An apparatus for making fibrillated dry-matter material

Abstract

This utility model discloses a dry process material preparation device for fibrillation, including a mixing tank and a mixing structure. The mixing tank is used to hold the electrode material to be mixed; the mixing structure is used to mix the electrode material and includes a mixing shaft and mixing blades. The mixing structure includes three sets of mixing blades arranged in the following order from top to bottom on the mixing shaft: angled blades, shearing blades, and bottom-scraping blades. This utility model solves the problems of uneven fibrillation and poor material dispersion during fibrillation, while improving product quality and achieving efficient and safe production.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a device for producing fibrillated dry materials. Background Technology

[0002] With the accelerated global energy structure transformation, the demand for high-performance power batteries in the new energy vehicle industry is experiencing explosive growth. Traditional wet electrode fabrication processes for lithium-ion batteries have significant limitations: this process requires organic solvents such as N-methylpyrrolidone (NMP) as dispersion media, generating large amounts of volatile organic compounds (VOCs) during PVDF binder dissolution, slurry mixing, and subsequent coating and drying. This not only necessitates complex solvent recovery systems but also poses occupational health hazards and environmental risks. The wet process has a production cycle exceeding 7 hours, high energy consumption, and large equipment footprint, severely hindering improvements in battery production efficiency. To overcome these technical bottlenecks, industry pioneers, represented by Tesla, began developing dry electrode fabrication technology. Its core lies in abandoning the solvent system and using mechanofibrillarization to form a three-dimensional network structure with binders such as polytetrafluoroethylene (PTFE), directly mixing and pressing the active materials and conductive agents to form a self-supporting electrode. This innovative process can significantly improve electrode energy density while reducing production costs, aligning better with green manufacturing principles. However, existing dry process technologies face challenges such as uneven fiberization of binders and poor material dispersion, necessitating the development of a dedicated fibrillation equipment. Summary of the Invention

[0003] The purpose of this invention is to provide a dry-process equipment for fibrillating materials, which solves the problems of uneven fibrillation degree and poor material dispersion during the fibrillation process, while improving product quality and achieving efficient and safe production.

[0004] To achieve the above objectives, the technical solution provided by this utility model is as follows:

[0005] This application provides a dry process material preparation equipment for fibrillation, including a mixing tank and a mixing structure. The mixing tank is used to hold electrode materials to be mixed; the mixing structure is used to mix the electrode materials and includes a mixing shaft and mixing blades.

[0006] The stirring structure includes three sets of stirring blades arranged in the following order from top to bottom on the stirring shaft: angled blades, shearing blades, and bottom scraping blades.

[0007] To optimize the above technical solution, the specific limitations also include:

[0008] Each blade of the angled impeller includes a horizontal section connected to the stirring shaft in the middle and an upwardly inclined section away from the stirring shaft, with the horizontal section and the upwardly inclined section connected at an angle.

[0009] The shearing blades include main shearing blades and auxiliary comb teeth. Each main shearing blade has a serrated cutting edge. The auxiliary comb teeth are arranged alternately with the main shearing blades, and the rear end of the auxiliary comb teeth is connected to the stirring shaft by a metal spring plate.

[0010] Each blade of the scraper blade consists of a frame and a scraper mounted on the frame.

[0011] Furthermore, the aforementioned equipment for producing fibrillated dry materials also includes:

[0012] The lifting device is provided, wherein the stirring structure is installed above the stirring tank, and the upper end of the stirring structure is connected to the lifting device. The stirring structure can extend downward into the stirring tank for stirring under the action of the lifting device.

[0013] A cooling device, comprising a cooling pipe connected to a cooling water source, the cooling pipe extending through the stirring shaft.

[0014] Furthermore, the fibrillated dry material production equipment also includes an electrostatic elimination mechanism, which includes a carbon brush array installed on the inner wall of the mixing tank, and the carbon brush array is connected to a grounding wire.

[0015] The carbon brush array is a ring-shaped carbon brush assembly array, and each carbon brush assembly in the array has a support spring at its end.

[0016] Preferably, the carbon brush assembly is mounted on a ceramic insulating base on the inner wall of the mixing tank by means of a support spring. The ceramic insulating base has a guide post at its center, and the carbon brush assembly is connected to a grounding wire passing through the side wall of the mixing tank via the guide post.

[0017] Furthermore, it also includes an upper cover, and the stirring structure can be retracted upwards into the upper cover under the action of the lifting device.

[0018] The stirring shaft has a nested structure, including an outer layer, a middle layer, and an inner layer. The upper end of the outer layer is connected to a first motor, and the lower part is connected to a folding blade. The upper end of the middle layer is connected to a second motor, and the lower part is connected to a shearing blade. The upper end of the inner layer is connected to a third motor, and the lower part is connected to a bottom scraping blade. The cooling pipe is located inside the middle layer.

