Slit coating die head

Abstract

The utility model discloses a slit coating die head and relates to the technical field of battery pole piece production. The die head comprises an upper die, a lower die and a gasket, and the gasket is clamped between the upper die and the lower die, so that the upper die, the lower die and the gasket are enclosed to form a slit runner; the slit runner is provided with a coating opening; the gasket comprises a gasket main body and a movable insertion strip, a mounting hole is formed in the gasket main body, the movable insertion strip is movably inserted into the mounting hole, and the movable insertion strip further extends into the slit flow channel. The slit coating die head disclosed by the utility model is used for adaptively coating pole pieces with different capacity specifications, so that the purchasing and maintenance cost is reduced, and the quality defect that the coating is not uniform when the die head is used is avoided.

Description

Technical Field

[0001] This utility model relates to the field of battery electrode production technology, and in particular to a slit coating die. Background Technology

[0002] Slit coating is a crucial process in lithium-ion battery manufacturing. The density (thickness) of the active material within the coating surface on the electrode is called the coating density. The coating density directly affects the capacity of the lithium-ion battery. If the coating density is too low, the battery capacity may not reach the nominal capacity; if the coating density is too high, it can easily lead to material waste and, in severe cases, even safety hazards.

[0003] In slot coaters, the coating flow rate of the slot coating die is a key factor affecting the coating density on the electrode sheet. Currently, the market typically uses dies with different coating flow rates to meet the coating needs of battery electrodes of different capacities. Therefore, when manufacturers use slot coating technology to produce battery electrodes, they need to purchase dies with different coating flow rates, which results in high procurement costs and is not conducive to industrial production.

[0004] To address this, existing technology discloses a slit coating die head, including a first die body, a second die body, and a gasket sandwiched between the two. The gasket is U-shaped, forming a slit flow channel and a glue outlet between the two die bodies. A liquid storage tank is formed on the inner surface of the first die body, where the resistance to fluid flow is less than that in the slit. A glue inlet and a regulating port are provided on the outer surface of the first die body. The glue inlet and regulating port are connected to the liquid storage tank through the flow channel, and a glue inlet hole and a regulating hole are formed on the wall of the liquid storage tank. There are two regulating holes, located at both ends of the liquid storage tank, and the glue inlet hole is located in the middle of the two regulating holes. An overflow pipe is connected to the regulating port, and a flow regulating valve is provided at the interface. This slit coating die head, by setting an additional regulating flow channel and a flow regulating valve, makes the flow of glue inside the die head controllable, facilitates emptying, and only requires controlling the flow regulating valve to obtain a relatively uniform coating.

[0005] However, the aforementioned slit coating die still has the following drawbacks:

[0006] 1. The above solution requires modification of the slit coating die head, which will make the structure of the slit coating die head more complex, making subsequent maintenance of the die head more difficult and increasing costs.

[0007] 2. The above-mentioned slit coating die head adopts the principle of adjusting the coating flow rate by adjusting the flow rate of the glue flowing out from the glue outlet. The principle is similar to diversion, that is, a part of the glue in the overflow tank flows back along the overflow pipe, and the flow rate of the glue flowing back from the overflow pipe is adjusted by the flow regulating valve, so as to controllably adjust the glue pressure inside the overflow tank, thereby reducing the glue flow rate at the glue outlet and adjusting the coating flow rate of the die head.

[0008] However, this adjustment structure and method are only suitable for coating fluids with low viscosity and fast coating speed, such as adhesives (which can quickly fill the overflow tank and flow out relatively evenly from the outlet). But when the coating medium is a coating fluid containing battery electrode coating material (with higher viscosity and slower coating speed), the battery electrode material coating fluid may experience the following during the process of flowing out from the outlet: the coating flow rate in the area closer to the adjustment port on the outlet is smaller, resulting in a lower coating density on the corresponding position of the electrode foil and a quality defect of uneven electrode coating. Utility Model Content

[0009] This invention provides a slit coating die head for coating electrodes of different capacity specifications and solves at least one of the aforementioned technical problems.

[0010] The technical solution of this utility model to solve the above problems is: to provide a slit coating die head, the die head comprising:

[0011] The upper mold, the lower mold, and the gasket are clamped between the upper mold and the lower mold so that the upper mold, the lower mold, and the gasket enclose a narrow flow channel.

