Membrane electrode ccm and its preparation system, method and application

Abstract

The application discloses a membrane electrode CCM and a preparation system, method and application thereof, and belongs to the technical field of membrane electrode preparation. The system comprises a plasma flow generating device, a material introducing device and a cooling device. The plasma flow generating device is provided with a material inlet and a material outlet. The material comprises a catalyst and an ionomer resin, and the ionomer resin is melted in the plasma flow generating device. The material introducing device is connected with the material inlet. The proton exchange membrane is placed on the cooling device. Under the action of the cooling device, the material comprising the catalyst and the molten ionomer resin in the plasma flow generating device is deposited on the surfaces of the two sides of the proton exchange membrane to form a catalytic layer after being sprayed out from the material outlet along with the plasma gas flow. Therefore, the production efficiency is improved, the production cost is reduced, VOC emission and chemical waste generation are avoided, the catalyst and the ionomer are uniformly distributed in the catalytic layer, the utilization rate of the catalyst and the ionomer is obviously superior to that of a membrane electrode catalytic layer prepared by a traditional coating method, and the pore structure of the catalytic layer is more favorable for gas permeation.

Description

Technical Field

[0001] This invention belongs to the field of fuel cell technology, specifically relating to a membrane electrode (CCM) and its preparation system, method, and application. Background Technology

[0002] The membrane electrode assembly (MEA) is the core component of a proton exchange membrane fuel cell, playing a crucial role in generating electrical energy and the electrochemical reactions that occur within the fuel cell. The MEA primarily consists of a catalyst layer (CLs), gas diffusion layers (GDLs), and membrane material. When hydrogen and oxygen are passed through the two sides of the MEA respectively, a potential difference is generated under the catalytic action of the catalyst layer, thus producing electrical energy for human use. The electrical performance of the MEA, the consistency between multiple units, the stability of power generation, and its durability directly determine the reliability and lifespan of the fuel cell. Currently, China's mass production capacity for fuel cells is gradually being established, with various manufacturing methods demonstrating different efficiencies, qualities, and costs.

[0003] The mainstream manufacturing processes for catalyst-coated proton exchange membranes (CCMs) are direct coating and transfer printing. The direct coating method involves thoroughly mixing catalyst powder, ionomer resin, alcohol solvent, and water to form a slurry. Then, through a dispersion process, the particles are ground to the required particle size to form an anode or cathode slurry, which is then coated onto both sides of the proton exchange membrane. After drying in a tunnel oven, the CCM is formed. The transfer printing method involves coating the cathode and anode slurries onto another carrier membrane, drying them in a tunnel oven to form cathode and anode coatings, respectively. Then, through hot-press transfer, the cathode and anode coatings are transferred to both sides of the proton exchange membrane to form the desired CCM. The manufacturing process of the membrane electrode also includes cutting the obtained CCM, sandwiching it in the middle using a pre-cut frame membrane of a specific shape, and hot-pressing or cold-pressing to form a 5-layer CCM. Finally, GDLs are attached to both sides of the 5-layer CCM to obtain the finished membrane electrode.

[0004] The aforementioned traditional methods involve processes such as slurry preparation, dispersion, catalyst coating, and transfer printing. Slurry preparation, in particular, is labor-intensive and time-consuming, and its quality determines the quality of the catalyst layer, thus influencing the performance of the membrane electrode assembly (MEA). However, the slurry preparation materials include organic solvents such as alcohols, which present challenges such as catalyst agglomeration, flammability, explosiveness, and high process control difficulty. The catalyst layer formation process during coating suffers from slurry waste, significant VOC emissions, and high energy consumption during drying. In the direct coating method, the solvent in the slurry corrodes and swells the proton exchange membrane, severely impacting the CCM's lifespan and quality stability. The transfer printing method requires high coating transfer efficiency and effectiveness, resulting in low transfer efficiency, defects such as light-transmitting spots and creases, high process control difficulty, reduced MEA quality, and increased manufacturing costs.

[0005] Therefore, existing membrane electrode CCM fabrication technology needs to be improved. Summary of the Invention

[0006] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, one objective of this invention is to provide a membrane electrode CCM and its preparation system, method, and application. Using this system to prepare the membrane electrode CCM eliminates the steps of slurry preparation, coating, and transfer printing in traditional manufacturing processes. The preparation process generates no VOC emissions or chemical waste, significantly shortening the membrane electrode manufacturing process, greatly improving production efficiency, and reducing production costs. Simultaneously, it avoids the corrosive and swelling effects of solvents on the proton exchange membrane in the direct coating method and the defects such as light transmission points and creases that easily occur in the transfer printing method. The catalyst and ionomers in the catalyst layer are uniformly distributed, and their utilization rate is significantly better than that of the membrane electrode catalyst layer prepared by the traditional coating method. The pore structure of the catalyst layer is more conducive to gas permeation, and the thickness of the catalyst layer is easy to control.

[0007] In one aspect of the invention, a system for fabricating a membrane electrode (CCM) is provided. According to an embodiment of the invention, the system comprises:

[0008] A plasma flow generating device is provided with a material inlet and an outlet, wherein the material includes a catalyst and an ionomer resin, and the ionomer resin is melted inside the plasma flow generating device;

[0009] A material inlet device, wherein the material inlet device is connected to the material inlet port;

[0010] A cooling device is provided, on which the proton exchange membrane is placed. Under the action of the cooling device, the material including the catalyst and molten ionomer resin in the plasma flow generator is ejected from the outlet along with the plasma flow and deposited on both sides of the proton exchange membrane to form a catalyst layer.

[0011] Therefore, using this system to prepare membrane electrode CCM can eliminate the traditional manufacturing processes of slurry preparation, coating, and transfer printing. There are no VOC emissions or chemical waste generated during the preparation process, which greatly shortens the membrane electrode manufacturing process, significantly improves production efficiency, and reduces production costs. At the same time, it can avoid the corrosion and swelling effect of solvents on proton exchange membranes in the direct coating method and the defects such as light transmission points and folds that are prone to occur in the transfer method. The catalyst and ionomer in the catalyst layer are evenly distributed, and their utilization rate is significantly better than that of the membrane electrode catalyst layer prepared by the traditional coating method. The pore structure of the catalyst layer is more conducive to gas permeation, and the thickness of the catalyst layer is easy to control.