[0019] The mixing tank has a jacket, and a temperature detection device is installed in the jacket.

[0020] Compared with the prior art, the beneficial effects of this utility model are:

[0021] This invention incorporates cooling pipes within the stirring structure to alleviate the high temperatures generated during stirring, thereby precisely controlling the stirring process within the required temperature range. This prevents partial thermal degradation of the material caused by localized overheating under the high-speed shearing action of the fibrillated stirring structure, ensuring the stirring process is precisely controlled within the required temperature range.

[0022] This invention utilizes a mixing structure with three sets of blades—angled blades, shearing blades, and bottom-scraping blades—to produce uniform, high-quality materials.

[0023] This invention reduces static electricity and improves safety through an electrostatic elimination mechanism. Attached Figure Description

[0024] Figure 1 : A schematic diagram of the structure of the fibrillated dry material production equipment of this utility model.

[0025] Figure 2 : Schematic diagram of the angled blade structure.

[0026] Figure 3 : Schematic diagram of the auxiliary structure of the shear blade.

[0027] Figure 4 : Side view of the bottom scraper blade.

[0028] Figure 5 : Schematic diagram of the carbon brush array structure.

[0029] Figure 6 Cross-sectional view of the nested structure of the stirring shaft.

[0030] Figure 7 Electron micrograph of cathode material stirred by a protofibrillation dry process material production equipment.

[0031] Figure 8 Electron micrograph of negative electrode material after being stirred by the protofibrillation dry material production equipment.

[0032] In the diagram: 1-Agitator, 2-Agitator shaft, 2-1-Outer structure, 2-2-Middle structure, 2-3-Inner structure, 3-Cooling pipe, 4-Angled blade, 5-Shearing blade, 6-Bottom scraper blade, 7-Horizontal section, 8-Upper inclined section, 9-Main shearing blade, 10-Auxiliary comb teeth, 11-Metal spring plate, 12-Frame, 13-Scraper, 14-Carbon brush assembly, 15-Upper cover, 16-Ceramic insulation base, 17-Guide post, 18-Reinforcing rib, 19-Supporting spring, 20-Inner wall of the agitator. Detailed Implementation

[0033] The present invention will be further described in detail below through specific embodiments. However, it should not be construed as the scope of the present invention being limited to the following embodiments. All technologies implemented based on the present invention fall within the scope of the present invention.

[0034] In the description of this utility model, it should also be noted that the orientation or positional relationship is based on the relationship shown in the accompanying drawings, and is only for the convenience of describing this utility model and simplifying the description, and is not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0035] This utility model provides a device for producing fibrillated dry materials, such as... Figure 1 As shown, it includes:

[0036] Stirring tank 1, the stirring tank is used to hold the electrode material to be stirred;

[0037] The stirring structure is installed above the mixing tank 1. The upper end of the stirring structure is connected to a lifting device. The stirring structure can extend downward into the mixing tank 1 for stirring under the action of the lifting device.

[0038] The cooling device includes a cooling pipe 3 connected to a cooling water source, and the cooling pipe 3 passes through the stirring structure.

[0039] And an electrostatic elimination mechanism, which includes a carbon brush array installed on the inner wall 20 of the mixing tank, the carbon brush array being connected to a grounding wire.

[0040] In the production of dry materials, common main materials such as PTFE are prone to fibrillation at 80-95℃. Therefore, fibrillation usually needs to be carried out in the range of 80-90℃. However, under the high-speed shearing action of the fibrillation stirring structure, local overheating is easily caused, exceeding 90℃, which will lead to partial thermal degradation of the material.

[0041] This invention alleviates the high temperatures generated during mixing by incorporating a cooling pipe 3 within the mixing structure. In some embodiments, the mixing tank has a jacket containing a temperature detection device to control the temperature during production. Combined with real-time temperature measurement, the mixing process can be precisely controlled within the required temperature range by setting the water temperature and flow rate in the cooling pipe 3. The mixing tank has a push-pull handle on its outer wall and casters at the bottom for easy material transfer after mixing.

[0042] Static electricity can accumulate during the stirring process. This invention reduces static electricity and improves safety by using a static elimination mechanism.

[0043] The stirring structure includes a stirring shaft 2 and three sets of stirring blades. The three sets of stirring blades are arranged on the stirring shaft 2 in the following order from top to bottom: angle blade 4, shearing blade 5, and bottom scraping blade 6.

[0044] In some implementations, such as Figure 2 As shown, each blade of the angled blade 4 includes a horizontal section 7 connected to the stirring shaft 2 in the middle and an upwardly inclined section 8 away from the stirring shaft 2. The horizontal section 7 and the upwardly inclined section 8 are connected at an angle, thereby forming a stirring vortex. The angled blade 4 plays the role of inward turning. During the stirring process, the material will move to all sides due to rotational inertia. The angled blade 4 mainly turns the material from all sides to the center. By continuously turning the material from all sides to the center, the mixing uniformity of the material can be improved, thereby achieving uniform stirring and fiberization treatment of the entire interior.

