A grinding and stirring device

Abstract

The application discloses a kind of grinding stirring devices, comprising: shell, stirring assembly, drive assembly and multiple grinding balls, shell is equipped with for accommodating battery slurry containing cavity;Stirring paddle is connected to the one end of main shaft and extends into containing cavity, and stirring paddle is arranged in arc shape;Drive assembly is drivingly connected with main shaft, can drive main shaft rotation and drive stirring paddle to stir battery slurry;Multiple grinding balls are arranged in containing cavity, can be driven by stirring paddle and grind battery slurry;So that battery slurry generates vortex, violent collision, extrusion and friction between vortex of different layers, between grinding ball and grinding ball, between grinding ball and stirring paddle and between the cavity wall of containing cavity, so as to grind active substance in battery slurry, reduce the diameter of active substance, so that active substance is more evenly distributed in battery slurry glue solution, improve the uniform consistency of battery slurry;Compared with the related art, the structure of the application is simpler, and the cost is lower.

Description

Technical Field

[0001] This application belongs to the field of battery production technology, specifically relating to a grinding and stirring device. Background Technology

[0002] Battery slurry is a stable suspension formed by uniformly dispersing solid components such as active materials, conductive agents, and binders in a solvent. It is the first step in the manufacturing of lithium-ion batteries and one of the most fundamental and critical steps that determines battery performance (capacity, rate capability, lifespan, and safety).

[0003] Battery slurry preparation methods are generally divided into dry mixing and wet mixing. In wet mixing, the binder is first dissolved in a solvent to form a gel, and then the conductive agent and active material are added and mixed to form a stable and continuous "conductive-adhesive" network. However, the active material is in particulate form and is prone to precipitation in the gel, resulting in poor consistency of the prepared battery slurry.

[0004] In related technologies, planetary mixers with multiple stirring shafts are usually used to stir battery slurry. However, on the one hand, the consistency of the final battery slurry is still poor; on the other hand, planetary mixers have a complex structure and high cost. Utility Model Content

[0005] This application aims to provide a grinding and mixing device that at least solves the problem that, while using a planetary mixer with multiple mixing shafts to mix battery slurry, the final consistency of the battery slurry is still poor; and the planetary mixer has a complex structure and high cost.

[0006] To solve the above-mentioned technical problems, this application is implemented as follows: In a first aspect, embodiments of this application propose a grinding and stirring device, comprising: a housing, a stirring assembly, a driving assembly, and a plurality of grinding balls. The housing is provided with a receiving cavity for containing battery slurry. The stirring assembly includes a main shaft and a stirring paddle, the stirring paddle being connected to one end of the main shaft and extending into the receiving cavity, the stirring paddle being arc-shaped. The driving assembly is kinetically connected to the main shaft, the driving assembly driving the main shaft to rotate, thereby driving the stirring paddle to stir the battery slurry. The plurality of grinding balls are disposed in the receiving cavity, and the plurality of grinding balls can grind the battery slurry under the drive of the stirring paddle.

[0007] Optionally, the central angle of the stirring paddle is α, satisfying: 170°≤α≤190°.

[0008] Optionally, the stirring assembly further includes a plurality of support members, which are spaced apart on both sides of the main shaft. One end of each support member is connected to the main shaft, and the other end is connected to the stirring paddle.

[0009] Optionally, the distance between two adjacent supports on the same side of the spindle is greater than the diameter of the grinding ball.

[0010] Optionally, the stacked volume of the plurality of grinding balls is S1, and the volume of the receiving cavity is S2, satisfying: 60%≤S1 / S2≤80%.

[0011] Optionally, the drive assembly includes a drive member and a transmission member. One side of the transmission member is connected to the drive member, and the other side of the transmission member is connected to the main shaft. The drive member drives the transmission member to rotate, thereby driving the main shaft to rotate.

[0012] Optionally, the grinding and stirring device further includes a cover plate, the receiving cavity has an opening, the cover plate seals the opening, the cover plate has a through hole, and the stirring assembly passes through the through hole.

[0013] Optionally, the stirring paddle is provided in multiples, and the multiple stirring paddles are arranged at circumferential intervals along the main shaft.

[0014] Optionally, the grinding and stirring device further includes a base, with one end of the main shaft away from the receiving cavity rotatably connected to the base, the base being used to limit the movement of the main shaft, and the drive assembly being mounted on the base.