[0012] In addition, the system for preparing a membrane electrode CCM according to the above embodiments of the present invention may also have the following additional technical features:

[0013] In some embodiments of the present invention, the material inlet includes a catalyst inlet and an ionomer resin inlet, and the material inlet device includes a catalyst inlet device and an ionomer resin inlet device. The catalyst inlet device is connected to the catalyst inlet, and the ionomer resin inlet device is connected to the ionomer resin inlet. Therefore, simultaneous spraying of the catalyst and ionomer resin can be achieved without pre-mixing them uniformly, and alternating plasma spraying of the catalyst and ionomer resin can be realized.

[0014] In some embodiments of the present invention, the ionomer resin introduction device has a preheating component. This allows the ionomer resin to be heated to near its melting point within the device, enabling it to melt rapidly upon entering the plasma flow generator and subsequently mix more uniformly with the catalyst.

[0015] In some embodiments of the present invention, the surface of the cooling device that contacts the proton exchange membrane is a two-dimensional arcuate platform. This allows the proton exchange membrane to be flattened and supported.

[0016] In some embodiments of the present invention, the arc length of the two-dimensional arcuate platform is 50-100 cm, and the radian is 1-10 rad. This allows it to flatten and support the proton exchange membrane.

[0017] In some embodiments of the present invention, the system for preparing a membrane electrode CCM further includes: a feed guide roller disposed upstream of the plasma flow generator and connected to the proton exchange membrane; and a discharge guide roller disposed downstream of the plasma flow generator and used to roll-press the proton exchange membrane forming the catalyst layer. This facilitates continuous production and improves the smoothness and compaction density of the CCM catalyst layer.

[0018] In a second aspect, the present invention provides a method for preparing a membrane electrode CCM using the above-described system. According to an embodiment of the present invention, the method includes: supplying a catalyst and an ionomer resin to a plasma flow generator via a material introduction device; the catalyst and the ionomer resin being ejected from an outlet on the plasma flow generator along with a high-temperature plasma flow; and, under the action of a cooling device, depositing on at least a portion of the upper surface and at least a portion of the lower surface of a proton exchange membrane, thereby forming a catalytic layer on at least a portion of the upper surface and at least a portion of the lower surface of the proton exchange membrane, respectively, to obtain the membrane electrode CCM.

[0019] Therefore, the method of this application for preparing membrane electrode CCM can eliminate the steps of slurry preparation, coating and transfer printing in the traditional manufacturing process. There are no VOC emissions and chemical waste generated during the preparation process, which greatly shortens the manufacturing process of membrane electrode, significantly improves production efficiency and reduces production costs. At the same time, it can avoid the corrosion and swelling effect of solvent on proton exchange membrane in the direct coating method and the defects such as light transmission points and folds that are easy to occur in the transfer method. The catalyst and ionomer in the catalyst layer are uniformly distributed, and their utilization rate is significantly better than that of the membrane electrode catalyst layer prepared by the traditional coating method. The pore structure of the catalyst layer is more conducive to gas permeation, and the thickness of the catalyst layer is easy to control.

[0020] In addition, the method for preparing a membrane electrode CCM using the above-described system according to the above embodiments of the present invention may also have the following additional technical features:

[0021] In some embodiments of the present invention, before the catalyst and the ionomer resin are supplied to the plasma flow generator via the material introduction device, the catalyst and the ionomer resin are pre-mixed outside the system to obtain mixed particles, and then the mixed particles are supplied to the plasma flow generator via the material introduction device. Thus, the catalyst and ionomer resin are uniformly distributed in the catalyst layer of the membrane electrode CCM.

[0022] In some embodiments of the present invention, the catalyst is supplied to the plasma flow generating device via a catalyst introduction device, and the ionomer resin is simultaneously supplied to the plasma flow generating device via an ionomer resin introduction device. Thus, the catalyst and ionomer resin are uniformly distributed in the catalyst layer of the membrane electrode CCM.

[0023] In some embodiments of the present invention, the catalyst is supplied to the plasma flow generator via a catalyst introduction device and then sprayed onto the surface of the proton exchange membrane, while the ionomer resin is supplied to the plasma flow generator via an ionomer resin introduction device and then sprayed onto the surface of the proton exchange membrane; the two processes are performed alternately. Thus, the catalyst and ionomer resin are uniformly distributed in the catalytic layer of the membrane electrode CCM.

[0024] In some embodiments of the present invention, the mass ratio of the ionomer resin to the catalyst is (0.8-1.2):1.

[0025] In some embodiments of the present invention, the temperature of the high-temperature plasma gas flow is 200-1000°C. This ensures that the ionomer resin is completely melted within the plasma flow generator, and the molten ionomer resin can then encapsulate the catalyst.

[0026] In some embodiments of the present invention, the ionomer resin is preheated to 50-300°C before being supplied to the plasma flow generator via the ionomer resin inlet device. This allows the ionomer resin to be heated to near its melting point in the ionomer resin inlet device, enabling it to melt rapidly upon entering the plasma flow generator and mix more uniformly with the catalyst.

[0027] In some embodiments of the present invention, the cooling temperature of the cooling device is -20 to 30°C. This facilitates material deposition on the proton exchange membrane and helps prevent deformation of the proton exchange membrane at high temperatures.

[0028] In some embodiments of the present invention, the catalyst comprises a support and an active material, the active material being loaded on the support, the support comprising carbon particles, and the active material comprising at least one of platinum metal, platinum-cobalt alloy, and iridium oxide.

[0029] In some embodiments of the present invention, the ionomer resin comprises a perfluorosulfonic acid resin, and the ion exchange equivalent of the ionomer resin is 700-1000 g / mol.

