Non-contact vacuum collaborative dispersion system based on vertical collision flow field and application

Abstract

The invention relates to a non-contact vacuum collaborative dispersion system based on a vertical collision flow field and application. The dispersion system comprises an acoustic energy emission module which comprises a base with an acoustic coupling cavity and an ultrasonic generation source, and the acoustic coupling cavity is filled with an acoustic coupling medium; a reaction unit; the flow field regulation and control module comprises a vacuum sealing assembly and a concentric sleeve type stator and rotor dispersion assembly; the concentric sleeve type stator and rotor dispersion assembly is configured to generate an axially downward mechanical shear jet flow; the ultrasonic generating source is configured to generate an axially upward acoustic radiation force field; and a high-energy vertical collision area is formed in the consumable test tube. According to the invention, a vacuum-shearing-ultrasonic three-field coupling system is constructed, a vertical collision flow field is formed in the consumable test tube, synchronous coupling of mechanical shearing, ultrasonic cavitation and vacuum defoaming is realized, homogenization of the whole system is realized, and the method is suitable for slurry preparation in the fields of fuel cells, electrolyzed water, solid-state batteries, functional coatings and the like.

Description

Technical Field

[0001] This invention relates to the field of nanomaterial preparation technology, and in particular to a non-contact vacuum synergistic dispersion system based on a vertical collision flow field and its application. Background Technology

[0002] The preparation of high-performance nanocatalyst slurries (such as slurries for the catalyst layer of proton exchange membrane fuel cells (PEMFCs)) is a core process in the manufacturing of new energy devices. An ideal slurry requires nanoparticles (such as Pt / C catalysts, M–N–C catalysts, metal oxide catalysts, graphene, etc.) to achieve a highly uniform, stable, and macroscopically defect-free dispersion in a liquid medium. Simultaneously, the slurry must completely eliminate entrained nanobubbles to prevent the formation of pinholes, cracks, and other microscopic defects during subsequent coating and drying processes. This ensures sufficient exposure of the catalyst's active sites, effective formation of the three-phase reaction interface, and guarantees the integrity and reliability of the overall conductive network of the electrode.

[0003] However, existing laboratory and pilot-scale dispersion equipment has the following significant structural and technological limitations when dealing with the research and development of high-performance materials:

[0004] 1. Severe risk of cross-contamination and data distortion: Existing equipment mostly uses fixed ultrasonic probes or non-removable stirring blades, making the cleaning process cumbersome and difficult to completely remove residues in dead corners. When conducting high-throughput screening experiments with multiple batches and multiple formulations, residues from previous batches can cause a severe "memory effect," leading to cross-contamination and distortion of catalytic activity data, seriously affecting the accuracy of scientific research judgments.

[0005] 2. Microscopic defects at the interface caused by the inability to simultaneously degas: Traditional dispersion processes are usually carried out in open or atmospheric pressure environments, which not only fail to remove the gas originally adsorbed inside the slurry, but also entrain a large number of micron-sized bubbles when stirred at high speed. These micro / nano bubbles tend to adsorb onto the surface of hydrophobic catalysts, forming a robust gas-liquid interface barrier that physically prevents the effective coating of catalyst particles by ionomers (such as Nafion), directly leading to the absence of the three-phase reaction interface and the generation of pinholes in the coating in the final membrane electrode.

[0006] 3. Addressing Insufficient Energy Coupling and Sample Loss in Novel Difficult-to-Disperse Materials: Especially for novel catalysts with complex pore structures and strong hydrophobicity (such as M–N–C), traditional equipment using only stirring or ultrasonic methods struggles to provide sufficient energy for deagglomeration, resulting in significant sample loss and unsuitability for high-throughput screening. These materials typically possess extremely high specific surface areas and complex pore structures, exhibiting strong van der Waals forces between particles, and making it difficult for gases to escape from the micropores. Single stirring methods lack sufficient shear force to break up dense agglomerates; while single ultrasonic methods offer high energy, they often lead to a pseudo-dispersion state for hydrophobic materials, characterized by "unbroken external agglomerates and unwetted internal pores." Furthermore, these precious samples synthesized in the laboratory are typically only milligrams in size; traditional equipment has a large dead volume and extremely high cleaning losses, severely limiting the high-throughput screening efficiency of the formulations.

