Coating die head and coating equipment
By designing an arc-shaped thinning block and a micrometer to work together in the coating die, the problem of deformation or cracking caused by the sharp point of the thinning zone in lithium battery production was solved, achieving high precision and stability in coating.
Patent Information
- Application Number
- CN202520197394.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-08
- Publication Date
- 2026-01-27
- Estimated Expiration
- 2035-02-08
AI Technical Summary
In the lithium battery production process, the traditional extrusion coating method has sharp points in the thinning area, which can lead to deformation or cracking during the drying process.
A coating die head design is adopted, including an upper die head, a lower die head, a micrometer, and a thinning block. The thinning block has an arc-shaped structure in the narrow slit coating space. The lifting and lowering of the thinning block is controlled by adjusting the micrometer to regulate the slurry flow rate. The arc-shaped surface provides a gradual transition and buffer space to avoid slurry accumulation and drying shrinkage deformation.
It effectively reduces slurry buildup and sharp point formation, avoids deformation or cracking during drying shrinkage, and improves coating accuracy and consistency.
Smart Images
Figure CN223832705U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of coating technology, specifically to a coating die and coating equipment. Background Technology
[0002] One crucial step in lithium battery production is electrode coating. The quality of the electrode coating directly impacts the ease of subsequent manufacturing processes, the overall quality, and production efficiency. Among these methods, extrusion coating is the most widely used due to its high precision and reliability. Extrusion coating, also known as slot extrusion coating, involves a feeding system that delivers the coating material to a coating die. The slurry is then extruded through a slit in the die, coating the outer surface of the battery electrode foil.
[0003] In the extrusion coating process, the positive electrode usually needs to be thinned to optimize the capacity matching between the positive and negative electrodes and make the overall N / P ratio more reasonable. However, the thinning area processed by the traditional turbulence strip has obvious sharp points. During the drying process, the stress shrinkage is inconsistent, which may cause deformation or cracking.
[0004] Therefore, how to eliminate the sharp points of the thinning zone as much as possible and avoid deformation or cracking during drying shrinkage has become a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content
[0005] The purpose of this application is to provide a coating die and coating equipment that can eliminate sharp points in the thinning zone as much as possible and avoid deformation or cracking during drying shrinkage.
[0006] To solve the above-mentioned technical problems, this application provides a coating die head, including an upper die head, a lower die head, a micrometer, and a thinning block. The upper die head is installed on the upper side of the lower die head, and a slit coating space for slurry flow is formed between the upper die head and the lower die head. The micrometer is disposed on the upper die head, and the thinning block is located inside the slit coating space and is drivenly connected to the micrometer. The sidewall of the thinning block facing the lower die head is an arc-shaped structure that protrudes towards the lower die head.
[0007] In this application example, the thinning block in the coating die acts as a flow barrier within the slit coating space. A micrometer is mounted on the upper die, and its lifting end is connected to the thinning block. Thus, adjusting the micrometer adjusts the lifting of the thinning block, thereby regulating the flow rate of the slurry extruded from the thinning zone. In other words, by adjusting the lifting of the thinning block, the flow rate of the slurry extruded from the thinning zone can be reduced, thereby achieving the purpose of thinning. Simultaneously, the sidewall of the thinning block facing the lower die is an arc-shaped structure that bulges downwards towards the die. On one hand, this arc-shaped surface provides a gradual transition for the slurry flow, making the changes in slurry flow rate and shear rate smoother. The arc-shaped surface also guides the slurry flow direction to conform to the arc-shaped wall, maintaining the stability of the slurry flow and minimizing flow separation, thereby reducing slurry accumulation and the formation of sharp points. On the other hand, this arc-shaped surface expands the extension area of the edge slurry, disperses surface tension, and provides a buffer space for the drying shrinkage of the slurry, thereby suppressing the formation of sharp points and minimizing deformation or cracking problems during drying shrinkage.
[0008] Optionally, the sidewalls are symmetrically arranged about the centerline of the thinned block along its length.
[0009] Wherein, the length direction of the thinning block is the length direction of the slit coating space.
[0010] Optionally, the distance between the lowest and highest points of the sidewall is H, and the value of H ranges from 0.6 mm to 1 mm.
[0011] Optionally, the two side walls along the length of the thinned block and the side walls are connected by rounded corners.
