Mixing assembly and mixing device

Abstract

A mixing assembly and a mixing device. The mixing assembly (100) comprises a helical ribbon impeller (10) and an axial flow impeller (20); the helical ribbon impeller (10) comprises helical ribbon blades (11) and a rotating shaft (12); the helical ribbon blades (11) are fixed to the rotating shaft (12) and are configured to mix a slurry; the axial flow impeller (20) comprises an axial flow blade (21) and a driving shaft (22); the axial flow blade (21) is arranged between the helical ribbon blades (11) and the rotating shaft (12) and is connected to the driving shaft (22); the axial flow blade (21) is provided with a plurality of oblique blade segments (211); the plurality of oblique blade segments (211) are sequentially arranged at intervals along the circumferential direction of the axial flow blade (21); and the oblique blade segments (211) are configured to drive the slurry to circulate axially.

Description

Stirring assembly and stirring device

[0001] Related applications

[0002] The present application claims priority to the Chinese patent application No. 202421944843.2, filed on August 12, 2024, and entitled “Stirring assembly and stirring device”, the entire content of which is incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to, but is not limited to, the technical field of slurry preparation in lithium battery electrodes, and in particular to a stirring assembly and a stirring device. BACKGROUND

[0004] In the manufacturing process of lithium batteries, the first process of lithium battery electrodes is slurry preparation, and the consistency of the slurry determines the performance of the lithium battery. Currently, the slurry preparation equipment on the market mainly includes PD double planetary mixers, circulating slurry preparation machines, and double screw slurry preparation machines. Among them, the negative electrode circulating slurry preparation machine needs to add SBR (styrene-butadiene rubber) to improve the adhesion and cohesion of the slurry and the current collector (copper foil). SBR is an oily rubber substance that needs to be fully mixed with graphite slurry and more uniformly adhered to the current collector.

[0005] In an alternative way, the stirring and dispersing units of the circulating slurry preparation machine and the double planetary mixer are both sawtooth-shaped dispersing discs for dispersion and screw belt paddles for stirring. The stirring and mixing capacity is insufficient, resulting in the phenomenon that the prepared slurry has a low roll-off force. When the above-mentioned slurry is applied to the lithium battery electrodes of the battery cell, it greatly increases the risk of material falling off during disassembly of the battery cell, thereby adversely affecting the safety and electrical performance of the battery. SUMMARY

[0006] The following is a summary of the subject matter of the detailed description herein. This summary is not intended to limit the scope of the claims.

[0007] According to various embodiments of the present application, a stirring assembly and a stirring device are provided.

[0008] The present application provides a stirring assembly, comprising:

[0009] The screw belt paddle comprises a screw belt paddle blade and a rotating shaft, the screw belt paddle blade is fixed to the rotating shaft and is arranged to stir the slurry.

[0010] The axial flow propeller paddle comprises an axial flow propeller blade and a driving shaft, the axial flow propeller blade is arranged between the screw belt paddle blade and the rotating shaft and is connected with the driving shaft, the axial flow propeller blade has a plurality of inclined paddle pieces, the plurality of inclined paddle pieces are arranged in sequence and at intervals along the circumferential direction of the axial flow propeller blade, and the inclined paddle pieces are arranged to drive the slurry to circulate axially.

[0011] In the process of stirring the slurry by the screw blade, the slurry is driven to circulate axially by the inclined blade on the axial flow propeller to achieve kneading of the slurry, which can greatly improve the mixing uniformity of the slurry after stirring by the stirring assembly and improve the roll pressure and peel force data of the slurry, so that the subsequent application of the slurry in the lithium battery electrode can improve the adhesion of the slurry after being compounded with the current collector, which can solve the problem of disassembly and material falling of the battery cell, thereby ensuring the safety and electrical performance of the lithium battery.

[0012] In an embodiment, the number of axial flow propeller blades is configured as multiple, and multiple axial flow propeller blades are arranged in sequence along the axial direction of the drive shaft.

[0013] The multiple axial flow propeller blades are used to achieve kneading of the slurry, which can further improve the mixing uniformity of the slurry after stirring by the stirring assembly.

[0014] In an embodiment, further comprising: an inclined blade, the inclined blade is arranged between the screw blade and the rotating shaft, and the inclined blade can rotate under the drive of the rotating shaft, and is configured to drive the slurry to circulate axially.