[0045] In some implementations, such as Figure 3 As shown, the shearing blade 5 includes a main shearing blade 9 and auxiliary comb teeth 10. Each main shearing blade 9 has a sharp blade surface at a 45° angle. The auxiliary comb teeth 10 are arranged alternately with the main shearing blade 9. The rear end of the auxiliary comb teeth 10 is connected to the stirring shaft 2 through a metal spring plate 11. The main shearing blade 9 is used for the main shearing action, and the auxiliary comb teeth 10 are used to supplement the main shearing blade 9. The shearing blade 5 plays the main role in dispersion and fiberization. It comes into contact with the material and shears it. During rotation, it continuously draws and fibers the adhesive, making it a key component for adhesive fiberization.

[0046] In some implementations, such as Figure 4 As shown, each blade of the bottom scraper 6 consists of a frame 12 and a scraper 13 mounted on the frame 12. The scraper 13 is preferably made of polytetrafluoroethylene and has stainless steel reinforcing ribs 18 embedded in it. Specifically, the gap between the scraper 13 and the bottom of the mixing tank is ≤1mm, which is used to forcibly scrape off the caking material and eliminate the material retention at the bottom of the tank. The bottom scraper 6 has two functions: one is to turn the material upward during the rotation of the blade, and the other is to scrape off the material in the dead corner position and mix it evenly.

[0047] Preferably, the cooling pipe 3 runs through the stirring shaft 2, wherein the connecting sections of the angled blade 4, the shearing blade 5 and the bottom scraping blade 6 with the cooling pipe 3, such as the horizontal section 7 of the angled blade 4, the main shearing blade 9 of the shearing blade 5, the rear end spring plate of the auxiliary comb teeth 10 of the shearing blade 5, and the skeleton 12 of the bottom scraping blade 6 are preferably made of a metal material that is easy to conduct heat.

[0048] In some implementations, such as Figure 5 As shown, the carbon brush array is a ring-shaped carbon brush assembly 14 array, and each carbon brush assembly 14 in the array has a metal support spring 19 at its end.

[0049] The carbon brush assembly 14 is mounted on a ceramic insulating base 16 located on the inner wall 20 of the mixing tank via a support spring 19. A guide post 17 is provided at the center of the ceramic insulating base 16, and the carbon brush assembly 14 is connected to a grounding wire passing through the side wall of the mixing tank 1 via the guide post 17. Static electricity generated by material friction is collected by the carbon brush and discharged from the grounding wire through the guide post 17. The ceramic insulating base 16 can maintain its insulation performance in a corrosive environment, eliminating the risk of current bypass.

[0050] Preferably, alternating reinforcing ribs 18 are provided on the inner wall 20 of the mixing tank, and the carbon brush assembly 14 is mounted on the reinforcing ribs 18 through a ceramic insulating base 16; the setting of the reinforcing ribs 18 can improve the rigidity of the mixing tank 1 and reduce the vibration amplitude.

[0051] In some embodiments, an upper cover 15 is also included, and the stirring structure can be retracted upwards into the upper cover 15 by the action of the lifting device. A lifting motor is also provided, and a lifting guide rail is provided at the rear of the entire stirring tank, which can be moved up and down.

[0052] In some implementations, the stirring shaft has a nested structure, such as... Figure 6 As shown, the stirring shaft has a nested structure, including an outer layer, a middle layer, and an inner layer. The upper end of the outer layer is connected to a first motor, and the lower part is connected to a folding blade. The upper end of the middle layer is connected to a second motor, and the lower part is connected to a shearing blade. The upper end of the inner layer is connected to a third motor, and the lower part is connected to a bottom scraper blade. Cooling pipes are located inside the middle layer. The stirring shaft is controlled by three motors. During normal production, the stirring blade 5 rotates at a high speed of 2000-3000 rpm and is independently controlled by one motor. The folding blade 4 and the bottom scraper blade 6 have slower stirring speeds of 20-50 rpm and are independently controlled by the other two motors. The specific connection method for controlling the rotation of different shafts through separate power sources can refer to existing technology and will not be elaborated here.

[0053] The dry materials treated in the above way can be better hot-pressed into films, and the electrode electrical properties are good.

[0054] The dry electrode method has the following advantages:

[0055] (1) Improve battery performance: Dry electrode technology does not use solvents, which can reduce energy loss during charge and discharge cycles and improve the energy density and capacity of the battery. The energy density of dry electrode can exceed 300Wh / kg and has the potential to reach 500Wh / kg.

