An extrusion coating composite gasket structure and an extrusion coater

Abstract

The application discloses an extrusion coating composite gasket structure and an extrusion coating machine, relates to the technical field of pole piece coating, and comprises a main body gasket and a strong cutting gasket. The main body gasket comprises a horizontal piece and two extended side pieces connected to the two sides of the horizontal piece, the horizontal piece and the two extended side pieces surround to form a hollow main slurry channel, and the main slurry channel is provided with a main slurry outlet in the direction of material coating. The strong cutting gasket comprises a connecting head, a strong cutting part and a flow blocking part connected between the connecting head and the strong cutting part, the connecting head is arranged at the middle position of the horizontal piece, the flow blocking part is located in the main slurry channel, and the strong cutting part is located at the main slurry outlet. The thickness of the strong cutting part is smaller than the thickness of the connecting head and the flow blocking part. Through the composite structure of the main body gasket and the strong cutting gasket, the amount of slurry at the middle position during positive electrode coating is reduced, and the lithium precipitation problem of positive electrode coating is solved. The strong cutting gasket can move forward and backward within a certain range, and the adjustment of the thinning width and thickness in the main slurry channel and outlet is realized.

Description

Technical Field

[0001] This invention relates to the field of electrode coating technology, specifically to an extrusion-coated composite gasket structure and an extrusion coating machine. Background Technology

[0002] The structure of the dual-outlet battery cell is shown in the attached figure. Figure 1 As shown.

[0003] Based on the cell length, current industrial battery electrode coating production methods often employ a one-to-two / four / multiple process. During stacking, the head of the negative electrode corresponds to the tail of the positive electrode. Because of the thinning area at the electrode head, the NP ratio (the ratio of the battery's negative electrode capacity to its motor capacity) of the thinned negative electrode area will be insufficient. Figure 2 As shown, the coating die at the positive electrode is prone to lithium plating during the later stages of cell development, leading to cell performance failure and even safety issues. Therefore, the coating die at the positive electrode needs to be thinned.

[0004] Typically, the coating die head of a coating machine consists of three parts: a lower die, a die head pad, and an upper die. Existing technologies have achieved thinning in the middle by adding branches to the pad, such as the pad and coating device for adjusting the thickness of the middle area of ​​the coating electrode disclosed in patent CN215542359U. However, this structure has two limitations: firstly, the thinning effect is limited; secondly, it cannot be adjusted according to the thinning requirements of different products, making it difficult to achieve the ideal balance effect of thinning treatment for the coating slurry of the positive and negative electrodes. Summary of the Invention

[0005] To address one or more shortcomings of the existing technology, the present invention provides an extrusion coating composite gasket structure and an extrusion coating machine, which is mainly applicable to positive electrode dies. It can effectively thin the middle of the die head, and the thinning width and thickness can be adjusted according to product requirements. This can avoid the problem of lithium plating on the gasket and facilitate employee operation and control.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An extrusion-coated composite gasket structure includes a main gasket and a shearing gasket. The main gasket is an integral structure, including a horizontal piece and two extended side pieces connected to both sides of the horizontal piece. The horizontal piece and the two extended side pieces surround and form a hollow main slurry channel. The main slurry channel is provided with a main slurry outlet facing the direction of material coating.

[0008] The shearing pad is an integral structure, including a connecting head, a shearing part, and a flow-blocking part connected between the connecting head and the shearing part. The connecting head is located in the middle of the cross plate, the flow-blocking part is located in the main slurry channel, and the shearing part is located at the main slurry outlet. The thickness of the shearing part is less than the thickness of the connecting head and the flow-blocking part.

[0009] As a further implementation, the main body gasket has several gasket positioning holes for connecting with the mold head.

[0010] As a further implementation, the connecting head is provided with a cutting positioning hole, which is an elliptical hole with the focus of the ellipse arranged perpendicular to the horizontal plate direction. The cutting shim is installed on the die head through the cutting positioning hole. At the same time, the installation position of the cutting shim can be moved back and forth to adjust the thickness and width of the thinning area, which can effectively meet the thinning requirements of the product.

