Coating gasket and coating device

Abstract

The utility model discloses a coating gasket 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 coating device has the advantages that the separation strip which can be extruded to generate elastic deformation is arranged between the first coating area and the second coating area, so that the coating weight can be accurately controlled, and the uniformity and consistency of pole piece coating are improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to lithium ion battery production technical field especially relates to a kind of coating gasket and coating device. BACKGROUND

[0002] With the development of society and the progress of science and technology, lithium ion battery is widely used in new energy vehicles, portable electronic devices and other fields due to its high energy density, long cycle life and other advantages. As one of the core components of lithium ion battery, the preparation process of electrode sheet directly affects the performance index of battery.

[0003] The traditional electrode sheet preparation process usually adopts coating method to coat active material on current collector to form electrode sheet. In order to facilitate subsequent tab welding, a tab area without coating active material is usually reserved at the head of electrode sheet during coating process. This coating method divides the coating area and the blank area by installing gasket in coating die.

[0004] However, with the continuous development of battery technology and the increasing demand for high-performance batteries in the market, the traditional electrode sheet coating method has been difficult to meet the current technical requirements. On the one hand, reserving tab area at the head of electrode sheet occupies a certain area, reduces the coating area of active material and reduces the energy density of battery; on the other hand, the tab is located at the head of electrode sheet, the transmission distance of electrons in the electrode sheet surface is longer, which increases the internal resistance of electrode sheet and affects the rate performance of battery.

[0005] In order to solve the above problems, the industry began to explore new electrode sheet design by setting tab area in the middle of electrode sheet. By moving the tab area to the middle of electrode sheet, the electron transmission path can be shortened, the internal resistance of electrode sheet can be reduced, and the rate performance of battery can be improved. At the same time, the middle tab design also helps to improve the safety performance of battery, avoiding the short circuit risk caused by the contact between tab area and active material area edge.

[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 electrode sheet, there is a large area of blank area in the middle of electrode sheet. These blank areas cannot be effectively utilized, occupy a large area of electrode sheet, resulting in the decrease of battery energy density and affecting the overall performance of battery.

[0007] In order to fully utilize the pole piece area and improve the battery energy density, the inventor has previously developed a new coating method, such as using a double-chamber coating die to coat. By providing two chambers in the coating die, respectively supplying coating slurry, a narrow tab area can be formed in the middle of the pole piece, reducing the white space area and improving the utilization rate of the pole piece. The double-chamber coating method solves the problem of area waste caused by the middle tab design to a certain extent, and realizes the improvement of the battery energy density.

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

[0009] In view of the above problems existing in the prior art, it is urgent to develop a new type of coating gasket which can realize precise control of the coating amount, improve the uniformity and consistency of the pole piece coating, and further improve the performance level of the battery. Practical new type content

[0010] The purpose of the present application is to provide a coating gasket which can realize precise control of the coating amount and improve the uniformity and consistency of the pole piece coating.

[0011] To achieve the above-mentioned purpose, the present application provides the following technical scheme:

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

[0013] The gasket body is also provided with a plurality of first openings and a plurality of second openings, the first opening corresponds to the bottom of the first coating area, and the second opening corresponds to the bottom of the second coating area;

[0014] The first coating area and the second coating area are provided with a separation strip which can be elastically deformed by extrusion.

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

[0016] Preferably, the gasket body and the corresponding position of the separation strip are provided with a groove, and the separation strip is partially embedded in the groove.

[0017] Preferably, the partition strip is fixed to the gasket body by means of adhesion.

[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 partition strip is 1: (2~4). The connection stability of the partition strip and the gasket body can be ensured while the partitioning effect is achieved.

[0020] Preferably, the side wall of the groove is provided with a clamping protrusion, and the side wall of the partition strip is provided with a clamping groove matched with the clamping protrusion.

[0021] Preferably, the partition strip is made of elastic material such as elastic silica gel or elastic rubber.

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

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

[0024] Preferably, the first coating area has a shape of being wide in front and narrow in back along the longitudinal direction, and the second coating area has a shape of being narrow in front and wide in 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 greater than the opening area of the second opening.

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

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

[0029] In addition, the utility model also provides a coating device which comprises an upper die head and a lower die head, and further comprises the coating gasket.