[0007] 4. Solvent Thermodynamic Phase Change Uncontrolled: Existing vacuum dispersion equipment often neglects the thermodynamic phase change of solvents. When processing slurries containing volatile solvents (such as isopropanol and ethanol), without effective temperature control and pressure threshold management, the high vacuum combined with the heat of cavitation generated by ultrasound can easily cause a sudden drop in the solvent's boiling point, resulting in "bumping" and volatilization. This not only leads to uncontrollable drift in the slurry's solid content but also damages the vacuum pump due to the intake of large amounts of solvent vapor, which is unacceptable in precise quantitative experiments. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention provides a non-contact vacuum collaborative dispersion system and its application based on a vertical collision flow field. It constructs a "vacuum-shear-ultrasound" three-field coupling system, forming a "vertical collision flow field" within a consumable test tube. This achieves simultaneous coupling of mechanical shearing, ultrasonic cavitation, and vacuum degassing, resulting in homogenization of the entire system. It effectively eliminates the physical obstruction of nanobubbles to the distribution of ionomers, making it suitable for slurry preparation in fields such as fuel cells, water electrolysis, solid-state batteries, and functional coatings.

[0009] The first aspect of this invention provides a non-contact vacuum cooperative dispersion system based on a vertical collision flow field, comprising:

[0010] The acoustic energy emission module includes a base with an acoustic coupling cavity and an ultrasonic generator located below the acoustic coupling cavity, the acoustic coupling cavity being filled with an acoustic coupling medium;

[0011] The reaction unit is a consumable test tube placed in the acoustic coupling cavity;

[0012] The flow field control module includes a vacuum sealing assembly, a concentric sleeve type stator and rotor dispersion assembly, and a dispersion drive for driving the concentric sleeve type stator and rotor dispersion assembly; the vacuum sealing assembly is used to form an airtight reaction chamber inside the consumable test tube, and the concentric sleeve type stator and rotor dispersion assembly extends into the airtight reaction chamber of the consumable test tube.

[0013] The concentric sleeve-type stator-rotor dispersion assembly is configured to generate an axially downward mechanical shear jet; the ultrasonic generator is configured to generate an axially upward acoustic radiation force field; the mechanical shear jet and the acoustic radiation force field work together to form a high-energy vertical collision zone within the consumable test tube.

[0014] Furthermore, the dispersion system also includes a temperature control module, which is located on the base and acts on the acoustic coupling cavity to regulate the temperature of the acoustic coupling medium.

[0015] Furthermore, the distributed system also includes a lifting mechanism; the flow field control module is fixed to the lifting end of the lifting mechanism.

[0016] The second aspect of the present invention provides an application of a non-contact vacuum collaborative dispersion system based on a vertical collision flow field for the dispersion of slurries; wherein the slurry is a proton exchange membrane fuel cell catalyst slurry, an electrolytic water catalyst slurry, a lithium-ion battery slurry, a solid electrolyte slurry, a nano-silver antibacterial coating slurry, or a titanium dioxide self-cleaning coating slurry.

[0017] Furthermore, the concentric sleeve-type stator-rotor dispersion assembly is used to generate strong shear force and forced convection circulation to achieve initial wetting and deagglomeration of powder in the slurry; the ultrasonic generator is used to generate non-contact high-frequency vibration and cavitation effect to break up micron- and submicron-scale particle agglomerates in the slurry; the vacuum sealing assembly is also used to provide the required vacuum degree for the airtight reaction chamber of the consumable test tube; the temperature control module is used to maintain the reaction temperature in the airtight reaction chamber of the consumable test tube below the solvent boiling point of the slurry under the corresponding vacuum degree, so as to avoid drastic phase change of the solvent while defoaming in vacuum.

[0018] Advantages of this invention: This invention provides a non-contact vacuum collaborative dispersion system and its application based on a vertical collision flow field. It constructs a "vacuum-shear-ultrasound" three-field coupling system, forming a "vertical collision flow field" within a consumable test tube. Through the synchronous coupling of mechanical shearing, ultrasonic cavitation, and vacuum degassing, the entire system achieves homogenization, solving core pain points in new energy device manufacturing such as uneven slurry dispersion, bubble residue, and cross-contamination. It is particularly effective in addressing the agglomeration problem of difficult-to-disperse nanomaterials (represented by M-N-C catalysts) with trace amounts of high-value materials and special surface properties (such as strong hydrophobicity and high porosity) in the laboratory research stage. It integrates thermodynamic temperature control and critical negative pressure control strategies, reducing the risk of phase transition runaway of volatile solvents in a vacuum environment and effectively eliminating the physical barrier of nanobubbles to ionomer distribution. This system is suitable for slurry preparation in fields such as fuel cells, water electrolysis, solid-state batteries, and functional coatings. Attached Figure Description

[0019] Figure 1This is a schematic diagram of a non-contact vacuum collaborative dispersion system based on a vertical collision flow field, as an example.

[0020] Figure 2 This is a schematic diagram of the flow field control module of a non-contact vacuum collaborative dispersion system based on a vertical collision flow field, as shown in an embodiment.