[0015] The inclined blade can drive the slurry to circulate axially while the screw blade is stirring the slurry, which can further improve the mixing uniformity of the slurry after stirring by the stirring assembly.

[0016] In an embodiment, the projection of the inclined blade in the radial direction of the rotating shaft towards the rotating shaft is arranged at a different position from the inclined blade in the axial direction of the rotating shaft.

[0017] Through the above structure, the inclined blade on the axial flow propeller and the inclined blade can avoid interference with each other during rotation, which can make the arrangement between the axial flow propeller and the screw blade more compact, and reduce the overall volume of the stirring assembly.

[0018] In an embodiment, the inclined blade and the axial flow propeller blade are correspondingly arranged, and the inclined blade is arranged above the corresponding axial flow propeller blade in the axial direction of the rotating shaft.

[0019] In an embodiment, further comprising: a baffle, the baffle is arranged between the screw blade and the rotating shaft.

[0020] The baffle is used to block the flow of part of the slurry to form a disordered vortex, which can further improve the mixing uniformity of the slurry after stirring by the stirring assembly.

[0021] In an embodiment, in the radial direction of the rotating shaft, the baffle and the drive shaft are arranged on both sides of the rotating shaft.

[0022] The baffle and the driving shaft arrangement are arranged on both sides of the rotating shaft in the radial direction, so as to avoid the position interference between the baffle and the axial flow propeller in the rotating process.

[0023] In an embodiment, further comprising: an inclined paddle, arranged between the screw paddle and the rotating shaft, and capable of rotating under the driving of the rotating shaft, and arranged to drive the axial circulation of the slurry.

[0024] The stirring assembly further comprises a baffle, which is arranged at least partially between the screw paddle and the rotating shaft.

[0025] Through the above structure, the mixing uniformity of the slurry after stirring by the stirring assembly can be further improved.

[0026] In an embodiment, a notch is formed in the baffle, the notch is arranged corresponding to the inclined paddle, and the inclined paddle partially extends into the corresponding notch.

[0027] The notch in the baffle accommodates part of the inclined paddle, so as to realize the avoidance of the baffle to the inclined paddle, so that the baffle can be arranged close to the inclined paddle, and the collision between the baffle and the inclined paddle is prevented.

[0028] A stirring device, comprising: a stirring assembly, the stirring assembly comprising:

[0029] A screw paddle comprising a screw paddle and a rotating shaft, the screw paddle being fixed to the rotating shaft and arranged to stir the slurry.

[0030] An axial flow propeller comprising an axial flow propeller and a driving shaft, the axial flow propeller being arranged between the screw paddle and the rotating shaft and connected to the driving shaft, the axial flow propeller having a plurality of inclined paddle pieces, the plurality of inclined paddle pieces being arranged in sequence and spaced along the circumferential direction of the axial flow propeller, and the inclined paddle pieces being arranged to drive the axial circulation of the slurry.

[0031] The details of one or more embodiments of the application are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the application will be apparent from the description, drawings, and claims.

[0032] Other aspects can become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0033] For a better description and illustration of the embodiments and / or examples of the inventions disclosed herein, reference can be made to one or more of the accompanying drawings. Additional details or examples used to describe the drawings should not be considered as limiting the scope of any of the disclosed inventions, the presently described embodiments and / or examples, and the best mode presently understood of these inventions.

[0034] Fig. 1 is a structural schematic diagram of a stirring assembly provided by an embodiment of the present application.

[0035] Fig. 2 is a comparative schematic diagram of the stirring assembly of different embodiments of the present application and a conventional sawtooth disperser disc peeling test. DETAILED DESCRIPTION

[0036] The present application provides a stirring assembly 100, which is applied to a circulating pulp preparation device, and specifically can be applied to a stirring device of the circulating pulp preparation device, where the circulating pulp preparation device is used to prepare slurry of lithium battery electrodes, and the stirring device can be specifically a disperser tank or a finished product tank of the circulating pulp preparation device.

[0037] As shown in Fig. 1, the stirring assembly 100 provided by an embodiment of the present application includes a ribbon paddle 10 and an axial propeller 20. The ribbon paddle 10 includes a ribbon paddle blade 11 and a rotating shaft 12, and the ribbon paddle blade 11 is fixed to the rotating shaft 12 and used to stir the slurry. The axial propeller 20 includes an axial propeller blade 21 and a driving shaft 22, and the axial propeller blade 21 is arranged between the ribbon paddle blade 11 and the rotating shaft 12 and connected to the driving shaft 22. The axial propeller blade 21 has a plurality of inclined paddle pieces 211, which are arranged in sequence and at intervals along the circumferential direction of the axial propeller blade 21, and the inclined paddle pieces 211 are used to drive the slurry to circulate axially.

