water, isopropanol and ionomer solution, and vibrate ultrasonically at 5-15°C for 1-2 hours to form catalyst liquid;

[0018] Step 2: Introduce the catalyst liquid into the liquid control system and place the alkaline ionomer film layer on the heating system;

[0019] Step 3: Turn on the heating system and heat it to above 50°C;

[0020] Step 4: Install an auxiliary film layer with a perforated structure on the surface of the heating system;

[0021] Step 5: Drive the spraying device to move, while introducing the catalyst liquid and air into the spraying device, and drive the spraying device to vibrate at a frequency of at least 1000 times / second.

[0022] Furthermore, in step three, the temperature of the heating system is raised to above 60°C.

[0023] Furthermore, the auxiliary film layer is made of tetrafluorosilicone.

[0024] The present invention also discloses an alkaline ionomer membrane electrode for fuel cells, prepared according to the above-described spraying method.

[0025] The present invention also discloses a fuel cell, including the above-described fuel cell alkaline ionomer membrane electrode.

[0026] The fuel cell membrane electrode spraying device and method of this invention integrates a heating system, a spraying system, a drive system, and a carrier gas system, achieving a liquid utilization rate of over 95%, automatic nozzle cleaning and non-clogging fine mist droplets, and a precise and automated spraying mode. It features uniform spraying effect and high repeatability of the spraying process. Compared with commercially available ultrasonic spraying devices, the integrated spraying system of this invention is smaller and space-saving, making it highly suitable for small-area spraying laboratory research. The fuel cell alkaline ionomer membrane electrode prepared by the fuel cell alkaline ionomer membrane electrode spraying method of this invention achieves a maximum power density of 124 mW / cm² in ammonia-fueled fuel cells.

[0027] The above description of the invention is merely an overview of the technical solution of this application. In order to enable those skilled in the art to better understand the technical solution of this application and to implement it based on the description and drawings, and to make the above-mentioned objectives and other objectives, features and advantages of this application easier to understand, the following description is provided in conjunction with the specific embodiments and drawings of this application. Attached Figure Description

[0028] The accompanying drawings are only used to illustrate the principles, implementation methods, applications, features, and effects of specific embodiments of this application and other related content, and should not be considered as limitations on this application.

[0029] In the accompanying drawings of the instruction manual:

[0030] Figure 1 This is a schematic diagram of the fuel cell membrane electrode spraying device of the present invention;

[0031] Figure 2 This is a schematic diagram of the heating system of the fuel cell membrane electrode spraying device of the present invention;

[0032] Figure 3 This is a schematic diagram showing the connection relationship between the heating device and the heating plate of the heating system of the fuel cell membrane electrode spraying device according to the present invention.

[0033] Figure 4 This is a schematic diagram of the structure of the spraying device of the fuel cell membrane electrode spraying device according to the present invention;

[0034] Figure 5 This is a schematic diagram of the liquid control system of the spraying system of the fuel cell membrane electrode spraying device of the present invention;

[0035] Figure 6 This is a schematic diagram showing the connection relationship between the drive system and the connecting pipe of the fuel cell membrane electrode spraying device of the present invention. Detailed Implementation

[0036] To illustrate the possible application scenarios, technical principles, implementable specific solutions, and achievable objectives and effects of this application in detail, the following description, in conjunction with the listed specific embodiments and accompanying drawings, provides a detailed explanation. The embodiments described herein are merely illustrative of the technical solutions of this application and are therefore intended to limit the scope of protection of this application.

[0037] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0038] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit this application.

[0039] In the description of this application, the term "and / or" is used to describe the logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and A and B exist simultaneously. Additionally, the character " / " in this document generally indicates that the preceding and following objects have an "or" logical relationship.

[0040] In this application, terms such as “first” and “second” are used only to distinguish one entity or operation from another, and do not necessarily require or imply any actual quantity, hierarchy or order relationship between these entities or operations.

[0041] Unless otherwise specified, the use of terms such as “comprising,” “including,” “having,” or other similar expressions in this application is intended to cover non-exclusive inclusion, which does not exclude the presence of additional elements in a process, method, or product that includes the stated elements, such that a process, method, or product that includes a list of elements may include not only those defined elements but also other elements not expressly listed, or elements inherent to such a process, method, or product.

[0042] Similar to the understanding in the Examination Guidelines, in this application, expressions such as "greater than," "less than," and "exceeding" are understood to exclude the stated number; expressions such as "above," "below," and "within" are understood to include the stated number. Furthermore, in the description of the embodiments in this application, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times," unless otherwise explicitly specified.