[0030] In some embodiments of the present invention, the particle size of the catalyst is 0.2-2.0 μm, and the particle size of the ionomer resin is 1-20 μm.

[0031] In some embodiments of the present invention, the active material comprises platinum metal and / or a platinum-cobalt alloy, and the platinum metal content in one side of the catalyst layer is 0.01-0.5 mg / cm³. 2 .

[0032] In some embodiments of the present invention, the porosity of the catalyst layer is 30%-80%. This facilitates gas permeation.

[0033] In some embodiments of the present invention, the method further includes: rolling the membrane electrode CCM.

[0034] In a third aspect, the present invention provides a membrane electrode CCM. According to embodiments of the present invention, the membrane electrode CCM is prepared using the system or method described above. Consequently, the catalyst and ionomer in the catalyst layer of this membrane electrode CCM are uniformly distributed, and their utilization rates are significantly better than those of membrane electrode catalyst layers prepared by conventional coating methods. The pore structure of the catalyst layer is also more conducive to gas permeation, resulting in a membrane electrode CCM with higher quality, longer lifespan, and lower cost.

[0035] In addition, the membrane electrode CCM according to the above embodiments of the present invention may also have the following additional technical features:

[0036] In some embodiments of the present invention, the active material of the catalyst in the anode and cathode catalyst layers of the membrane electrode CCM includes platinum metal and / or platinum-cobalt alloy, and the platinum metal content in the anode catalyst layer is X mg / cm³. 2 and the platinum metal content Y mg / cm³ in the cathode catalyst layer 2 The following relationship is satisfied: 0 < 3X ≤ Y.

[0037] In some embodiments of the present invention, the thickness of the anode catalyst layer is 0.5-6 μm, and the thickness of the cathode catalyst layer is 1-15 μm.

[0038] In a fourth aspect, the present invention provides a membrane electrode. According to an embodiment of the present invention, the membrane electrode comprises the above-described membrane electrode CCM. Thus, the catalyst and ionomer in the catalytic layer of this membrane electrode are uniformly distributed, and their utilization rate is significantly better than that of the catalytic layer of the membrane electrode prepared by the conventional coating method. The pore structure of the catalytic layer is more conducive to gas permeation, resulting in the membrane electrode having excellent electrical performance and a long lifespan, while also being less expensive.

[0039] In a fifth aspect, the present invention provides a fuel cell. According to an embodiment of the invention, the fuel cell includes the membrane electrode assembly described above. Therefore, the fuel cell exhibits excellent electrical performance and a long lifespan, while also being cost-effective.

[0040] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0041] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0042] Figure 1 This is a schematic diagram of a system structure for fabricating a membrane electrode CCM according to an embodiment of the present invention;

[0043] Figure 2 This is a schematic diagram of a system structure for fabricating a membrane electrode CCM according to another embodiment of the present invention;

[0044] Figure 3 This is a schematic diagram of a system structure for fabricating a membrane electrode CCM according to yet another embodiment of the present invention;

[0045] Figure 4 This is a schematic diagram of the structure of a membrane electrode CCM according to an embodiment of the present invention.

[0046] Figure label:

[0047] 100: Plasma flow generator; 11: Material inlet; 12: Outlet; 111: Catalyst inlet; 112: Ionomer resin inlet; 200: Material inlet device; 21: Catalyst inlet device; 22: Ionomer resin inlet device; 300: Cooling device; 31: Proton exchange membrane; 32: Catalytic layer; 400: Feed guide roller; 500: Discharge guide roller. Detailed Implementation

[0048] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0049] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," 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 explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0050] In this invention, unless otherwise explicitly 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," "over," and "on top" of 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.

[0051] In a first aspect, the present invention provides a system for fabricating a membrane electrode (CCM). According to an embodiment of the invention, reference is made to... Figure 1 The system includes: a plasma flow generator 100, a material introduction device 200, and a cooling device 300.

[0052] According to some embodiments of the present invention, the plasma flow generator 100 is provided with a material inlet 11 and an outlet 12, and is adapted to supply a material including a catalyst and an ionomer resin into the plasma flow generator 100 through the material inlet 11. Under the action of the high-temperature plasma flow, the ionomer resin melts in the plasma flow generator 100, and then the material including the catalyst and the molten ionomer resin can be ejected from the outlet 12 along with the high-temperature plasma flow. It should be noted that those skilled in the art can select the specific type of the plasma flow generator 100 according to actual needs, as long as the above functions can be achieved. At the same time, the specific type of plasma flow generated by the plasma flow generator 100 is not particularly limited, and those skilled in the art can select it according to actual needs. For example, it can be at least one of air, carbon dioxide, argon, and nitrogen, preferably at least one of air and nitrogen.

[0053] According to some embodiments of the present invention, the material introduction device 200 is connected to the material inlet 11 and is adapted to convey materials including a catalyst and an ionomer resin to the material inlet 11. It should be noted that those skilled in the art can select the specific type of the material introduction device 200 according to actual needs, as long as it can achieve the above-mentioned functions; for example, the material introduction device 200 is a material introduction pipe. Referring to some specific embodiments of the present invention... Figure 2-3The material inlet 11 includes a catalyst inlet 111 and an ionomer resin inlet 112. The material inlet device 200 includes a catalyst inlet device 21 and an ionomer resin inlet device 22. The catalyst inlet device 21 is connected to the catalyst inlet 111, and the ionomer resin inlet device 22 is connected to the ionomer resin inlet 112. Therefore, simultaneous spraying of the catalyst and ionomer resin can be achieved without pre-mixing them evenly, and alternating plasma spraying of the catalyst and ionomer resin can be realized.

[0054] Furthermore, the ionomer resin introduction device 22 has a preheating component (not shown), which is suitable for heating the ionomer resin to near its melting point in the ionomer resin introduction device 22, so that it can melt rapidly after entering the plasma flow generator 100, and subsequently mix more evenly with the catalyst. It should be noted that those skilled in the art can select the specific type of preheating component according to actual needs, as long as the heating function can be achieved, which will not be elaborated here.