[0038] The present application includes the following advantages: in the process of stirring the slurry by the ribbon paddle blade 11 on the ribbon paddle 10, the slurry is driven to circulate axially by the inclined paddle pieces 211 on the axial propeller 20, so as to realize kneading of the slurry, which can greatly improve the mixing uniformity of the slurry after stirring by the stirring assembly 100, and improve the roll pressure peeling force data of the slurry, so that the slurry can improve the adhesion after being applied to the lithium battery electrode and being compounded with the current collector, which can solve the problem of disassembling and dropping of the battery cell, thereby ensuring the safety and electrical performance of the lithium battery. Here, the current collector specifically refers to a copper foil of the lithium battery electrode. It should be noted that, since the axial propeller blade 21 is arranged between the ribbon paddle blade 11 and the rotating shaft 12, the arrangement of the axial propeller 20 does not increase the overall size of the stirring assembly 100.

[0039] It should be noted that the axial flow propeller 20 drives the inclined paddle 211 to push and extrude the slurry obliquely downward in the rotating process, so that the slurry is driven to circulate axially, and finally achieves the kneading effect on the slurry to fully mix the slurry. Here, the number of inclined paddles 211 in the axial flow propeller 21 is configured to be three. Of course, in other embodiments, the number of inclined paddles 211 in the axial flow propeller 21 can also be configured to be two, four, or even more. It should be noted that the inclination angle of the inclined paddle 211 is between 30° and 45°, which can be set according to the use requirements, wherein the axial circulation of the above-mentioned slurry specifically refers to the circulation of the slurry at a certain angle with the circulation direction of the slurry when the slurry is stirred by the ribbon paddle 11.

[0040] As shown in FIG. 1, the ribbon paddle 11 is sleeved on one end of the rotating shaft 12 in the circumferential limiting manner, and the assembly connection between the ribbon paddle 11 and the rotating shaft 12 is achieved. When the stirring assembly 100 works, the rotation of the rotating shaft 12 can drive the ribbon paddle 11 to stir the slurry. It should be noted that the above-mentioned ribbon paddle 11 on the ribbon 10 can be in the conventional manner of the existing ribbon, which will not be expanded here.

[0041] As shown in FIG. 1, in one embodiment, the rotating shaft 12 is provided with an inclined paddle 13, which is arranged between the ribbon paddle 11 and the rotating shaft 12, and the inclined paddle 13 can rotate under the drive of the rotating shaft 12 to drive the slurry to circulate axially. That is, the ribbon 10 can drive the slurry to circulate axially while stirring the slurry with the ribbon paddle 11, which can further improve the mixing uniformity of the slurry after stirring by the stirring assembly 100. Here, the inclined paddle 13 is sleeved on the rotating shaft 12 in the circumferential limiting manner, and the assembly connection of the inclined paddle 13 on the rotating shaft 12 is achieved, wherein each inclined paddle 13 includes two symmetrical blades 131.

[0042] As shown in FIG. 1, the number of axial flow propeller blades 21 is configured to be multiple, and the multiple axial flow propeller blades 21 are fixed to the driving shaft 22 in sequence along the axial direction of the driving shaft 22. When the stirring assembly 100 works, the rotation of the driving shaft 22 can drive the axial flow propeller blades 21 to knead the slurry. The stirring assembly 100 of the present application uses multiple axial flow propeller blades 21 to knead the slurry, which can further improve the mixing uniformity of the slurry after stirring by the stirring assembly 100. Here, the number of axial flow propeller blades 21 is configured to be two, of course, in other embodiments, the number of axial flow propeller blades 21 can also be configured to be one, three, or even more, which will not be expanded here.

[0043] As shown in FIG. 1, in one embodiment, the projection of the inclined paddle 211 on the axial flow propeller blade 21 in the radial direction of the rotating shaft 12 is arranged at a different position in the axial direction of the rotating shaft 12 from the inclined paddle 13, that is, the inclined paddle 211 on the axial flow propeller blade 20 is arranged in a staggered manner with the inclined paddle 13 on the ribbon paddle 10, and the inclined paddle 211 and the inclined paddle 13 are arranged to avoid interference with each other during rotation, so that the axial flow propeller blade 20 and the ribbon paddle 10 can be arranged more compactly, and the stirring assembly 100 can be added to the original ribbon paddle 10. Here, the projection of the inclined paddle 211 on the axial flow propeller blade 21 and the inclined paddle 13 on the ribbon paddle 10 in the axial direction of the rotating shaft 12 partially overlaps.