[0021] Figure 3 A comparison of the particle size of the PEMFC cathode catalyst slurry prepared in Application Example 1 and the comparative example.

[0022] Figure 4 A comparison diagram of the zeta potential of the PEMFC cathode catalyst slurry prepared in Application Example 1 and the comparative example.

[0023] Figure 5 Laser microscope image of the membrane electrode of the PEMFC slurry prepared in Application Example 1;

[0024] Figure 6 Laser microscope image of the membrane electrode of the PEMFC slurry prepared for comparison;

[0025] Figure 7 The H2-O2 polarization curves and power density comparison diagrams of the membrane electrodes prepared in Application Example 1 and the comparative example are respectively assembled into fuel cells.

[0026] Figure 8 H2-air polarization curves and power density comparison diagrams of the membrane electrodes prepared in Application Example 1 and the comparative example, respectively, assembled into fuel cells;

[0027] Among them, 1-acoustic energy emission module, 2-reaction unit, 3-flow field control module, 4-lifting mechanism, 11-base, 12-ultrasonic generator, 13-acoustic coupling cavity, 14-acoustic coupling medium, 15-temperature control module, 31-vacuum sealing assembly, 32-dispersion drive component, 33-concentric sleeve type stator and rotor dispersion assembly, 311-vacuum sealing cover, 312-sealing gasket, 331-outer static sleeve, 332-stator housing, 333-shear slit, 334-inner drive shaft, 335-rotor blade, 336-fixed flange seat, 41-vertical column, 42-cantilever, C-mechanical shear jet, D-acoustic radiation force field, E-high-energy vertical collision zone. Detailed Implementation

[0028] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0029] Example

[0030] Please refer to Figure 1 and Figure 2 As shown, a non-contact vacuum collaborative dispersion system based on a vertical collision flow field includes: an acoustic energy emission module 1, comprising a base 11 with an acoustic coupling cavity 13 and an ultrasonic source 12 located below the acoustic coupling cavity, the acoustic coupling cavity 13 being filled with an acoustic coupling medium 14; a reaction unit 2, which is a consumable test tube placed in the acoustic coupling cavity 13; and a flow field control module 3, comprising a vacuum sealing assembly 31, a concentric sleeve-type stator-rotor dispersion assembly 33, and a dispersion drive component 32 for driving the concentric sleeve-type stator-rotor dispersion assembly 33; the vacuum sealing assembly 31 is used to form an airtight reaction chamber inside the consumable test tube, and... The concentric sleeve-type stator-rotor dispersion assembly 33 extends into the airtight reaction chamber of the consumable test tube; the concentric sleeve-type stator-rotor dispersion assembly 33 is configured to generate an axially downward mechanical shear jet C; the ultrasonic source 12 is configured to generate an axially upward acoustic radiation force field D; the mechanical shear jet C and the acoustic radiation force field D cooperate to form a high-energy vertical collision zone E in the consumable test tube; the dispersion system also includes a temperature control module 15, which is set on the base 11 and acts on the acoustic coupling cavity 13 to regulate the temperature of the acoustic coupling medium 14; the dispersion system also includes a lifting mechanism 4; the flow field control module 3 is fixed to the lifting end of the lifting mechanism 4.

