Coating roller, coating machine and double-layer turn-back gap coating system

Abstract

The utility model relates to a coating roller, a coating machine and a double-layer turn-back gap coating system. The coating roller comprises an inflatable mandrel and at least one shaft sleeve, the shaft sleeve is sleeved outside the inflatable mandrel, the outer surface of the shaft sleeve is provided with at least one groove along the axial direction and / or the circumferential direction of the inflatable mandrel, the shaft sleeve is provided with a plurality of ink cells, and the ink cells are arranged on the outer surface of the shaft sleeve at intervals to form a grid area. The coating machine comprises the coating roller. According to the scheme provided by the invention, small-gap coating can be carried out on the pole piece, and the problem of delayed response is avoided, so that the coating quality of the pole piece is improved.

Description

Technical Field

[0001] This application relates to the field of battery manufacturing technology, and in particular to coating rollers, coating machines and double-layer fold-back gap coating systems. Background Technology

[0002] During the manufacturing process of battery electrodes, the electrodes need to be coated and then dried. This process requires the use of coating rollers to apply the slurry onto the electrodes.

[0003] In related technologies, for areas on the electrode that need to be left blank, gap valves are usually used to control the output of slurry, thereby achieving gaps on the electrode. However, when coating the electrode with small gaps at high speed, the gap valve response is prone to delay, resulting in low repeatability of the blanking spacing in the electrode coating. Furthermore, the high-speed opening and closing of the valve shears the slurry, changes the flow characteristics of the slurry, and generates pulses in the slurry flow, causing fluctuations in the coating thickness and affecting the coating effect. Utility Model Content

[0004] To address or partially address the problems existing in related technologies, this application provides a coating roller, a coating machine, and a double-layer fold-back gap coating system, which can coat electrodes with small gaps without delaying response, thereby improving the coating quality of electrodes.

[0005] Some embodiments of this application provide a coating roller, which includes an air-expanded mandrel and at least one bushing; each bushing is respectively sleeved on the outside of the air-expanded mandrel, and at least one groove is formed on the outer surface of each bushing along the axial and / or circumferential direction of the air-expanded mandrel. Each bushing has a plurality of mesh holes, and the mesh holes are arranged at intervals on the outer surface of the bushing to form a grid area.

[0006] Furthermore, there are two or more bushings, which are distributed at intervals along the axial direction of the air expansion mandrel outside the air expansion mandrel.

[0007] Furthermore, the grid area includes a transition area and a main area. The transition area is disposed adjacent to the groove, and the main area is located on the side of the transition area away from the groove. The depth of the mesh cells in the main area is greater than the depth of the mesh cells in the transition area. In the main area, the depth of each mesh cell is equal. In the transition area, the depth of each mesh cell gradually increases from the side closer to the groove to the side farther from the groove.

[0008] Furthermore, the depth of the holes is 10~50μm.

[0009] Furthermore, the ratio of the hole depth in the transition zone to the mesh depth in the main zone is 5:6~7.

[0010] Furthermore, the connection between the opening of the groove and the outer surface of the bushing forms a first transition section, which is a right angle, a rounded corner, a 45° chamfer, or an inner octagon.

[0011] Furthermore, the width of the opening of the mesh hole is greater than the width of the bottom of the mesh hole.

[0012] Furthermore, a second transition section is formed at the connection between the bottom of the groove and the sidewall of the groove. The second transition section is arc-shaped and tangent to the sidewall of the groove.

[0013] Some embodiments of this application provide a coating machine that includes the aforementioned coating roller.

[0014] Some embodiments of this application also provide a double-layer fold-back gap coating system, which includes an unwinding device, a roller assembly, a flipping device, a winding device, two drying devices, and two coating machines; the unwinding device, one of the coating machines, one of the drying devices, the flipping device, the other coating machine, the other drying device, and the winding device are arranged sequentially along the transmission direction of the electrode sheet, the roller assembly is used to drive the electrode sheet, the unwinding device is used to release the electrode sheet, the winding device is used to wind the electrode sheet, the drying device is used to dry the electrode sheet, and the flipping device is used to flip the electrode sheet.

