Device and method for improving slurry supply stability in water electrolysis membrane electrode preparation

Abstract

The invention relates to a device and method for improving slurry supply stability in water electrolysis membrane electrode preparation, a slurry container is arranged on a magnetic stirrer and is connected with a connecting tee joint through a first pipeline, the first pipeline is provided with a first electromagnetic valve, a sample injector system comprises a sample injection cylinder and a push rod, the push rod is inserted into the sample injection cylinder in a pluggable manner, and the push rod is provided with a second electromagnetic valve. The output end of the sample injection cylinder is connected with the connecting tee joint through a second pipeline, a second electromagnetic valve is arranged on the second pipeline, connecting assemblies are arranged at the two ends of the sleeve assembly, the connecting assembly at the input end of the sleeve assembly is connected with the connecting tee joint through a third pipeline, and the connecting assembly at the output end of the sleeve assembly is connected with the discharging pipeline. A third electromagnetic valve and a material pump are arranged on the discharging pipeline, the sleeve assembly comprises a temperature adjusting sleeve and a slurry pipeline, the third pipeline, the slurry pipeline and the discharging pipeline are sequentially communicated, and a sleeve tee joint is arranged on the temperature adjusting sleeve and connected with a cooling-water machine. According to the invention, stable slurry supply in the preparation process of the water electrolysis membrane electrode can be ensured.

Description

Technical Field

[0001] The invention relates to the field of water electrolysis membrane electrode preparation, in particular to a device and method for improving slurry feeding stability in water electrolysis membrane electrode preparation. Background Art

[0002] Membrane Electrode Assembly (MEA) is the core component of proton exchange membrane water electrolyzer, and its preparation process has an important impact on the performance and life of the electrolyzer. According to the different catalyst supports, there are two main methods: catalyst preparation on substrate (Catalyst-Coated Substrate, CCS) and catalyst preparation on membrane (Catalyst-Coated Membrane, CCM). In addition to CCS and CCM methods, there are some other membrane electrode preparation process routes, such as electrochemical deposition, sputtering, direct coating, etc.

[0003] The above methods involving membrane electrode preparation all require the pre-preparation of precious metal catalyst slurry. During the slurry preparation process and membrane electrode preparation process, due to factors such as poor stirring of the feed tank, too long feed pipeline, too large feed pipeline diameter, high specific gravity of precious metal catalyst, and high working environment temperature, it is easy to cause the slurry state in the pipeline to be unstable, which in turn leads to slurry flow interruption, siphoning, slurry backflow, and obvious catalyst slurry sedimentation in the pipeline, thereby affecting the quality of the membrane electrode, and then affecting the performance of the membrane electrode, and even causing the failure of the membrane electrode. In addition, because the gas can be compressed, if there are bubbles in the slurry, the slurry pipeline will form a "positive pressure" or "negative pressure" due to the presence of bubbles. The on and off moment of the pipeline solenoid valve will affect the discharge / suction, which will cause flow differences. If the flow difference is superimposed on the slurry sedimentation, it will further affect the consistency of the designed load. For example, the design load per unit area of ​​the membrane electrode size is 1.5mg / cm 2 ±4%, due to settlement, the local load will exceed or fail to meet the standard.

[0004] Currently, there are not many patents and solutions in the field of fuel cells for enhancing or improving the stability of slurry during preparation, storage and feeding.

[0005] CN114243034B discloses an anti-precipitation catalyst slurry and a preparation method thereof, which mainly forms a fuel cell catalyst slurry by adding honeycomb nanopowders to the catalyst slurry, and adopts electrostatic mixing, freeze drying and a variety of dispersion methods to improve electrical performance and stability. Its disadvantages are: 1. Not all catalyst slurry systems are suitable for adding nanoporous carbon. For the preparation of membrane electrode slurry in scenarios with high durability requirements, graphitized carbon carriers are often used as precious metal catalyst carriers. At this time, adding nanoporous carbon is obviously inappropriate; 2. A freeze drying process is added, which is only suitable for laboratory-level catalyst slurry preparation, not suitable for large-scale application of fuel cell membrane electrode production lines, and will reduce the continuous production efficiency of production line membrane electrodes.

[0006] Patent CN113505518B discloses a simplified modeling method for simulating the preparation process of catalyst slurry for proton exchange membrane fuel cells, which ignores the role of ionomers and establishes a mathematical model of the kinetic behavior of catalyst particles in solvents under external action. From the perspective of modeling and simulation, the mechanism of multi-component interaction within the catalyst slurry is discussed, providing guidance for the preparation of fuel cell catalyst slurries with better performance. Its shortcomings are: 1. The role of ionomers as adhesives in the preparation process of fuel cell catalyst slurry is ignored. The content of ionomers, that is, the core parameter N / C ratio of the fuel cell catalyst system design, often determines the approximate range of catalyst viscosity and the basic performance of the membrane electrode; 2. The boundary parameters involved in the simple simulation process are limited, so the catalyst slurry stability index e is different from the actual catalyst stability.