[0031] Specifically, the base 11 is provided with an upper-opening receiving groove; the ultrasonic generator 12 is an ultrasonic transducer, installed inside the base 11 and located directly below the receiving groove; the bottom of the receiving groove is made of rigid acoustic material; an upper-opening coupling cup is placed inside the receiving groove, and the cup cavity of the coupling cup serves as the acoustic coupling cavity 13; the acoustic coupling cavity 13 is filled with the acoustic coupling medium 14; a temperature control module 15 is provided inside the base 11 surrounding the receiving groove; the temperature control module 15 is at least one of a fluid circulation jacket, an electrothermal cooling module, an air-cooled heat dissipation channel, or a phase change medium cold storage tank, and the temperature control module 15 is thermally connected to the coupling cup; the consumable test tube is detachably installed inside the coupling cup; the ultrasonic generator 12 generates an ultrasonic source. The ultrasonic waves are transmitted from bottom to top into the slurry through a rigid acoustic material, a coupling cup, an acoustic coupling medium, and a consumable test tube, forming an axially upward acoustic radiation force field D. The vacuum sealing assembly 31 includes a vacuum sealing cover 311 and a sealing gasket 312. The vacuum sealing assembly 31 is located directly above the consumable test tube and can seal or open the upper opening of the consumable test tube. The vacuum sealing cover 311 also has a vacuum evacuation interface, one end of which is connected to the airtight reaction chamber of the consumable test tube, and the other end is connected to a vacuum device. The concentric sleeve-type stator-rotor dispersion assembly 33 includes an outer stationary sleeve 331 and an inner drive shaft 334. The top end of the outer stationary sleeve 331 is connected to the vacuum seal via a fixed flange seat 336. The cap 311 is rigidly connected to a stator housing 332 with a downward opening at the bottom. The top end of the inner drive shaft 334 passes through the vacuum-sealed cap 311 and is fixedly connected to the output end of the dispersion drive component 32. The bottom end is fixed with a rotor blade 335. The side wall of the stator housing 332 has multiple shear slits 333 circumferentially opened. The rotor blade 335 is located inside the stator housing 332. The dispersion drive component 32 is a motor. The rotor blade 335 is used to rotate inside the stator housing 332 under the drive of the motor and the inner drive shaft 334, acting on the slurry. Under the constraint of the consumable test tube and the stator housing 332, it generates an axially downward mechanical shear jet C. The slurry is also under the action of the rotor blade 335. The material is drawn into the stator housing 332 through the shear slit 333 and sheared at the shear slit 333. The lifting mechanism 4 includes a vertical column 41 and a cantilever 42 that can be raised and lowered along the vertical column 41. The vacuum sealing assembly 31 is fixed to the cantilever 42. The lifting mechanism 4 also includes a lifting drive for driving the cantilever 42 to rise and fall relative to the vertical column 41. The lifting drive is used to drive the cantilever 42 to rise and fall, thereby driving the vacuum sealing assembly 31 to rise and fall, thereby causing the concentric sleeve type stator-rotor dispersion assembly 33 to be inserted downward into the consumable test tube or moved upward out of the consumable test tube. It is also used to drive the vacuum sealing assembly 31 to press downward against the consumable test tube for sealing or to open the upper opening of the consumable test tube upward.

[0032] The following is an application example of a non-contact vacuum collaborative dispersion system based on a vertical collision flow field used in slurry preparation according to this embodiment.

[0033] Application Example 1

[0034] This application example uses a non-contact vacuum co-dispersion system based on a vertical collision flow field, as described in the previous example, to prepare a proton exchange membrane fuel cell (PEMFC) anode catalyst slurry. The specific experimental operation is as follows: 5 mg of Pt / C catalyst (60 wt%) was accurately weighed and placed in a 10 mL consumable test tube. 60 μL of Nafion solution (5 wt% in water, DuPont) and 5 mL of isopropanol solvent were added sequentially. The consumable test tube containing the materials was placed into the coupling cup of the base. The temperature control module was activated to stabilize the temperature of the acoustic coupling medium at 10℃-15℃ to counteract the ultrasonic thermal effect and increase the solvent boiling point. The flow field control module was lowered by the lifting mechanism to seal the consumable test tube with the vacuum sealing cap. The "critical negative pressure control method" was used to adjust and maintain the gas pressure inside the consumable test tube between -0.06 MPa and -0.08 MPa (this pressure range is below the bubble desorption threshold but above the explosive boiling threshold of isopropanol at low temperatures). Then, the motor (speed set to 1000 rpm) and the bottom ultrasonic generator are started simultaneously. The motor drives the concentric sleeve type stator and rotor dispersion assembly to generate an axially downward mechanical shear jet, and the ultrasonic generator generates an axially upward acoustic radiation force field. The slurry is subjected to multi-field coupling treatment in a low temperature vacuum environment for 15 minutes. After the treatment is completed, the anode catalyst slurry for proton exchange membrane fuel cell (PEMFC) is obtained.

[0035] This application example uses a non-contact vacuum co-dispersion system based on a vertical collision flow field, as described in the previous example, to prepare a proton exchange membrane fuel cell (PEMFC) cathode catalyst slurry. The specific experimental operation is as follows: 30 mg of M–N–C catalyst was accurately weighed and placed in a 10 mL consumable test tube. 400 μL of Nafion solution (5 wt% in water, DuPont) and 7 mL of isopropanol were added sequentially. Then, the preparation was carried out using a method similar to that described above. The slurry was subjected to multi-field coupling treatment under low-temperature vacuum environment for 60 min. After the treatment was completed, the proton exchange membrane fuel cell (PEMFC) cathode catalyst slurry was obtained.

[0036] This application example also provides a membrane electrode prepared using the above-mentioned proton exchange membrane fuel cell (PEMFC) anode catalyst slurry and cathode catalyst slurry; the specific method is as follows: the proton exchange membrane fuel cell (PEMFC) anode catalyst slurry is sprayed onto the Nafion 211 proton exchange membrane by ultrasonic spraying (feeding at a rate of 0.5 mL / min) to prepare the anode side of the membrane electrode; the proton exchange membrane fuel cell (PEMFC) cathode catalyst slurry is sprayed onto the other side of the above-mentioned proton exchange membrane by ultrasonic spraying (feeding at a rate of 0.2 mL / min) to prepare the membrane electrode.