[0015] Optionally, the grinding ball is made of zirconium and has a diameter D that satisfies the following condition: 3mm ≤ D ≤ 40mm.

[0016] In the embodiments of this application, the grinding and stirring device includes: a housing, a stirring assembly, a driving assembly, and multiple grinding balls. The housing has a receiving cavity for containing battery slurry. The stirring assembly includes a main shaft and a stirring paddle, with the stirring paddle connected to one end of the main shaft and extending into the receiving cavity. The stirring paddle is arc-shaped. The driving assembly is driven by the main shaft and drives the main shaft to rotate, thereby driving the stirring paddle to stir the battery slurry. Multiple grinding balls are disposed in the receiving cavity and can grind the battery slurry under the drive of the stirring paddle. In this way, the multiple grinding balls can be driven by the stirring paddle to move within the receiving cavity, thereby generating eddies in the battery slurry. Violent collisions, compressions, and friction occur between different layers of eddies, between grinding balls, between grinding balls and the stirring paddle, and between the walls of the receiving cavity. This grinds the active material in the battery slurry, reduces the diameter of the active material, and facilitates a more uniform distribution of the active material in the battery slurry, improving the uniformity of the battery slurry. Compared with related technologies, the structure of this application is simpler and the cost is lower.

[0017] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0018] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a partial cross-sectional view of a grinding and stirring apparatus according to an embodiment of this application; Figure 2 This is an exploded view of a grinding and stirring apparatus according to an embodiment of this application; Figure 3 This is a schematic diagram of a stirring paddle according to an embodiment of this application; Figure 4 This is a solid content test chart of the battery slurry prepared according to the embodiments of this application; Figure 5 This is a resistance test diagram of a battery cell prepared according to an embodiment of this application.

[0019] Figure label: 1: Shell; 10: Receiving cavity; 101: Cavity opening; 2: Stirring assembly; 21: Main shaft; 22: Stirring paddle; 23: Support component; 3: Drive assembly; 31: Drive component; 32: Transmission component; 4: Grinding ball; 5: Cover plate; 51: Through hole. Detailed Implementation

[0020] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0021] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0022] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element 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 application.

[0023] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0024] Before explaining the grinding and stirring apparatus provided in the embodiments of this application, the application scenarios of the grinding and stirring apparatus provided in the embodiments of this application will be specifically described: Battery slurry specifically refers to positive electrode active material slurry or negative electrode active material slurry. Taking positive electrode active material slurry as an example, during wet mixing, the binder PVDF (Polyvinylidene Fluoride) and solvent NMP (N-Methyl-2-pyrrolidone) are usually mixed to form a gel. Then, the conductive agent and active material are added to the gel and stirred. The active material is generally in the form of solid particles. However, battery slurry has "pseudo-thickness" and "pseudo-plasticity." "Pseudo-thickness" specifically refers to the characteristic that the viscosity of the slurry increases with the increase of shear rate (or shear stress); that is, the faster and more vigorously you stir, the thicker it appears and the greater the resistance. "Pseudo-plasticity" specifically refers to the characteristic that the viscosity of the slurry decreases with the increase of shear rate (or shear stress); that is, the faster and more vigorously you stir, the thinner it appears and the better the fluidity. Once stirring stops, it will return to a high viscosity state. Therefore, even when stirred, the active substances that are in the form of solid particles are difficult to distribute evenly throughout the adhesive.

[0025] Taking the stirring of battery slurry in a tank as an example: active materials in the form of solid particles tend to deposit at the bottom of the tank, resulting in a higher solid content in the battery slurry at the bottom and a lower solid content at the top. In other words, the solid content of the battery slurry in the tank is unstable. This will affect the coating effect of the electrode sheet when the battery slurry is coated, resulting in poor dispersion of active materials on the metal foil. Uneven distribution of active materials after coating can easily lead to higher internal resistance of the battery. Solid content specifically refers to the mass percentage of solid matter (active material) in the battery slurry.

[0026] In related technologies, planetary mixers are usually used to stir battery slurry. Specifically, they achieve strong stirring and dispersion through a combination of revolution and rotation. However, the consistency of the solid content of the final battery slurry is still poor, and the structure of planetary mixers is more complex and the cost is higher.

