Coating pads and extrusion coating heads
By designing a coating gasket for extruding the coating head, the problem of thick edges of the coating edges is solved by using the limiting member contact and limiting the slurry edges, ensuring that the capacity and energy density of the battery cell are not reduced.
Patent Information
- Application Number
- CN202420660708.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-01
- Publication Date
- 2025-04-01
- Estimated Expiration
- 2034-04-01
AI Technical Summary
In the coating process of electrode sheets, the slurry fluid characteristics cause the formation of semi-moon-shaped convex features on both sides of the coating, resulting in a "thick edge" phenomenon, affecting the neatness of the coating and the capacity and energy density of the battery cell.
A coating gasket is designed, including a gasket base and at least two gasket sides extending outward from one side of the gasket base. Each gasket side is provided with a discharge port at a distance, and a limiting member is provided on both sides of the discharge port to contact and limit the edge of the slurry flowing outward from the discharge port, preventing it from diffusion and flowing outward.
By increasing the contact time of edge slurry and reducing its flow rate, the thick edge phenomenon in the edge area of the coating is effectively improved, and the thinning area of the coating edge is avoided, ensuring that the capacity and energy density of the battery cell are not reduced.
Smart Images
Figure CN222695167U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of coating equipment, in particular to a coating gasket and an extrusion coating head. Background Art
[0002] With the rapid development of new energy products, the requirements for the safety, consistency, and energy density of lithium-ion batteries are becoming increasingly higher. In the battery manufacturing process, ensuring the stability of the coating surface density and the consistency of thickness in the coating process is a key factor in ensuring the consistency, safety, and energy density of the battery.
[0003] At present, in the coating process of producing electrode pole pieces, due to the fluid characteristics of the slurry, the edges of the coating are prone to form half-moon shaped protrusions (the thickness is greater than the thickness of the normal area). This sudden increase in thickness at the edge of the pole piece is called the "thick edge" phenomenon. Usually, when the thick edge phenomenon occurs, the thickness of the coating edge will be several microns to more than ten microns thicker than the normal area. When rolling up after coating and drying, hundreds of layers of pole pieces are rolled up into one roll, and the thickness of the coating side edge protrusions accumulates to several millimeters, which will cause the pole roll to have a bulging edge phenomenon, which is easy to cause the pole piece to break, which seriously affects the coating and rolling uniformity and the subsequent process. In the prior art, it is usually adopted to set a chamfer on the outer edge of the discharge port of the coating gasket of the extrusion coating head to improve the flow of the slurry inside the extrusion coating head, thereby improving the thick edge phenomenon in the coating edge area; but this chamfering method will increase the thinning area of the coating edge (that is, the area where the coating thickness is less than the thickness of the normal area), resulting in a decrease in the capacity and energy density of the battery cell. Utility Model Content
[0004] The utility model provides a coating gasket and an extrusion coating head, which are intended to improve the thick edge phenomenon of the coating edge area without increasing the thinning area of the coating edge, thereby avoiding the reduction of the capacity and energy density of the battery cell.
[0005] To achieve the above-mentioned purpose, the coated gasket proposed in the utility model includes a gasket base and at least two gasket side portions extending outward from one side of the gasket base, each gasket side portion is arranged at intervals along the length direction of the gasket base, and a discharge port is formed between any two adjacent gasket side portions. Each gasket side portion is provided with a limiter on the side facing away from the gasket base, and the two sides of each discharge port are respectively the first wall surfaces of the two adjacent gasket side portions, and the end of the outermost limiter close to the discharge port is adjacent to the first wall surface of the gasket side portion where it is located, and the two end ends of the limiter located between the two adjacent discharge ports respectively correspond to the two first wall surfaces adjacent to the gasket side portion where it is located, and the limiter does not exceed the first wall surface of the gasket side portion where it is located.
[0006] In some embodiments, an end of the limiting member adjacent to the first wall is flush with the adjacent first wall.
[0007] In some embodiments, a dimension of an end portion of the stopper adjacent to the first wall surface in a thickness direction of the gasket side portion is greater than or equal to the thickness of the gasket side portion.
[0008] In some embodiments, the first wall surface of the gasket side portion is perpendicular to the length direction of the gasket base.
[0009] In some embodiments, the limiting member is fixed to the side of the gasket by welding or bonding.
[0010] In some embodiments, the limiting member is a box body for containing a surfactant, and at least one outlet hole is provided on the end of the limiting member adjacent to the first wall.
[0011] In some embodiments, there are multiple outlet holes on the end of the limiting member adjacent to the first wall surface, and the multiple outlet holes are evenly distributed.