[0007] The above patents do not involve the solution to prevent slurry sedimentation in the water electrolysis membrane electrode preparation process and the slurry tank external feeding system. In solving the membrane electrode manufacturing process in the water electrolysis field, optimizing slurry stability, especially reducing the impact of slurry sedimentation on the performance of prepared membrane electrode products, is still one of the problems that process developers need to face. Summary of the invention

[0008] The object of the present invention is to provide a device and method for improving the stability of slurry feeding in the preparation of water electrolysis membrane electrodes, which can reduce the occurrence of abnormal conditions such as sedimentation, flow interruption, siphoning, backflow, etc. caused by environmental factors such as temperature and feeding pressure in the slurry feeding pipeline of the membrane electrode product, thereby ensuring the stability of the slurry feeding in the process of preparing water electrolysis membrane electrodes, and further ensuring the performance of the membrane electrode product.

[0009] The objective of the present invention is achieved through the following technical solutions:

[0010] A device for improving the stability of slurry feeding in the preparation of water electrolysis membrane electrodes, comprising a magnetic stirrer, a slurry container, an injector system, a connecting tee, a sleeve assembly and a chiller, wherein the slurry container is arranged on the magnetic stirrer, and the upper end of the slurry container is connected to the corresponding port of the connecting tee through a first pipeline, a first solenoid valve is arranged on the first pipeline, the injector system comprises an injection cylinder and a push rod, wherein the push rod can be inserted and inserted into the injection cylinder, and a feed push plate is arranged at the front end of the push rod located in the injection cylinder, and the output end of the injection cylinder is connected to the connecting tee through a second pipeline. The corresponding port of the tee is connected, and a second solenoid valve is provided on the second pipeline. Connecting components are provided at both ends of the sleeve assembly, and the connecting component at the input end of the sleeve assembly is connected to the corresponding port on the connecting tee through the third pipeline, and the connecting component at the output end is connected to the discharge pipeline. A third solenoid valve and a material pump are provided on the discharge pipeline. The sleeve assembly includes a temperature regulating sleeve and a slurry pipeline arranged in the temperature regulating sleeve, and the third pipeline, the slurry pipeline and the discharge pipeline are connected in sequence. A sleeve tee is provided on the temperature regulating sleeve to connect to the chiller.

[0011] The injector system includes a shell, a motor, a lead screw and a push block, wherein a mounting plate is provided in the shell, the motor and the lead screw are both provided on the mounting plate, and the lead screw is driven to rotate by the motor, the injector tube is provided at the upper end of the shell, the upper end of the push block is fixedly connected to the rear end of the push rod, the lower end extends into the interior of the shell and is provided with a nut sleeved on the lead screw, the upper end of the shell is provided with a movable slot for the push block to move, and a one-way exhaust valve is provided at the output end of the injector tube.

[0012] The pushing capacity of the injection cylinder is 5-100 ml, and the pumping speed of the push rod is 1-3 ml / min.

[0013] The connecting assembly includes a first pipe joint, a connecting sleeve and a second pipe joint, wherein the connecting sleeve is provided with a first thread groove at one end and a second thread groove at the other end, one end of the first pipe joint is threadedly inserted in the first thread groove, and the other end is connected to the third pipe, and one end of the second pipe joint is threadedly inserted in the second thread groove, and the other end is connected to the discharge pipe.

[0014] The outer end of the first pipeline joint is provided with a first pipeline threaded socket.

[0015] The outer end of the second pipeline joint is provided with a second pipeline threaded socket and an adjusting sleeve nut, wherein the end of the slurry pipeline is threadedly plugged into the second pipeline threaded socket, and the adjusting sleeve nut is fixedly connected to the corresponding end of the temperature regulating sleeve.

[0016] The temperature regulating sleeve is provided with two sleeve tees, wherein the chiller output end is connected to the sleeve tee near the temperature regulating sleeve input end through a circulating water inlet pipeline, and the chiller input end is connected to the sleeve tee near the temperature regulating sleeve output end through a circulating water return pipeline.

[0017] The sleeve tee includes an installation sleeve, a joint sleeve and a fixing nut, wherein the installation sleeve is fixed on the temperature regulating sleeve, and threaded sections are provided at both ends of the installation sleeve, water inlet grooves are evenly distributed along the circumferential direction in the middle of the installation sleeve, and connecting grooves are evenly distributed along the circumferential direction at the position of the temperature regulating sleeve corresponding to the installation sleeve, and the connecting grooves are connected with the water inlet grooves, the joint sleeve includes two left and right half sleeves, and a threaded opening is provided at the outer end of the half sleeve and a half joint is provided at the inner end, the threaded opening at the outer end of the half sleeve is threadedly fixed to the threaded section at the corresponding end of the installation sleeve, and the half joint at the inner end of the half sleeve is combined into a complete joint and fixed by the fixing nut set.