[0037] Application Example 2

[0038] This application example uses a non-contact vacuum synergistic dispersion system based on a vertical collision flow field, as described in the previous example, to prepare an OER catalyst slurry for water electrolysis. The specific experimental operation is as follows: 50 mg of IrO2 nanoparticles, 10 mg of conductive carbon black (Vulcan XC-72R), 100 μL of Nafion solution (5 wt% in water, DuPont), and 5 mL of N-methylpyrrolidone (NMP) were weighed and mixed in a 20 mL consumable test tube; the consumable test tube containing the materials was placed into the coupling cup of the base; the flow field control module was lowered by the lifting mechanism to seal the consumable test tube with the vacuum sealing cap; the mixture was mechanically stirred at 800 rpm for 10 min at atmospheric pressure to achieve initial wetting and mixing; then, stirring was maintained (200 rpm), and the vacuum pump was started to reduce the pressure to -0.09 MPa. Under vacuum conditions, the ultrasonic generator was activated, and intermittent ultrasonic treatment (2 seconds of operation followed by a 1-second interval) was performed for 20 minutes, with the temperature controlled at 20±3℃ throughout the process using a temperature control module. Then, the pressure was restored to atmospheric pressure, resulting in a uniform, stable, and bubble-free OER catalyst slurry. The slurry from this application example can be directly used for coating rotating ring-disc electrodes or preparing electrodes for large-area electrolytic cells. In this application example, for high-density materials such as IrO2, mechanical shear jet C counteracts gravitational sedimentation, and combined with the acoustic radiation force field D at the bottom, achieving dispersion without dead zones.

[0039] Application Example 3

[0040] This application example uses a non-contact vacuum co-dispersion system based on a vertical collision flow field, as described in the previous example, to prepare a high-nickel ternary (NCM811) lithium-ion battery cathode slurry. The specific experimental operation is as follows: 920 mg of high-nickel LiNi... 0.8 Co 0.1 Mn 0.1O2 (NCM811) positive electrode active material, 40 mg Super P conductive agent, 40 mg KS-6 graphene conductive agent, and 80 mg polyvinylidene fluoride (PVDF) binder were added to 8 mL of N-methylpyrrolidone (NMP) solvent and placed in a 50 mL consumable test tube. The flow field control module was lowered by a lifting mechanism to seal the consumable test tube with a vacuum sealing cap. The motor was started, and the material was first mechanically stirred at a high speed of 1500 rpm for 20 min to completely break up the large agglomerates of the active material and completely dissolve the PVDF. Then, the vacuum equipment was started and the vacuum was evacuated to -0.09 MPa. Under the conditions of maintaining vacuum and low speed (400 rpm) stirring, the bottom ultrasonic generator was used in pulse mode (on for 2 s, off for 1 s) for 30 min, while the temperature was controlled below 25℃ by the temperature control module. The high-nickel ternary (NCM811) lithium-ion battery positive electrode slurry was obtained. This application example disperses NCM811 in a vacuum environment, effectively isolating moisture, reducing pores in the slurry, and increasing the density of the electrode. It effectively solves the problem of high-nickel materials being sensitive to moisture and prone to agglomeration. The vacuum degassing process greatly reduces pores in the slurry, making the coated electrode more dense and uniform, which is beneficial to improving the volumetric energy density and cycle stability of the battery.

[0041] Application Example 4

[0042] This application example uses a non-contact vacuum co-dispersion system based on a vertical collision flow field, as described in the previous example, to prepare a sulfide solid electrolyte slurry. The specific experimental operation is as follows: The dispersion system is placed in an argon-protected glove box. 500 mg of Li6PS5Cl sulfide solid electrolyte powder, 50 mg of vapor-grown carbon fiber (VGCF), and 5 mL of a hydrogenated naphthalene / heptane mixed solvent (volume ratio 1:4) are added to a 10 mL consumable test tube. The flow field control module is lowered by a lifting mechanism to seal the consumable test tube with a vacuum sealing cap. The motor is started, and mechanical stirring is performed at 800 rpm for 15 min for premixing. Subsequently, the vacuum equipment is started to evacuate to -0.09 MPa. Under negative pressure and continuous low-speed (300 rpm) stirring, ultrasonic source treatment is started for 25 min, while the temperature is maintained at 25±3℃ by the temperature control module to obtain the sulfide solid electrolyte slurry. In this application example, samples were loaded into consumable test tubes inside a glove box. Vacuum was then used to remove trace amounts of moisture and oxygen entrained in the solvent and powder, protecting the sulfide electrolyte from oxidation. Simultaneously, all air bubbles generated during dispersion were removed. A vacuum-sealed cap was used to achieve negative pressure dispersion throughout the process, preventing oxidation and hydrolysis, resulting in a highly uniform and defect-free electrolyte slurry. The slurry from this application example can be used to prepare large-area, high-ionic-conductivity solid electrolyte membranes using casting or spraying methods.