[0012] In some embodiments, an extension portion is extended from one end of the gasket side away from the gasket base toward the discharge port.
[0013] The utility model also proposes an extrusion coating head, comprising an upper die head, a lower die head and the above-mentioned coating gasket, wherein the gasket base and the gasket side of the coating gasket are clamped between the upper die head and the lower die head, and the limit piece is located outside the clamping space between the upper die head and the lower die head.
[0014] In some embodiments, the dimension of the limiting member in the discharge direction of the extrusion coating head is smaller than the coating gap of the extrusion coating head.
[0015] The technical solution of the coating gasket of the utility model is that when it is applied to the extrusion coating head for coating work, the edge of the slurry extruded from the slit outlet will also contact the end parts of the limiting members on both sides, thereby increasing the contact time of the edge slurry and reducing the speed of the edge slurry, which can effectively improve the thick edge phenomenon in the edge area of the coating; compared with the prior art solution of setting a chamfer on the outer edge of the discharge port, the coating gasket solution of the utility model not only does not set a chamfer on the outer edge of the discharge port, but also uses the limiting members to contact and limit the edge of the slurry coming out of the discharge port, thereby blocking the slurry edge from diffusing and flowing outward, effectively avoiding the increase of the thinning area of the coating edge, and ensuring that the thinning area of the coating edge is very small, thereby avoiding the reduction of the battery cell capacity and energy density. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a structural schematic diagram of an implementation scheme of a coating gasket in an embodiment of the utility model;
[0017] Figure 2 It is a structural schematic diagram of another implementation scheme of the coating gasket in one embodiment of the utility model;
[0018] Figure 3 This is a schematic structural diagram of an extrusion coating head in one embodiment of the utility model;
[0019] Figure 4 It is a structural schematic diagram of the end portion of the limiting member in one embodiment of the utility model.
[0020] Explanation of the accompanying figures: 10 - gasket base, 20 - gasket side, 30 - limiter, 40 - discharge port, S1 - first wall, 21 - extension part, 31 - outlet hole, 100 - upper die head, 200 - lower die head, 300 - coating gasket. DETAILED DESCRIPTION
[0021] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0022] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.
[0023] It should also be noted that when an element is referred to as being "fixed on" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element at the same time. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element at the same time.
[0024] In addition, the descriptions of "first", "second", etc. in the present utility model are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.
[0025] The utility model provides a coating gasket which is used for being assembled in an extrusion coating head of a slit extrusion coating machine.
[0026] See also Figure 1 and Figure 2 In the present embodiment, the coated gasket 300 includes a gasket base 10 and at least two gasket side portions 20 extending outward from one side of the gasket base 10. The two outermost gasket side portions 20 and the gasket base 10 enclose a slurry accommodation space. The gasket side portions 20 are spaced apart along the length direction of the gasket base 10, and a discharge port 40 is formed between any two adjacent gasket side portions 20. A limiting member 30 is provided on the side of each gasket side portion 20 facing away from the gasket base 10. The two sides of each discharge port 40 are respectively the first wall surfaces S1 of the two adjacent gasket side portions 20. The end of the outermost limiting member 30 close to the discharge port 40 is adjacent to the first wall surface S1 of the gasket side portion 20 where it is located, and the limiting member 30 does not exceed the first wall surface S1 of the gasket side portion 20 where it is located. When the number of gasket side portions 20 is greater than two (refer to Figure 2 ), the two end portions of the limiting member 30 located between two adjacent discharge ports 40 respectively correspond to the two first wall surfaces S1 adjacent to the gasket side portion 20 where it is located, that is, the two ends of the limiting member 30 on the middle gasket side portion 20 respectively correspond to the two first wall surfaces S1 adjacent to the gasket side portion 20, and both ends of the limiting member 30 do not exceed the first wall surface S1 of the gasket side portion 20 where it is located.
[0027] Figure 1 The structure diagram of the coating gasket 300 only includes two gasket side portions 20, and the discharge port 40 is one at this time; Figure 2 The structure diagram of the coated gasket 300 is shown as including three gasket side portions 20, and at this time, there are two discharge ports 40; of course, in other embodiments, the coated gasket 300 may also include more gasket side portions 20 (for example, 4, 5, 6, etc.). One discharge port 40 is applied with a slurry coating, and multiple discharge ports 40 can apply multiple slurry coatings at the same time. According to the coating requirements, the coated gasket 300 with different numbers of gasket side portions 20 can be selected for coating.