[0056] (2) Reduced cost: The preparation process of dry electrode technology is relatively simple, which can reduce the use of solvents and wastewater treatment in the production process. The number of equipment and the planned land area are greatly reduced. The electrode drying and solvent recovery process is eliminated, resulting in lower cell manufacturing costs.

[0057] (3) Environmental advantages: Since no solvents are used, the dry electrode technology reduces the emission of harmful substances during the production process, which meets the current global requirements for environmental protection and sustainable development.

[0058] The technical solution of the present invention will be further described in detail below with reference to specific embodiments:

[0059] The positive electrode ternary NCM material, conductive agent SP, and PTFE were added together to the mixing tank 1 in the proportions shown in Table 1; the equipment of this invention was used as Example 1, and the conventional double planetary mixer in the prior art was used as Comparative Example 1;

[0060] The stirring speed and dispersion speed are set separately. The stirring speed refers to the speed at which the material is mixed evenly after being added to the mixing tank, and the dispersion speed refers to the speed at which the PTFE is fiberized. The actual temperature during the stirring process is controlled by setting a cooling device to maintain it at about 80°C.

[0061] About one hour after fiberization, the material was tested to form a self-supporting membrane using a twin-roll press. The results are shown in Table 1. Ordinary mixers cannot make the PTFE binder form a stringy state.

[0062] Table 1

[0063]

[0064] Verification has shown that the equipment of this invention can produce high-quality fibrous materials.

[0065] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Any simple modifications, equivalent substitutions, and improvements made by those skilled in the art to the above embodiments without departing from the scope of the present utility model's technical solution and based on the technical essence of the present utility model shall still fall within the protection scope of the present utility model's technical solution.

Claims

1. A device for producing fibrillated dry materials, characterized in that: The device includes a mixing tank and a stirring structure. The mixing tank is used to hold electrode material to be stirred. The stirring structure is used to stir the electrode material and includes a stirring shaft and stirring blades. The stirring structure includes three sets of stirring blades arranged in the following order from top to bottom on the stirring shaft: angled blades, shearing blades, and bottom scraping blades.

2. The equipment for producing fibrillated dry materials according to claim 1, characterized in that: Each blade of the angled impeller includes a horizontal section connected to the stirring shaft in the middle and an upwardly inclined section away from the stirring shaft, with the horizontal section and the upwardly inclined section connected at an angle.

3. The equipment for producing fibrillated dry materials according to claim 1, characterized in that: The shearing blades include main shearing blades and auxiliary comb teeth. Each main shearing blade has a serrated cutting edge. The auxiliary comb teeth are arranged alternately with the main shearing blades, and the rear end of the auxiliary comb teeth is connected to the stirring shaft by a metal spring plate.

4. The equipment for producing fibrillated dry materials according to claim 1, characterized in that: Each blade of the scraper blade consists of a frame and a scraper mounted on the frame.

5. The equipment for producing fibrillated dry materials according to claim 1, characterized in that: The aforementioned fibrillated dry material production equipment also includes: The lifting device is provided, wherein the stirring structure is installed above the stirring tank, and the upper end of the stirring structure is connected to the lifting device. The stirring structure can extend downward into the stirring tank for stirring under the action of the lifting device. A cooling device, comprising a cooling pipe connected to a cooling water source, the cooling pipe extending through the stirring shaft.

6. The equipment for producing fibrillated dry materials according to claim 1, characterized in that: The fibrillated dry material production equipment also includes an electrostatic elimination mechanism, which includes a carbon brush array installed on the inner wall of the mixing tank, and the carbon brush array is connected to a grounding wire.

7. The equipment for producing fibrillated dry materials according to claim 6, characterized in that: The carbon brush array is a ring-shaped carbon brush assembly array, and each carbon brush assembly in the array has a support spring at its end; the carbon brush assembly is mounted on a ceramic insulating seat set on the inner wall of the mixing tank by means of the support spring, and a guide post is provided at the center of the ceramic insulating seat, and the carbon brush assembly is connected to a grounding wire passing through the side wall of the mixing tank by means of the guide post.

8. The equipment for producing fibrillated dry materials according to claim 5, characterized in that: It also includes an upper cover, and the stirring structure can be retracted upwards into the upper cover under the action of the lifting device.

9. The equipment for producing fibrillated dry materials according to claim 5, characterized in that: The stirring shaft has a nested structure, including an outer layer, a middle layer, and an inner layer. The upper end of the outer layer is connected to a first motor, and the lower part is connected to a folding blade. The upper end of the middle layer is connected to a second motor, and the lower part is connected to a shearing blade. The upper end of the inner layer is connected to a third motor, and the lower part is connected to a bottom scraping blade. The cooling pipe is located inside the middle layer.

10. The equipment for producing fibrillated dry materials according to claim 1, characterized in that: The mixing tank has a jacket, and a temperature detection device is installed in the jacket.

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