[0027] Therefore, this application provides a grinding and stirring device. The grinding and stirring device provided in this application will be described in detail below with reference to the accompanying drawings and specific embodiments and application scenarios.

[0028] like Figures 1 to 3 As shown, a grinding and stirring apparatus according to some embodiments of this application includes: a housing 1, a stirring assembly 2, a driving assembly 3, and a plurality of grinding balls 4. The housing 1 is provided with a receiving cavity 10 for containing battery slurry. The stirring assembly 2 includes a main shaft 21 and a stirring paddle 22. The stirring paddle 22 is connected to one end of the main shaft 21 and extends into the receiving cavity 10. The stirring paddle 22 is arranged in an arc shape. The driving assembly 3 is driven to rotate the main shaft 21 to drive the stirring paddle 22 to stir the battery slurry. The plurality of grinding balls 4 are disposed in the receiving cavity 10 and can grind the battery slurry under the drive of the stirring paddle 22.

[0029] In this embodiment, multiple grinding balls 4 can move in a circular motion within the receiving cavity 10 under the drive of the stirring paddle 22, thereby generating eddies in the battery slurry. Intense collisions, compressions, and friction occur between the eddies in different layers (from top to bottom) within the receiving cavity 10, between the grinding balls 4, and between the grinding balls 4 and the stirring paddle 22 and the cavity wall of the receiving cavity 10. This grinds the active material within the battery slurry, reducing its diameter and facilitating a more uniform distribution of the active material in the battery slurry, thus improving the uniformity of the battery slurry. Compared to related technologies, this application has a simpler structure and lower cost. Furthermore, by setting the stirring paddle 22 to an arc shape, the battery slurry can be agitated to a greater extent, resulting in more intense circular motion and eddies in the battery slurry and the grinding balls 4.

[0030] It should be noted that the stirring paddle 22 is connected to one end of the main shaft 21 that extends into the receiving cavity 10. The stirring paddle 22 is arc-shaped, so that it can contact the battery slurry over a larger area, thereby agitating the battery slurry to a greater extent. At the same time, it can drive more grinding balls 4 to rotate in a circular motion to grind the active materials in the battery slurry.

[0031] In specific applications, the drive component 3 is connected to the main shaft 21 for transmission. The drive component 3 can be a motor and transmission components, such as a cylinder and transmission components, that can drive the main shaft to rotate. The transmission components can be belts, gear sets, chains, etc. Those skilled in the art can set them according to actual needs, and this application does not limit them.

[0032] Understandably, in practical applications, there is a certain gap between the stirring paddle 22 and the bottom and sidewalls of the receiving cavity 10, so that the stirring paddle 22 can rotate smoothly without friction with the bottom or sidewalls of the receiving cavity 10.

[0033] Specifically, the grinding ball 4 can be a spherical structure made of materials such as zirconium oxide, zirconium, alumina, stainless steel, or zirconium silicate. Those skilled in the art can choose according to actual needs, and this application does not limit this. The grinding ball 4 can be driven by the stirring paddle 22 and the battery slurry to perform circumferential motion in the battery slurry, thereby causing violent impact, rolling, and shearing on the active materials and conductive agents in the battery slurry. This makes the active material particles smaller and can break up the "soft agglomerates" and "hard agglomerates" of the active materials and conductive agents. This makes the active materials in the battery slurry easier to disperse and improves the uniformity of the battery slurry, that is, the consistency of the solid content of the battery slurry is better. Therefore, after the battery slurry is prepared, it is not necessary to measure and select battery slurries with similar solid contents for uniform coating.

[0034] Understandably, the grinding and stirring device also includes a control component, which is electrically connected to the drive assembly 3. The control component can control the start and stop of the drive assembly 3. Specifically, the control component can be a switch or the like.

[0035] In practical applications, the battery slurry preparation process using the grinding and stirring device proposed in this application is as follows: Taking the positive electrode active material slurry as an example: PVDF and NMP are mixed to form a sol solution, a conductive agent and active material are added to the sol solution and initially stirred to form a wet mixture, the wet mixture is placed in the grinding and stirring device for grinding and stirring, and the viscosity, solid content and particle size of the prepared battery slurry are measured after the measurement values ​​meet the requirements. After the above measurement values ​​meet the requirements, processes such as iron removal and sieving are carried out to obtain the final battery slurry.