[0055] According to some embodiments of the present invention, the proton exchange membrane 31 is placed on a cooling device 300. Under the action of the cooling device 300, the material including the catalyst and molten ionomer resin in the plasma flow generator 100 is ejected from the outlet 12 with the plasma flow and deposited on one side surface of the proton exchange membrane 31 to form a catalyst layer 32. Then the proton exchange membrane 31 is flipped over, and a catalyst layer 32 is formed on the other side surface in the same manner to obtain the membrane electrode CCM. Figure 4 The inventors discovered that, on the one hand, materials are more easily deposited under the action of the cooling device; on the other hand, the cooling device can prevent the proton exchange membrane from deforming at high temperatures. It should be noted that those skilled in the art can select the specific type of cooling device 300 according to actual needs, as long as it can achieve the above-mentioned functions. Meanwhile, the specific type of proton exchange membrane 31 is not particularly limited; those skilled in the art can select it according to actual needs. For example, it can be Nafion-H, a nano-carbon composite proton exchange membrane, a graphite composite proton exchange membrane, a polyaniline composite proton exchange membrane, or a polypyrrole composite proton exchange membrane.

[0056] Furthermore, the surface in the cooling device 300 that contacts the proton exchange membrane 31 is a two-dimensional arcuate platform with a length of 50-100 cm and an arc radius of 1-10 rad. The inventors have discovered that the arcuate platform design of the cooling device can flatten and support the proton exchange membrane, which is beneficial to the uniform distribution of the catalyst and ionomer resin.

[0057] Therefore, using this system to prepare membrane electrode CCM can eliminate the traditional manufacturing processes of slurry preparation, coating, and transfer printing. There are no VOC emissions or chemical waste generated during the preparation process, which greatly shortens the membrane electrode manufacturing process, significantly improves production efficiency, and reduces production costs. At the same time, it can avoid the corrosion and swelling effect of solvents on proton exchange membranes in the direct coating method and the defects such as light transmission points and folds that are prone to occur in the transfer method. The catalyst and ionomer in the catalyst layer are evenly distributed, and their utilization rate is significantly better than that of the membrane electrode catalyst layer prepared by the traditional coating method. The pore structure of the catalyst layer is more conducive to gas permeation, and the thickness of the catalyst layer is easy to control.

[0058] According to some embodiments of the present invention, reference Figure 3 The system further includes: an infeed guide roller 400 and an outfeed guide roller 500.

[0059] According to some embodiments of the present invention, reference Figure 3 The feed guide roller 400 is located upstream of the plasma flow generator 100 and is connected to the proton exchange membrane 31, which is conducive to realizing continuous production.

[0060] According to some embodiments of the present invention, reference Figure 3 The discharge guide roller 500 is located downstream of the plasma flow generator 100 and is suitable for rolling the proton exchange membrane 31 forming the catalyst layer 32, thereby improving the flatness and compaction density of the catalyst layer 32. Specifically, the discharge guide roller 500 is a pair of stainless steel rollers that roll the proton exchange membrane 31 forming the catalyst layer 32, and the rolling pressure is 10-200 kg, preferably 80-150 kg.

[0061] In a second aspect, the present invention provides a method for preparing a membrane electrode (CCM) using the above-described system. According to an embodiment of the invention, the method includes: supplying a catalyst and an ionomer resin to a plasma flow generator via a material introduction device; ejecting the catalyst and ionomer resin from an outlet on the plasma flow generator along with a high-temperature plasma flow; and depositing them on at least a portion of the upper surface and at least a portion of the lower surface of the proton exchange membrane under the action of a cooling device.

[0062] In this step, the catalyst and ionomer resin are supplied to the plasma flow generator via a material introduction device. The ionomer resin melts within the plasma flow generator, and the catalyst and molten ionomer resin are ejected from the outlet of the plasma flow generator along with the high-temperature plasma gas flow. Under the action of a cooling device, they are deposited on at least a portion of the upper and lower surfaces of the proton exchange membrane, thereby forming a catalyst layer with a porosity of 30%-80%, preferably 45-65%, on at least a portion of the upper and lower surfaces of the proton exchange membrane, respectively, to obtain the membrane electrode chemiluminescence (CCM). It should be noted that the specific types of plasma gas flow and proton exchange membrane are the same as described above and will not be repeated here.

[0063] According to some embodiments of the present invention, before the catalyst and ionomer resin are supplied to the plasma flow generator via the material introduction device, the catalyst and ionomer resin are mixed outside the system to obtain mixed particles. The mixed particles are then supplied to the plasma flow generator via the material introduction device. After the ionomer resin is fully melted by the high-temperature plasma gas flow, it coats the surface of the catalyst. The catalyst with a uniformly coated ionomer film is ejected with the high-temperature plasma gas flow and deposited on the surface of the proton exchange membrane under the action of the cooling device.

[0064] According to some embodiments of the present invention, a catalyst is supplied to a plasma flow generator via a catalyst introduction device, and an ionomer resin is simultaneously supplied to the plasma flow generator via an ionomer resin introduction device. The ionomer resin is fully melted under the action of a high-temperature plasma flow. After the molten ionomer resin and catalyst are mixed in the plasma flow generator, the molten ionomer resin coats the catalyst surface. The catalyst with a uniformly coated ionomer film is ejected with the high-temperature plasma flow and deposited on the proton exchange membrane surface under the action of a cooling device.

[0065] According to some embodiments of the present invention, the catalyst is supplied to the plasma flow generator via a catalyst introduction device and then sprayed onto the surface of the proton exchange membrane, and the ionomer resin is supplied to the plasma flow generator via an ionomer resin introduction device and then sprayed onto the surface of the proton exchange membrane, with the two processes performed alternately. Specifically, the catalyst can be sprayed onto the surface of the proton exchange membrane first, followed by the spraying of the ionomer resin. The molten ionomer resin can coat the catalyst on the proton exchange membrane, and subsequent spraying processes can be performed alternately in this order. Alternatively, the ionomer resin can be sprayed onto the surface of the proton exchange membrane first, followed by the spraying of the catalyst. The molten ionomer resin on the proton exchange membrane can coat the deposited catalyst, and subsequent spraying processes can be performed alternately in this order.

