Coating gasket, manufacturing method thereof and coating device

Abstract

The invention discloses a coating gasket, a manufacturing method thereof and a coating device, the coating gasket comprises a gasket body, the gasket body is provided with a plurality of first coating areas and a plurality of second coating areas, and the first coating areas and the second coating areas are adjacent and alternately arranged; the gasket body is further provided with a plurality of first open holes and a plurality of second open holes, the first open holes correspond to the bottom of the first coating area, and the second open holes correspond to the bottom of the second coating area. A separation strip capable of generating elastic deformation after being extruded is arranged between the first coating area and the second coating area. Compared with the prior art, the pole piece coating device has the advantages that the separation strip capable of generating elastic deformation after being extruded is arranged between the first coating area and the second coating area, so that the coating amount can be accurately controlled, and the pole piece coating uniformity and consistency are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of lithium ion battery production, and in particular relates to a coating gasket and a manufacturing method and a coating device thereof. Background Art

[0002] With the development of society and the advancement of science and technology, lithium-ion batteries have been widely used in new energy vehicles, portable electronic devices and other fields due to their advantages such as high energy density and long cycle life. As one of the core components of lithium-ion batteries, the preparation process of electrode plates directly affects the performance indicators of batteries.

[0003] The traditional electrode preparation process usually adopts the coating method to coat the active material on the current collector to form the electrode electrode. In order to facilitate the subsequent electrode ear welding, during the coating process, a section of the electrode ear area that is not coated with active material is usually reserved at the head of the electrode. This coating method installs a gasket in the coating die head and uses the gasket to control the coating area, thereby realizing the division of the coating area and the blank area.

[0004] However, with the continuous development of battery technology and the growing market demand for high-performance batteries, the traditional electrode coating method has been unable to meet the current technical requirements. On the one hand, the reserved pole ear area at the pole head will occupy a certain area, reducing the coating area of ​​the active material and reducing the energy density of the battery; on the other hand, the pole ear is located at the pole head, and the transmission distance of electrons within the pole surface is long, which increases the internal resistance of the pole and affects the rate performance of the battery.

[0005] In order to solve the above problems, the industry has begun to explore a new pole piece design that sets a pole ear area in the middle of the pole piece. By moving the pole ear area to the middle of the pole piece, the electron transmission path can be shortened, the pole piece internal resistance can be reduced, and the battery's rate performance can be improved. At the same time, the middle pole ear design also helps to improve the safety performance of the battery, avoiding the risk of short circuit caused by contact between the pole ear area and the edge of the active material area.

[0006] However, although the middle tab design has advantages in reducing internal resistance and improving safety, it also brings new challenges. Since the tab area is located in the middle of the pole piece, there is a large blank area in the middle of the pole piece. These blank areas cannot be effectively utilized, occupying a large area of ​​the pole piece, resulting in a decrease in battery energy density and affecting the overall performance of the battery.

[0007] In order to make full use of the pole piece area and improve the battery energy density, the inventor has previously developed a new coating method, such as using a double-cavity coating die for coating. By setting two cavities in the coating die and supplying coating slurry separately, a narrow pole ear area can be formed in the middle of the pole piece, reducing the blank area and improving the utilization rate of the pole piece. The double-cavity coating method solves the area waste problem caused by the middle pole ear design to a certain extent and achieves an increase in battery energy density.

[0008] However, the double-cavity coating method still has some shortcomings in controlling the coating amount. This method controls the amount of coating by adjusting the gap between the pressing block and the gasket groove with a micrometer. The larger the gap, the greater the flow of electrode slurry flowing through; the smaller the gap, the smaller the flow of electrode slurry flowing through. However, due to the thickness of the gasket spacer, when the pressing block acts on the gasket spacer, the gap between the pressing block and the gasket groove cannot be further adjusted, resulting in the inability to achieve precise control of the coating amount. This inaccuracy in coating amount control may lead to uneven thickness of the pole piece, affecting the consistency and performance of the battery.

[0009] In view of the above-mentioned problems existing in the prior art, it is urgent to develop a new type of coating gasket that can achieve precise control of the coating amount, improve the uniformity and consistency of the electrode coating, and further improve the performance level of the battery. Summary of the invention

[0010] The purpose of the present invention is to provide a coating gasket to address the deficiencies of the prior art, which can achieve precise control of the coating amount and improve the uniformity and consistency of the electrode coating.