[0036] In some embodiments of this application, the solid content of battery slurry prepared by related technologies and battery slurry prepared using the grinding and stirring device proposed in this application, as well as the resistance of battery cells prepared using the corresponding battery slurry, are measured and compared. The entire preparation process is identical except for the addition of the grinding and stirring device proposed in this application for grinding and stirring. The battery slurry prepared by related technologies serves as a comparative example, while the battery slurry prepared by the grinding and stirring device proposed in this application serves as an example. The final test structures are shown in Table 1 below: Table 1:

[0037] As can be seen from Table 1 above, the solid content of the battery slurry prepared using the grinding and stirring device proposed in this application is increased by 4 times compared with the related technologies. The average resistance of the battery cells prepared using the battery slurry is reduced by 0.02%, and the total time is reduced by 0.5 hours. Therefore, it can be concluded that the battery slurry prepared using the grinding and stirring device proposed in this application has better uniformity, a shorter process flow, and better coating effect.

[0038] like Figure 3 As shown, in some embodiments of this application, the central angle of the stirring paddle 22 is α, which satisfies: 170°≤α≤190°.

[0039] In this embodiment, by setting the central angle α of the stirring paddle 22 within a reasonable range, the battery slurry can be effectively pumped from the center of the receiving cavity 10 toward the side wall of the receiving cavity, forming a strong radial flow. This breaks the liquid surface vortex, allowing the battery slurry in each region of the receiving cavity 10 to be rapidly exchanged and mixed. The strong radial flow can also carry the active material at the bottom and surface of the receiving cavity 10 into the high shear zone, thereby reducing the diameter of the active material by grinding with the grinding balls 4 and improving the uniformity of the distribution of the active material.

[0040] In specific applications, the central angle α of the agitator 22 can be set to any value such as 170°, 175°, 180°, 185°, 190°, or a range between two arbitrary values.

[0041] Understandably, the stirring paddle 22 is specifically arc-shaped, and the central angle corresponding to the arc shape refers to the central angle corresponding to the arc surface of the stirring paddle 22. In actual measurement, it can be calculated by measuring the arc length and radius of the arc surface of the stirring paddle 22.

[0042] like Figure 1 and Figure 2 As shown, in some embodiments of this application, the stirring assembly 2 also includes a plurality of support members 23, which are spaced apart on both sides of the main shaft 21. One end of each support member 23 is connected to the main shaft 21, and the other end is connected to the stirring paddle 22.

[0043] In this embodiment, multiple support members 23 are spaced apart on both sides of the main shaft 21. One end of each support member 23 is connected to the main shaft 21, and the other end is connected to the stirring paddle 22. Thus, the multiple support members 23 can form a "reinforcing rib", which improves the structural strength and connection reliability of the stirring paddle 22. At the same time, the multiple support members 23 can stir the battery slurry and drive the grinding ball 4 to perform circumferential motion.

[0044] In specific applications, multiple support members 23 are spaced apart on both sides of the main shaft 21, and the two sides of the main shaft 21 correspond to different arc-shaped areas of the agitator 22, so that each area of ​​the agitator 22 can be connected to the main shaft 21 through the support member 23.

[0045] Understandably, one end of each support member 23 is connected to the main shaft 21, and the other end is connected to the agitator 22. Specifically, the connection can be welded, bolted, or otherwise, and those skilled in the art can make the connection according to actual needs. The support member 23 can be made of a high-strength material, such as stainless steel.

[0046] like Figure 1 As shown, in some embodiments of this application, the distance between two adjacent support members 23 located on the same side of the spindle 21 is greater than the diameter of the grinding ball 4.

[0047] In this embodiment, by setting the distance between two adjacent support members 23 on the same side of the main shaft 21 to be greater than the diameter of the grinding ball 4, the grinding ball 4 can pass through the two adjacent support members 23, thereby facilitating the movement of the grinding ball 4 in the receiving cavity 10 and improving the grinding efficiency of the grinding ball 4 on the active material in the battery slurry.

[0048] In specific applications, the spacing between two adjacent support members 23 on the same side of the main shaft 21 specifically refers to the minimum distance between two adjacent support members 23 along the direction perpendicular to the support member 23.