[0030] Compared with the prior art, the utility model has at least the following beneficial effects:

[0031] 1) The coating gasket provided by the utility model, by setting up the first coating area and the second coating area alternately on the gasket body and setting up the first opening and the second opening corresponding to it respectively at the bottom, the independent control of the coating amount of different areas can be realized; when the first coating area is coated, continuous coating is adopted, the pole piece with complete coating layer can be obtained; when the second coating area is coated, intermittent coating is adopted, the pole piece with the coating layer and the blank area alternating can be obtained; wherein, the first coating area and the second coating area can be designed with different length and width according to the actual demand, the first opening and the second opening corresponding to it can also be designed with different size and shape, so as to realize the accurate adjustment of the coating amount of different areas.

[0032] 2) The utility model sets up the separation strip that can produce elastic deformation when being extruded between the first coating area and the second coating area, can play the key role in the coating process. When the pressing block extrudes the separation strip, the elastic separation strip can be further compressed, so as to further reduce the gap between the pressing block and the gasket body, and restore the original shape after extrusion release; therefore, through the elastic deformation of the separation strip, the fine adjustment of the coating gap can be realized, and then the accurate control of the coating amount is realized. The design of this elastic separation strip can significantly improve the accuracy and reliability of the coating amount control. BRIEF DESCRIPTION OF DRAWINGS

[0033] Fig. 1 It is the three-dimensional structure schematic view of the coating gasket of an embodiment of the utility model;

[0034] Fig. 2 It is the plan view of the coating gasket of an embodiment of the utility model;

[0035] Fig. 3 It is the structure exploded view of the coating gasket of an embodiment of the utility model.

[0036] In the drawing: 1, gasket body; 11, first coating area; 12, second coating area; 13, first opening; 14, second opening; 15, reinforcing rib; 16, fixed hole; 2, separation strip; 3, groove. DETAILED DESCRIPTION

[0037] The technical scheme in the embodiments of the utility model will be described clearly and completely in combination with the drawings in the embodiments of the utility model, obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the ordinary skill in the art without creative labor belong to the scope of protection of the utility model.

[0038] Please refer to the drawings of the embodiments of the utility model Figs. 1-3According to the first aspect of the present application, the present application provides a coating 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;

[0039] The gasket body 1 is also provided with a plurality of first openings 13 and a plurality of second openings 14, the first openings 13 correspond to the bottom of the first coating areas 11, and the second openings 14 correspond to the bottom of the second coating areas 12; wherein the first openings 13 are connected to the first material cavity of the double-cavity coating die, for guiding the slurry to the first coating areas 11 of the gasket body 1; the second openings 14 are connected to the second material cavity of the double-cavity coating die, for guiding the slurry to the second coating areas 12 of the gasket body 1.

[0040] The first coating areas 11 and the second coating areas 12 are provided with a separation strip 2 which can be elastically deformed by being extruded.

[0041] The gasket body 1 is also provided with a plurality of first openings 13 and a plurality of second openings 14, the first openings 13 correspond to the bottom of the first coating areas 11, and the second openings 14 correspond to the bottom of the second coating areas 12; wherein the first openings 13 are connected to the first material cavity of the double-cavity coating die, for guiding the slurry to the first coating areas 11 of the gasket body 1; the second openings 14 are connected to the second material cavity of the double-cavity coating die, for guiding the slurry to the second coating areas 12 of the gasket body 1.

[0042] The gasket body 1 is also provided with a plurality of first openings 13 and a plurality of second openings 14, the first openings 13 correspond to the bottom of the first coating areas 11, and the second openings 14 correspond to the bottom of the second coating areas 12; wherein the first openings 13 are connected to the first material cavity of the double-cavity coating die, for guiding the slurry to the first coating areas 11 of the gasket body 1; the second openings 14 are connected to the second material cavity of the double-cavity coating die, for guiding the slurry to the second coating areas 12 of the gasket body 1.

[0043] In an embodiment according to the present application, the gasket body 1 is an integrally formed structure, preferably made of steel, the gasket body 1 is provided with a groove 3 at the corresponding position of the separation strip 2, and the separation strip 2 is partially embedded in the groove 3; preferably, the separation strip 2 and the groove 3 are connected in interference fit, improving the stability of the connection.