[0043] Application Example 5

[0044] This application example uses a non-contact vacuum synergistic dispersion system based on a vertical collision flow field, as described in the previous example, to prepare a nano-silver antibacterial coating slurry. The specific experimental procedure is as follows: 100 mg of nano-silver particles (particle size 20-40 nm), 200 mg of aqueous polyurethane dispersion, 20 mg of leveling agent, and 7 mL of deionized water / ethanol (volume ratio 3:4) mixed solvent are weighed and added to a 30 mL consumable test tube; the flow field control module is lowered via a lifting mechanism to seal the consumable test tube with a vacuum sealing cap; the motor is started, and mechanical stirring is performed at 900 rpm for 10 min under normal pressure to initially disperse the nano-silver in the resin system; the vacuum equipment is started, and the vacuum is evacuated to -0.09 MPa; under vacuum conditions, an ultrasonic generator is started, and slow stirring at 400 rpm is performed simultaneously for 20 min, while the temperature is controlled below 30°C using a temperature control module; the nano-silver antibacterial coating slurry is obtained. In this application example, the vacuum environment effectively prevents the incorporation of air bubbles caused by high-speed dispersion and removes the gas adsorbed on the surface of the nano-silver. By using shear and ultrasonic coupling, the agglomeration of the nano-silver is prevented, ensuring the full deagglomeration of the nano-silver particles and their monodispersity in the resin. As a result, the antibacterial components of the antibacterial coating formed by this slurry are evenly distributed and the surface is smooth and dense.

[0045] Application Example 6

[0046] This application example uses a non-contact vacuum synergistic dispersion system based on a vertical collision flow field, as described in the previous example, to prepare a TiO2 clean coating slurry. The specific experimental operation is as follows: 200 mg of P25 type nano-TiO2 (anatase / rutile mixed phase), 150 mg of silicone-acrylic emulsion, 50 mg of fluorocarbon surfactant, and 6 mL of ethanol / ethyl acetate (volume ratio 1:2) mixed solvent are placed in a 15 mL consumable test tube; the flow field control module is lowered by a lifting mechanism to seal the consumable test tube with a vacuum sealing cap; the motor is started and the mixture is stirred at 1000 rpm for 15 min for premixing; the vacuum equipment is started and the vacuum is evacuated to -0.09 MPa. Under negative pressure and continuous low-speed (350 rpm) stirring, the ultrasonic generator is started for ultrasonic dispersion for 22 min. The temperature is controlled below 20°C by the temperature control module to obtain the TiO2 clean coating slurry. In this application example, the integrated vacuum dispersion process significantly reduces air bubbles within the slurry, achieving uniform dispersion of P25 and the emulsion, and ensuring the uniform distribution of the nano-TiO2 photocatalyst and the low surface energy fluorocarbon components. The coating formed by the TiO2 clean coating slurry in this application example exhibits excellent photocatalytic self-cleaning properties and hydrophobic and antifouling properties, as well as good transparency and strong adhesion.

[0047] Comparative Example

[0048] This comparative example uses a traditional open-top stirring method combined with trough ultrasonication to prepare proton exchange membrane fuel cell (PEMFC) catalyst slurry. The specific experimental procedures are as follows: First, 5 mg of Pt / C (60 wt%), 60 μL of Nafion solution (5 wt% in water, DuPont), and 5 mL of isopropanol solvent were placed in a 10 mL test tube to prepare the anode-side slurry of the membrane electrode. Then, 30 mg of M–N–C catalyst, 400 μL of Nafion solution (5 wt% in water, DuPont), and 7 mL of isopropanol were added to a 10 mL test tube to prepare the cathode-side slurry of the membrane electrode. The test tubes containing the anode slurry and the test tubes containing the cathode slurry were transferred to a tank-type ultrasonic cleaner (ice-water bath) and ultrasonically treated for 30 min and 120 min respectively (the water needed to be changed and ice added during the process due to the rise in water temperature); the corresponding slurries were then transferred to a vacuum drying oven for static degassing for 30-60 min; thus, the anode catalyst slurry and cathode catalyst slurry for proton exchange membrane fuel cells (PEMFC) were obtained respectively.