[0015] The technical solution provided in this application can include the following beneficial results: by setting grooves on the outer surface of the bushing, the coating roller can leave blank areas on the electrode corresponding to the areas that need to be left blank when coating the electrode. Combined with the grid area, the adhesion of the slurry is enhanced, thereby realizing high-speed coating of multiple small gaps on the electrode. Compared with the traditional method of using the opening and closing of the gap valve to achieve gap blanking, this application leaves blank areas on the electrode through grooves, which does not have the problem of delay. Moreover, the size of the area that needs to be left blank can be achieved by designing grooves of different sizes. For small gap blanking, the corresponding effect can also be achieved by designing narrower grooves. This can effectively improve the edge effect of electrode coating, avoid the problem of response delay, and thus improve the quality of gap coating.

[0016] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0017] The above and other objects, features and advantages of this application will become more apparent from the following description of exemplary embodiments of this application in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components.

[0018] Figure 1This is a schematic diagram of the coating roller structure shown in the embodiments of this application;

[0019] Figure 2 This is a cross-sectional view of the bushing shown in an embodiment of this application;

[0020] Figure 3 This is a schematic diagram of the bushing structure shown in the embodiments of this application;

[0021] Figure 4 This is another structural schematic diagram of the bushing shown in the embodiments of this application;

[0022] Figure 5 This is a schematic diagram of the electrode sheet shown in the embodiments of this application;

[0023] Figure 6 This is a schematic diagram of the structure of the air-expanded mandrel shown in the embodiments of this application;

[0024] Figure 7 This is a schematic diagram of a groove with rounded corners in the first transition section shown in an embodiment of this application;

[0025] Figure 8 This is a schematic diagram of a groove structure with a first transition section at a 45° angle, as shown in an embodiment of this application;

[0026] Figure 9 This is a schematic diagram of the first transition section being an octagonal groove structure shown in an embodiment of this application;

[0027] Figure 10 This is a schematic diagram of a right-angled groove shown in an embodiment of this application;

[0028] Figure 11 This is a schematic diagram of a double-layer fold-back gap coating system shown in an embodiment of this application.

[0029] Reference numerals: 1. Air-expanded mandrel; 11. Mandrel; 12. Housing; 13. Connector; 14. Expansion strip; 2. Bushing; 21. Groove; 22. Cell; 3. Electrode; 31. Blank area; 4. Coating machine; 5. Unwinding device; 6. Roller assembly; 7. Turning device; 8. Winding device; 9. Drying device. Detailed Implementation

[0030] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make this application more thorough and complete, and to fully convey the scope of this application to those skilled in the art.

[0031] It should be understood that although the terms "first," "second," "third," etc., may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0032] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and 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.

[0033] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0034] In related technologies, for areas on the electrode where blanking is required, gap valves are typically used to control the output of the slurry, thus creating blank spaces on the electrode. However, when applying high-speed coating with small gaps to the electrode, the gap valve response is prone to delays, resulting in low repeatability of the blanking spacing. Furthermore, the high-speed opening and closing of the valve shears the slurry, altering its flow characteristics and causing pulses in the slurry flow, leading to fluctuations in coating thickness and affecting the coating effect. To address these issues, this application provides a coating roller, a coating machine, and a double-layer folding gap coating system, which can perform small-gap coating on the electrode without delaying the response, thereby improving the coating quality of the electrode.

[0035] The technical solutions of the embodiments of this application are described in detail below with reference to the accompanying drawings.