[0044] The gasket body 1 is also provided with a plurality of first openings 13 and a plurality of second openings 14, the first openings 13 correspond to the bottom of the first coating areas 11, and the second openings 14 correspond to the bottom of the second coating areas 12; wherein the first openings 13 are connected to the first material cavity of the double-cavity coating die, for guiding the slurry to the first coating areas 11 of the gasket body 1; the second openings 14 are connected to the second material cavity of the double-cavity coating die, for guiding the slurry to the second coating areas 12 of the gasket body 1.

[0045] In an embodiment according to the present application, the partition strip 2 is directly fixed to the gasket body 1 by means of adhesion. For example, the partition strip 2 is adhered to the surface of the gasket body 1 by means of glue.

[0046] In an embodiment according to the present application, the thickness of the partition strip 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. The height consistency of the partition strip 2 and the coating area in the vertical direction can be ensured, the influence of the height difference in the coating process on the coating quality can be avoided, and the uniformity and consistency of the coating can be further improved.

[0047] In an embodiment according to the present application, the ratio of the depth of the groove 3 to the thickness of the partition strip 2 is 1: (2~4). The connection stability of the partition strip 2 and the gasket body 1 can be ensured while playing a partitioning role. It should be noted that the specific thickness ratio can be adjusted according to actual needs, as long as the connection stability of the partition strip 2 and the gasket body 1 can be ensured while playing a partitioning role.

[0048] In an embodiment according to the present application, the side wall of the groove 3 is provided with a clamping protrusion, and the side wall of the partition strip 2 is provided with a clamping groove matched with the clamping protrusion; the connection stability of the partition strip 2 and the gasket body 1 can be further improved.

[0049] In an embodiment according to the present application, the partition strip 2 is made of elastic materials such as elastic silica gel or elastic rubber, and preferably is made of ethylene propylene diene rubber. These materials can endow the partition strip 2 with good elasticity and flexibility, so that it can produce moderate deformation when being extruded and restore to its original state after the extrusion is released. It should be noted that other materials capable of elastic deformation can also be used.

[0050] In an embodiment according to 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 uniformly arranged along the first coating area 11. The uniformly distributed reinforcing ribs 15 enhance the structural strength of the first coating area 11, prevent deformation under high pressure, and ensure the uniformity and stability of the coating.

[0051] In an embodiment according to 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 matched with the length of the first coating area 11, and the length of the second opening 14 is matched with the length of the second coating area 12. The coating amount of the non-tab welding area can be ensured while reducing the coating amount of the tab welding area.

[0052] In an embodiment according to the present application, the first coating area 11 is in a shape of being wider in front and narrower in back along the longitudinal direction, and the second coating area 12 is in a shape of being narrower in front and wider in back along the longitudinal direction. In this way, the slurry flow 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 be adjusted in width and narrowness in front and back as needed to control the coating flow.

[0053] In an embodiment according to the present application, the bottom of the first coating area 11 is lower than the bottom of the second coating area 12. The first coating area 11 is used to realize the coating of continuous coating layers, and the second coating area 12 is used to realize the coating of intermittent coating layers (coating layers and blank areas are alternated), so that the coating heights of the two different areas can be controlled to facilitate the control of the blank area. It should be noted that the first coating area 11 and the second coating area 12 can also be used reversely during coating; that is, the first coating area 11 is used to realize the coating of intermittent coating layers (coating layers and blank areas are alternated), and the second coating area 12 is used to realize the coating of continuous coating layers.

[0054] In an embodiment according to the present application, the opening area of the first opening 13 is larger than the opening area of the second opening 14. During coating, the first coating area 11 coats a larger area, so a larger feeding space is needed; the second coating area 12 coats a smaller area, so a slightly smaller feeding space can be used; in this way, the differential control of the coating amount of different areas can be realized.

[0055] In an embodiment according to the present application, the top of the separation strip 2 is in a sharp corner structure, and the upper edge of the separation strip 2 is 0.1-2.5 mm lower than the upper edge of the gasket body 1. In this way, the slurry on both sides (two coating areas) of the separation strip 2 can be better fused at the joint to prevent the coating thickness at the joint from being uneven.

[0056] In an embodiment according to the present application, the gasket body 1 is provided with a plurality of fixing holes 16; the installation and fixation of the coating gasket on the coating device can be facilitated, and the stability and reliability of the coating process can be improved.