[0028] like Figure 3As shown, when the coated gasket 300 of this embodiment is assembled on the extrusion coating head, the gasket base 10 and the gasket side 20 of the coated gasket 300 are clamped between the upper die head 100 and the lower die head 200 of the extrusion coating head, and the upper die head 100, the lower die head 200 and the discharge port 40 of the coated gasket 300 enclose a slit outlet, and the limiter 30 is located outside the clamping area of the upper die head 100 and the lower die head 200, that is, distributed on both sides of the edges of each slit outlet. During the coating process of the extrusion coating head using the coating gasket 300 of the present embodiment, the edges of the slurry extruded from the slit outlet will also contact the ends of the limiting members 30 on both sides, thereby increasing the contact time of the edge slurry and reducing the speed of the edge slurry, which can effectively improve the thick edge phenomenon in the edge area of the coating. Compared with the prior art solution of setting a chamfer on the outer edge of the discharge port 40, the solution of the coating gasket 300 of the present embodiment not only does not set a chamfer on the outer edge of the discharge port 40, but also uses the limiting member 30 to contact and limit the edge of the slurry coming out of the discharge port 40, thereby blocking the edge of the slurry from diffusing and flowing outward, effectively avoiding the increase of the thinning area of the coating edge, and ensuring that the thinning area of the coating edge is very small, thereby avoiding the reduction of the battery cell capacity and energy density.
[0029] See also Figure 1 and Figure 2 In some embodiments, the end of the limiter 30 adjacent to the first wall S1 is flush with the first wall S1 adjacent to the limiter 30. By setting the end of the limiter 30 flush with the first wall S1 (i.e., the side of the discharge port 40), the limiters 30 on both sides of the discharge port 40 are in smoother contact with the slurry extruded from the discharge port 40, which better improves the flow condition of the edge slurry, thereby achieving a better improvement effect on the thick edge phenomenon. Of course, in other embodiments, the end of the limiter 30 adjacent to the first wall S1 can also form a smaller step with the first wall S1, or the end of the limiter 30 adjacent to the first wall S1 can be set at a smaller angle inclined outward with the first wall S1, both of which can initiate a certain improvement effect on the thick edge phenomenon of the coating edge.
[0030] In some embodiments, the dimension of the end of the limit member 30 adjacent to the first wall S1 in the thickness direction of the gasket side 20 is greater than or equal to the thickness of the gasket side 20, thereby ensuring that the end of the limit member 30 adjacent to the first wall S1 can contact the entire edge side of the slurry coming out of the discharge port 40, thereby better improving the flow condition of the edge slurry and achieving a better improvement effect on the thick edge phenomenon.
[0031] See also Figure 1 and Figure 2In some embodiments, the first wall S1 of the gasket side portion 20 is perpendicular to the length direction of the gasket substrate 10, so that the discharge port 40 will not divert and diffuse the slurry to the two sides of the coating edge, and after the slurry flows out of the discharge port 40, the slurry edge is also contacted by the limiter 30, further blocking the slurry edge from diffusing and flowing outward. Therefore, the increase of the thinning area of the coating edge is better avoided, and the thinning area of the coating edge can be ensured to be smaller, thereby ensuring a higher battery cell capacity and energy density.
[0032] In some embodiments, the stopper 30 and the gasket side portion 20 can be fixed by welding, or by bonding. Of course, in other embodiments, the stopper 30 and the gasket side portion 20 can also be fixed by other installation and fixing methods, such as by interlocking, clamping, magnetic attraction, etc., or the stopper 30 can also be integrally formed with the gasket side portion 20.
[0033] Combination Figure 1 , Figure 2 , and see Figure 4 In some embodiments, the stopper 30 is a box for containing a surfactant, and at least one outlet hole 31 is provided on the end of the stopper 30 adjacent to the first wall S1. When the coating gasket 300 is mounted on the extrusion coating head for coating, the edge of the slurry flowing out of the discharge port 40 contacts the end face of the box, and the surfactant in the box contacts the slurry through the outlet hole 31 on the end face, thereby reducing the surface tension of the slurry at the edge of the slurry and changing the slurry properties at the edge of the slurry, thereby achieving better improvement of the thick edge phenomenon at the edge of the coating, and making the consistency of the slurry coating better. Of course, in some other embodiments, the stopper 30 can also be a stopper block, a stopper rod, a stopper plate and other structures.