[0049] This comparative example also provides a membrane electrode, specifically: the anode catalyst slurry prepared in this comparative example is sprayed onto the Nafion 211 proton exchange membrane by ultrasonic spraying (feeding at a speed of 0.5 mL / min) to form the anode side of the membrane electrode; the cathode catalyst slurry prepared in this comparative example is sprayed onto the other side of the above-mentioned proton exchange membrane by ultrasonic spraying (feeding at a speed of 0.2 mL / min) to form the cathode side of the membrane electrode, thus forming the membrane electrode.

[0050] The particle size of the proton exchange membrane fuel cell (PEMFC) cathode catalyst slurry prepared in the corresponding use case 1 and comparative example was measured, as follows: Figure 3 As shown, A is the cathode catalyst slurry of the application example, and B is the cathode catalyst slurry of the comparative example. From Figure 3 As can be seen from the example, the cathode catalyst slurry prepared using the dispersion system of the embodiment in Application Example 1 has an average particle size (Z) of 360.8 nm and a particle size distribution index (PDI) as low as 0.07675, indicating that the particles are extremely uniformly dispersed and the system has excellent monodispersity. In contrast, the cathode catalyst slurry prepared using the conventional dispersion method in the comparative example has an average particle size of 692.0 nm and a PDI as high as 0.3679, showing a wider particle size distribution and significant agglomeration. In comparison, when the dispersion system of the present invention is used for cathode catalyst slurry, it can more effectively break up particle agglomerates and achieve finer and more uniform nanoscale dispersion.

[0051] Zeta potential tests were performed on the proton exchange membrane fuel cell (PEMFC) cathode catalyst slurries prepared for both Example 1 and the comparative example, as detailed below. Figure 4 As shown, A is the cathode catalyst slurry of the application example, and B is the cathode catalyst slurry of the comparative example. From Figure 4 It can be seen that the Zeta potential of the cathode catalyst slurry prepared using the dispersion system of the example in Application Example 1 is -52.04 mV, while the Zeta potential of the cathode catalyst slurry prepared using the conventional dispersion method in the comparative example is -54.72 mV. Both have high absolute values ​​(far exceeding the stability threshold of ±30 mV), indicating that both slurries possess good electrostatic stability and can effectively resist particle flocculation and agglomeration; although the two values ​​are close, combined with Figure 3 The significantly optimized particle size distribution shows that when the dispersion system of the present invention is used in cathode catalyst slurry, it achieves excellent dispersion without sacrificing the colloidal stability of the system, thus ensuring the long-term stability of the slurry.

[0052] The membrane electrodes prepared for Example 1 and the comparative example were analyzed using laser microscopy; specifically as follows: Figure 5 and Figure 6 As shown. Among them, Figure 5 The image shows a laser microscope image of the membrane electrode of the PEMFC slurry prepared in Example 1. Figure 6 Laser microscope images of the membrane electrodes of the PEMFC slurry prepared for comparison; from Figure 5 It can be clearly observed that the surface of the membrane electrode in Application Example 1 exhibits a highly uniform, dense, and smooth morphology, without obvious large aggregates or pore defects; from Figure 6 It can be clearly observed that, in contrast, the surface of the comparative membrane electrode exhibits significant particle agglomeration and microstructural inhomogeneity. This morphological difference directly confirms that the high-quality slurry prepared using the dispersion system of this invention can be directly transformed into a higher-quality electrode film, which is beneficial for reaction mass transfer and current collection.

[0053] The membrane electrode assembly (MEA) of Application Example 1 and the MEA of the comparative example were assembled into fuel cells with a diffusion layer, a gasket, and a fuel cell test fixture, respectively. The H2-O2 and H2-air polarization curves and power density of the fuel cells were tested using the Qunyi Scribner 850e fuel cell test system, as detailed below. Figure 7 and Figure 8 As shown, A represents the H2-O2 polarization curve and power density test results of the fuel cell assembled with the membrane electrode assembly in the application example, and B represents the H2-air polarization curve and power density test results of the fuel cell assembled with the membrane electrode assembly in the comparative example.

[0054] Figure 7To compare the H2-O2 polarization curves and power density of fuel cells assembled from the membrane electrodes prepared in Example 1 and the comparative example, respectively, from... Figure 7 It can be clearly observed that the membrane electrode prepared using the dispersion system of the present invention exhibits significant performance advantages across the entire current density range, especially in the high current density region, where its voltage drop is significantly smoother, indicating that the battery has superior mass transport characteristics and lower concentration polarization. Ultimately, the fuel cell assembled using the membrane electrode of Example 1 achieved 1.242 W / cm². –2 The peak power density is 0.913 W / cm², compared to the 0.913 W / cm² of the fuel cell assembled with a comparative membrane electrode assembly. –2 The performance improvement is as high as 36%; this directly confirms that the slurry prepared by the dispersion system of the present invention is conducive to the formation of a uniform and dense catalytic layer structure of the membrane electrode, which can more effectively promote the mass transfer of reactant gases, proton conduction and electron transport, thereby greatly improving the high-load operation capability of the battery.