[0018] After the joint sleeve is assembled, a transition cavity is formed inside, and the connecting groove on the temperature regulating sleeve is staggered with the joint position. The inner end of one half sleeve in the joint sleeve except the half joint is provided with an inner protrusion, and the inner end of the other half sleeve except the half joint is provided with an outer protrusion. After the two half sleeves are assembled, the inner protrusion and the outer protrusion are interlocked, and a sealing element is provided between the inner protrusion and the outer protrusion.

[0019] A method for improving the stability of slurry feeding in the preparation of water electrolysis membrane electrodes comprises the following steps:

[0020] Step 1: Start the magnetic stirrer to stir the slurry in the slurry container;

[0021] Step 2: After the stirring is completed, the first solenoid valve and the second solenoid valve are opened, and the third solenoid valve remains closed, and then the injector system starts to drive the push rod to retreat at a set speed and draw a set amount of slurry in the slurry container into the injector cylinder;

[0022] Step 3: The first solenoid valve and the second solenoid valve are closed, and then the push rod reciprocates to pump to discharge the bubbles in the slurry, and at the same time the chiller is started to fill the temperature regulating sleeve with cold water of the set temperature;

[0023] Step 4: After the exhaust is completed and the circulating water temperature in the temperature regulating sleeve is stable, the first solenoid valve remains closed, the second solenoid valve and the third solenoid valve are opened, and the material pump on the discharge pipeline is started at the same time, and the slurry in the injector system is output and moves along the third pipeline, the sleeve assembly and the discharge pipeline in sequence.

[0024] The advantages and positive effects of the present invention are:

[0025] 1. The present invention firstly utilizes the injector system to exhaust the slurry, thereby avoiding the retention of bubbles in the slurry, and the push rod of the injector system can accurately control the pumping speed to ensure that the slurry in the pipeline will not be interrupted. Secondly, considering the influence of temperature on the slurry sedimentation rate, the present invention utilizes a chiller to fill circulating cold water into the temperature regulating sleeve to ensure that the slurry pipeline is in a low temperature environment, thereby avoiding slurry sedimentation. Thirdly, the present invention minimizes the number of valves, connectors, etc. used in the pipeline, thereby reducing the influence of pressure and other factors on the slurry. Therefore, the present invention can reduce the occurrence of abnormal conditions such as sedimentation, interruption of flow, siphoning, backflow, etc. caused by environmental factors such as temperature and feed pressure in the slurry supply pipeline of the membrane electrode product, thereby ensuring the stability of the slurry supply and the performance of the membrane electrode product.

[0026] 2. The sample injector system of the present invention realizes exhaust by automatic pumping driven by a motor, and the motor can accurately control the pumping rate of the push rod in the injection tube by transmitting torque through the screw nut, thereby ensuring that the pressure P2 of the pipeline part is not too small during the pumping process to cause flow interruption and generate bubbles in the slurry.

[0027] 3. The slurry pipeline of the present invention is arranged in the temperature regulating sleeve to form a sleeve assembly, and the two ends of the sleeve assembly are respectively connected to the third pipeline and the discharge pipeline through the connecting assembly, so that the connection and fixation of the temperature regulating sleeve can be ensured, and the third pipeline, the slurry pipeline and the discharge pipeline can be ensured to be connected in sequence.

[0028] 4. The temperature regulating sleeve of the present invention is provided with a sleeve tee for connecting with the chiller, and the installation sleeve of the sleeve tee is fixed on the temperature regulating sleeve and has a certain thickness, so that when the joint sleeve is installed, it can be ensured that its two half-sleeves pass over the second pipe joint in the connecting assembly, and then the outer ends of the half-sleeves are respectively threaded and fixed on the corresponding ends of the installation sleeve, and the half joints at the inner ends of the half-sleeves are combined to form a complete joint and are fixed with a fixing nut to achieve connection with a circulating water inlet pipeline or a circulating water return pipeline. Therefore, the present invention can use a full length of slurry pipeline and temperature regulating pipeline to realize slurry transmission, thereby further reducing the number of valves, connectors and other components on the pipeline, thereby reducing the influence of pressure on the slurry, and the above-mentioned sleeve tee structure will not affect the slurry pipeline and the temperature regulating pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic diagram of the overall structure of the device of the present invention,

[0030] Figure 2 for Figure 1 Schematic diagram of the structure of the sample injector system.

[0031] Figure 3 for Figure 1 Schematic diagram of the appearance of the connected components.

[0032] Figure 4 for Figure 3 A cross-sectional view of the connecting component in FIG.

[0033] Figure 5 for Figure 1 Cross-sectional view of the middle casing tee,

[0034] Figure 6 Schematic diagram of the relationship between the volume and pressure of each part of the present invention.