[0049] Understandably, the grinding ball 4 can be driven by the battery slurry, the stirring paddle 22, and the support member 23 to make a circular motion within the receiving cavity 10. The distance between two adjacent support members 23 is set to be greater than the diameter of the grinding ball 4, so that the grinding ball 4 can continuously make a circular motion within the receiving cavity 10, instead of being driven only by the support member 23.

[0050] like Figure 1 As shown, in some embodiments of this application, the stacked volume of the plurality of grinding balls 4 is S1, and the volume of the receiving cavity 10 is S2, satisfying: 60%≤S1 / S2≤80%.

[0051] In this embodiment of the application, by setting the ratio S1 / S2 between the stacked volume S1 of the multiple grinding balls 4 and the volume S2 of the receiving cavity 10 to be within a reasonable range, that is, the filling rate of the grinding balls 4 (the percentage of the volume of the grinding balls 4 in the receiving cavity 10 to the effective volume of the receiving cavity 10) is within a reasonable range, the grinding efficiency can be guaranteed while reducing energy loss and lowering the probability of the battery slurry deteriorating due to excessive temperature.

[0052] It should be explained that when the ratio of the total volume S1 of the multiple grinding balls 4 to the volume S2 of the receiving cavity 10 is S1 / S2 < 60%, that is, the total volume of the grinding balls 4 is too small, the grinding efficiency will not be high enough, resulting in an excessively long grinding and stirring time. On the other hand, when the ratio of the total volume S1 of the multiple grinding balls 4 to the volume S2 of the receiving cavity 10 is S1 / S2 > 80%, that is, the total volume of the grinding balls 4 is too large, the fluidity of the battery slurry will be poor, the overall energy loss of the grinding and stirring device will be large, and the heat generation will be severe, which may cause the battery slurry to denature due to high temperature.

[0053] In specific applications, the ratio S1 / S2 between the accumulated volume S1 of multiple grinding balls 4 and the volume S2 of the receiving cavity 10 can be set to any value such as 60%, 65%, 70%, 75%, 80% or a range between two arbitrary values.

[0054] It should be noted that the accumulated volume S1 of the multiple grinding balls 4 specifically refers to the total space volume occupied by the multiple grinding balls 4 when naturally stacked. This volume includes not only the volume of the grinding balls 4 themselves, but also the gaps between the grinding balls 4. In practical applications, it is generally calculated using the packing density and total mass. For example, if the volume S2 of the accommodating cavity 10 is 10L, and it needs to be filled with grinding balls 4 at a filling rate of 75%, then the accumulated volume S1 of the grinding balls 4 = 10 L × 0.75 = 7.5 L. Taking the packing density of the grinding balls 4 as an example of 3.6 kg / L, then 7.5 L × 3.6 kg / L = 27 kg of grinding balls 4 need to be added.

[0055] like Figure 1 and Figure 2 As shown, in some embodiments of this application, the drive assembly 3 includes a drive member 31 and a transmission member 32. One side of the transmission member 32 is connected to the drive member 31, and the other side of the transmission member 32 is connected to the main shaft 21. The drive member 31 drives the transmission member 32 to rotate, thereby driving the main shaft 21 to rotate.

[0056] In this embodiment, the drive component 31 drives the transmission component 32 to rotate, thereby driving the main shaft 21 to rotate. This facilitates the adjustment of the drive power of the drive component 31 according to actual needs, and allows for the adjustment of the torque and speed of the main shaft 21 as needed, while also facilitating layout.

[0057] In specific applications, the driving component 31 can be a driving component that drives a motor, cylinder, hydraulic cylinder, etc. to rotate, and the transmission component 32 can be a gear set, belt, chain, worm gear, etc. to transmit the rotation of the driving component 31 to the main shaft 21.

[0058] Preferably, the transmission component 32 is a belt, which can buffer and reduce vibration and noise; specifically, when the transmission component 32 is a belt, pulleys are installed at the output ends of the main shaft 21 and the drive component 31, which facilitates belt installation and power transmission.

[0059] like Figure 1 and Figure 2 As shown, in some embodiments of this application, the grinding and stirring device further includes a cover plate 5, the receiving cavity 10 has a cavity opening 101, the cover plate 5 covers the cavity opening 101, the cover plate 5 is provided with a through hole 51, and the stirring assembly 2 passes through the through hole 51.