[0043] In the description of the embodiments of this application, the space-related expressions used, such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiments or drawings. They are only for the purpose of describing the specific embodiments of this application or for the reader's understanding, and do not indicate or imply that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0044] Unless otherwise expressly specified or limited, the terms "installation," "connection," "linking," "fixing," and "setting," as used in the description of the embodiments of this application, should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two components or the interaction between two components. For those skilled in the art to which this application pertains, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0045] like Figures 1-6 As shown, the fuel cell membrane electrode coating device of the present invention includes a heating system 1, a coating system 2, a drive system 3, and a carrier gas system 4.

[0046] The heating system 1 is used to heat and adsorb and fix alkaline ionomer film layers, neutral ionomer film layers, or acidic ionomer film layers.

[0047] The spraying system 2 includes a spraying device 21 and a liquid control system 22, which is connected to the spraying device 21. The spraying device 21 is internally equipped with a vibration device capable of driving the device to vibrate. The minimum vibration frequency of the spraying device 21 is 1000 times / second. The spraying end of the spraying device 21 has multiple openings evenly distributed, with the diameter of the openings ranging from 5 to 20 millimeters. The liquid control system 22 is used to introduce catalyst liquid into the spraying device 21.

[0048] The drive system 3 is used to drive the spraying system 2 to move;

[0049] The carrier gas system 4 is connected to the spraying device 21 of the spraying system 2, and the carrier gas system 4 is used to supply air to the spraying device 21.

[0050] The fuel cell membrane electrode spraying device of the present invention integrates the heating system, spraying system, drive system and carrier gas system to achieve a precise automated spraying mode and improve system integration; it has the characteristics of uniform spraying effect and high repeatability of spraying process; it effectively improves the spraying accuracy and spraying quality of alkaline ionomer membrane electrode spraying, and can be used to spray small area alkaline ionomer membrane layers.

[0051] like Figure 1 and Figure 2As shown, the heating system 1 includes a power supply device 11, multiple support devices 12, a heating plate 13, a sintering plate 14, multiple connecting pipes 15, and a vacuum device 16. Multiple support devices 12 are positioned above the power supply device 11 and are simultaneously connected to the heating plate 13, supporting the heating plate 13 above the power supply device 11. The sintering plate 14 is fixed above the heating plate 13 and is also connected to the vacuum device 16. The sintering plate 14 is used to support and adsorb alkaline ions. A polymer film layer is used for subsequent spraying processes. The vacuum device 16 adsorbs and fixes the alkaline ionomer film layer material onto the sintering plate 14 by drawing a vacuum. The heating plate 13 is electrically connected to the power supply device 11, which heats the heating plate 13 to achieve a temperature increase. Through the heating of the heating plate 13 and the vacuum adsorption effect of the sintering plate 14 and the vacuum device 16, the alkaline ionomer film layer for spraying can be stably fixed on the sintering plate 14, reducing possible errors during the spraying process. This design prevents wrinkling and deformation of the alkaline ionomer film during spraying, thereby improving the accuracy of subsequent spraying. Multiple connecting pipes 15 are interconnected, forming a closed-loop structure. These pipes are arranged along the outer contour of the heating plate 13 and surround the outer periphery of the sintering plate 14. Preferably, the power supply device 11 is also connected to a controllable trigger module and a temperature detection device. The controllable trigger module allows adjustment of the time ratio and frequency, improving system reliability and simplifying the internal structure. To enhance the safety performance of the heating system 1 and monitor its operation, a corresponding alarm output system is preferably connected to the power supply device 11. This alarm output system is a relay contact switch. When the operating temperature of the power supply 1 exceeds the alarm temperature, the AC contactor can be controlled to disconnect the heating power supply, providing a safety function. The heating plate 13 is made of a metallic material, such as easily conductive aerospace aluminum, with a thermal conductivity of 100–160 W / mC.The sintered plate 14 is provided with multiple suction cups, each with multiple through holes, thereby enabling the sintered plate 14 to have a greater adsorption force. The diameter of the through holes on the suction cups ranges from 0.2 to 0.8 micrometers. The outer periphery of the sintered plate 14 is sealed and fixed by a sealing strip. The sealing strip is used to isolate the air from the contact surface of the sintered plate 14, preventing vacuum loss, thereby improving the fixing effect of the sintered plate 14, better preventing wrinkles in the alkaline ionomer film layer during spraying, and improving the uniformity of the spraying thickness. The vacuum device 16 adopts oil-free vacuuming and is equipped with an external manual filter to adjust the air flow rate and control the vacuum degree. The vacuum degree of the vacuum device 16 ranges from 0.01 to 0.09 MPa. The heating plate 13 has a heating range of 25 to 100°C, and the temperature detection device is a K-type or T-type temperature detector.