[0035] Among them, 1 is a magnetic stirrer, 2 is a slurry container, 3 is a first pipeline, 301 is a first solenoid valve, 4 is an injector system, 401 is a push rod, 402 is an injection tube, 403 is a feed push plate, 404 is a one-way exhaust valve, 405 is a push block, 406 is a limit block, 407 is a lead screw, 408 is a motor, 409 is a housing, 410 is a mounting plate, 5 is a second pipeline, 501 is a second solenoid valve, 6 is a connecting tee, 7 is a third pipeline, 8 is a connecting assembly, 801 is a first pipeline joint, 8011 is a first pipeline threaded socket, 802 is a connecting sleeve, 8021 is a first thread groove, 8022 is a second thread groove, 8023 is a third pipeline joint, 8024 is a third pipeline joint, 8025 is a third pipeline joint, 8026 is a third pipeline joint, 8027 is a third pipeline joint, 8028 is a third pipeline joint, 8029 is a third pipeline joint, 8030 is a third pipeline joint, 8031 ​​is a third pipeline joint, 8032 is a third pipeline joint, 8033 is a third pipeline joint, 8034 is a third pipeline joint, 8035 is a third pipeline joint, 8036 is a third pipeline joint, 8037 is a third pipeline joint, 8038 is a third pipeline joint, 8039 is a third pipeline joint, 8040 is a third pipeline joint, 8041 is a third pipeline joint, 8042 is a third pipeline joint, 8043 is a third pipeline joint, 8044 is a third pipeline joint, 8045 is a third pipeline joint, 8046 is a third pipeline joint, 8047 is a third pipeline joint 03 is the second pipe joint, 8031 ​​is the adjusting sleeve nut, 8032 is the second pipe threaded socket, 9 is the chiller, 10 is the circulating water inlet pipeline, 11 is the circulating water return pipeline, 12 is the temperature regulating sleeve, 1201 is the connecting groove, 13 is the slurry pipeline, 14 is the sleeve tee, 1401 is the installation sleeve, 14011 is the water inlet groove, 1402 is the joint sleeve, 14021 is the threaded opening, 14022 is the inner protrusion, 14023 is the outer protrusion, 1403 is the half joint, 1404 is the transition chamber, 1405 is the fixing nut, 15 is the discharge pipeline, 1501 is the third solenoid valve, and 16 is the sleeve assembly. DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with the accompanying drawings.

[0037] like Figures 1 to 6As shown, the present invention includes a magnetic stirrer 1, a slurry container 2, an injector system 4, a connecting tee 6, a sleeve assembly 16 and a chiller 9, wherein the slurry container 2 is arranged on the magnetic stirrer 1, and the slurry container 2 is connected to the corresponding port of the connecting tee 6 through a first pipeline 3, and the first pipeline 3 is provided with a first solenoid valve 301, and the injector system 4 includes an injection cylinder 402 and a push rod 401, wherein the push rod 401 can be inserted and inserted in the injection cylinder 402, and the push rod 401 is located in the injection cylinder 4 02 is provided with a feed push plate 403 at the front end, the output end of the injection cylinder 402 is connected to the corresponding port of the connecting tee 6 through the second pipeline 5, the second pipeline 5 is provided with a second solenoid valve 501, both ends of the sleeve assembly 16 are provided with connecting components 8, and the connecting component 8 at the input end of the sleeve assembly 16 is connected to the corresponding port on the connecting tee 6 through the third pipeline 7, and the connecting component 8 at the output end is connected to the discharge pipeline 15, and the discharge pipeline 15 is provided with a third solenoid valve 1501 and a material pump, such as Figure 1 and Figures 4-5 As shown, the sleeve assembly 16 includes a temperature regulating sleeve 12 and a slurry pipeline 13 arranged in the temperature regulating sleeve 12, and the third pipeline 7, the slurry pipeline 13, and the discharge pipeline 15 are connected in sequence. The temperature regulating sleeve 12 is provided with a sleeve tee 14 connected to the chiller 9.

[0038] like Figure 2 As shown, in this embodiment, the sample injector system 4 includes a shell 409, a motor 408, a lead screw 407 and a push block 405, wherein a mounting plate 410 is provided in the shell 409, the motor 408 and the lead screw 407 are both provided on the mounting plate 410, and the lead screw 407 is driven to rotate by the motor 408, the sample injection tube 402 is provided at the upper end of the shell 409, the upper end of the push block 405 is fixedly connected to the rear end of the push rod 401, the lower end extends into the interior of the shell 409 and is provided with a nut sleeved on the lead screw 407, the rotation of the lead screw 407 drives the push block 405 to move through the nut, and then drives the push rod 401 to move, the upper end of the shell 409 is provided with a movable slot for the push block 405 to move, and the output end of the sample injection tube 402 is provided with a one-way exhaust valve 404, which is a commercially available product.

[0039] When the present invention works, Figure 1As shown, the first solenoid valve 301 and the second solenoid valve 501 are opened first, and then the motor 408 is started to drive the push rod 401 to retreat to draw a set amount of slurry in the slurry container 2 into the injection cylinder 402, and then the first solenoid valve 301 and the second solenoid valve 501 are closed, and the push rod 401 moves back and forth to pump to discharge the bubbles in the slurry, and the discharged gas is discharged through the one-way exhaust valve 404. At the same time, since the one-way exhaust valve 404 is a one-way exhaust, external air will not enter the injection cylinder 402. The one-way exhaust valve 404 can be connected to an exhaust pipeline, and a gas flow sensor is provided on the exhaust pipeline, which is a commercially available product. When the gas flow sensor cannot detect gas flow in the pipeline, the injector system 4 completes the exhaust, and then the second solenoid valve 501 and the third solenoid valve 1501 are opened, and the material pump on the discharge pipeline 15 is started to drive the slurry to move along the third pipeline 7, the sleeve assembly 16 and the discharge pipeline 15 in sequence and finally output.