[0060] In this embodiment, the cover plate 5 is sealed at the cavity opening 101, which can reduce the leakage of battery slurry caused by splashing or volatilization during the stirring process in the cavity 10, and at the same time prevent external impurities (such as dust, moisture, etc.) from entering the cavity 10 and contaminating the battery slurry; the through hole 51 facilitates the insertion of the main shaft 21 of the stirring assembly 2.

[0061] In specific applications, the cover plate 5 covers the cavity 101, and a sealing ring (such as an O-ring, silicone gasket, etc.) is provided between the cover plate 5 and the housing 1. The cover plate 5 and the housing 1 are tightly connected by bolts, buckles, etc. to form a seal. The main shaft 21 passes through the through hole 51, and a dynamic seal is formed between the main shaft 21 and the through hole 51. For example, a rotary oil seal is provided between the two.

[0062] Understandably, in actual use, there is a certain gap between the spindle 21 and the through hole 51, thereby reducing the friction between the spindle 21 and the through hole 51 when the spindle rotates, and the two have a certain degree of concentricity.

[0063] In some embodiments of this application, multiple agitators 22 are provided, and the multiple agitators 22 are arranged at circumferential intervals along the main shaft 21.

[0064] In this embodiment, multiple stirring paddles 22 are arranged at intervals along the circumference of the main shaft 21, and each stirring paddle 22 is connected to one end of the main shaft 21 that extends into the receiving cavity 10, thereby further improving the stirring efficiency of the grinding and stirring device, reducing the stirring time of the battery slurry, and improving the processing efficiency.

[0065] In practical applications, multiple agitators 22 can simultaneously agitate the battery slurry multiple times, thereby ensuring that the battery slurry is agitated by agitators 22 at multiple angles of the main shaft 21, thus reducing the existence of "weak flow zones" and improving the uniformity of the battery slurry.

[0066] Understandably, the number of stirring paddles 22 can be 3, 4, etc. When there are 3 stirring paddles 22, the angle between two adjacent stirring paddles 22 is 120°; when there are 4 stirring paddles 22, the angle between two adjacent stirring paddles 22 is 90°; of course, multiple stirring paddles 22 can also be set asymmetrically. Those skilled in the art can set them according to actual needs, and this application does not limit them.

[0067] like Figure 1 and Figure 2 As shown, in some embodiments of this application, the grinding and stirring device further includes a base (not shown in the figure), one end of the main shaft 21 away from the receiving cavity 10 is rotatably connected to the base, the base is used to limit the main shaft 21, and the drive assembly 3 is mounted on the base.

[0068] In this embodiment, the base can provide a support point for the spindle 21, reduce the possibility of the spindle 21 falling during movement, and provide a mounting platform for the drive component 31 of the drive assembly 3.

[0069] In practical applications, the spindle 21 and the base are rotatably connected by bearings. Of course, in actual applications, bearings are also provided at the bottom of the cavity 10. The end of the spindle 21 away from the cavity opening 101 extends into the bearing at the bottom of the cavity, thereby rotatably connecting with the housing 1. In this way, the spindle 21 can form two rotation base points at both ends (bearings at the base and the bottom of the cavity), thereby reducing the swaying and vibration of the spindle 21 during rotation.

[0070] like Figure 1 and Figure 2 As shown, in some embodiments of this application, the grinding ball 4 is made of zirconium material, and the diameter of the grinding ball 4 is D, satisfying: 3mm≤D≤40mm In this embodiment, the grinding ball 4 is specifically made of zirconium material, which can have high wear resistance and strength. At the same time, by setting the diameter D of the grinding ball 4 within a reasonable range, the grinding effect can be guaranteed while reducing the overall amount of grinding ball 4 used, thus improving the convenience of operation.

[0071] It should be noted that when the diameter D of the grinding ball 4 is less than 3 mm, the grinding ball 4 is too small and cannot effectively grind the active material in the battery slurry; while when the diameter D of the grinding ball 4 is greater than 40 mm, the grinding ball 4 is too large and is not easily driven by the battery slurry and the stirring paddle 22.

[0072] In specific applications, the diameter D of the grinding ball 4 can be set to any value or a range between two arbitrary values, such as 3mm, 5mm, 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm.