[0036] See Figure 1-5The coating roller includes an air-expanding mandrel 1 and at least one bushing 2, with each bushing 2 fitted over the air-expanding mandrel 1. When a bushing 2 needs to be replaced, the old bushing 2 can be removed from the air-expanding mandrel 1, and a new bushing 2 can be fitted onto the air-expanding mandrel 1. Each bushing 2 has at least one groove 21 on its outer surface along the axial and / or circumferential direction of the air-expanding mandrel 1. The groove 21 is elongated and corresponds to the uncoated area 31 of the electrode 3. The width of the groove 21 is less than or equal to the width of the uncoated area. When the coating roller coats the electrode 3, since there is no slurry at the opening of the groove 21, the position of the electrode 3 corresponding to the groove 21 will not be coated with slurry when the groove 21 faces the electrode 3, thus forming the uncoated area 31 on the electrode 3. Each bushing 2 has multiple openings 22. These openings 22 improve the adhesion of the slurry to the bushing 2, allowing some of the slurry to enter. The openings 22 temporarily hold the slurry in place before coating the electrode 3. The openings 22 are arranged alternately on the outer surface of the bushing 2, forming a grid area. This grid area is used to adhere the slurry. When the coating roller coats the electrode 3, the slurry adhered to the grid area can be applied to the electrode 3. The number and distribution of the grid areas can be adjusted according to the specific requirements of the coating width of the electrode 3. There can be one or multiple grid areas to meet different coating scenarios.

[0037] See Figure 1-4 In the actual coating of electrode 3, the number of grooves 21 can be adjusted according to the specific requirements of the coating width, and the size and extension direction of the grooves 21 can be adjusted according to the specific requirements of the coating process. In some embodiments, the grooves 21 extend circumferentially along the bushing 2, and the number of grooves 21 can be one, two, or more. See also Figure 3 In some embodiments, the number of grooves 21 is at least two, with at least one groove 21 extending axially along the bushing 2 and at least one groove 21 extending circumferentially along the bushing 2, wherein at least two grooves 21 intersect. See also Figure 4 In some embodiments, the groove 21 extends along the axial direction of the bushing 2, and the number of grooves 21 can be one, two or more.

[0038] This application provides a groove 21 on the outer surface of the bushing 2, allowing the coating roller to leave blank areas on the electrode 3 when coating the electrode 3. This, combined with the grid area, enhances the adhesion of the slurry, enabling high-speed coating of multiple small gaps on the electrode 3. Compared to the traditional method of using gap valves to achieve gap blanking, leaving blank areas on the electrode 3 through the groove 21 eliminates the problem of delay. Furthermore, the size of the area to be left blank can be achieved by designing grooves 21 of different sizes. For small gaps, the corresponding effect can also be achieved by designing narrower grooves 21. This application can effectively improve the edge effect of electrode 3 coating, avoid response delay problems, and thus improve the quality of gap coating.

[0039] See Figure 1 and Figure 6 The type of air expansion mandrel 1 is not limited to slat-type air expansion mandrels, key-type air expansion mandrels, and differential slip air expansion mandrels. Taking a slat-type air expansion mandrel as an example, the air expansion mandrel 1 includes a mandrel 11, a housing 12, a connector 13, an air nozzle, and an expansion strip 14. The mandrel 11 is located inside the housing 12, and an air cavity is opened inside the mandrel 11. The mandrel 11 is connected to the expansion strip 14 through the connector. The expansion strip 14 is located on the surface of the housing 12, and a limiting groove is provided on the surface of the expansion strip 14 to increase the friction with the bushing 2 and prevent the bushing 2 from being misaligned with the mandrel 11. The mandrel 11 is connected to an air pump through the air nozzle for inflation and deflation. When inflated, the mandrel 11 expands, and the mandrel 13 pushes the connecting... The connector 13 moves away from the central axis of the shaft core 11, and pushes the expansion strip 14 away from the central axis of the shaft core 11. The expansion strip 14 squeezes the inner wall of the bushing 2 to fix the bushing 2. When the air is released, the shaft core 11 contracts and the bushing 2 is detached from the air-expanded mandrel 1, which can realize the quick replacement of the bushing 2. The bushing 2 and the shaft core 11 adopt a modular connection to match different process requirements. The bushing 2 is tightly fixed by inflation expansion, ensuring that the fixing and release of the bushing 2 are completed quickly and stably.