[0040] In this embodiment, the push capacity of the injection tube 402 can be selected within the range of 5 to 100 ml. When preparing a small-sized fuel cell membrane electrode, a 5 ml injector can be selected. There is less slurry in the injector, which is convenient for fast in and out of the slurry to prevent the slurry from staying in the injector for a long time and causing the precipitation of the precious metal catalyst. When preparing a large-sized PEM water electrolysis membrane electrode, a 10 to 50 ml injector can be selected for the amount of slurry required for a single spraying to meet the single spraying capacity requirements.

[0041] In addition, the feeding / discharging (pumping) speed of the sampler system also has special requirements. According to the relationship between flow rate and pressure, under the premise that the volume of fluid flowing through each part of the pipeline per second is equal, the pressure of the part with high flow rate is small, and the pressure of the part with low flow rate is large. The relationship between the volume and pressure of the slurry container 2, the sample injection cylinder 402 and the pipeline in the present invention is as follows: Figure 6 As shown, the volume V2>V1>V3, the pressure P3>P1>P2, in order to ensure that P2 of the pipeline part is not too small during the extraction process, thereby causing the flow to be interrupted and bubbles to be generated in the slurry, the measures taken by the present invention are:

[0042] 1. The diameter of the injector should be as small as possible, such as 5ml or 10ml;

[0043] 2. Use as few valves and connectors as possible in the feed pipeline to minimize pressure loss;

[0044] 3. The pumping speed of the sampler cannot be too high. The actual measured range of this embodiment is between 1.0 and 3.0 ml / min. This speed can be accurately controlled by the motor screw nut structure.

[0045] like Figure 1As shown, while the slurry is sequentially output through the third pipeline 7, the sleeve assembly 16 and the discharge pipeline 15, the chiller 9 is also started to input cold water of the set temperature into the temperature regulating sleeve 12 in the sleeve assembly 16. The reason for this design is that the temperature has a greater impact on the slurry settling rate, specifically:

[0046] The effect of temperature on sedimentation rate is a complex process involving multiple physical and chemical factors, including solvent viscosity, particle aggregation, etc.

[0047] 1. Solvent viscosity:

[0048] For most liquids, as the temperature increases, their viscosity usually decreases. This is because the increase in temperature increases the thermal motion of the liquid molecules, weakening the interaction between the molecules and thus reducing the viscosity. According to Stokes' law:

[0049] F=6πηrv

[0050] In the above formula, F is the resistance, η is the viscosity of the fluid, r is the radius of the solute ball, v is the speed of the solute ball in the fluid, and the sedimentation speed v of the solute particle ball in the fluid is inversely proportional to the viscosity η of the fluid. As the temperature of the solvent system increases, the fluid viscosity η decreases, and the sedimentation speed v of the solute particle ball increases. Therefore, under the condition of rising temperature, the sedimentation speed will increase.

[0051] 2. Particle aggregation: For the slurry prepared by water electrolysis membrane electrode, in some cases, the increase in temperature may cause the solute particles to aggregate in the solution to form larger clusters. The sedimentation rate of these clusters may be faster or slower than that of individual particles, depending on factors such as the size, shape and density of the clusters.

[0052] In addition, since the influence of temperature on the sedimentation rate of slurry is multifaceted, including the influence on factors such as fluid viscosity, solute solubility, molecular motion and aggregation, in specific cases, these factors may also interact and jointly determine the change in sedimentation rate. Therefore, when conducting relevant experiments or engineering applications, it is necessary to fully consider the influence of temperature on the sedimentation rate and take corresponding measures to optimize the sedimentation process. In order to ensure that the slurry runs at low temperature to avoid sedimentation, the present invention adopts the above-mentioned sleeve assembly 16, chiller 9 and other devices.

[0053] like Figures 3-4As shown, in this embodiment, the connecting component 8 includes a first pipe joint 801, a connecting sleeve 802 and a second pipe joint 803, wherein the connecting sleeve 802 is provided with a first thread groove 8021 at one end and a second thread groove 8022 at the other end, the first pipe joint 801 is threadedly inserted into the first thread groove 8021 at one end, and is provided with a first pipe threaded socket 8011 at the other end, the third pipeline 7 and the discharge pipeline 15 are respectively threadedly inserted into the first pipe threaded socket 8011 on the corresponding connecting component 8, and the second pipe joint 803 is threadedly inserted into the second thread groove 8022 at one end. A second pipeline threaded socket 8032 is provided at the other end, and the end of the slurry pipeline 13 is threadedly inserted into the second pipeline threaded socket 8032. In addition, an adjusting sleeve nut 8031 ​​is provided on the second pipeline joint 803 and is threadedly connected to the corresponding end of the temperature regulating sleeve 12, and the adjusting sleeve nut 8031 ​​is arranged at the corresponding end of the temperature regulating sleeve 12, so that the third pipeline 7, the slurry pipeline 13, and the discharge pipeline 15 are connected in sequence through the corresponding connecting components 8 respectively, and the temperature regulating sleeve 12 wraps the slurry pipeline 13 and the two ends are also fixed on the corresponding connecting components 8.