[0066] Furthermore, the mass ratio of the ionomer resin to the catalyst is (0.8-1.2):1, and the temperature of the high-temperature plasma gas flow is 200-1000°C, preferably 300-600°C, and the cooling temperature of the cooling device is -20-30°C.

[0067] Furthermore, before supplying the ionomer resin to the plasma flow generator via the ionomer resin introduction device, the ionomer resin introduction device is preheated to 50-300°C, preferably 100-160°C. The inventors have discovered that by preheating the ionomer resin to the above temperature range in the ionomer resin introduction device, the ionomer resin can be heated to near its melting point, allowing it to melt rapidly upon entering the plasma flow generator and mix more uniformly with the catalyst.

[0068] It should be noted that those skilled in the art can select the specific types of catalyst and ionomer resin according to actual needs. For example, the catalyst includes a support and an active material, with the active material supported on the support, wherein the support includes carbon particles, and the active material includes at least one of platinum metal, platinum-cobalt alloy, and iridium oxide; the ionomer resin includes perfluorosulfonic acid resin. Further, the ion exchange equivalent of the above-mentioned ionomer resin is 700-1000 g / mol. Further, the particle size of the above-mentioned catalyst is 0.2-2.0 μm, and the particle size of the ionomer resin is 1-20 μm.

[0069] According to some embodiments of the present invention, the active material of the catalyst includes platinum metal and / or platinum-cobalt alloy, and the platinum metal content in the single-sided catalyst layer is 0.01-0.5 mg / cm³. 2 The inventors discovered that if the platinum content is too low, the power density of the membrane electrode will decrease, failing to provide sufficient electrochemical reaction space; while if the platinum content is too high, the product cost will increase.

[0070] Furthermore, the above method also includes: rolling the above-mentioned membrane electrode CCM under a rolling pressure of 10-200 kg, preferably 80-150 kg. This helps to improve the smoothness and compaction density of the catalyst layer.

[0071] The inventors discovered that the method described in this application for preparing membrane electrode CCMs eliminates the steps of slurry preparation, coating, and transfer printing in traditional manufacturing processes. The preparation process generates no VOC emissions or chemical waste, significantly shortening the membrane electrode manufacturing process, greatly improving production efficiency, and reducing production costs. It also avoids the corrosive and swelling effects of solvents on the proton exchange membrane in the direct coating method and the defects such as light transmission points and creases that easily occur in the transfer printing method. The catalyst and ionomers in the catalyst layer are evenly distributed, and their utilization rate is significantly better than that of the membrane electrode catalyst layer prepared by the traditional coating method. The pore structure of the catalyst layer is more conducive to gas permeation, and the thickness of the catalyst layer is easy to control.

[0072] In a third aspect, the present invention provides a membrane electrode CCM. According to embodiments of the present invention, the membrane electrode CCM is prepared using the system or method described above. Consequently, the catalyst and ionomer in the catalyst layer of the membrane electrode CCM are uniformly distributed, and their utilization rates are significantly better than those of membrane electrode catalyst layers prepared by conventional coating methods. The pore structure of the catalyst layer is also more conducive to gas permeation, resulting in a membrane electrode CCM with higher quality, longer lifespan, and lower cost.

[0073] Furthermore, the active material of the catalyst in the anode and cathode catalyst layers of the aforementioned membrane electrode CCM includes platinum metal and / or platinum-cobalt alloy, with the platinum metal content in the anode catalyst layer being X mg / cm³. 2 Platinum metal content Y mg / cm³ in the cathode catalyst layer 2 The following relationship must be satisfied: 0 < 3X ≤ Y. The inventors discovered that a catalyst layer combination that satisfies the above relationship can maximize the utilization of platinum metal particles in the catalyst layer, provide sufficient electrochemical reaction sites, meet the membrane electrode power density requirements, and reduce the amount of catalyst used.

[0074] Furthermore, the thickness of the anode catalyst layer is 0.5-6 μm, and the thickness of the cathode catalyst layer is 1-15 μm. The inventors discovered that if the thickness of the anode catalyst layer is too small, the platinum metal content is insufficient, affecting the power density of the battery; while if the thickness of the anode catalyst layer is too large, it results in catalyst waste. Similarly, if the thickness of the cathode catalyst layer is too small, it affects the power density of the battery; while if the thickness of the cathode catalyst layer is too large, it results in catalyst waste.

[0075] It should be noted that the features and advantages described for the system or method for preparing the membrane electrode CCM described above also apply to this membrane electrode CCM, and will not be repeated here.

[0076] In a fourth aspect, the present invention provides a membrane electrode. According to an embodiment of the present invention, the membrane electrode includes the aforementioned membrane electrode CCM. Thus, the catalyst and ionomer in the catalytic layer of this membrane electrode are uniformly distributed, and their utilization rate is significantly better than that of the catalytic layer of a membrane electrode prepared by a conventional coating method. The pore structure of the catalytic layer is more conducive to gas permeation, resulting in excellent electrical performance and a long lifespan for the membrane electrode, while also being cost-effective. It should be noted that the features and advantages described for the aforementioned membrane electrode CCM also apply to this membrane electrode, and will not be repeated here.

[0077] In a fifth aspect, the present invention provides a fuel cell. According to an embodiment of the invention, the fuel cell includes the membrane electrode assembly described above. Therefore, the fuel cell exhibits excellent electrical performance and a long lifespan, while also being cost-effective. It should be noted that the features and advantages described for the membrane electrode assembly also apply to this fuel cell, and will not be repeated here.

[0078] The embodiments of the present invention are described in detail below. It should be noted that the embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. In addition, unless otherwise specified, all reagents used in the following embodiments are commercially available or can be synthesized according to the methods described herein or known to others. For reaction conditions not listed, they are also readily available to those skilled in the art.