[0052] like Figure 3 As shown, the power supply device 11 includes an AC contactor 110, a solid-state relay 111, and an instrument 112. The AC contactor 110 is connected to an external power source to provide power to the heating plate 13. Specifically, the AC contactor 110 is electrically connected to the neutral and live wires of the external power source, the instrument 112, and the positive terminal of the solid-state relay 111. The end of the AC contactor 110 connected to the instrument 112 is normally closed. Preferably, the AC contactor 110 includes a temperature alarm control device. When the temperature of the AC contactor reaches the rated temperature, the temperature alarm control device will issue an alarm and cut off the heating plate. A thermal power supply is provided to protect the power supply device 11; the negative terminal of the solid-state relay 111 is connected to the negative terminal of the instrument 112, and the positive terminal of the solid-state relay 111 is connected to the positive terminal of the instrument 112. The instrument 112 is also connected to the neutral and live wires of the external power supply; the solid-state relay 111 and the instrument are simultaneously connected to the heating plate 13 to provide power to the heating plate 13; more specifically, the driving current of the solid-state relay 111 is 3-7 mA, for example, 5 mA; the instrument 112 adopts a standard PID or AI regulation method, has self-tuning and self-learning functions, and excellent control characteristics with no overshoot and no undershoot.

[0053] like Figure 3As shown, the spraying device 21 of the spraying system 2 includes a main body 210 and an inlet device 211. The inlet device 211 is fixed to one end of the main body 210. Multiple openings are formed at one end of the main body 210 opposite to the inlet device 211. These openings are evenly arranged, and their diameter ranges from 5 to 20 mm. The inlet device 211 is used to introduce liquid into the main body 210. After passing through the main body 210, the liquid is discharged through the multiple openings at the other end of the main body 210. A gas inlet 212 is provided on the side of the main body 210. The body 210 is connected to the carrier gas system 4 through the gas inlet 212, and the carrier gas system 4 introduces gas into the body 210 through the gas inlet 212. The body 210 of the spraying device 21 is connected to an ultrasonic source, and a vibration device, such as a piezoelectric transducer, is installed inside the body of the spraying device 21. Through ultrasonic waves and under the action of the vibration device, the spraying device 21 can vibrate, converting electrical energy into mechanical energy. Fluid enters the body 210 through the inlet device 211, and air enters the body 210 through the gas inlet 212. The main body 210 is mixed with the fluid. Under the action of ultrasound, the main body 210 vibrates up and down, causing the liquid mixed with air to be discharged in an atomized manner through the opening at the end of the main body 210. This achieves a uniform and stable thin film coating. The vibration frequency of the main body 210 is 1500-2000 times / second. The introducing device 211 is used to introduce the catalyst liquid in the liquid control system 22 into the main body 210. Preferably, in order to improve the spraying effect of the spraying device 21, a multi-opening is provided at one end of the main body 210 of the spraying device 21. The system includes a filter screen to remove impurities from the liquid, improving the atomization effect of the spraying. The spraying system 2 employs a fine control mode with independent air and liquid control. During the spraying process, the liquid is discharged in an atomized manner through the spraying device 21. With the independently controlled liquid and air input, the atomization size and distribution can be precisely controlled, allowing micron-sized fine droplets to evaporate rapidly, thereby producing a uniform micron-sized thin film coating. This reduces spraying errors during the spraying process, improves spraying quality, and also allows for control of the spraying amount, making it suitable for small-area spraying.