[0054] like Figure 1 As shown, two sleeve tees 14 are provided on the temperature regulating sleeve 12, wherein the output end of the chiller 9 is connected to the sleeve tee 14 near the input end of the temperature regulating sleeve 12 through a circulating water inlet pipeline 10, and the input end of the chiller 9 is connected to the sleeve tee 14 near the output end of the temperature regulating sleeve 12 through a circulating water return pipeline 11. The chiller 9 is a commercially available product, and a temperature sensor can be provided at a suitable position on the temperature regulating sleeve 12 as needed to detect the temperature in the pipe in real time and adjust the cold water temperature in time, and the temperature sensor is a commercially available product.

[0055] like Figure 5 As shown, in this embodiment, the sleeve tee 14 includes a mounting sleeve 1401, a joint sleeve 1402 and a fixing nut 15, wherein the mounting sleeve 1401 is fixed on the temperature regulating sleeve 12, and both ends of the mounting sleeve 1401 are provided with threaded sections, the middle part of the mounting sleeve 1401 is evenly provided with water inlet grooves 14011 along the circumferential direction, and the position of the temperature regulating sleeve 12 corresponding to the mounting sleeve 1401 is evenly provided with connecting grooves 1201 along the circumferential direction, and the connecting grooves 1201 are connected with the water inlet grooves 14011, the joint sleeve 1402 includes two left and right half sleeves, and the outer end of the half sleeve is provided with a threaded opening 14021, and the inner end is provided with a half joint 1403, when installing, the two half sleeves are firstly sleeved on the temperature regulating sleeve 12 in sequence, and the thickness of the mounting sleeve 1401 is to ensure that the half sleeve can pass through Figure 4The second pipe joint 803 shown in the figure, then the threaded opening 14021 at the outer end of the half sleeve is threadedly fixed to the threaded section at the corresponding end of the mounting sleeve 1401, and the half joint 1403 at the inner end of the half sleeve is combined into a complete joint and fixed by the fixing nut 15 to ensure sealing, and the fixing nut 15 is fixedly connected to the circulating water inlet pipe 10 or the circulating water return pipe 11. Figure 5 As shown, the inner end of one half-sleeve in the joint sleeve 1402, except for the half joint 1403, is provided with an inner protrusion 14022, and the inner end of the other half-sleeve, except for the half joint 1403, is provided with an outer protrusion 14023. After the two half-sleeves are combined, the inner protrusion 14022 and the outer protrusion 14023 are interlocked with each other. A sealing gasket or other sealing element can be provided between the inner protrusion 14022 and the outer protrusion 14023 as needed to ensure the sealing performance after the two half-sleeves are combined. The sleeve tee 14 of this embodiment is easy to install, and because it is the connection between the joint sleeve 1402 and the installation sleeve 1401, it will not affect the temperature regulating sleeve 12 and the slurry pipeline 13. In addition, as shown in FIG. Figure 5 As shown, after the joint sleeve 1402 is assembled, a transition chamber 1404 is formed inside, and the connecting groove 1201 on the temperature regulating sleeve 12 is staggered from the joint position, so that cold water first enters the transition chamber 1404, and then flows to both sides and flows into the temperature regulating sleeve 12 through the connecting groove 1201, so that the slurry pipeline 13 in the temperature regulating sleeve 12 will not be impacted at the moment of flowing in. Therefore, the present invention can use a complete length of slurry pipeline and temperature regulating pipeline to realize slurry transmission, thereby further reducing the number of valves, connectors, etc. in the pipeline, and reducing the influence of pressure on the slurry.

[0056] The working principle of the present invention is:

[0057] The present invention comprises the following steps when working:

[0058] Step 1: The magnetic stirrer 1 is started to stir the slurry in the slurry container 2, and the magnetic stirrer 1 is a commercially available product;

[0059] Step 2: After the stirring is completed, the first solenoid valve 301 and the second solenoid valve 501 are opened, and the third solenoid valve 1501 remains closed, and then the injector system 4 starts to drive the push rod 401 to retreat at a set speed and draw a set amount of slurry in the slurry container 2 into the injector cylinder 402;

[0060] Step 3: The first solenoid valve 301 and the second solenoid valve 501 are closed, and then the push rod 401 reciprocates to pump to discharge the bubbles in the slurry, and at the same time the chiller 9 is started to fill the temperature regulating sleeve 12 with cold water of the set temperature;

[0061] Step 4: After the exhaust is completed and the circulating water temperature in the temperature regulating sleeve 12 is stabilized, the first solenoid valve 301 remains closed, the second solenoid valve 501 and the third solenoid valve 1501 are opened, and the material pump on the discharge pipeline 15 is started at the same time, and the slurry in the sampler system 4 is output and moves along the third pipeline 7, the sleeve assembly 16 and the discharge pipeline 15 in sequence.