[0012] The slit channel has a coating opening;

[0013] The gasket includes a gasket body and a movable connector strip. The gasket body has an installation hole, and the movable connector strip is movably inserted into the installation hole. The movable connector strip also extends into the slit channel.

[0014] Furthermore, the movable connector also extends to the outside of the mold body formed by the upper mold and the lower mold.

[0015] Furthermore, the movable connector is positioned perpendicularly to the coating opening, and the movable connector moves vertically to move away from or towards the coating opening.

[0016] Furthermore, the mounting holes are provided in multiple ways, and the number of movable connectors is approximately equal to the number of mounting holes.

[0017] Furthermore, the spacing between any two adjacent mounting holes is equal.

[0018] Furthermore, the thickness of the movable connector strip is 0.3mm to 2mm, and the thickness of the movable connector strip is less than the thickness of the gasket body.

[0019] Furthermore, the thickness of the gasket body is 0.8mm to 3mm.

[0020] Furthermore, a sealing element is provided in the insertion gap between the movable connector and the gasket body, and the sealing element is an elastic sealing element.

[0021] Furthermore, the gasket body includes a mounting body and extensions respectively disposed at both ends of the mounting body, the extensions being disposed toward the coating opening.

[0022] Furthermore, the end of the extension facing the central region of the mounting body is provided with a chamfer, and the chamfer is located on the side of the extension facing the coating opening.

[0023] The beneficial effects of this utility model are:

[0024] 1. Only the gasket on the slit coating die head was structurally modified. When the coating flow rate of the die head is not accurately adjusted, technicians only need to repair or replace the gasket. The maintenance and modification costs are low, and the procurement costs are further reduced.

[0025] 2. Technicians can adjust the coating flow rate of the die head by moving the movable connector strip to change the size of the area blocked by the movable connector strip on the coating opening, and to adjust the size of the area in the slit channel where the coating fluid can flow out. It is applicable to coating fluids of various viscosities and flow rates.

[0026] 3. There is a gap between adjacent movable connectors, and the gap between any two adjacent movable connectors is the same size to ensure that the coating fluid can flow out evenly from the coating opening. Attached Figure Description

[0027] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention. In these drawings, similar reference numerals are used to denote similar elements. The drawings described below are some embodiments of the present invention, but not all embodiments. Other drawings will be readily available to those skilled in the art based on these drawings without any inventive effort.

[0028] Figure 1 This is an overall structural diagram of the mold head in this embodiment;

[0029] Figure 2 for Figure 1AA cross-sectional structure diagram;

[0030] Figure 3 for Figure 2 Enlarged view of point A;

[0031] Figure 4 This is a front view of the gasket in this embodiment;

[0032] Figure 5 This is a top view of the gasket in this embodiment;

[0033] Figure 6 for Figure 5 Enlarged view of point B;

[0034] 11-Upper mold, 12-Lower mold, 13-Slit channel, 14-Coating opening, 15-Gasket, 151-Gasket body, 1511-Mounting body, 1512-Extension, 1513-Chamfer, 152-Modible connector, 153-Mounting hole, 16-Seal, 17-Groove, 18-Channel. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0036] Please see Figure 1 , refer to Figure 1 As shown in the diagram, a slit coating die head according to a specific embodiment of this utility model mainly includes an upper die 11, a lower die 12, and a gasket 15. The gasket 15 is a U-shaped plate or a C-shaped plate. The upper die 11 and the lower die 12 are respectively attached and fixedly installed on the upper and lower sides of the gasket 15 to form a slit channel 13 in the middle blank area of ​​the gasket 15. The coating opening 14 of the slit channel 13 is the U-shaped opening or C-shaped opening of the gasket 15. The interior of the upper die 11 is provided with a channel 18 that connects downward to the slit channel 13 and forms an interface on the upper end face of the upper die 11. A feeding device is connected to the interface to supply coating fluid containing electrode coating material into the slit channel 13.