[0057] According to a second aspect of the present application, the present application also provides a manufacturing method of the above-mentioned coating gasket, comprising the following steps:

[0058] 1) cutting or stamping the gasket body 1 to form the first coating area 11 and the second coating area 12 which are alternately arranged;

[0059] 2) opening the first opening 13 at the bottom position of the first coating area 11 on the gasket body 1, and opening the second opening 14 at the bottom position of the second coating area 12 on the gasket body 1;

[0060] 3) a groove 3 is formed 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 separation strip 2 is partially embedded in the groove 3 for fixation, i.e. the coating gasket is obtained;

[0061] And / or, the elastic separation strip 2 is directly fixed to the gasket body 1 by adhesion, i.e. the coating gasket is obtained.

[0062] The manufacturing method of the coating gasket described above can efficiently and accurately manufacture the coating gasket with the above advantages, and the manufacturing method is simple to operate and easy to realize industrialized production, and has good practicability and popularization value.

[0063] According to the third aspect of the present application, the present application also provides a coating device comprising an upper die head and a lower die head, the coating device further comprising the coating gasket described above, and the coating gasket is arranged between the upper die head and the lower die head. Wherein the first opening 13 is connected to one of the two material cavities 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 cavity 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, and a pole piece with a complete coating layer can be obtained; when the second coating area 12 is coated, intermittent (jump gap) coating is adopted, and a pole piece with alternating coating layer and blank area can be obtained. When the coating amount of each coating area needs to be controlled, the gap between the micrometer adjusting block and the gasket body 1 can be adjusted to control the coating amount, and when a smaller gap is needed, the separation strip 2 is extruded by the adjusting block at this time. Due to the good elasticity of the separation strip 2, it can produce moderate deformation when extruded, and restore to the original state after extrusion release.

[0064] Wherein, the coating gasket of the present application is applied to the coating device and arranged between the upper die head and the lower die head, which can play its unique advantages in the coating process, realize accurate control of the coating amount of different areas of the pole piece, improve the uniformity and consistency of the pole piece coating, and finally obtain high-quality and high-performance battery pole pieces.

[0065] It should be noted that the contents not described in detail in the present specification belong to the prior art known to those skilled in the art, which will not be described here.

[0066] According to the disclosure and teaching of the above description, the person skilled in the art of the present application can also change and modify the above embodiments. Therefore, the present application is not limited to the above specific embodiments, and any obvious improvement, replacement or modification made by the person skilled in the art on the basis of the present application belongs to the protection scope of the present application. In addition, although some specific terms are used in the specification, these terms are only for convenience of description and do not constitute any limitation on the present application.

Claims

1. A coated gasket characterized by: The gasket body is provided with a plurality of first coating areas and a plurality of second coating areas, the first coating areas and the second coating areas are arranged adjacently and alternately; The gasket body is further provided with a plurality of first openings and a plurality of second openings, the first openings correspond to the bottoms of the first coating areas, and the second openings correspond to the bottoms of the second coating areas; The first coating areas and the second coating areas are provided with a partition strip which can be elastically deformed by extrusion.

2. The coated gasket of claim 1, wherein: The gasket body is an integral structure; and / or, the gasket body is provided with a groove at a position corresponding to the partition strip, and the partition strip is partially embedded in the groove; and / or, the partition strip is fixed to the gasket body by adhesion.

3. The coated gasket of claim 2, wherein: 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.

4. The coated gasket of claim 2 or 3, wherein: The ratio of the depth of the groove to the thickness of the partition strip is 1: (2-4).

5. The coated gasket of claim 1, wherein: The partition strip is elastic silica gel or elastic rubber.

6. The coated gasket of claim 1, wherein: The first coating area is provided with a plurality of reinforcing ribs, and the reinforcing ribs are uniformly arranged along the first coating area.

7. The coated gasket of claim 1, wherein: The length of the first coating area is greater than the length of the second coating area; the length of the first opening is adapted to the length of the first coating area, and the length of the second opening is adapted to the length of the second coating area.

8. The coated gasket of claim 1, wherein: 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 greater than the opening area of the second opening.

9. The coated gasket of claim 1, wherein: The top of the partition strip is a sharp corner structure, and the upper edge of the partition strip is 0.1-2.5 mm lower than the upper edge of the gasket body.

10. A coating apparatus comprising an upper die and a lower die, characterized in that: The coating device further comprises the coating gasket according to any one of claims 1-9, and the coating gasket is arranged between the upper die head and the lower die head.

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