[0054] like Figure 4As shown, the liquid control system 22 includes a moving shaft 220, a fixing device 221, a transmission device 222, a power device 223, and an injection device 224. The power device 223 is electrically connected to the transmission device 222 and also electrically connected to the injection device 224. One side of the transmission device 222 is connected to the moving shaft 220, which passes through the middle of the fixing device 221 and can reciprocate within the fixing device 221. The other end of the moving shaft 220 is connected to the injection device 224. The power device 223 can drive the transmission device 222 to move the moving shaft 220, thereby causing the injection device 224 to reciprocate linearly along the extension direction of the moving shaft 220. The other end of the injection device 224 is connected to the inlet device 211 of the spraying device 21. Specifically, the power unit 223 can drive the moving shaft 220 to move, and simultaneously drive the injection device 224 connected to the fixed device 221 to introduce catalyst liquid into the spraying device 21. More specifically, by controlling the output power of the power unit 223, the moving speed of the fixed device 221 relative to the moving shaft 220 and the flow rate of the catalyst liquid introduced by the injection device 224 into the spraying device 21 are controlled. This allows the size of the injection device 224 to be changed and adjusted according to the flow rate of the catalyst liquid, improving the controllability and flexibility of the system, as well as the uniformity of the alkaline ionomer film thickness during the spraying process, thus improving the spraying effect and quality. In order to achieve a uniform coating after spraying, the liquid control system 22 controls the catalyst liquid to enter the spraying device 21 at a flow rate of 2 to 10 ml / min.

[0055] exist Figure 5In the drive system 3, a spraying track 31 and a control device 32 are included. Two electrodes at one end of the control device 32 are simultaneously connected to the spraying track 31. The control device 32 can control the movement of the spraying track 31, thereby driving the spraying device 21 located on the spraying track 31 to move along a predetermined track to achieve uniform spraying of the alkaline ionomer film at different locations. The control device 32 is also connected to the main body 210 of the spraying device 21. The control device 32 can drive the spraying device 21 to vibrate, so that the liquid in the spraying device 21 can be sprayed onto the alkaline ionomer film in a mist form. Specifically, the spraying track 31 includes a first guide rail 311 and a second guide rail 312, which are perpendicular to each other. The second guide rail 312 is vertically fixed to the connecting pipe 15. The second guide rail 313 can move along the... The connecting pipe 15 extends in a linear reciprocating motion. The spraying device 21 is mounted on the first guide rail 311 and can reciprocate linearly along the extension direction of the first guide rail 311. The first guide rail 311 can move back and forth along the extension direction of the second guide rail 312. Under the combined action of the first guide rail 311, the second guide rail 312, and the connecting pipe 15, the control device 32 can control the spraying device 21 to move along a specified trajectory, thereby enabling the spraying device 21 to spray the catalyst liquid onto a specific location on the alkaline ionomer film layer. This achieves automated spraying, improves the spraying range, spraying efficiency, and the accuracy of the coating's position on the alkaline ionomer film layer, and prevents unnecessary waste caused by over-spraying during the spraying process. More specifically, the control system 32 is a numerically controlled electrode control system.

[0056] like Figure 1 As shown, the carrier gas system 4 includes a gas cylinder 41 and a flow controller 42. The outlet of the gas cylinder 41 is connected to the flow controller 42, which in turn is connected to the gas inlet 212 of the spraying device 2. The gas cylinder 41 is used to introduce air into the spraying device 2, and the flow controller 42 is used to control the flow rate and velocity of the air flowing into the spraying device 21. This allows the carrier gas system 4 to flexibly adjust the amount of air introduced into the spraying device 2 according to the actual spraying situation, so as to meet the spraying effect under different spraying conditions and thus ensure the spraying effect of the spraying device 2. Preferably, in order to achieve a more uniform and stable spraying effect, the flow controller 42 controls the air to be introduced into the spraying device 21 at a rate of 50-20 ml / min.

[0057] The fuel cell membrane electrode coating device of this invention has advantages such as integrated rapid suction, convenience and efficiency, stronger suction, accurate temperature measurement, and excellent programmed temperature rise rate. It can quickly fix the ionomer membrane layer without displacement, while preventing deformation and shrinkage of the ionomer membrane layer upon contact with the dispersion liquid. This coating device can break the liquid into uniform micron-sized atomized droplets, thereby achieving a more uniform, thinner, and more controllable thin film coating. It minimizes the problems of nozzle clogging and sedimentation or agglomeration of small liquid particles; it provides a stable and precise liquid during the coating process; by combining ultrasound with the atomizing nozzle, it achieves precise coating, saves slurry, ensures coating quality, and improves coating efficiency. This coating device integrates all modules, and the modules work together to improve the system's integrity, achieving a liquid utilization rate of >95%, automatic nozzle cleaning and clogging-free fine mist droplets, and a precise and automated coating mode. The integrated coating system of this invention is smaller in size and does not take up space, effectively preventing waste during the coating process for small-area ionomer membrane layers.