[0012] Optionally, the coating die head includes a plurality of micrometers, and the plurality of micrometers are distributed along the length direction of the slit coating space;
[0013] The number of the thinning blocks is n, n=1,2,3… The coating die head also includes adjustment blocks, the number of which is n+1. The adjustment blocks are located inside the slit coating space and are driven and connected to other micrometers except for the micrometer connected to the thinning blocks. The thinning blocks are located between two adjacent adjustment blocks, and the opposite sidewalls of the adjustment blocks and the thinning blocks are in contact.
[0014] Optionally, the coating die head includes a plurality of micrometers, and the plurality of micrometers are distributed along the length direction of the slit coating space;
[0015] The number of the thinning blocks is n, n=1,2,3… The coating die head also includes adjustment blocks, the number of which is n+1. The adjustment blocks are located inside the slit coating space and are driven and connected to other micrometers except for the micrometer connected to the thinning blocks. The thinning blocks are located between two adjacent adjustment blocks, and there is a gap between the opposing sidewalls of the adjustment blocks and the thinning blocks.
[0016] Optionally, the distance between the opposite sidewalls of the adjusting block and the thinning block is W, and the value of W is in the range of: W < 0.3 mm.
[0017] Optionally, the coating die head includes a plurality of micrometers, and the plurality of micrometers are distributed along the length direction of the slit coating space;
[0018] The thinning block and the micrometer are detachably connected, and the thinning block can be connected to either of the micrometers.
[0019] Optionally, the thinning block and the micrometer are connected by threads.
[0020] This application also provides a coating apparatus, including the aforementioned coating die.
[0021] The coating equipment of this application includes the aforementioned coating die head, and therefore has the same technical effect as the aforementioned coating die head, which will not be repeated here. Attached Figure Description
[0022] Figure 1 A schematic diagram of the structure of a specific embodiment of the coating die provided in this application;
[0023] Figure 2 for Figure 1 Top view of the coating die;
[0024] Figure 3 for Figure 2 A cross-sectional view of the coating die along the DD direction;
[0025] Figure 4 for Figure 3 Enlarged view of region A in the middle;
[0026] Figure 5 for Figure 1 A schematic diagram of the structure of one of the micrometers and the thinning block in the coating die head;
[0027] in, Figures 1-5 The accompanying figure labels are as follows:
[0028] 1-Upper die head; 2-Lower die head; 3-Micrometer; 4-Thinning block; 41-Side wall; 5-Adjusting block; a-Slit coating space. Detailed Implementation
[0029] To enable those skilled in the art to better understand the technical solutions of this application, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0030] Please refer to Figures 1-5 , Figure 1 A schematic diagram of the structure of a specific embodiment of the coating die provided in this application; Figure 2 for Figure 1 Top view of the coating die; Figure 3 for Figure 2 A cross-sectional view of the coating die along the DD direction; Figure 4 for Figure 3 Enlarged view of region A in the middle; Figure 5 for Figure 1 A schematic diagram of the structure of one of the micrometers and the thinning block in the coating die.
[0031] This embodiment provides a coating die head, including an upper die head 1, a lower die head 2, a micrometer 3, and a thinning block 4. The upper die head 1 is installed on the upper side of the lower die head 2, and a slit coating space a for slurry flow is formed between the upper die head 1 and the lower die head 2. The micrometer 3 is disposed on the upper die head 1, and the thinning block 4 is located inside the slit coating space a and is drivenly connected to the micrometer 3. The lower sidewall 41 of the thinning block 4 facing the lower die head 2 is an arc-shaped structure that protrudes in the direction of the lower die head 2.
[0032] In this embodiment, the thinning block 4 acts as a flow-blocking element inside the slit coating space a. A micrometer 3 is mounted on the upper die 1. Specifically, the micrometer 3 is fixed to the upper die 1 by a fastener to prevent movement and avoid affecting the accuracy of the material zone. The lifting end of the micrometer 3 is connected to the thinning block 4. Thus, adjusting the micrometer 3 adjusts the lifting of the thinning block 4, thereby adjusting the flow rate of the slurry extruded from the thinning zone. In other words, adjusting the lifting of the thinning block 4 reduces the flow rate of the slurry extruded from the thinning zone, achieving the purpose of thinning. Using the micrometer 3 to lift the thinning block 4 eliminates the need for a separate drive mechanism, and the micrometer 3 has a fine-tuning function. The micrometer 3 allows for micron-level control of the thinning block 4, improving the accuracy of its lifting along the height direction, thereby improving the adjustment accuracy of the slurry thickness in the thinning zone.