[0044] As shown in FIG. 1, the inclined paddle 13 is arranged corresponding to the axial flow propeller blade 21, and the inclined paddle 13 is arranged above the corresponding axial flow propeller blade 21 in the axial direction of the rotating shaft 12. It can be understood that in other embodiments, the number of inclined paddles 13 and the number of axial flow propeller blades 21 can also be different, and the inclined paddle 13 can also be arranged below the corresponding axial flow propeller blade 21, which will not be described here.

[0045] As shown in FIG. 1, the stirring assembly 100 further comprises a baffle 30, the baffle 30 is at least partially inserted between the ribbon paddle blade 11 and the rotating shaft 12, and part of the flowing slurry can hit the baffle 30. That is, the stirring assembly 100 can use the baffle 30 to block part of the slurry flow, so that the slurry forms a disordered vortex, which can further improve the mixing uniformity of the slurry after stirring by the stirring assembly 100. It should be noted that since the baffle 30 is at least partially inserted between the ribbon paddle blade 11 and the rotating shaft 12, the arrangement of the baffle 30 does not increase the overall size of the stirring assembly 100.

[0046] In one embodiment, the baffle 30 is arranged on the side of the ribbon paddle 10 away from the axial flow propeller blade 20 on the rotating shaft 12, and the baffle 30 can be provided with a notch 31 in order to avoid the inclined paddle 13 on the ribbon paddle 10, the notch 31 is arranged corresponding to the inclined paddle 13, and part of the inclined paddle 13 can extend into the corresponding notch 31.

[0047] As can be seen from the above, when the stirring assembly 100 of the present application works, the axial flow propeller blade 21 on the axial flow propeller blade 20 and the inclined paddle 13 on the ribbon paddle 10 can respectively drive the slurry to circulate axially, and in this process, the baffle 30 can block the flow of part of the slurry to form a disordered vortex, so that the slurry can be fully stirred to greatly improve the mixing uniformity of the slurry after stirring by the stirring assembly 100, and improve the data of the roll pressure and stripping force of the slurry.

[0048] It should be noted that the stirring assembly 100 of the present application is applied to the circulating pulp preparation process equipment. By promoting the axial circulation of the pulp and the mixing and exchange of the pulp at different positions in the tank, the mixing uniformity of the pulp in the stirring tank can be improved, thereby improving the adhesion of the pulp prepared by the circulating pulp preparation process equipment after being combined with the current collector. This can solve the problem of poor adhesion of the negative electrode circulating pulp preparation machine in the industry, which can solve the quality risk of material falling off during the disassembly of the battery cell in actual production. Moreover, the whole electrode SEM view interface of the electrode sheet prepared by collecting the pulp and the current collector after drying is good, and the mixing uniformity and consistency are high.

[0049] As shown in FIG. 2, in the original process, when the traditional sawtooth dispersing disc is used in the stirring and dispersing unit of the circulating pulp preparation process equipment, the roller pressing peeling force of the pulp prepared by the circulating pulp preparation process equipment is 3.73 N / m. In scheme one, when only the axial flow propeller 20 is used in the stirring and dispersing unit of the circulating pulp preparation process equipment, the roller pressing peeling force of the pulp prepared by the circulating pulp preparation process equipment is 5.22 N / m. In scheme two, when the inclined paddle 13 is arranged on the rotating shaft 12 of the screw belt paddle 10 on the basis of the axial flow propeller 20 used in the stirring and dispersing unit of the circulating pulp preparation process equipment, the roller pressing peeling force of the pulp prepared by the circulating pulp preparation process equipment is 5.71 N / m. In scheme three, when the axial flow propeller 20 is used, the inclined paddle 13 is arranged on the rotating shaft 12 of the screw belt paddle 10, and the baffle 30 is additionally arranged in the stirring and dispersing unit of the circulating pulp preparation process equipment, the roller pressing peeling force of the pulp prepared by the circulating pulp preparation process equipment is 6.56 N / m. Obviously, by comparing the data of the roller pressing peeling force of the pulp, it can be concluded that when the stirring assembly 100 of the present application is applied to the circulating pulp preparation process equipment, the roller pressing peeling force of the prepared pulp can be greatly improved. This can greatly reduce the quality risk of material falling off when the pulp is subsequently applied to the lithium battery electrode, and improve the consistency of the quality of the lithium battery product. It can be understood that for those skilled in the art, when the roller pressing peeling force of the pulp is greater than or equal to 5 N / m, the problem of material falling off after the pulp is combined with the current collector during the disassembly of the battery cell can be solved.