[0040] See Figure 1-5The grid area includes a transition zone and a main zone. The transition zone is adjacent to the groove 21, and the main zone is located on the side of the transition zone away from the groove 21. The depth of the cells 22 in the main zone is greater than the depth of the cells 22 in the transition zone. The transition zone surrounds the groove 21. In the main zone, the depth of each cell 22 is equal, ensuring that the slurry in the coating area of ​​the electrode 3 corresponding to the main zone is uniform when the electrode 3 is coated. In the transition zone, the depth of each cell 22 gradually increases from the side closer to the groove 21 to the side farther away from the groove 21. Specifically, the closer to the groove 21, the shallower the depth of the cell 22. Preferably, the cells 22 in the transition zone adopt a depth gradient decreasing design. This design can reduce the amount of slurry viscosity at the edge of the coating area and thin the thickness of the coating area edge, thereby effectively reducing the edge effect of the coating area. In addition, it is conducive to a more uniform distribution of slurry on the electrode substrate 3, while improving and reducing the phenomenon of excessive edge thickness caused by low flow resistance in the edge area, thereby improving the coating quality. The gradient decreasing depth of the cells 22 can reduce the amount of slurry stored in the cells 22 near the groove 21, avoiding slurry accumulation or sagging caused by changes in edge tension. The coverage area of ​​the main area on the outer surface of the bushing 2 is greater than the coverage area of ​​the transition zone on the outer surface of the bushing 2, ensuring that the electrode 3 has sufficient coating area and that the slurry on the coating area of ​​the electrode 3 is sufficiently uniform.

[0041] See Figure 1-2 The depth of the mesh cells 22 is 10~50μm. This depth ensures that the slurry can adhere to the mesh cells 22, and that the slurry will not completely enter the mesh cells 22 and then be unable to exit. Preferably, the ratio of the mesh depth of the mesh cells 22 in the transition zone to the mesh depth of the main zone is 5:6~7, ensuring that the mesh cells 22 in the transition zone do not adhere to excessive slurry.

[0042] See Figure 7-10 The connection between the opening of the groove 21 and the outer surface of the bushing 2 forms a first transition section, which can be a right angle, a rounded corner, a 45° chamfer, or an inner octagon. (See also...) Figure 7 In some embodiments, the first transition section is rounded, with a radius ranging from 0.5 to 1 mm. The first transition section forms a smooth transition with the sidewall of the groove 21. The rounded corner structure of the first transition section facilitates the smooth flow of the slurry from the opening edge of the groove 21 under centrifugal force or the action of a scraper, reducing the contact force of the slurry at the opening edge of the groove 21 and preventing slurry residue from appearing at the opening edge of the groove 21, thereby improving coating uniformity. See also... Figure 8 In some embodiments, the first transition section is a 45° chamfer with a width of 0.5~1mm. The 45° chamfer design increases the opening area of ​​the groove 21, reduces slurry flow resistance, minimizes slurry tailing, compensates for edge tension differences, and improves edge consistency. (See also...) Figure 9In some embodiments, the first transition section is an inward octagon, with the opening angle ranging from 30° to 60°. This inward octagonal design increases the contact area between the slurry and the bushing 2, enhances the structural stability of the bushing 2, and reduces deformation of the bushing 2. See also... Figure 6-10 By forming a first transition section at the connection between the opening of the groove 21 and the outer surface of the bushing 2, the fluid resistance of the slurry at the opening of the groove 21 can be reduced, the slurry can be prevented from forming a stagnant area due to edge turbulence, the wear rate of the bushing 2 can be reduced, thereby extending the maintenance cycle of the bushing 2. In addition, when the coating roller coats the electrode 3, the slurry adhering to the mesh 22 can flow more easily on the outer surface of the bushing 2, thereby making the slurry coating more uniform when coating the electrode 3.