[0011] To achieve the above object, the present invention provides the following technical solutions:

[0012] A coating gasket comprises a gasket body, wherein the gasket body is provided with a plurality of first coating areas and a plurality of second coating areas, wherein the first coating areas are adjacent to and alternately arranged with the second coating areas;

[0013] The gasket body is further provided with a plurality of first openings and a plurality of second openings, wherein the first openings correspond to the bottom of the first coating area, and the second openings correspond to the bottom of the second coating area;

[0014] A separation strip which can be squeezed to generate elastic deformation is arranged between the first coating area and the second coating area.

[0015] Preferably, the gasket body is an integrally formed structure.

[0016] Preferably, a groove is provided at a position of the gasket body corresponding to the dividing strip, and the dividing strip is partially embedded in the groove.

[0017] Preferably, the partition strip is fixed to the gasket body by bonding.

[0018] Preferably, the thickness of the partition strip exposed on the upper surface of the gasket body is the same as the wall thickness of the first coating area or the second coating area.

[0019] Preferably, the ratio of the depth of the groove to the thickness of the separator is 1:(2-4), which can ensure the stability of the connection between the separator and the gasket body while playing a separating role.

[0020] Preferably, the side wall of the groove is provided with a locking protrusion, and the side wall of the partition strip is provided with a locking groove that cooperates with the locking protrusion.

[0021] Preferably, the separator strip is made of elastic material such as elastic silicone or elastic rubber.

[0022] Preferably, the first coating area is provided with a plurality of reinforcing ribs, and the plurality of reinforcing ribs are evenly arranged along the first coating area.

[0023] Preferably, the length of the first coating area is greater than that of the second coating area; the length of the first opening matches the length of the first coating area, and the length of the second opening matches the length of the second coating area.

[0024] Preferably, the first coating area is in a shape that is wide at the front and narrow at the back along the longitudinal direction, and the second coating area is in a shape that is narrow at the front and wide at the back along the longitudinal direction.

[0025] Preferably, the bottom height of the first coating area is lower than the bottom height of the second coating area.

[0026] Preferably, the opening area of ​​the first opening is larger than the opening area of ​​the second opening.

[0027] Preferably, the top of the separator strip is a pointed structure, and the upper edge of the separator strip is 0.1 to 2.5 mm lower than the upper edge of the gasket body. That is, the upper edge of the separator strip does not exceed the upper edge of the gasket body, and the distance between the upper edge of the separator strip and the upper edge of the gasket body is 0.1 to 2.5 mm.

[0028] Preferably, the gasket body is provided with a plurality of fixing holes.

[0029] In addition, the present invention also provides a method for manufacturing the above-mentioned coated gasket, comprising the following steps:

[0030] 1) Cutting or punching the gasket body to form alternately arranged first coating areas and second coating areas;

[0031] 2) a first opening is formed on the gasket body at a bottom position corresponding to the first coating area, and a second opening is formed on the gasket body at a bottom position corresponding to the second coating area;

[0032] 3) A groove is formed on the gasket body at a position corresponding to the interval between the first coating area and the second coating area, and the elastic partition strip is partially embedded in the groove for fixing, thereby obtaining the coated gasket;

[0033] And / or, the elastic separation strip is fixed to the gasket body by bonding, thereby obtaining the coated gasket.

[0034] In addition, the present invention also provides a coating device, including an upper die head and a lower die head, the coating device also includes the above-mentioned coating gasket, and the coating gasket is arranged between the upper die head and the lower die head.

[0035] Compared with the prior art, the present invention has at least the following beneficial effects:

[0036] 1) The coating gasket provided by the present invention can realize independent control of the coating amount of different areas by arranging alternating first coating areas and second coating areas on the gasket body, and respectively opening corresponding first openings and second openings at the bottom thereof; when the first coating area is coated, continuous coating is adopted to obtain a pole piece with a complete coating layer; when the second coating area is coated, intermittent coating is adopted to obtain a pole piece with alternating coating layers and blank areas; wherein the first coating area and the second coating area can be designed with different lengths and widths according to actual needs, and the corresponding first openings and second openings can also be designed with different sizes and shapes, so as to realize precise adjustment of the coating amount of different areas.