[0033] Meanwhile, the lower sidewall 41 of the thinning block 4 facing the downward die head 2 is an arc-shaped structure that protrudes in the direction of the downward die head 2. On the one hand, the arc-shaped surface can provide a gradual transition for the slurry flow, making the change in slurry flow rate smoother. The arc-shaped surface can also guide the slurry flow direction to fit with the arc-shaped wall, maintaining the flow stability of the slurry and avoiding flow separation as much as possible, thereby reducing slurry accumulation and the formation of sharp points. On the other hand, the arc-shaped surface can expand the extension area of the edge slurry, disperse the surface tension, and provide a buffer space for the drying shrinkage of the slurry, thereby suppressing the formation of sharp points and thus avoiding deformation or cracking problems during drying shrinkage as much as possible.
[0034] Please continue to refer to this. Figure 4 and Figure 5 In this embodiment, the lower sidewall 41 is symmetrically arranged about the center line L of the thinning block 4 in the length direction;
[0035] Wherein, the length direction of the thinned block 4 is the length direction of the slit coating space a, and the length direction of the slit coating space a is as follows: Figure 4 As indicated by the middle arrow.
[0036] As set up above, the symmetrical arc-shaped surface ensures that the flow path and resistance of the slurry are completely consistent on both sides of the centerline L, avoiding flow deviation caused by geometric asymmetry and ensuring that the coating thickness is uniform in the length direction of the slit coating space a. At the same time, the symmetrical structure ensures that the arc-shaped surfaces on both sides of the centerline L are subjected to the same slurry scouring and wear rate, avoiding local failure caused by excessive wear on one side and extending the service life of the thinning block 4.
[0037] like Figure 5 As shown, in this embodiment, the distance between the lowest point and the highest point of the lower sidewall 41 of the thinning block 4 facing the lower die head 2 is H, and the value of H ranges from 0.6mm to 1mm.
[0038] Among them, by Figure 5 As can be seen, the lowest point of the lower sidewall 41 is located in the middle of the length direction of the thinning block 4, and the highest point of the lower sidewall 41 is located at both ends of the length direction of the thinning block 4. H can take values of 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, etc. It has been verified that when H>1mm, it may lead to insufficient flow resistance and fail to achieve the purpose of thinning; when H<0.6mm, it may not be able to effectively suppress shear mutation, and may still cause slurry accumulation and the formation of sharp points. Therefore, in this embodiment, the value range of H is 0.6mm-1mm. The thinning block 4 can fully play its role in blocking the flow and achieve the purpose of thinning, and effectively suppress shear mutation, reduce slurry accumulation and the formation of sharp points, and avoid deformation or cracking problems during drying shrinkage as much as possible.
[0039] Furthermore, in some embodiments, the two side walls of the thinning block 4 distributed along the length direction of the slit coating space a and the lower side wall 41 of the thinning block 4 facing the lower die head 2 are connected by rounded corners.
[0040] As set up above, the two side walls distributed along the length of the slit coating space a in the thinning block 4 and the lower side wall 41 of the thinning block 4 facing the downward die head 2 are connected by rounded corners, which can make the slurry flow path smooth and continuous, avoid flow separation caused by geometric abrupt changes, reduce the formation of dead zones, ensure uniform slurry distribution in the thinning zone, and avoid the appearance of stripes or lumps in the coating.
[0041] Please continue to refer to this. Figure 3 and Figure 4 In this embodiment, the coating die head includes multiple micrometers 3, and the multiple micrometers 3 are distributed along the length direction of the slit coating space a.
[0042] The number of thinning blocks 4 is n, n=1,2,3… The coating die head also includes adjustment blocks 5, the number of adjustment blocks 5 is n+1. The adjustment blocks 5 are located inside the slit coating space a and are driven connected to other micrometers 3 except for the micrometer 3 connected to the thinning blocks 4. The thinning blocks 4 are located between two adjacent adjustment blocks 5, and the relative sidewalls of the adjustment blocks 5 and the thinning blocks 4 are in contact.