[0043] See Figure 2-5 The width of the opening of the mesh 22 is greater than the width of the bottom of the mesh 22. The wider opening of the mesh 22 facilitates the flow of slurry from the opening into the mesh 22 when the bushing 2 is dipped in slurry, ensuring that each mesh 22 is coated with slurry. Conversely, the narrower bottom of the mesh 22 facilitates the flow of slurry from the bottom of the mesh 22 to the opening when the bushing 2 is coated with the electrode 3, preventing excessive slurry residue in the mesh 22 during coating. This facilitates the uniform distribution of slurry on the outer surface of the bushing 2 and reduces slurry residue on the outer surface of the bushing 2 during electrode coating. Preferably, the cavity 22 is a regular hexagonal truncated pyramid with a trapezoidal longitudinal section. The regular hexagonal truncated pyramid cavity 22 helps reduce air bubbles generated by the slurry on the surface of the electrode 3 during coating, thereby improving coating quality. Furthermore, the regular hexagonal truncated pyramid cavity 22 can improve the structural strength of the bushing 2 and reduce the impact of opening the cavity 22 on the structural strength of the bushing 2.

[0044] See Figure 2 The connection between the bottom of the groove 21 and the sidewall of the groove 21 forms a second transition section. The second transition section is arc-shaped and tangent to the sidewall of the groove 21. Preferably, the second transition section has a rounded corner and the radius of the second transition section is 0.5~1mm.

[0045] Corresponding to the aforementioned application function implementation device embodiments, this application also provides a coating machine and corresponding embodiments.

[0046] The coating machine includes a coating roller and a frame body, with the coating roller mounted on the frame body.

[0047] This application uses a coating roller with replaceable bushing 2. When bushing 2 is worn, only bushing 2 needs to be replaced, without replacing the entire coating roller. The replacement process is simple and does not require complicated disassembly, reducing equipment downtime for maintenance and saving material and labor costs. By replacing bushing 2 with different patterns, the coating machine can meet a variety of process requirements.

[0048] Corresponding to the aforementioned application function implementation device embodiments, this application also provides a double-layer fold-back gap coating system and corresponding embodiments.

[0049] See Figure 11 The double-layer fold-back gap coating system includes an unwinding device 5, a roller assembly 6, a turning device 7, a winding device 8, two drying devices 9, and two coating machines 4; one coating machine 4 is located above the other coating machine 4, and one drying device 9 is located above the other drying device 9; the drying device 9 is a double-layer fold-back coating baking oven. The unwinding device 5, the upper coating machine 4, the upper drying device 9, the turning device 7, the lower coating machine 4, the lower drying device 9, and the winding device 8 are arranged sequentially along the transmission direction of the electrode sheet 3. The roller assembly 6 is used to drive the electrode sheet 3, the unwinding device 5 is used to release the electrode sheet 3, the winding device 8 is used to wind the electrode sheet 3, the drying device 9 is used to dry the electrode sheet 3, and the turning device 7 is used to turn the electrode sheet 3 over. In actual operation, electrode 3 has a first side and a second side. Unwinding device 5 releases electrode 3, which is then driven by roller assembly 6 to the upper coating machine 4. The coating machine 4 precisely coats the first side. After coating, electrode 3 enters the upper drying device 9 for two folding and baking cycles. After exiting the oven, flipping device 7 flips electrode 3 180°, at which point the orientation of the first side and the second side are interchanged. Subsequently, electrode 3 passes through the lower coating machine 4, which coats the second side of electrode 3. After coating, electrode 3 enters the lower drying device 9 for two folding and baking cycles. After exiting the lower oven, electrode 3 is then wound into winding device 8 by roller assembly 6, thus completing the electrode production process.