[0037] 2) The present invention provides a separator strip between the first coating area and the second coating area that can be squeezed to produce elastic deformation, which can play a key role in the coating process. When the pressure block squeezes the separator strip, the elastic separator strip can be further compressed, thereby further reducing the gap between the pressure block and the gasket body, and returns to its original state after the squeezing is released; therefore, through the elastic deformation of the separator strip, the coating gap can be finely adjusted, thereby achieving precise control of the coating amount. The design of this elastic separator strip can significantly improve the accuracy and reliability of coating amount control. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the three-dimensional structure of a coating gasket according to an embodiment of the present invention;

[0039] Figure 2 A top view of a coating gasket according to an embodiment of the present invention;

[0040] Figure 3 The structure of the coating gasket according to one embodiment of the present invention is exploded.

[0041] In the figure: 1. gasket body; 11. first coating area; 12. second coating area; 13. first opening; 14. second opening; 15. reinforcing rib; 16. fixing hole; 2. dividing strip; 3. groove. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] Please see attached Figures 1 to 3 According to a first aspect of the present application, the present application provides a coated gasket, comprising a gasket body 1, the gasket body 1 is provided with a plurality of first coating areas 11 and a plurality of second coating areas 12, the first coating areas 11 and the second coating areas 12 are adjacent and alternately arranged;

[0044] The gasket body 1 is further provided with a plurality of first openings 13 and a plurality of second openings 14, wherein the first openings 13 correspond to the bottom of the first coating area 11, and the second openings 14 correspond to the bottom of the second coating area 12; wherein the first openings 13 are connected to the first cavity of the double-cavity coating die head, and are used to guide the slurry to the first coating area 11 of the gasket body 1; and the second openings 14 are connected to the second cavity of the double-cavity coating die head, and are used to guide the slurry to the second coating area 12 of the gasket body 1;

[0045] A separation strip 2 which can be squeezed to generate elastic deformation is arranged between the first coating area 11 and the second coating area 12 .

[0046] Among them, the coated gasket provided by the present invention can achieve independent control of the coating amount in different areas by arranging alternating first coating areas 11 and second coating areas 12 on the gasket body 1, and opening corresponding first openings 13 and second openings 14 at the bottom thereof; when the first coating area 11 is coated, continuous coating is adopted to obtain a pole piece with a complete coating layer; when the second coating area 12 is coated, intermittent (skip gap) coating is adopted to obtain a pole piece with alternating coating layers and blank areas.

[0047] Among them, the present invention sets a separator strip 2 that can be squeezed and elastically deformed between the first coating area 11 and the second coating area 12, which can play a key role in the coating process. When the pressing block squeezes the separator strip 2, the elastic separator strip 2 can be further compressed, thereby further reducing the gap between the pressing block and the gasket body 1; through the elastic deformation of the separator strip 2, the coating gap can be finely adjusted, thereby achieving precise control of the coating amount.

[0048] In one embodiment of the present application, the gasket body 1 is an integrally formed structure, preferably made of steel, and a groove 3 is provided at a position corresponding to the gasket body 1 and the dividing strip 2, and the dividing strip 2 is partially embedded in the groove 3; preferably, the dividing strip 2 and the groove 3 are connected by an interference fit to improve the stability of the connection.

[0049] Among them, this embodiment adopts an integrally formed gasket body 1, and a groove 3 corresponding to the dividing strip 2 is provided on the gasket body 1, and the dividing strip 2 is partially embedded in the groove 3, so that the dividing strip 2 and the gasket body 1 can be reliably connected and fixed. At the same time, the integrally formed gasket body 1 also simplifies the manufacturing process of the coated gasket and reduces the production cost.

[0050] In one embodiment of the present application, the partition strip 2 is directly fixed to the gasket body 1 by bonding. For example, the partition strip 2 is bonded to the surface of the gasket body 1 by glue.

[0051] In one embodiment of the present application, the thickness of the separator 2 exposed on the upper surface of the gasket body 1 is the same as the wall thickness of the first coating area 11 or the second coating area 12. This ensures that the separator 2 and the coating area have the same height in the vertical direction, avoids the influence of the height difference during the coating process on the coating quality, and can further improve the uniformity and consistency of the coating.

[0052] In one embodiment of the present application, the ratio of the depth of the groove 3 to the thickness of the separator 2 is 1:(2-4). This can ensure the stability of the connection between the separator 2 and the gasket body 1 while playing a role of separation. It should be noted that the specific thickness ratio of the two can be adjusted according to actual needs, as long as the separation bar 2 and the gasket body 1 can be connected stably while playing a role of separation.