[0011] As a further implementation, the thickness H3 of the connecting head and the flow-blocking part is 0.5-3.0mm, which is the same as the thickness of the main body gasket, so as to match the main body gasket and facilitate installation and mold head closure.

[0012] As a further implementation, the thickness D1 of the shearing section is 5%-95% of the thickness H3, which can reduce the slurry flow rate of the shearing section and achieve thinning of the middle of the electrode sheet.

[0013] As a further implementation, the end of the cutting section is set to a rectangle, the length H2 of the cutting section parallel to the horizontal plate is 2-50mm, and the width H1 perpendicular to the horizontal plate is 5-25mm.

[0014] As a further implementation, the distance H0 from the strong cutting section to the connection between the main slurry channel and the flow-blocking section is 0-30mm, so as to control the advance amount of the slurry entering the thinning area, thereby controlling the thinning intensity.

[0015] As a further implementation, both the main body gasket and the shearing gasket are made of high-strength stainless steel.

[0016] As a further implementation, the two extended side plates are chamfered at opposite ends on both sides of the main slurry outlet, which can control the thinning width and thickness according to the thinning requirements of different products.

[0017] As a further implementation, the distance between the outer end of the connecting head and the inner wall of the transverse plate is 0-2mm. Adjusting the position of the shearing shim within this range can ensure the best slurry reduction effect of the electrode.

[0018] On the other hand, the present invention also provides an extrusion coating machine, which includes a coating die head, the coating die head including an upper die, a lower die and a die head gasket, the die head gasket adopting the extrusion coating composite gasket structure described in any of the above claims.

[0019] By adopting the above technical solution, the beneficial effects of the present invention are as follows:

[0020] 1. This invention incorporates a strong-shearing pad in the middle of the main pad to form a composite pad structure. This structure not only allows for slurry diversion and slows slurry flow, but also reduces the amount of slurry in the middle during positive electrode coating, effectively preventing lithium plating during positive electrode coating. Furthermore, the strong-shearing pad can move back and forth within a certain range relative to the main pad, thereby adjusting the distance between the strong-shearing pad and the back roller of the material coating area. This enables adjustment of the thinning width and thickness within the main slurry channel and outlet, improving the controllability of the thinning effect.

[0021] 2. This utility model can also be applied to negative electrode coating dies, which can reduce material loss and increase energy density. Attached Figure Description

[0022] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0023] Figure 1 This is a plan view of an embodiment of the present invention;

[0024] Figure 2 This is a planar schematic diagram of the shear pad according to an embodiment of the present invention;

[0025] Figure 3 This is a schematic diagram showing the dimensional design of the shearing section of the shearing pad according to an embodiment of the present invention.

[0026] In the diagram: 1. Main gasket; 11. Horizontal piece; 12. Extended side piece; 13. Main slurry channel; 14. Main slurry outlet; 15. Gasket positioning hole;

[0027] 2. Shearing pad; 21. Connecting head; 22. Baffle; 23. Shearing part; 24. Shearing positioning hole. Detailed Implementation

[0028] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0029] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments of the present invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0030] Example 1

[0031] In one typical embodiment of this application, an extrusion-coated composite gasket structure is provided, such as... Figure 1-3 As shown, it includes a main gasket 1 and a shearing gasket 2. The main gasket 1 is an integral structure, including a horizontal piece 11 and two extended side pieces 12 connected to both sides of the horizontal piece. The horizontal piece 11 and the two extended side pieces 12 surround to form a hollow main slurry channel 13. The main slurry channel 13 is provided with a main slurry outlet 14 facing the direction of material coating.

[0032] The shearing pad 2 is an integral structure, including a connecting head 21, a shearing part 23, and a flow-blocking part 22 connected between the connecting head and the shearing part. The connecting head 21 is located in the middle of the cross plate 11, the flow-blocking part 22 is located in the main slurry channel 13, and the shearing part 23 is located at the main slurry outlet 14. The thickness of the shearing part 23 is less than the thickness of the connecting head 21 and the flow-blocking part 22.