[0043] As set up above, the adjusting block 5 is located inside the slit coating space a and is driven and connected to other micrometers 3 except for the micrometer 3 connected to the thinning block 4. By finely adjusting the position of the adjusting block 5 through the micrometer 3, the cross-sectional area of the slit coating space a can be changed, thereby controlling the thickness of the slurry. The thinning block 4 is located between two adjacent adjusting blocks 5. The relative sidewalls of the adjusting block 5 and the thinning block 4 are in contact, which can make the structure of the coating die head more compact, reduce slurry leakage during the coating process, and maintain the pressure balance inside the coating die head, ensuring that the slurry can flow out evenly, thereby improving the coating accuracy, coating quality and coating consistency.
[0044] The relative sidewalls of the adjusting block 5 and the thinning block 4 are in contact, but without generating a squeezing force, thus avoiding interference with the position adjustment of the adjusting block 5 and the thinning block 4.
[0045] In some other embodiments of this application, the coating die includes multiple micrometers 3, and the multiple micrometers 3 are distributed along the length direction of the slit coating space a.
[0046] The number of thinning blocks 4 is n, n=1,2,3… The coating die head also includes adjustment blocks 5, the number of adjustment blocks 5 is n+1. The adjustment blocks 5 are located inside the slit coating space a and are driven connected to other micrometers 3 except for the micrometer 3 connected to the thinning blocks 4. The thinning blocks 4 are located between two adjacent adjustment blocks 5, and there is a gap between the relative sidewalls of the adjustment blocks 5 and the thinning blocks 4.
[0047] As shown above, there is a gap between the opposing sidewalls of the adjusting block 5 and the thinning block 4. On the one hand, this facilitates the installation of the adjusting block 5 and the thinning block 4, reduces the dimensional accuracy of the adjusting block 5 and the thinning block 4, reduces the processing difficulty of the adjusting block 5 and the thinning block 4, and improves production efficiency. On the other hand, the reasonable gap design can reduce the friction and wear between the adjusting block 5 and the thinning block 4, and extend the service life of the adjusting block 5 and the thinning block 4.
[0048] The distance between the relative sidewalls of the adjusting block 5 and the thinning block 4 is defined as W, and the value of W is in the range of: W < 0.3 mm.
[0049] Wherein, W can take values of 0.1mm, 0.15mm, 0.2mm, 0.25mm, etc. Verification has shown that when W > 0.3mm, the distance between the relative sidewalls of the adjusting block 5 and the thinning block 4 is too large, which may lead to slurry leakage during the coating process and make it impossible to maintain the pressure balance inside the coating die, affecting the coating quality. Therefore, in this embodiment, the distance between the relative sidewalls of the adjusting block 5 and the thinning block 4 has the above-mentioned value range. This not only reduces slurry leakage during the coating process and maintains the pressure balance inside the coating die, ensuring coating quality, but also facilitates the installation of the adjusting block 5 and the thinning block 4, reduces friction and wear between them, and extends their service life.
[0050] Furthermore, in this embodiment, the coating die includes multiple micrometers 3, which are distributed along the length of the slit coating space a.
[0051] The thinning block 4 and the micrometer 3 are detachably connected, and the thinning block 4 can be connected to any micrometer 3.
[0052] Since the position requirements of the thinning area may differ in different electrodes, and the position of the thinning block 4 needs to correspond to the position of the thinning area, this embodiment sets the thinning block 4 and the micrometer 3 to be detachably connected. The thinning block 4 can be connected to any micrometer 3, which facilitates the adjustment of the position of the thinning block 4 according to the position of the thinning area. This allows the coating die head of this embodiment to meet the coating requirements of different electrodes, improves the flexibility of the coating die head of this embodiment, increases the applicability of the coating die head of this embodiment, and improves the utilization rate of the coating die head of this embodiment.
[0053] In this embodiment, the thinning block 4 and the micrometer 3 are connected by threads.
[0054] Specifically, the thinning block 4 has a threaded hole at the end facing the micrometer 3, and the micrometer 3 has a connecting part at the end near the thinning block 4. The outer peripheral wall of the connecting part has external threads, and the connecting part is inserted into the threaded hole of the thinning block 4 and screwed in for fixation. In this way, the thinning block 4 and the micrometer 3 are connected by threads, which not only ensures the reliability of the connection between the thinning block 4 and the micrometer 3, but also facilitates the installation and disassembly of the thinning block 4, improving operational convenience.