[0050] The double-layer fold-back gap coating system uses two double-layer fold-back coating drying units 9, thereby reducing the production line footprint and optimizing the workshop layout. The system employs grooved rollers 21 with replaceable bushings 2 to achieve high-speed, stable gap coating. Two drying units 9 are used to fold-back and bake the electrode 3 twice, resulting in a total of four baking cycles for the first and second surfaces of the electrode 3, significantly improving baking efficiency and quality. Different materials or specifications of bushings 2 can be selected according to coating requirements, matching different sizes of grooves 21 to adapt to various coating scenarios. The combination design of longitudinal and transverse grooves 21 allows for quick switching between "strip coating" and "full-area coating."

[0051] This application provides a groove 21 on the outer surface of the bushing 2, so that when the coating roller coats the electrode 3, the groove 21 can leave blank areas on the electrode 3 corresponding to the areas that need to be left blank. This, together with the grid area, strengthens the adhesion of the slurry, thereby achieving high-speed coating of the electrode 3 with multiple small gaps and reducing the use of gap valves, thus reducing the space occupied by the entire system.

[0052] The solution of this application has been described in detail above with reference to the accompanying drawings. In the above embodiments, the descriptions of each embodiment have different focuses; for parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments. Those skilled in the art should also understand that the actions and modules involved in the specification are not necessarily essential to this application. Furthermore, it is understood that the steps in the method of this application embodiment can be adjusted, combined, and deleted according to actual needs, and the modules in the device of this application embodiment can be combined, divided, and deleted according to actual needs.

[0053] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A coating roll, characterized in that include: Air-expanded mandrel; At least one bushing, each bushing being sleeved on the outside of the air expansion mandrel, each bushing having at least one groove on its outer surface along the axial and / or circumferential direction of the air expansion mandrel, each bushing having a plurality of mesh holes, the mesh holes being arranged at intervals on the outer surface of the bushing to form a grid area.

2. The coating roll of claim 1, wherein: There are two or more bushings, and the bushings are distributed at intervals along the axial direction of the air expansion mandrel outside the air expansion mandrel.

3. The coating roll of claim 1, wherein: The grid area includes a transition area and a main area. The transition area is adjacent to the groove, and the main area is located on the side of the transition area away from the groove. The depth of the mesh cells in the main area is greater than the depth of the mesh cells in the transition area. In the main area, the depth of each mesh cell is equal. In the transition area, the depth of each mesh cell gradually increases from the side closer to the groove to the side farther away from the groove.

4. The coating roll of claim 3, wherein: The depth of the holes is 10~50μm.

5. The coating roll of claim 4, wherein: The ratio of the hole depth in the transition zone to the mesh depth in the main zone is 5:6~7.

6. The coating roll of claim 1, wherein: The connection between the opening of the groove and the outer surface of the bushing forms a first transition section, which is a right angle, a rounded corner, a 45° chamfer, or an inner octagon.

7. The coating roll of claim 1, wherein: The width of the opening of the mesh hole is greater than the width of the bottom of the mesh hole.

8. The coating roll of claim 1, wherein: The connection between the bottom of the groove and the sidewall of the groove forms a second transition section, which is arc-shaped and tangent to the sidewall of the groove.

9. A coater characterized by comprising: Includes the coating roller as described in any one of claims 1 to 8.

10. A double-layered turn-back gap coating system comprising an unwinding device, a roller assembly, a turning device, a winding device, two drying devices and two coating machines according to claim 9, characterized in that: The unwinding device, one of the coating machines, one of the drying devices, the flipping device, another coating machine, another drying device, and the winding device are arranged sequentially along the transmission direction of the electrode sheet. The roller assembly is used to drive the electrode sheet transmission, the unwinding device is used to release the electrode sheet, the winding device is used to wind up the electrode sheet, the drying device is used to dry the electrode sheet, and the flipping device is used to flip the electrode sheet.

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