[0073] In some embodiments of this application, battery slurry prepared using equipment based on related technologies is used as a comparative example, while battery slurry prepared using the grinding and stirring apparatus of this application is used as an example. The examples differ from the comparative examples only in that the grinding and stirring apparatus proposed in this application is used to grind and stir the battery slurry; all other processes and material dosages are the same. Multiple batch tests have yielded similar results. Figure 4 The solid content comparison shown is as follows: the blue line represents the solid content of the battery slurry in the comparative example, and the orange line represents the solid content of the battery slurry in the example. The vertical axis represents the solid content (%), and the horizontal axis represents the batch (tank) of the battery slurry. It can be seen that the battery slurry prepared using the grinding and stirring apparatus proposed in this application has better consistency in solid content.

[0074] Furthermore, the battery slurry prepared in the comparative and examples is simultaneously coated to form a battery cell. Except for the battery slurry used for coating, the other structures of the battery cells are the same, thereby achieving the desired result. Figure 5 The comparison results of the cell resistance values ​​shown are as follows: the blue line represents the cells in the comparative example, the orange line represents the cells in the embodiment, the vertical axis represents the cell resistance (MΩ), and the horizontal axis represents the number of cells. It can be seen that the cells prepared using the battery slurry prepared by the grinding and stirring apparatus proposed in this application have lower resistance values.

[0075] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0076] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A grinding and stirring device, characterized in that, include: The housing (1) is provided with a receiving cavity (10) for containing battery slurry; The stirring assembly (2) includes a main shaft (21) and a stirring paddle (22). The stirring paddle (22) is connected to one end of the main shaft (21) and extends into the receiving cavity (10). The stirring paddle (22) is arranged in an arc shape. The drive assembly (3) is connected to the main shaft (21) for transmission. The drive assembly (3) drives the main shaft (21) to rotate so as to drive the stirring paddle (22) to stir the battery slurry. Multiple grinding balls (4) are disposed in the receiving cavity (10), and the multiple grinding balls (4) can grind the battery slurry under the drive of the stirring paddle (22).

2. The grinding and stirring apparatus according to claim 1, characterized in that, The central angle of the stirring paddle (22) is α, which satisfies: 170°≤α≤190°.

3. The grinding and stirring apparatus according to claim 2, characterized in that, The stirring assembly (2) also includes a plurality of support members (23), which are spaced apart on both sides of the main shaft (21). One end of each support member (23) is connected to the main shaft (21), and the other end is connected to the stirring paddle (22).

4. The grinding and stirring apparatus according to claim 3, characterized in that, The distance between two adjacent support members (23) on the same side of the main shaft (21) is greater than the diameter of the grinding ball (4).

5. The grinding and stirring apparatus according to any one of claims 1-4, characterized in that, The stacked volume of the multiple grinding balls (4) is S1, and the volume of the receiving cavity (10) is S2, satisfying: 60%≤S1 / S2≤80%.

6. The grinding and stirring apparatus according to any one of claims 1-4, characterized in that, The drive assembly (3) includes a drive member (31) and a transmission member (32). One side of the transmission member (32) is connected to the drive member (31), and the other side of the transmission member (32) is connected to the main shaft (21). The drive member (31) drives the transmission member (32) to rotate, thereby driving the main shaft (21) to rotate.

7. The grinding and stirring apparatus according to any one of claims 1-4, characterized in that, The grinding and stirring device also includes a cover plate (5), and the receiving cavity (10) has a cavity opening (101). The cover plate (5) covers the cavity opening (101), and the cover plate (5) has a through hole (51). The stirring component (2) passes through the through hole (51).

8. The grinding and stirring apparatus according to claim 1, characterized in that, The stirring paddle (22) is provided in multiple ways, and the multiple stirring paddles (22) are arranged at circumferential intervals along the main shaft (21).

9. The grinding and stirring apparatus according to claim 1, characterized in that, The grinding and stirring device also includes a base, and one end of the main shaft (21) away from the receiving cavity (10) is rotatably connected to the base. The base is used to limit the main shaft (21), and the drive assembly (3) is installed on the base.

10. The grinding and stirring apparatus according to claim 1, characterized in that, The grinding ball (4) is made of zirconium material, and the diameter of the grinding ball (4) is D, which satisfies: 3mm≤D≤40mm.

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