[0079] Example 1

[0080] use Figure 3 The system shown is used to prepare a membrane electrode (CCM). The preparation steps are as follows: A catalyst is supplied to a plasma flow generator via a catalyst introduction device. Simultaneously, an ionomer resin (a perfluorosulfonic acid resin solid particle with an ion exchange equivalent of 850-900 g / mol and a particle size distribution of D90 = 5 μm) is supplied to the plasma flow generator via an ionomer resin introduction device (the plasma is N2, the plasma flow temperature is 350℃, and the preheating temperature of the ionomer resin introduction device is 160℃). The mass ratio of catalyst to ionomer resin is 1:0.8. The ionomer resin is fully melted under the action of the high-temperature plasma flow. After the molten ionomer resin and catalyst are mixed in the plasma flow generator, the mixture coats the catalyst. On the surface, a catalyst uniformly coated with an ionomer film is ejected by a high-temperature plasma gas stream and, under the action of a cooling device (table surface arc length 50cm, arc radius 1rad, temperature 0℃), an anodic catalyst layer (anode catalyst is a mixed catalyst of platinum and iridium oxide supported on a carbon support, with a particle size distribution D90 = 1.0μm) is deposited on the upper surface of the proton exchange membrane. A cathode catalyst layer (cathode catalyst is a Pt catalyst supported on a carbon support, with a particle size distribution D90 = 1.0μm) is deposited on the lower surface of the proton exchange membrane. Both the cathode and anodic catalyst layers are formed in a single spraying process, followed by roll pressing (roller pressure 50kg) to obtain the membrane electrode CCM (cathode catalyst layer thickness 9μm, platinum metal content 0.35mg / cm²). 2 The thickness of the anode catalyst layer is 2 μm, and the platinum metal content is 0.05 mg / cm³. 2 The porosity of both the deposited anode and cathode catalyst layers is 60%.

[0081] After the obtained semi-finished CCM is cut into pieces of a certain shape, the cut CCM is sandwiched in the middle with two layers of frame film. After encapsulation, a 5-layer CCM is obtained. The two sides of the obtained 5-layer CCM are then bonded and assembled with GDL to obtain the hydrogen fuel cell membrane electrode.

[0082] Example 2

[0083] use Figure 3 The system shown is used to prepare a membrane electrode (CCM). The preparation steps are as follows: The catalyst is supplied to a plasma flow generator (the plasma is N2, the plasma temperature is 450℃, and the preheating temperature of the ionomer resin introduction device is 170℃) via a catalyst introduction device. Simultaneously, the ionomer resin (the ionomer resin is perfluorosulfonic acid resin solid particles with an ion exchange equivalent of 850-900 g / mol and a particle size distribution of D90 = 5 μm) is supplied to the plasma flow generator via an ionomer resin introduction device. The mass ratio of catalyst to ionomer resin is 1:1. The ionomer resin is fully melted under the action of the high-temperature plasma flow. After the molten ionomer resin and catalyst are mixed in the plasma flow generator, they coat the surface of the catalyst. On the surface of the proton exchange membrane, a catalyst uniformly coated with an ionomer film is ejected by a high-temperature plasma gas stream. Under the action of a cooling device (table surface arc length 60cm, arc radius 3rad, temperature -5℃), an anodic catalyst layer (anode catalyst is a carbon-supported platinum and iridium oxide catalyst with a particle size distribution D90 = 0.85μm) is deposited. On the lower surface of the proton exchange membrane, a cathode catalyst layer (cathode catalyst is a carbon-supported Pt catalyst with a particle size distribution D90 = 1.0μm) is deposited. Both the cathode and anodic catalyst layers are formed in a single spraying process, followed by roll pressing (roller pressure 60kg) to obtain the membrane electrode mulch (CCM) (cathode catalyst layer thickness 7μm, platinum metal content 0.30mg / cm³). 2 The thickness of the anode catalyst layer is 2 μm, and the platinum metal content is 0.05 mg / cm³. 2 The porosity of both the deposited anode and cathode catalyst layers is 55%.

[0084] After the obtained semi-finished CCM is cut into pieces of a certain shape, the cut CCM is sandwiched in the middle with two layers of frame film. After encapsulation, a 5-layer CCM is obtained. The two sides of the obtained 5-layer CCM are then bonded and assembled with GDL to obtain the hydrogen fuel cell membrane electrode.

[0085] Example 3

[0086] use Figure 3The system shown is used to prepare a membrane electrode (CCM). The preparation steps are as follows: The catalyst is supplied to a plasma flow generator (the plasma is N2, the plasma temperature is 490℃, and the ionomer resin introduction device is preheated to 170℃) via a catalyst introduction device. Simultaneously, the ionomer resin (a perfluorosulfonic acid resin solid particle with an ion exchange equivalent of 850-900 g / mol and a particle size distribution of D90 = 10 μm) is supplied to the plasma flow generator via an ionomer resin introduction device. The mass ratio of catalyst to ionomer resin is 1:0.85. The ionomer resin is fully melted under the action of the high-temperature plasma flow. After the molten ionomer resin and catalyst are mixed in the plasma flow generator, they are coated onto the catalyst. On the surface of the catalyst, a uniformly coated ionomer film is ejected by a high-temperature plasma gas stream. Under the action of a cooling device (table surface arc length 70cm, arc radius 5rad, temperature -10℃), an anodic catalyst layer (anode catalyst is a carbon-supported platinum and iridium oxide catalyst with a particle size distribution D90 = 0.9μm) is deposited on the upper surface of the proton exchange membrane. A cathode catalyst layer (cathode catalyst is a carbon-supported Pt catalyst with a particle size distribution D90 = 1.0μm) is deposited on the lower surface of the proton exchange membrane. Both the cathode and anodic catalyst layers are formed in a single spraying process, followed by roll pressing (roller pressure 70kg) to obtain the membrane electrode CCM (cathode catalyst layer thickness 7μm, platinum metal content 0.30mg / cm²). 2 The thickness of the anode catalyst layer is 2 μm, and the platinum metal content is 0.05 mg / cm³. 2 The porosity of both the deposited anode and cathode catalyst layers is 66%.