[0033] In this embodiment, the back roller for slurry coating is located outside the main slurry outlet. The shearing pad is disposed between the main pads. The flow blocking part diverts the slurry in the main slurry channel. The shearing part is located in the middle of the main slurry outlet, causing most of the slurry to flow out from both sides, and a small portion of the slurry to flow out along the shearing part, thereby thinning the coating in the middle of the electrode sheet.

[0034] Specifically, to achieve the connection and fixation between the composite gasket structure and the mold head, the main gasket 1 is provided with gasket positioning holes, such as... Figure 1 As shown, the main body gasket 1 has several evenly distributed gasket positioning holes 15. The size and spacing of the gasket positioning holes can be determined according to the needs of different mold heads. During installation, the mold head is fixedly connected to the gasket positioning hole by the mold head fixing nut.

[0035] Specifically, the shearing shim 2 is positioned in the middle of the main shim 1 to ensure that the coating on the electrode sheet is cut in the middle. To facilitate the installation of the shearing shim, a shearing positioning hole is provided on the connecting head of the shearing shim. Figure 1 , 2As shown, two strong-cutting positioning holes 24 are formed on the connecting head 21, and the strong-cutting shim 2 is installed on the die head through the strong-cutting positioning holes 24. Furthermore, to achieve adjustable thinning effect, in this embodiment, as... Figure 1 , 2 As shown, the strong cutting positioning hole 24 is set as an elliptical hole, and the focus of the ellipse is arranged along the direction perpendicular to the horizontal plate. This allows the strong cutting pad to be finely adjusted back and forth along the direction perpendicular to the horizontal plate when it is installed on the die head, thereby changing the distance from the back roller of the material coating area. When the distance is greater, the amount of slurry coated on the foil per unit time increases and the overflow angle becomes larger; when the distance is closer, the amount of slurry coated on the foil per unit time decreases and the overflow angle becomes smaller, thereby realizing the adjustment of the thickness and width of the thinning area. In application, specific adjustments can be made according to the thinning requirements of the product to better achieve the ideal thinning effect.

[0036] Specifically, to meet the thinning requirements, the thickness of the shearing shim varies in different parts, such as... Figure 2 As shown, the thickness H3 of the connecting head 21 and the flow-blocking part 22 is 0.5-3.0 mm, the same as the thickness of the main gasket 1. This allows the thickness H3 of the main gasket to be determined according to the coating thickness of different products, ensuring that the thickness of the shearing gasket is consistent with the thickness of the main gasket. This facilitates matching and installation with the main gasket and does not affect the slurry fluid circulation direction inside the die head. The thickness D1 of the shearing part 23 is 5%-95% of the thickness H3, which can reduce the slurry flow rate in the shearing part and achieve thinning of the electrode in the middle.

[0037] In this embodiment, as Figure 2 , 3 As shown, the end of the cutting section 23 is rectangular. The length H2 of the cutting section parallel to the cross section is 2-50 mm, and the width H1 perpendicular to the cross section is 5-25 mm. The distance H0 from the cutting section 23 extending into the main slurry channel and connecting with the flow-blocking section is 0-30 mm. This is to control the flow rate of slurry into the thinning zone, thereby controlling the thinning effect. Figure 3 As shown, the width H1 and distance H0 can be combined in various ways. Within a certain range of the flow-blocking section, the larger H0 is, the more significant the thinning effect on the middle of the slurry. Conversely, the smaller H1 is, the weaker the thinning ability on the slurry flow rate. Therefore, different specifications of strong-cutting pads can be selected according to the actual coating process to achieve precise flow control, meet the thinning requirements of different products, and achieve an ideal balance in the thinning treatment of positive and negative electrode coating slurries.