[0050] In addition, the present application also provides a stirring device comprising the above-mentioned stirring assembly 100.

[0051] It should be noted that the process flow state of the existing circulating pulping process equipment in the slurry preparation process is: circulating tank-dispersing tank-finished product tank-transferring tank. Specifically, after the powder material is mixed in the high mixing bin, it needs to be self-circulated in the circulating tank to ensure that the powder material and the liquid material are fully contacted and mixed. This process is similar to the kneading process of traditional double-planet equipment. The high-viscosity slurry after circulation will be transferred to the dispersing tank for secondary dispersion and further shearing. Through high-speed shearing, the slurry viscosity and fineness can reach the set viscosity value, so that the prepared slurry can be uniformly coated on the current collector. The dispersed slurry is transferred to the finished product tank for vacuum degassing and slow stirring process, and then transferred to the coating transfer tank for coating. If the stirring assembly 100 of the present application is applied to the finished product tank, the dispersing tank process can be directly omitted. Thus, the overall process time of the circulating slurry machine in the production process mode can be saved, and the overall time of the circulating slurry machine during slurry preparation can be compressed from 160 minutes to 100 minutes, the production efficiency is improved by 37%, and the slurry production efficiency is greatly improved.

[0052] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, but as long as the combinations of the technical features do not exist, they should be considered as within the scope of the present disclosure.

[0053] The above-described embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the patent scope of the application. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A stirring assembly, comprising: a screw propeller comprising screw propeller blades and a rotating shaft, the screw propeller blades being fixed to the rotating shaft and arranged to stir slurry; a propeller comprising propeller blades and a driving shaft, the propeller blades being arranged between the screw propeller blades and the rotating shaft and connected to the driving shaft, the propeller blades having a plurality of inclined blades arranged in sequence along a circumferential direction of the propeller blades and arranged to drive the slurry to circulate axially.

2. The whipping assembly of claim 1, wherein: The number of the propeller blades is configured to be multiple, and the multiple propeller blades are arranged in sequence along an axial direction of the driving shaft.

3. The whipping assembly of claim 1, further comprising: An inclined blade is arranged between the screw propeller blades and the rotating shaft, and the inclined blade is capable of rotating under the drive of the rotating shaft and arranged to drive the slurry to circulate axially.

4. The stirring assembly of claim 3, wherein: A projection of the inclined blade in a radial direction of the rotating shaft towards the rotating shaft is arranged at a different position in an axial direction of the rotating shaft from the inclined blade.

5. The stirring assembly of claim 4, wherein: The inclined blade is arranged corresponding to the propeller blade, and the inclined blade is arranged above the corresponding propeller blade in the axial direction of the rotating shaft.

6. The stirring assembly of claim 1, further comprising: A baffle is arranged at least partially between the screw propeller blades and the rotating shaft.

7. The whipping assembly of claim 6, wherein: In the radial direction of the rotating shaft, the baffle is arranged on both sides of the rotating shaft from the driving shaft.

8. The stirring assembly of claim 1, further comprising: An inclined blade is arranged between the screw propeller blades and the rotating shaft, and the inclined blade is capable of rotating under the drive of the rotating shaft and arranged to drive the slurry to circulate axially. The stirring assembly further comprises a baffle arranged at least partially between the screw propeller blades and the rotating shaft.

9. The whipping assembly of claim 8, wherein: A notch is formed in the baffle, the notch is arranged corresponding to the inclined blade, and the inclined blade partially extends into the corresponding notch.

10. A stirring device comprising: A stirring assembly, comprising: a screw propeller comprising screw propeller blades and a rotating shaft, the screw propeller blades being fixed to the rotating shaft and arranged to stir slurry; a propeller comprising propeller blades and a driving shaft, the propeller blades being arranged between the screw propeller blades and the rotating shaft and connected to the driving shaft, the propeller blades having a plurality of inclined blades arranged in sequence along a circumferential direction of the propeller blades and arranged to drive the slurry to circulate axially.

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