[0055] Of course, the thinning block 4 and the micrometer 3 are not limited to the above-mentioned threaded connection method. In some embodiments of this application, the thinning block 4 and the micrometer 3 can be quickly locked and unlocked by the snap-fit of the protrusion (buckle) and the groove (slot), which is reliable and easy to disassemble and assemble. In other embodiments of this application, the thinning block 4 and the micrometer 3 are provided with corresponding connecting holes, and a connecting pin is also included. The connecting pin is inserted into the corresponding connecting hole to realize the connection between the thinning block 4 and the micrometer 3. The structure is simple, the connection is reliable, and it can be quickly disassembled.
[0056] In addition, such as Figure 4 As shown, the inner wall of the threaded hole of the thinning block 4 has a first step facing the micrometer 3, and the micrometer 3 has a second step facing the thinning block 4. During the process of connecting the thinning block 4 and the micrometer 3, when the first step and the second step abut, it indicates that the thinning block 4 and the micrometer 3 have been connected in place. It can be seen that the first step and the second step can play an indicative role, improve the assembly efficiency and assembly consistency of the thinning block 4 and the micrometer 3, and avoid the problem of the thinning block 4 and the micrometer 3 not being fully connected.
[0057] This embodiment also provides a coating device, including the aforementioned coating die head.
[0058] The coating equipment in this embodiment includes the aforementioned coating die head, and therefore has the same technical effects as the aforementioned coating die head, which will not be repeated here.
[0059] The above are merely preferred embodiments of this application. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.
Claims
1. A coating die head, characterized in that, The device includes an upper die head (1), a lower die head (2), a micrometer (3), and a thinning block (4). The upper die head (1) is installed on the upper side of the lower die head (2). A slit coating space (a) for slurry flow is formed between the upper die head (1) and the lower die head (2). The micrometer (3) is disposed on the upper die head (1). The thinning block (4) is located inside the slit coating space (a) and is driven to connect with the micrometer (3). The lower sidewall (41) of the thinning block (4) facing the lower die head (2) is an arc-shaped structure that protrudes towards the lower die head (2).
2. The coating die head according to claim 1, characterized in that, The lower sidewall (41) is symmetrically arranged about the center line (L) of the length direction of the thinning block (4); The length direction of the thinning block (4) is the length direction of the slit coating space (a).
3. The coating die head according to claim 2, characterized in that, The distance between the lowest and highest points of the lower sidewall (41) is H, and the value of H ranges from 0.6 mm to 1 mm.
4. The coating die head according to any one of claims 1-3, characterized in that, The two side walls and the lower side wall (41) of the thinned block (4) along its length are connected by rounded corners.
5. The coating die head according to any one of claims 1-3, characterized in that, The coating die head includes multiple micrometers (3), and the multiple micrometers (3) are distributed along the length direction of the slit coating space (a); The number of the thinning blocks (4) is n, n=1,2,3… The coating die head also includes an adjustment block (5), the number of the adjustment blocks (5) is n+1, the adjustment block (5) is located inside the slit coating space (a), and is driven connected to the other micrometers (3) except the micrometer (3) connected to the thinning block (4), the thinning block (4) is located between two adjacent adjustment blocks (5), and the relative sidewalls of the adjustment block (5) and the thinning block (4) are in contact.
6. The coating die head according to any one of claims 1-3, characterized in that, The coating die head includes multiple micrometers (3), and the multiple micrometers (3) are distributed along the length direction of the slit coating space (a); The number of the thinning blocks (4) is n, n=1,2,3… The coating die head also includes an adjustment block (5), the number of the adjustment blocks (5) is n+1, the adjustment block (5) is located inside the slit coating space (a) and is driven connected to the other micrometers (3) except the micrometer (3) connected to the thinning block (4), the thinning block (4) is located between two adjacent adjustment blocks (5), and there is a gap between the adjustment block (5) and the opposite sidewall of the thinning block (4).
7. The coating die head according to claim 6, characterized in that, The distance between the relative sidewalls of the adjusting block (5) and the thinning block (4) is W, and the value of W is in the range of W < 0.3 mm.
8. The coating die head according to any one of claims 1-3, characterized in that, The coating die head includes multiple micrometers (3), and the multiple micrometers (3) are distributed along the length direction of the slit coating space (a); The thinning block (4) and the micrometer (3) are detachably connected, and the thinning block (4) can be connected to any of the micrometers (3).
9. The coating die head according to any one of claims 1-3, characterized in that, The thinning block (4) and the micrometer (3) are connected by threads.
10. A coating apparatus, characterized in that, Includes the coating die head as described in any one of claims 1-9.