[0087] After the obtained semi-finished CCM is cut into pieces of a certain shape, the cut CCM is sandwiched in the middle with two layers of frame film. After encapsulation, a 5-layer CCM is obtained. The two sides of the obtained 5-layer CCM are then bonded and assembled with GDL to obtain the hydrogen fuel cell membrane electrode.

[0088] Example 4

[0089] use Figure 3The system shown is used to prepare a membrane electrode (CCM). The preparation steps are as follows: The catalyst is supplied to the plasma flow generator (the plasma is air, the plasma flow temperature is 350℃, and the ionomer resin introduction device is preheated to 160℃) via a catalyst introduction device. Simultaneously, the ionomer resin (the ionomer resin is perfluorosulfonic acid resin solid particles with an ion exchange equivalent of 850-900 g / mol and a particle size distribution of D90 = 5 μm) is supplied to the plasma flow generator via the ionomer resin introduction device. The mass ratio of catalyst to ionomer resin is 1:0.95. The ionomer resin is fully melted under the action of the high-temperature plasma flow. After the molten ionomer resin and catalyst are mixed in the plasma flow generator, they are coated onto the catalyst. On the surface of the catalyst, a uniformly coated ionomer film is ejected by a high-temperature plasma gas stream. Under the action of a cooling device (tabletop arc length 80cm, arc radius 7rad, temperature 0℃), an anodic catalyst layer (anode catalyst is a carbon-supported platinum and iridium oxide catalyst with a particle size distribution D90 = 0.9μm) is deposited on the upper surface of the proton exchange membrane. A cathode catalyst layer (cathode catalyst is a carbon-supported Pt catalyst with a particle size distribution D90 = 1.0μm) is deposited on the lower surface of the proton exchange membrane. Both the cathode and anodic catalyst layers are formed in a single spraying process, followed by roll pressing (roller pressure 80kg) to obtain the membrane electrode mulch (CCM) (cathode catalyst layer thickness 7μm, platinum metal content 0.25mg / cm²). 2 The thickness of the anode catalyst layer is 2 μm, and the platinum metal content is 0.05 mg / cm³. 2 The porosity of both the deposited anode and cathode catalyst layers is 66%.

[0090] After the obtained semi-finished CCM is cut into pieces of a certain shape, the cut CCM is sandwiched in the middle with two layers of frame film. After encapsulation, a 5-layer CCM is obtained. The two sides of the obtained 5-layer CCM are then bonded and assembled with GDL to obtain the hydrogen fuel cell membrane electrode.

[0091] Example 5

[0092] use Figure 3The system shown is used to prepare a membrane electrode (CCM). The preparation steps are as follows: The catalyst is supplied to the plasma flow generator (the plasma is air, the plasma flow temperature is 350℃, and the ionomer resin introduction device is preheated to 160℃) via a catalyst introduction device. Simultaneously, the ionomer resin (the ionomer resin is perfluorosulfonic acid resin solid particles with an ion exchange equivalent of 850-900 g / mol and a particle size distribution of D90 = 5 μm) is supplied to the plasma flow generator via the ionomer resin introduction device. The mass ratio of catalyst to ionomer resin is 1:0.9. The ionomer resin is fully melted under the action of the high-temperature plasma flow. After the molten ionomer resin and catalyst are mixed in the plasma flow generator, they coat the catalyst. On the surface, a catalyst uniformly coated with an ionomer film is ejected by a high-temperature plasma gas stream and, under the action of a cooling device (table surface arc length 100cm, arc radius 10rad, temperature 0℃), an anodic catalyst layer (anodic catalyst is a carbon-supported platinum and iridium oxide catalyst with a particle size distribution D90 = 0.9μm) is deposited on the upper surface of the proton exchange membrane. A cathode catalyst layer (cathode catalyst is a carbon-supported Pt catalyst with a particle size distribution D90 = 1.0μm) is deposited on the lower surface of the proton exchange membrane. Both the cathode and anodic catalyst layers are formed in a single spraying process, followed by roll pressing (roller pressure 80kg) to obtain the membrane electrode CCM (cathode catalyst layer thickness 7μm, platinum metal content 0.20mg / cm²). 2 The thickness of the anode catalyst layer is 2 μm, and the platinum metal content is 0.03 mg / cm³. 2 The porosity of both the deposited anode and cathode catalyst layers is 66%.

[0093] After the obtained semi-finished CCM is cut into pieces of a certain shape, the cut CCM is sandwiched in the middle with two layers of frame film. After encapsulation, a 5-layer CCM is obtained. The two sides of the obtained 5-layer CCM are then bonded and assembled with GDL to obtain the hydrogen fuel cell membrane electrode.

[0094] Comparative Example

[0095] Following the conventional membrane electrode method, the same catalysts and ionomers as in Example 5 were used for both the cathode and anode, with a mass ratio of 1:0.9. Cathode and anode slurries were prepared using solvents such as water and ethanol, respectively, and coated onto the carrier membrane. The anode and cathode catalyst layers were obtained by drying in a tunnel furnace. The Pt metal loading of the anode catalyst layer was 0.05 mg / cm³. 2 The cathode catalyst layer has a thickness of 2 μm and a Pt metal loading of 0.3 mg / cm³. 2 The thickness is 7μm. Then, the anode and cathode catalyst layers are transferred to both sides of the proton exchange membrane to obtain CCM.

[0096] After the obtained semi-finished CCM is cut into pieces of a certain shape, the cut CCM is sandwiched in the middle with two layers of frame film. After encapsulation, a 5-layer CCM is obtained. The two sides of the obtained 5-layer CCM are then bonded and assembled with GDL to obtain the hydrogen fuel cell membrane electrode.

[0097] Finally, the membrane electrode products of Examples 1 to 5 and the comparative examples were subjected to electrical performance tests and durability tests, and the test results are shown in Table 1.