[0034] In some embodiments, there are multiple outlet holes 31 on the end of the stopper 30 adjacent to the first wall surface S1, and the multiple outlet holes 31 are evenly distributed. By adopting a solution of evenly distributing multiple outlet holes 31 on the end of the stopper 30 adjacent to the first wall surface S1, the surfactant is discharged through the evenly distributed multiple outlet holes 31, so that the contact between the surfactant and the edge slurry is more uniform, ensuring the uniformity of the change in the slurry properties of the edge slurry, making the thickness of the slurry coating edge uniform and stable, and better improving the consistency of the slurry coating. Among them, the outlet holes 31 can be round holes, square holes, triangular holes, strip holes, etc.
[0035] In some embodiments, an extension portion 21 extends from one end of the gasket side portion 20 away from the gasket base 10 toward the discharge port 40. The extension portion 21 is provided on the gasket side portion 20 to shrink the size of the discharge port 40 to achieve the coating width required by the slurry coating.
[0036] See also Figure 3 The utility model also proposes an extrusion coating head, including an upper die head 100, a lower die head 200 and the above-mentioned coating gasket 300. The specific structure of the coating gasket 300 refers to the above-mentioned embodiment. Since the extrusion coating head adopts all the technical solutions of all the embodiments of the above-mentioned coating gasket 300, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here. Among them, the gasket base 10 and the gasket side 20 of the coating gasket 300 are clamped between the upper die head 100 and the lower die head 200, and the limiter 30 is located outside the clamping space between the upper die head 100 and the lower die head 200; that is, the upper die head 100, the lower die head 200 and the discharge port 40 of the coating gasket 300 are surrounded by a slit outlet, and the limiter 30 is correspondingly distributed on both sides of the edge of each slit outlet, and contacts the edge of the slurry extruded from each slit outlet respectively, so as to reduce the flow speed of the edge slurry and change the flow condition of the edge slurry.
[0037] In some embodiments, the size of the limiter 30 in the discharge direction of the extrusion coating head is smaller than the coating gap of the extrusion coating head (i.e., the distance between the slit outlet of the extrusion coating head and the current collector conveying roller), so as to prevent the limiter 30 from contacting the current collector on the conveying roller and scraping the slurry coating.
[0038] The above description is only a partial or preferred embodiment of the present invention. Neither the text nor the drawings can limit the scope of protection of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the overall concept of the present invention, or direct / indirect application in other related technical fields are included in the scope of protection of the present invention.
Claims
1. A coated gasket, comprising a gasket base and at least two gasket side portions extending outward from one side of the gasket base, wherein the gasket side portions are arranged at intervals along the length direction of the gasket base, and a discharge port is formed between any two adjacent gasket side portions, characterized in that: A limiting piece is provided on the side of each gasket side facing away from the gasket base, and the two sides of each discharge port are respectively the first wall surfaces of the two adjacent gasket side portions, the end of the outermost limiting piece close to the discharge port is adjacent to the first wall surface of the gasket side portion where it is located, and the two end portions of the limiting piece located between the two adjacent discharge ports respectively correspond to the two first wall surfaces adjacent to the gasket side portion where it is located, and the limiting piece does not exceed the first wall surface of the gasket side portion where it is located.
2. The coated gasket according to claim 1, characterized in that: An end portion of the limiting member adjacent to the first wall is flush with the adjacent first wall.
3. The coated gasket according to claim 1, characterized in that: A dimension of an end portion of the stopper adjacent to the first wall surface in a thickness direction of the gasket side portion is greater than or equal to the thickness of the gasket side portion.
4. The coated gasket according to claim 1, characterized in that: The first wall surface of the gasket side portion is perpendicular to the length direction of the gasket base.
5. The coated gasket according to claim 1, characterized in that: The limiting member is fixed to the side portion of the gasket by welding or bonding.
6. The coated gasket according to any one of claims 1 to 5, characterized in that The limiting member is a box body for containing a surfactant, and at least one outlet hole is provided on the end of the limiting member adjacent to the first wall surface.
7. The coated gasket according to claim 6, characterized in that: There are multiple outlet holes on the end of the limiting member adjacent to the first wall surface, and the multiple outlet holes are evenly distributed.
8. The coated gasket according to claim 6, characterized in that: An extension portion is provided at one end of the gasket side away from the gasket base and extending toward the discharge port.
9. An extrusion coating head, characterized in that: It comprises an upper die, a lower die and the coated gasket according to any one of claims 1 to 8, wherein the gasket base and the gasket side of the coated gasket are clamped between the upper die and the lower die, and the limiter is located outside the clamping space between the upper die and the lower die.
10. The extrusion coating head according to claim 9, characterized in that: The dimension of the limiting member in the discharge direction of the extrusion coating head is smaller than the coating gap of the extrusion coating head.