[0037] Furthermore, the gasket 15 includes a gasket body 151 and a movable insert strip 152. The gasket body 151 is clamped and fixed by the upper mold 11 and the lower mold 12. The movable insert strip 152 is movably inserted into the gasket body 151 laterally. The left end of the movable insert strip 152 passes through the gasket 15 and extends into the slit channel 13.

[0038] In addition, in this embodiment, the lower end face of the upper mold 11 and the upper end face of the lower mold 12 are provided with grooves 17 for accumulating coating fluid. The grooves 17 are connected to the slit channel 13 and the channel 18 in the aforementioned embodiment.

[0039] It should be noted that in other embodiments, channel 18 may also be provided on the lower mold 12, or on both the upper mold 11 and the lower mold 12.

[0040] In other embodiments, the gasket 15 is clamped by the upper mold 11 and the lower mold 12, and is further fixedly installed on the upper mold 11 or the lower mold 12 by a threaded fixing structure.

[0041] In response, technicians can... Figure 1 Pushing the movable connector 152 in the horizontal left and right directions increases or decreases the volume of the main body portion of the movable connector 152 that is inserted into the slit channel 13, thereby decreasing or increasing the volume of the slit channel 13. This adjusts the size of the area in the slit channel 13 where the coating fluid can flow out to the coating opening 14, and thus adjusts the amount of coating fluid flowing out from the coating opening 14 per unit time.

[0042] Furthermore, in this embodiment, when the feeding speed of the feeding device is constant, the larger the volume of the body of the movable connector 152 inserted into the slit channel 13 and the closer the left end of the movable connector 152 is to the coating opening 14, the less coating fluid flows out from the coating opening 14 per unit time, the smaller the flow rate of the coating die head, and the lower the coating surface density. When the left end of the movable connector 152 is flush with the coating opening 14, the flow rate of the coating die head is the smallest. The smaller the volume of the body of the movable connector 152 inserted into the slit channel 13 and the farther the left end of the movable connector 152 is from the coating opening 14, the more coating fluid flows out from the coating opening 14 per unit time, the greater the flow rate of the coating die head, and the greater the coating surface density. When the adjusted left end is flush with the U-shaped bottom or C-shaped bottom of the gasket 15, the flow rate of the coating die head is the largest.

[0043] Further, please refer to Figures 1 to 3 In this embodiment, to prevent the movable connector 152 from affecting the flow path of the coating fluid in the slit channel 13, and to prevent the movable connector 152 from causing the coating fluid to flow unevenly from the coating opening 14, a plurality of ribbed grooves are formed inside the gasket body 151. Figure 1 The mounting holes 153 are arranged horizontally in the left and right directions. The number of movable connector strips 152 is equal to the number of mounting holes 153. Each mounting hole 153 has a movable connector strip 152 inserted into it, and the spacing between any two adjacent movable connector strips 152 is equal.

[0044] In response, when the technicians insert multiple movable connector strips 152 into each mounting hole 153, the width of the gap between any two movable connector strips 152 is also equal, so that the coating fluid can flow evenly along each gap of equal width to the coating opening 14, thereby ensuring that the coating fluid can flow out evenly from the coating opening 14.

[0045] It should be noted that in other embodiments, the movable connector 152 can also be set as a single piece, and the mounting hole 153 can also be set as a single piece. However, several strip-shaped gaps should be equally spaced on the body of the movable connector 152 that is inserted into the slit channel 13 to ensure uniform coating.

[0046] Furthermore, in this embodiment, in order to avoid the coating flow rate of the die head being too small due to the excessive thickness of the movable connector strip 152, or to avoid the insufficient adjustment effect of the movable connector strip 152 on the coating flow rate of the die head due to its insufficient thickness, the preferred thickness of the gasket body 151 is 0.8mm to 3mm, and the preferred thickness of the movable connector strip 152 is 0.3mm to 2mm.

[0047] Additionally, it should be noted that in this embodiment, in order to ensure that the movable connector strip 152 can be movably connected to the gasket body 151 through the mounting hole 153, the thickness of the movable connector strip 152 cannot be greater than the thickness of the gasket body 151.