[0098] Power density calculation method: Based on the polarization curves tested under hydrogen air conditions of 75℃ and anode / cathode back pressure of 250 / 260 kPa, at 2.0 A / cm 2 Record the voltage; power density = current density * voltage.

[0099] Durability testing method: Membrane electrode life test, referring to national standard GB / T 38914-2020 (test until the membrane electrode meets the failure criterion: 1A / cm). 2 (Voltage attenuation of 10%).

[0100] Table 1. Electrical performance data of membrane electrodes prepared in Examples 1-5 and comparative examples.

[0101]

[0102] Conclusion: Compared with the conventional method used in the comparative examples, the membrane electrodes prepared in Examples 1-5 eliminate the steps of slurry preparation, coating, and transfer printing. The preparation process generates no VOC emissions or chemical waste, significantly shortening the membrane electrode manufacturing process. Furthermore, Table 1 shows that the membrane electrodes prepared in Examples 1-5 have comparable power density and durability to those prepared in the comparative examples. This demonstrates that the membrane electrode preparation process of this application can improve production efficiency while maintaining the power density and durability of the membrane electrodes.

[0103] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0104] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A system for preparing a membrane electrode CCM, characterized in that, include: A plasma flow generating device is provided with a material inlet and an outlet, wherein the material is a catalyst and an ionomer resin, and the ionomer resin is melted inside the plasma flow generating device; A material inlet device, wherein the material inlet device is connected to the material inlet port; A cooling device is provided, on which a proton exchange membrane is placed. Under the action of the cooling device, the material including the catalyst and molten ionomer resin in the plasma flow generator is ejected from the outlet along with the plasma flow and deposited on both sides of the proton exchange membrane to form a catalyst layer. The material inlet is composed of a catalyst inlet and an ionomer resin inlet, and the material inlet device is composed of a catalyst inlet device and an ionomer resin inlet device. The catalyst inlet device is connected to the catalyst inlet, and the ionomer resin inlet device is connected to the ionomer resin inlet. The ionomer resin introduction device has a preheating component; The preheating component can heat the ionomer resin to near its melting point in the ionomer resin inlet device, so that it can melt rapidly after entering the plasma flow generator. The surface of the cooling device that contacts the proton exchange membrane is a two-dimensional arcuate platform. The arc length of the two-dimensional arc-shaped platform is 50-100cm, and the arc degree is 1-10rad; The system for preparing the membrane electrode CCM further includes: A feed guide roller is located upstream of the plasma flow generator and is connected to the proton exchange membrane. The discharge guide roller is located downstream of the plasma flow generator and is used to roll the proton exchange membrane forming the catalyst layer.

2. A method for preparing a membrane electrode CCM using the system of claim 1, characterized in that, include: The catalyst and the ionomer resin are supplied to the plasma flow generator via a material introduction device. The catalyst and the ionomer resin are ejected from the outlet of the plasma flow generator along with the high-temperature plasma flow and deposited on at least part of the upper surface and at least part of the lower surface of the proton exchange membrane under the action of the cooling device, so as to form a catalytic layer on at least part of the upper surface and at least part of the lower surface of the proton exchange membrane, respectively, to obtain the membrane electrode CCM. Before supplying the ionomer resin to the plasma flow generator via the ionomer resin inlet device, the ionomer resin inlet device is preheated to 50-300°C.

3. The method according to claim 2, characterized in that, Before the catalyst and ionomer resin are supplied to the plasma flow generator via the material introduction device, the catalyst and the ionomer resin are mixed outside the system to obtain mixed particles, and then the mixed particles are supplied to the plasma flow generator via the material introduction device.

4. The method according to claim 2, characterized in that, The catalyst is supplied to the plasma flow generator via a catalyst introduction device, and the ionomer resin is supplied to the plasma flow generator via an ionomer resin introduction device.

5. The method according to claim 2, characterized in that, The catalyst is supplied to the plasma flow generator via a catalyst introduction device and then sprayed onto the surface of the proton exchange membrane. The ionomer resin is supplied to the plasma flow generator via an ionomer resin introduction device and then sprayed onto the surface of the proton exchange membrane. The two processes are performed alternately.

6. The method according to claim 2, characterized in that, The mass ratio of the ionomer resin to the catalyst is (0.8-1.2):1; Optionally, the temperature of the high-temperature plasma gas flow is 200-1000℃; Optionally, the cooling temperature of the cooling device is -20~30℃; Optionally, the catalyst comprises a support and an active material, the active material being supported on the support, and the support comprising carbon particles, the active material comprising at least one of platinum metal, platinum-cobalt alloy, and iridium oxide; Optionally, the catalyst has a particle size of 0.2-2.0 μm, and the ionomer resin has a particle size of 1-20 μm; Optionally, the active material comprises platinum metal and / or a platinum-cobalt alloy, and the platinum metal content in one side of the catalyst layer is 0.01-0.5 mg / cm³. 2 ; Optionally, the porosity of the catalyst layer is 30%-80%; Optionally, the ionomer resin includes a perfluorosulfonic acid resin, and the ion exchange equivalent of the ionomer resin is 700-1000 g / mol; Optionally, it further includes: rolling the membrane electrode CCM.

7. A membrane electrode CCM, characterized in that, The membrane electrode CCM is prepared using the system described in claim 1 or the method described in any one of claims 2-6.

8. The membrane electrode CCM according to claim 7, characterized in that, The active materials of the catalyst in the anode and cathode catalyst layers of the membrane electrode CCM include platinum metal and / or platinum-cobalt alloy, and the platinum metal content in the anode catalyst layer is X mg / cm³. 2 and the platinum metal content Y mg / cm³ in the cathode catalyst layer 2 The following relationship must be satisfied: 0 < 3X ≤ Y; Optionally, the thickness of the anode catalyst layer is 0.5-6 μm, and the thickness of the cathode catalyst layer is 1-15 μm.

9. A membrane electrode, characterized in that, Includes the membrane electrode CCM as described in claim 8.

10. A fuel cell, characterized in that, Includes the membrane electrode as described in claim 9.

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