[0053] In one embodiment of the present application, the side wall of the groove 3 is provided with a latching protrusion, and the side wall of the dividing strip 2 is provided with a latching groove that cooperates with the latching protrusion; the stability of the connection between the dividing strip 2 and the gasket body 1 can be further improved.

[0054] In one embodiment of the present application, the partition strip 2 is made of elastic materials such as elastic silicone or elastic rubber, preferably EPDM rubber. These materials can give the partition strip 2 good elasticity and flexibility, so that it can produce moderate deformation when squeezed and return to its original shape after the squeeze is released. It should be noted that other materials that can undergo elastic deformation can also be used.

[0055] In one embodiment of the present application, the first coating area 11 is provided with a plurality of reinforcing ribs 15, and the plurality of reinforcing ribs 15 are evenly arranged along the first coating area 11. The evenly distributed reinforcing ribs 15 enhance the structural strength of the first coating area 11, prevent deformation under high pressure, and ensure uniformity and stability of coating.

[0056] In one embodiment of the present application, the length of the first coating area 11 is greater than the length of the second coating area 12; the length of the first opening 13 is adapted to the length of the first coating area 11, and the length of the second opening 14 is adapted to the length of the second coating area 12. The coating amount of the tab welding area can be reduced while ensuring the coating amount of the non-tab welding area.

[0057] In one embodiment of the present application, the first coating area 11 is wide in the front and narrow in the back along the longitudinal direction, and the second coating area 12 is narrow in the front and wide in the back along the longitudinal direction. In this way, the slurry flow rate of the two coating areas can be better controlled. It should be noted that the first coating area 11 and the second coating area 12 can adjust the width of the front and back according to actual needs to control the coating flow rate.

[0058] In one embodiment of the present application, the bottom height of the first coating area 11 is lower than the bottom height of the second coating area 12. The first coating area 11 is used to achieve the coating of a continuous coating layer, and the second coating area 12 is used to achieve the coating of an intermittent coating layer (the coating layer and the blank area are alternated). Therefore, the coating height of the two different areas can be controlled to facilitate the control of the blank area. It should be noted that during coating, the first coating area 11 and the second coating area 12 can also be used in reverse; that is, the first coating area 11 is used to achieve the coating of an intermittent coating layer (the coating layer and the blank area are alternated); the second coating area 12 is used to achieve the coating of a continuous coating layer.

[0059] In one embodiment of the present application, the opening area of ​​the first opening 13 is larger than the opening area of ​​the second opening 14. During the coating process, the first coating area 11 is coated with a larger area, so a larger feed space is required; the second coating area 12 is coated with a smaller area, and a slightly smaller feed space can be used; in this way, differential control of the coating amount in different areas can be achieved.

[0060] In one embodiment of the present application, the top of the partition strip 2 is a sharp-angle structure, and the upper edge of the partition strip 2 is 0.1 to 2.5 mm lower than the upper edge of the gasket body 1. This ensures that the slurry on both sides of the partition strip 2 (two coating areas) can be better integrated at the joint, preventing uneven coating thickness at the joint.

[0061] In one embodiment of the present application, the gasket body 1 is provided with a plurality of fixing holes 16 , which can facilitate the installation and fixation of the coating gasket on the coating device, thereby improving the stability and reliability of the coating process.

[0062] According to the second aspect of the present application, the present application also provides a method for manufacturing the above-mentioned coated gasket, comprising the following steps:

[0063] 1) Cutting or punching the gasket body 1 to form alternately arranged first coating areas 11 and second coating areas 12;

[0064] 2) a first opening 13 is formed on the gasket body 1 at a bottom position corresponding to the first coating area 11, and a second opening 14 is formed on the gasket body 1 at a bottom position corresponding to the second coating area 12;

[0065] 3) A groove 3 is provided on the gasket body 1 at a position corresponding to the interval between the first coating area 11 and the second coating area 12; the elastic partition strip 2 is partially embedded in the groove 3 and fixed, thereby obtaining the coated gasket;

[0066] And / or, the elastic separation strip 2 is directly fixed to the gasket body 1 by bonding, so as to obtain the coated gasket.

[0067] The method for producing the coated gasket of the present invention can efficiently and accurately produce the coated gasket having the above advantages. The method is simple to operate, easy to realize industrial production, and has good practicality and promotion value.