[0038] In addition, such as Figure 1As shown, the outer end of the connecting head 21 protrudes a certain distance from the inner wall of the cross plate 11, further reducing the area of ​​the main slurry channel and shortening the distance between the strong cutting zone and the back roller, thus more effectively reducing the slurry in the middle. In this embodiment, the distance between the outer end of the connecting head 21 and the inner wall of the cross plate 11 is 0-2mm. Adjusting the position of the strong cutting shim within this range can achieve the best slurry reduction effect on the electrode.

[0039] In this embodiment, both the gasket body and the shearing gasket are made of high-strength stainless steel.

[0040] In this embodiment, the two extended side plates 12 are respectively chamfered at opposite ends on both sides of the main slurry outlet 14, in order to control the width and thickness of the thinning zone.

[0041] This embodiment can be applied to the positive electrode coating die head, solving the performance failure and safety issues caused by lithium plating at the positive electrode tail corresponding to the negative electrode head in dual-head tab structure cells. Simultaneously, this embodiment employs a composite structure of a main gasket and a central high-strength cutting gasket, with the high-strength cutting gasket movable back and forth, meeting the thickness and width requirements of different products for the thinning area. This not only solves the performance failure and safety issues caused by lithium plating at the positive electrode tail corresponding to the negative electrode head, but also ensures convenient installation and operation for employees, making it economical and practical. Furthermore, in addition to solving the lithium plating problem in the positive electrode, this embodiment can also be applied to the negative electrode die head to reduce slurry loss in the thinning area, increasing battery energy density while saving material costs and improving enterprise efficiency.

[0042] Example 2

[0043] In another typical embodiment of the present invention, an extrusion coating machine is provided, which includes a coating die head, the coating die head including an upper die, a lower die and a die head gasket, the die head gasket adopting the extrusion coating composite gasket structure in Embodiment 1.

[0044] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Those skilled in the art should understand that the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An extrusion-coated composite gasket structure, characterized in that, It includes a main gasket and a shearing gasket. The main gasket is an integral structure, including a horizontal piece and two extended side pieces connected to both sides of the horizontal piece. The horizontal piece and the two extended side pieces surround and form a hollow main slurry channel. The main slurry channel is provided with a main slurry outlet facing the direction of material coating. The shearing pad is an integral structure, including a connecting head, a shearing part, and a flow-blocking part connecting the connecting head and the shearing part. The connecting head is located in the middle of the cross plate, the flow-blocking part is located in the main slurry channel, and the shearing part is located at the main slurry outlet. The thickness of the shearing part is less than the thickness of the connecting head and the flow-blocking part. The connecting head is provided with a strong cutting positioning hole, which is an elliptical hole with the focus of the ellipse arranged perpendicular to the horizontal plate. The strong cutting pad is installed on the die head through the strong cutting positioning hole. The end of the strong cutting part is set as a rectangle. The length H2 of the strong cutting part parallel to the horizontal plate is 2-50mm, and the width H1 perpendicular to the horizontal plate is 5-25mm. The distance H0 between the strong cutting part extending into the main slurry channel and connecting with the flow blocking part is 0-30mm. The distance between the outer end of the connecting head and the inner wall of the horizontal plate is 0-2mm.

2. The extrusion-coated composite gasket structure as described in claim 1, characterized in that, The main body gasket has several gasket positioning holes for connecting with the mold head.

3. The extrusion-coated composite gasket structure as described in claim 1, characterized in that, The thickness H3 of the connecting head and the flow-blocking part is 0.5-3.0 mm, which is the same as the thickness of the main gasket.

4. The extrusion-coated composite gasket structure as described in claim 3, characterized in that, The thickness D1 of the sheared portion is 5%-95% of the thickness H3.

5. The extrusion-coated composite gasket structure as described in claim 1, characterized in that, Both the main gasket and the shearing gasket are made of stainless steel.

6. The extrusion-coated composite gasket structure as described in claim 1, characterized in that, The two extended side plates are chamfered at opposite ends on both sides of the main slurry outlet.

7. An extrusion coating machine, comprising a coating die head, the coating die head including an upper die, a lower die, and a die head gasket, characterized in that, The die head gasket adopts an extrusion-coated composite gasket structure as described in any one of claims 1-6.

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