[0058] The present invention also discloses a spraying method, comprising the following steps:

[0059] Step 1: Mix Pt / C catalyst, deionized water, isopropanol and ionomer solution, and vibrate ultrasonically for 1 to 2 hours at 5 to 15°C to form catalyst liquid;

[0060] Step 2: Introduce the catalyst liquid into the liquid control system and place the alkaline ionomer film layer on the heating system;

[0061] Step 3: Turn on the heating system and heat it to above 50°C, such as above 60°C, to accelerate the volatilization of isopropanol in the catalyst liquid and the overall solidification of the catalyst liquid.

[0062] Step 4: Install an auxiliary film layer with a perforated structure on the surface of the heating system;

[0063] Step 5: Drive the spraying device to move, while introducing the catalyst liquid and air into the spraying device, and drive the spraying device to vibrate at a frequency of at least 1000 times / second.

[0064] Step 6: After spraying, turn off the heating system and let the alkaline ionomer film cool for 5-15 minutes.

[0065] In step one, 200-500 μL of deionized water is added to the Pt / C catalyst to wet the catalyst, followed by the addition of 25% of the mass of the Pt / C catalyst ionomer solution, and finally isopropanol is added and mixed evenly.

[0066] In step four, an auxiliary film layer, such as a PTFE silicone pad, is covered over the sintering plate in the heating system. The intermediate structure of the auxiliary film layer is used to position the spraying position on the alkaline ionomer film layer.

[0067] In step five, the spraying trajectory is set in the control device of the drive system, the control system is turned on, and the control system drives the spraying device of the spraying system to spray according to the set spraying trajectory. The liquid control system introduces the catalyst liquid into the spraying device, and the carrier gas system introduces the gas into the gas inlet of the spraying device. The spraying device vibrates under the action of the control system and discharges the catalyst liquid mixed with air and sprays it evenly on the alkaline ionomer film layer.

[0068] After spraying, turn off the heating system 11 and cool for 5-15 minutes to allow the sprayed alkaline ionomer film to cool and solidify. Then, turn off the vacuum device 16, and position the other side of the alkaline ionomer film towards the spraying device 21. Repeat the above steps to complete the spraying of the other side of the alkaline ionomer film. Finally, immerse the sprayed alkaline ionomer film in a potassium hydroxide solution for 24 hours and rinse with deionized water.

[0069] This invention also discloses an alkaline ionomer membrane electrode for fuel cells, prepared according to the above-described spraying method. When the fuel cell uses ammonia as fuel, the alkaline ionomer membrane electrode can achieve a maximum power density of 124 mW / cm².

[0070] The present invention also discloses a fuel cell, including the above-described fuel cell alkaline ionomer membrane electrode.

[0071] It should be noted that although the above embodiments have been described herein, this does not limit the scope of patent protection of the present invention. Therefore, any changes and modifications made to the embodiments described herein based on the innovative concept of the present invention, or equivalent structural or procedural transformations made using the content of the present invention's specification and drawings, directly or indirectly applying the above technical solutions to other related technical fields, are all included within the scope of patent protection of the present invention.

Claims

1. A fuel cell membrane electrode coating apparatus, comprising a heating system, a coating system, a drive system, and a carrier gas system, characterized in that: The heating system is used to heat and adsorb and fix the alkaline ionomer film layer; The spraying system includes a spraying device and a liquid control system, the liquid control system being connected to the spraying device; the spraying device is equipped with a vibration device that can drive the spraying device to vibrate, the minimum vibration frequency of the spraying device is 1000 times / second, and multiple openings are uniformly arranged on the spraying end of the spraying device, the diameter of the openings ranging from 5 to 20 mm; the liquid control system is used to introduce catalyst liquid into the spraying device. The drive system is used to drive the spraying system to move; The carrier gas system is connected to the spraying device of the spraying system, and the carrier gas system is used to supply air to the spraying device; The spraying device of the spraying system includes a main body and an inlet device. The inlet device is fixed to one end of the main body. The main body has multiple openings at one end opposite to the inlet device. The multiple openings are evenly arranged and the diameter of the openings ranges from 5 to 20 mm. The inlet device is used to introduce liquid into the main body, and the liquid is discharged through multiple openings at the other end of the main body after passing through the main body; a gas inlet is provided on the side of the main body, and the main body is connected to the carrier gas system through the gas inlet, and the carrier gas system introduces gas into the interior of the main body through the gas inlet; The main body of the spraying device is connected to the ultrasonic source. A vibration device is installed inside the main body of the spraying device. The spraying device can vibrate through the ultrasonic waves and under the action of the vibration device, converting electrical energy into mechanical energy. Fluid enters the main body through the inlet device, and air enters the main body through the gas inlet and mixes with the fluid. Under the action of the ultrasonic waves, the main body vibrates up and down, so that the liquid mixed with air is discharged in an atomized manner through the opening at the end of the main body. The main body of the spraying device has a filter screen at one end with multiple openings, which is used to remove messy droplets from the liquid.