[0055] Figure 8 To compare the H2-air polarization curves and power density of fuel cells assembled from the membrane electrodes prepared in Example 1 and the comparative example, respectively, from... Figure 8 It can be clearly observed that the trend is consistent with that under H2-O2 conditions; the membrane electrode prepared using the dispersion system of this invention exhibits superior overall performance, and the assembled fuel cell shows significantly lower performance degradation in the high current density region compared to the fuel cell assembled with the comparative membrane electrode, highlighting better mass transfer efficiency; the fuel cell assembled with the membrane electrode of Example 1 achieved 0.621 W cm⁻¹ –2 The ultrasonic dispersion electrode is 0.492 W / cm². –2 This result further confirms the universal advantages of the dispersion system of the present invention, indicating that the electrodes prepared by the dispersion system of the present invention not only have excellent performance under high-purity O2 conditions, but also, under actual working conditions such as air containing N2 dilution, which is more likely to cause mass transfer limitation, the efficient three-phase interface and pore structure constructed by it can more effectively ensure the reaction to proceed, thereby obtaining higher power output.

[0056] The above embodiments should not limit the present invention in any way. All technical solutions obtained by equivalent substitution or equivalent conversion fall within the protection scope of the present invention.

Claims

1. A non-contact vacuum collaborative dispersion system based on a vertical collision flow field, characterized in that, include: The acoustic energy emission module (1) includes a base (11) with an acoustic coupling cavity (13) and an ultrasonic generator (12) located below the acoustic coupling cavity, the acoustic coupling cavity (13) being filled with an acoustic coupling medium (14); The reaction unit (2) is a consumable test tube placed in the acoustic coupling cavity (13); The flow field control module (3) includes a vacuum sealing assembly (31), a concentric sleeve type stator-rotor dispersion assembly (33), and a dispersion drive component (32) for driving the concentric sleeve type stator-rotor dispersion assembly (33); the vacuum sealing assembly (31) is used to form an airtight reaction chamber inside the consumable test tube, and the concentric sleeve type stator-rotor dispersion assembly (33) extends into the airtight reaction chamber of the consumable test tube; The concentric sleeve-type stator-rotor dispersion assembly (33) is configured to generate an axially downward mechanical shear jet (C); the ultrasonic source (12) is configured to generate an axially upward acoustic radiation force field (D); the mechanical shear jet (C) and the acoustic radiation force field (D) work together to form a high-energy vertical collision zone (E) inside the consumable test tube.

2. The non-contact vacuum collaborative dispersion system based on a vertical collision flow field according to claim 1, characterized in that, The dispersion system also includes a temperature control module (15), which is located on the base (11) and acts on the acoustic coupling cavity (13) to adjust the temperature of the acoustic coupling medium (14).

3. The non-contact vacuum collaborative dispersion system based on a vertical collision flow field according to claim 1, characterized in that, The distributed system also includes a lifting mechanism (4); the flow field control module (3) is fixed to the lifting end of the lifting mechanism (4).

4. An application of a non-contact vacuum collaborative dispersion system based on a vertical collision flow field, characterized in that, The dispersion system is used for dispersing slurries; wherein the slurry is a proton exchange membrane fuel cell catalyst slurry, an electrolysis water catalyst slurry, a lithium-ion battery slurry, a solid electrolyte slurry, a nano-silver antibacterial coating slurry, or a titanium dioxide self-cleaning coating slurry.

5. The application of the non-contact vacuum collaborative dispersion system based on a vertical collision flow field according to claim 4, characterized in that, The concentric sleeve type stator and rotor dispersion assembly (33) is used to generate strong shear force and forced convection circulation to achieve initial wetting and initial deagglomeration of powder in slurry; the ultrasonic generator (12) is used to generate non-contact high-frequency vibration and cavitation effect to break up micron- and submicron-scale particle agglomerates in slurry; the vacuum sealing assembly (31) is also used to provide the required vacuum degree for the airtight reaction chamber of consumable test tube; the temperature control module (15) is used to maintain the reaction temperature in the airtight reaction chamber of consumable test tube below the solvent boiling point of slurry under the corresponding vacuum degree, so as to avoid drastic phase change of solvent while defoaming in vacuum.

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