[0062] Several application examples are listed below to further illustrate the working process of the present invention.

[0063] Application Example 1:

[0064] In this application example, the slurry is prepared by 10 g of 70% Pt content catalyst and 21 g of 5% Nafion solution, stirred for 5 minutes, and the specific parameters are: the anode is designed according to the membrane electrode loading 1.5 mg / cm 2 The catalyst Pt content is 70%, the slurry solid content is 3.5%, the N / C ratio is 0.7, the slurry density is 0.94mg / ml, the nozzle movement speed is 140mm / s and the adjacent interval is set 6mm, and the catalyst layer surface area is 32×32cm 2 .

[0065] In this application example, the circulating water temperature of the chiller 9 is 5°C, the sampler system 4 extracts 10ml, and the extraction speed is 5ml / min. It is ensured that the extraction speed will not cause flow interruption and bubble generation in the pipeline due to small pipe diameter and low pressure. The discharge speed is 1.6ml / min and the number of spraying times is calculated. The ultrasonic generator power is set to 5w and the ultrasonic nozzle operating frequency is set to 140khz.

[0066] After completing the parameter setting, the slurry is processed according to the above steps, and the spraying equipment is started to spray the catalyst on a piece of PTFE or PET film to make a catalytic layer. After it is completely dried, different positions are selected to test using the differential weight method. The consistency of the catalyst loading at different positions, that is, after the treatment of the present invention, can effectively ensure the stability of the slurry feeding. The differential weight method is a well-known technology in the art.

[0067] Application Example 2:

[0068] In this application example, IrO 2 The catalyst slurry is prepared by using raw materials such as 85% IrO2 catalyst, 5% ionomer, organic solvent, deionized water, etc. according to a certain N / c ratio and Ir content component ratio to prepare PEM water electrolysis membrane electrode catalyst slurry in an environment of 5°C. The above is a well-known technology in the art.

[0069] In this application example, the circulating water temperature, the extraction volume and speed of the sampler system 4 are the same as those in Application Example 1. The slurry is processed according to the above steps, and the spraying equipment is started to spray the catalyst on a piece of PTFE or PET film to form a catalytic layer. After it is completely dried, different positions are selected to test the consistency of the catalyst loading at different positions using the differential weight method.

Claims

1. A device for improving the stability of slurry feeding in the preparation of water electrolysis membrane electrodes, characterized in that: The invention comprises a magnetic stirrer (1), a slurry container (2), an injector system (4), a connecting tee (6), a sleeve assembly (16) and a chiller (9), wherein the slurry container (2) is arranged on the magnetic stirrer (1), and the upper end of the slurry container (2) is connected to the corresponding port of the connecting tee (6) through a first pipeline (3), the first pipeline (3) is provided with a first solenoid valve (301), the injector system (4) comprises an injector barrel (402) and a push rod (401), wherein the push rod (401) can be inserted and withdrawn into the injector barrel (402), and a feed push plate (403) is provided at the front end of the push rod (401) located in the injector barrel (402), and the output end of the injector barrel (402) is connected to the corresponding port of the connecting tee (6) through a second pipeline (5). The second pipeline (5) is connected, and a second solenoid valve (501) is provided on the second pipeline (5). Both ends of the sleeve assembly (16) are provided with connecting assemblies (8), and the connecting assembly (8) at the input end of the sleeve assembly (16) is connected to the corresponding port on the connecting tee (6) through the third pipeline (7), and the connecting assembly (8) at the output end is connected to the discharge pipeline (15), and the discharge pipeline (15) is provided with a third solenoid valve (1501) and a material pump. The sleeve assembly (16) includes a temperature regulating sleeve (12) and a slurry pipeline (13) provided in the temperature regulating sleeve (12), and the third pipeline (7), the slurry pipeline (13), and the discharge pipeline (15) are connected in sequence. The temperature regulating sleeve (12) is provided with a sleeve tee (14) connected to the chiller (9).

2. The device for improving the stability of slurry feeding in the preparation of water electrolysis membrane electrodes according to claim 1, characterized in that: The sample injector system (4) comprises a housing (409), a motor (408), a lead screw (407) and a push block (405), wherein a mounting plate (410) is provided in the housing (409), the motor (408) and the lead screw (407) are both provided on the mounting plate (410), and the lead screw (407) is driven to rotate by the motor (408), the sample injector (402) is provided at the upper end of the housing (409), the upper end of the push block (405) is fixedly connected to the rear end of the push rod (401), the lower end extends into the housing (409) and is provided with a nut sleeved on the lead screw (407), the upper end of the housing (409) is provided with a movable slot for the push block (405) to move, and a one-way exhaust valve (404) is provided at the output end of the sample injector (402).