2. The fuel cell membrane electrode spraying apparatus according to claim 1, characterized in that: The heating system includes a power supply device, a heating plate, a sintering plate, multiple connecting pipes, and a vacuum device; the heating plate and the power supply device are electrically connected, and the sintering plate is fixed above the heating plate; The sintering plate is connected to the vacuum device, and the plurality of connecting pipes are connected to each other to form a closed loop structure. The plurality of connecting pipes are arranged along the outer contour of the heating plate and are arranged around the outer periphery of the sintering plate.

3. The fuel cell membrane electrode spraying apparatus according to claim 2, characterized in that: The heating plate is made of metal and has a thermal conductivity of 100-160 W / mC.

4. The fuel cell membrane electrode spraying apparatus according to claim 2, characterized in that: The sintering plate is provided with multiple suction cups, and the suction cups are provided with multiple through holes, the diameter of which ranges from 0.2 to 0.8 micrometers.

5. The fuel cell membrane electrode spraying apparatus according to claim 2, characterized in that: A sealing strip is provided on the outer periphery of the sintering plate.

6. The fuel cell membrane electrode spraying apparatus according to claim 2, characterized in that: The vacuum device is externally connected to a filter device, and the vacuum degree of the vacuum device is in the range of 0.01-0.09 MPa.

7. The fuel cell membrane electrode spraying apparatus according to claim 1, characterized in that: The spraying device of the spraying system includes a main body and an inlet device. The inlet device is fixed on the main body at one end away from the opening. A gas inlet is provided on the side of the main body and is connected to the carrier gas system.

8. The fuel cell membrane electrode spraying apparatus according to claim 7, characterized in that: A filter screen is provided at one end of the main body where multiple openings are provided.

9. The fuel cell membrane electrode spraying apparatus according to claim 1, characterized in that: The liquid control system includes a moving shaft, a fixed device, a transmission device, a power device, and an injection device. The power device is electrically connected to the transmission device. One side of the transmission device is connected to the moving shaft, and the moving shaft is movably mounted on the fixed device. The other end of the moving shaft is fixedly connected to the injection device. The power device can drive the transmission device to move the moving shaft and the injection device in a linear reciprocating motion along the extension direction of the moving shaft.

10. The fuel cell membrane electrode spraying apparatus according to claim 1, characterized in that: The drive system includes a spraying track and a control device; the spraying track includes a first guide rail and a second guide rail, the first guide rail is movably mounted on the second guide rail, the installation direction of the first guide rail is perpendicular to the installation direction of the second guide rail, the second guide rail is vertically mounted on the heating system, the control system is electrically connected to the spraying system, and the control system is used to control the movement of the spraying device on the first guide rail.

11. The fuel cell membrane electrode spraying apparatus according to claim 1, characterized in that: The carrier gas system includes a gas cylinder and a flow controller. The outlet of the gas cylinder is connected to the flow controller, and the flow controller is also connected to the spraying device.

12. A spraying method using the fuel cell membrane electrode spraying apparatus according to any one of claims 1-11, characterized in that: include Step 1: Mix Pt / C catalyst, deionized water, isopropanol and ionomer solution, and vibrate ultrasonically at 5-15°C for 1-2 hours to form catalyst liquid; Step 2: Introduce the catalyst liquid into the liquid control system and place the ionomer film layer on the heating system; Step 3: Turn on the heating system and heat it to above 50°C; Step 4: Install an auxiliary film layer with a perforated structure on the surface of the heating system; Step 5: Drive the spraying device to move, while introducing the catalyst liquid and air into the spraying device, and drive the spraying device to vibrate at a frequency of at least 1000 times / second. Step 6: After spraying, turn off the heating system and let the alkaline ionomer film cool for 5-15 minutes.

13. The spraying method according to claim 12, characterized in that: In step three, the temperature of the heating system is raised to above 60°C.

14. The spraying method according to claim 12, characterized in that: The auxiliary film layer is made of tetrafluorosilicone.

15. A fuel cell alkaline ionomer membrane electrode, characterized in that: Prepared by the spraying method according to claim 12.

16. A fuel cell, characterized in that: The fuel cell includes the alkaline ionomer membrane electrode as described in claim 15.

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