[0068] According to the third aspect of the present application, the present application also provides a coating device, including an upper die head and a lower die head, and the coating device also includes the above-mentioned coating gasket, and the coating gasket is arranged between the upper die head and the lower die head. Among them, the first opening 13 is connected to one of the material chambers of the double-cavity coating die head, and is used to guide the slurry to the first coating area 11 of the gasket body 1; the second opening 14 is connected to the other material chamber of the double-cavity coating die head, and is used to guide the slurry to the second coating area 12 of the gasket body 1. When the first coating area 11 is coated, continuous coating is adopted to obtain a pole piece with a complete coating layer; when the second coating area 12 is coated, intermittent (skip gap) coating is adopted, and a pole piece with alternating coating layers and blank areas can be obtained. When it is necessary to control the coating amount of each coating area, the gap between the pressing block and the gasket body 1 can be adjusted by a micrometer. When a smaller gap is needed, the pressing block squeezes the dividing strip 2. Since the dividing strip 2 has good elasticity, it can produce moderate deformation when squeezed and return to its original shape after the squeezing is released.

[0069] Among them, the coating gasket of the present invention is applied to the coating device and arranged between the upper die head and the lower die head. It can give play to its unique advantages in the coating process, realize the precise control of the coating amount in different areas of the electrode, improve the uniformity and consistency of the electrode coating, and finally obtain high-quality and high-performance battery electrodes.

[0070] It should be noted that the contents not described in detail in this specification belong to the prior art known to professional and technical personnel in the field and will not be repeated here.

[0071] According to the disclosure and teaching of the above description, those skilled in the art to which the present invention belongs can also change and modify the above embodiment. Therefore, the present invention is not limited to the above specific embodiment, and any obvious improvement, replacement or modification made by those skilled in the art on the basis of the present invention belongs to the protection scope of the present invention. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any limitation to the present invention.

Claims

1. A coated gasket, characterized in that: The gasket body comprises a gasket body, wherein the gasket body is provided with a plurality of first coating areas and a plurality of second coating areas, wherein the first coating areas are adjacent to and alternately arranged with the second coating areas; The gasket body is further provided with a plurality of first openings and a plurality of second openings, wherein the first openings correspond to the bottom of the first coating area, and the second openings correspond to the bottom of the second coating area; A separation strip which can be squeezed to generate elastic deformation is arranged between the first coating area and the second coating area.

2. The coating gasket according to claim 1, characterized in that: The gasket body is an integrally formed structure; and / or, a groove is provided at a position of the gasket body corresponding to the dividing strip, and the dividing strip is partially embedded in the groove; and / or, the dividing strip is fixed to the gasket body by bonding.

3. The coating gasket according to claim 2, characterized in that: The thickness of the partition strip exposed on the upper surface of the gasket body is the same as the wall thickness of the first coating area or the second coating area; And / or, the ratio of the depth of the groove to the thickness of the partition strip is 1:(2-4).

4. The coating gasket according to claim 1, characterized in that: The separation strip is made of elastic silica gel or elastic rubber.

5. The coated gasket according to claim 1, characterized in that: The first coating area is provided with a plurality of reinforcing ribs, and the plurality of reinforcing ribs are evenly arranged along the first coating area.

6. The coated gasket according to claim 1, characterized in that: The length of the first coating area is greater than that of the second coating area; the length of the first opening matches the length of the first coating area, and the length of the second opening matches the length of the second coating area.

7. The coated gasket according to claim 1, characterized in that: The bottom height of the first coating area is lower than the bottom height of the second coating area; the opening area of ​​the first opening is larger than the opening area of ​​the second opening.

8. The coated gasket according to claim 1, characterized in that: The top of the partition strip is a pointed structure, and the upper edge of the partition strip is 0.1 to 2.5 mm lower than the upper edge of the gasket body.

9. A method for manufacturing a coated gasket according to any one of claims 1 to 8, characterized in that: The following steps are involved: 1) Cutting or punching the gasket body to form alternately arranged first coating areas and second coating areas; 2) a first opening is formed on the gasket body at a bottom position corresponding to the first coating area, and a second opening is formed on the gasket body at a bottom position corresponding to the second coating area; 3) A groove is formed on the gasket body at a position corresponding to the interval between the first coating area and the second coating area, and the elastic partition strip is partially embedded in the groove for fixing, thereby obtaining the coated gasket; And / or, the elastic separation strip is fixed to the gasket body by bonding, thereby obtaining the coated gasket.

10. A coating device, comprising an upper die head and a lower die head, characterized in that: The coating device further comprises a coating gasket as claimed in any one of claims 1 to 8, wherein the coating gasket is arranged between the upper die head and the lower die head.

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