[0048] Further, please refer to Figure 1 To facilitate adjustment of the insertion depth of the movable connector 152 from the outside of the die head, and to avoid the need to disassemble the die head to adjust the movable connector 152, in this embodiment, several movable connectors 152 are arranged towards... Figure 1 It extends to the right side of the mold body formed by the upper mold 11 and the lower mold 12.

[0049] Further, please refer to Figure 1 and Figure 2 In this embodiment, in order to make it easier to adjust the movable connector 152 and to make the coating fluid flow out evenly, several movable connectors 152 are arranged vertically toward the coating opening 14, and each movable connector 152 is perpendicular to the coating opening 14.

[0050] It should be noted that in other embodiments, the movable connector 152 may also be set at an appropriate angle, for example, at an angle of 0 to 10° relative to the gasket body 151, without affecting the uniform flow of the coating fluid from the coating opening 14.

[0051] Further, please refer to Figure 2 and Figure 3 and refer to Figure 2As shown in the orientation, in this embodiment, in order to form a coating thinning area on both sides of the electrode, the gasket body 151 includes a mounting body 1511 and extensions 1512 respectively disposed at both ends of the mounting body 1511. Both extensions 1512 are disposed towards the coating opening 14. Both extensions 1512 are L-shaped plates. The upper ends of both extensions 1512 and the side facing the middle of the mounting body 1511 are both provided with a chamfer 1513. The width of the chamfer 1513 in the horizontal left-right direction is the width of the thinning area.

[0052] For further details, please refer to Figure 1 and Figure 4 , refer to Figure 1 As shown in the diagram, in this embodiment, when there is a gap between the movable connector 152 and the mounting hole 153, the coating fluid may flow out from the right end of the gasket 15 along the gap, causing coating fluid leakage.

[0053] To prevent leakage of the coating fluid, a seal 16 is provided at the right end of the gasket 15. The seal 16 is formed by multiple sealing rings that can be fitted onto the movable connector 152 and inserted to the right into the gap between the movable connector 152 and the mounting hole 153.

[0054] In this embodiment, in order to improve the sealing effect and not to generate too much resistance to the movement of the movable connector 152 in the mounting hole 153, the seal 16 is made of an elastic material such as rubber or resin.

[0055] Anything not mentioned above applies to existing technologies.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A slit coating die, characterized in that, The die head includes: The upper mold (11), the lower mold (12), and the gasket (15) are clamped between the upper mold (11) and the lower mold (12) so that the upper mold (11), the lower mold (12), and the gasket (15) enclose a slit channel (13); the slit channel (13) has a coating opening (14); The gasket (15) includes a gasket body (151) and a movable connector (152). The gasket body (151) has an installation hole (153). The movable connector (152) is movably inserted into the installation hole (153). The movable connector (152) also extends into the slit channel (13).

2. The die head according to claim 1, characterized in that, The movable connector (152) also extends out of the mold body formed by the upper mold (11) and the lower mold (12).

3. The die head as described in claim 1, characterized in that, The movable connector (152) is arranged vertically toward the coating opening (14), and the movable connector (152) moves vertically to move away from or toward the coating opening (14).

4. The die head according to claim 1, characterized in that, The mounting holes (153) are provided in multiple ways, and the number of movable connectors (152) is equal to the number of mounting holes (153).

5. The die head according to claim 4, characterized in that, The spacing between any two adjacent movable connectors (152) is equal.

6. The die head according to claim 1, characterized in that, The thickness of the movable connector (152) is 0.3mm to 2mm, and the thickness of the movable connector (152) is less than the thickness of the gasket body (151).

7. The die head according to claim 1, characterized in that, The thickness of the gasket body (151) is 0.8 mm to 3 mm.

8. The die head according to claim 1, characterized in that, A sealing element (16) is provided in the insertion gap between the movable plug strip (152) and the gasket body (151), and the sealing element (16) is an elastic sealing element.

9. The die head according to claim 1, characterized in that, The gasket body (151) includes an mounting body (1511) and extensions (1512) respectively disposed at both ends of the mounting body (1511), the extensions (1512) being disposed toward the coating opening (14).

10. The die head according to claim 9, characterized in that, The end of the extension (1512) facing the central region of the mounting body (1511) is provided with a chamfer (1513), and the chamfer (1513) is located on the side of the extension (1512) facing the coating opening (14).

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