3. The device for improving the stability of slurry feeding in the preparation of water electrolysis membrane electrodes according to claim 1, characterized in that: The pushing capacity of the injection cylinder (402) is 5 to 100 ml, and the pumping speed of the push rod (401) is 1 to 3 ml / min.

4. The device for improving the stability of slurry feeding in the preparation of water electrolysis membrane electrodes according to claim 1, characterized in that: The connection assembly (8) comprises a first pipe joint (801), a connection sleeve (802) and a second pipe joint (803), wherein the connection sleeve (802) is provided with a first thread groove (8021) at one end and a second thread groove (8022) at the other end; one end of the first pipe joint (801) is threadedly inserted into the first thread groove (8021) and the other end is connected to the third pipe (7); one end of the second pipe joint (803) is threadedly inserted into the second thread groove (8022) and the other end is connected to the discharge pipe (15).

5. The device for improving the stability of slurry feeding in the preparation of water electrolysis membrane electrodes according to claim 4, characterized in that: The outer end of the first pipeline joint (801) is provided with a first pipeline threaded socket (8011).

6. The device for improving the stability of slurry feeding in the preparation of water electrolysis membrane electrodes according to claim 4, characterized in that: The outer end of the second pipe joint (803) is provided with a second pipe threaded socket (8032) and an adjusting sleeve nut (8031), wherein the end of the slurry pipe (13) is threadedly connected to the second pipe threaded socket (8032), and the adjusting sleeve nut (8031) is fixedly connected to the corresponding end of the temperature regulating sleeve (12).

7. The device for improving the stability of slurry feeding in the preparation of water electrolysis membrane electrodes according to claim 1, characterized in that: The temperature regulating sleeve (12) is provided with two sleeve tees (14), wherein the output end of the chiller (9) is connected to the sleeve tee (14) near the input end of the temperature regulating sleeve (12) via a circulating water inlet pipeline (10), and the input end of the chiller (9) is connected to the sleeve tee (14) near the output end of the temperature regulating sleeve (12) via a circulating water return pipeline (11).

8. The device for improving the stability of slurry feeding in the preparation of water electrolysis membrane electrode according to claim 1 or 7, characterized in that: The sleeve tee (14) comprises a mounting sleeve (1401), a joint sleeve (1402) and a fixing nut (15), wherein the mounting sleeve (1401) is fixedly mounted on the temperature regulating sleeve (12), and both ends of the mounting sleeve (1401) are provided with threaded sections, the middle of the mounting sleeve (1401) is provided with water inlet grooves (14011) evenly distributed along the circumferential direction, and the position of the temperature regulating sleeve (12) corresponding to the mounting sleeve (1401) is provided with connecting grooves (12011) evenly distributed along the circumferential direction. ), and the connecting groove (1201) is connected to the water inlet groove (14011), the joint sleeve (1402) includes two left and right half sleeves, and the outer end of the half sleeve is provided with a threaded opening (14021), and the inner end is provided with a half joint (1403), the threaded opening (14021) at the outer end of the half sleeve is threadedly fixed to the threaded section of the corresponding end of the installation sleeve (1401), and the half joint (1403) at the inner end of the half sleeve is combined into a complete joint and fixed by the fixing nut (15).

9. The device for improving the stability of slurry feeding in the preparation of water electrolysis membrane electrodes according to claim 8, characterized in that: After the joint sleeve (1402) is assembled, a transition cavity (1404) is formed inside, and the connecting groove (1201) on the temperature regulating sleeve (12) is staggered from the joint position. The inner end of one half sleeve in the joint sleeve (1402) except the half joint (1403) is provided with an inner protrusion (14022), and the inner end of the other half sleeve except the half joint (1403) is provided with an outer protrusion (14023). After the two half sleeves are assembled, the inner protrusion (14022) and the outer protrusion (14023) are interlocked, and a sealing element is provided between the inner protrusion (14022) and the outer protrusion (14023).

10. A method for improving the stability of slurry feeding in the preparation of water electrolysis membrane electrodes according to claim 1, characterized in that: The steps include: Step 1: The magnetic stirrer (1) is started to stir the slurry in the slurry container (2); Step 2: After the stirring is completed, the first solenoid valve (301) and the second solenoid valve (501) are opened, and the third solenoid valve (1501) remains closed, and then the injector system (4) starts to drive the push rod (401) to retreat at a set speed and draw a set amount of slurry in the slurry container (2) into the injection cylinder (402); Step 3: The first solenoid valve (301) and the second solenoid valve (501) are closed, and then the push rod (401) moves back and forth to pump out the bubbles in the slurry, and at the same time the chiller (9) is started to fill the temperature regulating sleeve (12) with cold water of a set temperature; Step 4: After the exhaust is completed and the temperature of the circulating water in the temperature regulating sleeve (12) is stabilized, the first solenoid valve (301) remains closed, the second solenoid valve (501) and the third solenoid valve (1501) are opened, and at the same time, the material pump on the discharge pipeline (15) is started, and the slurry in the sampler system (4) is output and moves in sequence along the third pipeline (7), the sleeve assembly (16) and the discharge pipeline (15).

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