Coating gasket, coating die head and coating device

Abstract

The utility model discloses a coating gasket, a coating die head and a coating device. The coating gasket comprises a bottom plate and a side plate, a first groove is formed in the bottom plate, and the thickness of the first groove is the same as that of the bottom plate; the side plates are symmetrically connected to the two sides of the bottom plate, second grooves are formed in the edges, close to one side of the bottom plate, of the side plates, and the thickness of the second grooves is smaller than that of the side plates. According to the utility model, the problems that only two sides are thinned and other material areas are not thinned during coating are solved, so that positive and negative pole pieces can be randomly matched in a winding or laminating process without lithium precipitation and safety risks, the battery capacity is improved, the production efficiency is improved, and meanwhile, slurry can be saved, scrap can be reduced, and the cost can be reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of coating, and in particular relates to a coating gasket, a coating die head and a coating device. Background Art

[0002] Extrusion coating mainly uses a screw pump to transport the slurry to the die head, and then sprays the slurry on the foil through the die lip. Extrusion coating has fast speed, large coating width, high efficiency and large production capacity; the slurry is transported in a closed manner and can be recycled, with little environmental interference and high slurry utilization rate; pole pieces of different sizes can be produced through extrusion valves and gaskets, with strong adaptability; simple operation and high degree of automation, it is currently the most commonly used coating method in the lithium battery industry. Existing coating gaskets are usually regular rectangular groove structures, and the slurry is coated on the substrate through the opening of the coating gasket and the slit formed between the upper and lower die heads. Since the slurry usually enters the cavity formed by the upper and lower die heads and the coating gasket from the middle position of the lower die head, the slurry flows more smoothly in the middle position of the cavity than at both ends, and the lateral surface density trend is a parabola with an opening downward.

[0003] The existing extrusion coating machine has a large intermittent coating width. After the positive and negative electrodes are coated, only the material areas on the left and right sides of the electrode sheets are thinned, and the material areas in other areas are not thinned. The lateral surface density trend is a parabola that opens downward. After roller pressing and slitting, the positive and negative electrode sheets are generally cut into 3-10 material areas respectively. In the winding / stacking process, the electrode sheets in different material areas of the positive and negative electrodes are randomly matched. If the thinned material area of ​​the positive electrode sheet matches the non-thinned material area of ​​the negative electrode, the capacity is low and the excess capacity of the negative electrode sheet causes waste; if the non-thinned material area of ​​the positive electrode sheet matches the thinned material area of ​​the negative electrode, the N / P ratio is low, there will be a certain risk of lithium precipitation, and even cause safety problems and losses to the company. Utility Model Content

[0004] The purpose of the utility model is to overcome the deficiencies in the prior art and provide a coating gasket, a coating die head and a coating device, which solve the problem that only two sides are thinned during coating while other material areas are not thinned, so that the positive and negative electrode sheets can be randomly matched in the winding or stacking process without lithium precipitation and safety risks, thereby increasing the battery capacity and improving production efficiency, while being able to save slurry, reduce scrap and reduce costs.

[0005] The utility model provides the following technical solutions:

[0006] In a first aspect, there is provided a coating gasket, comprising a bottom plate and a side plate;

[0007] The bottom plate is provided with a first groove, and the thickness of the first groove is the same as the thickness of the bottom plate;

[0008] The side plates are symmetrically connected to the two sides of the bottom plate. A second groove is provided at the edge of the side plate close to one side of the bottom plate. The thickness of the second groove is smaller than the thickness of the side plate.

[0009] Furthermore, the bottom plate and the side plate are rectangular plates with the same thickness, and the bottom plate and the side plate are an integrally formed structure.

[0010] Furthermore, the distance between two adjacent first grooves is 10-20 mm, and the distance between the first groove at the edge of the bottom plate and the side plate is 5-10 mm.

[0011] Furthermore, the depth of the first groove is less than half the width of the bottom plate.

[0012] Furthermore, the first groove is an arc-shaped groove recessed inward from the side of the bottom plate.

[0013] Furthermore, the thickness of the second groove is less than half of the thickness of the side plate.

[0014] Furthermore, the second groove is a right triangle, and the lengths of the two right-angled sides are 2-5 mm.

[0015] Furthermore, the bottom plate and the side plates are both provided with mounting holes penetrating the plate body.

[0016] In a second aspect, a coating die is provided, comprising an upper die, a lower die and the coating gasket described in the first aspect, wherein the coating gasket is arranged between the upper die and the lower die.

[0017] In a third aspect, a coating device is provided, comprising the coating gasket described in the first aspect or the coating die head described in the second aspect.

[0018] Compared with the prior art, the beneficial effects of the utility model are:

[0019] (1) In the utility model, a first groove is provided on the bottom plate. When the slurry flows into the cavity formed between the upper and lower die heads and the gasket, it is blocked by the steps formed between the first grooves, and the slurry flows toward the first groove, so that the pressure on both sides of the first groove increases, thereby thinning the slurry on both sides of each first groove; at the same time, a second groove is provided at the edge of the side plate close to one side of the bottom plate. When the slurry flows at the side plate, the existence of the second groove can widen the coating width and have a thinning effect, solving the problem that only the two sides of the coating are thinned, while other material areas are not thinned, so that the positive and negative electrode sheets can be randomly matched in the winding or lamination process without lithium precipitation and safety risks, thereby increasing the battery capacity and improving the production efficiency;

[0020] (2) In the present invention, the thickness of the first groove is the same as that of the bottom plate, and the thickness of the second groove is less than that of the side plate, which is adapted to the characteristic that the surface density trend of the slurry is a parabola opening downward, so that the two sides of the coating and other material areas are evenly thinned, which is convenient for the positive and negative electrode sheets in the winding or stacking process, and can be randomly matched without lithium precipitation and safety risks; at the same time, due to the increased coating width thinning due to the existence of the second groove, it is used to discharge waste scraps after slitting, which can save slurry, reduce scrap, and reduce costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of a coating gasket in an embodiment of the utility model;

[0022] Figure 2 It is a schematic structural diagram of a coating die head in an embodiment of the utility model;

[0023] The markings in the figure are: 1, bottom plate; 2, side plate; 3, mounting hole; 4, second groove; 5, first groove; 6, lower die head; 7, upper die head; 8, cavity; 9, feed port. DETAILED DESCRIPTION

[0024] The utility model is further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the utility model, and cannot be used to limit the protection scope of the utility model.

[0025] It should be noted that, in the description of the present invention, the directions or positional relationships indicated by terms such as "front", "rear", "left", "right", "up", "down", "inside" and "outside" are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0026] Example 1

[0027] like Figure 1 As shown, this embodiment provides a coating gasket, including a bottom plate 1 and a side plate 2; the bottom plate 1 and the side plate 2 are rectangular plates with the same thickness, and two sides of the bottom plate 1 are vertically and symmetrically connected with two side plates 2. The bottom plate 1 and the side plate 2 are an integrally formed structure, which is easy to process.

[0028] The bottom plate 1 is provided with a first groove 5, which is an arc-shaped groove that is recessed inward from the side of the bottom plate 1, and can provide a stable thinning effect. The thickness of the first groove 5 is the same as that of the bottom plate 1; there is a certain distance between two adjacent first grooves 5 according to the required pole piece width. Specifically, the distance a between two adjacent first grooves 5 is 10-20mm, and the distance b between the first groove at the edge of the bottom plate 1 and the side plate 2 is 5-10mm, so that the steps formed between adjacent first grooves 5 and between the first groove and the side plate 1 produce a blocking force within a suitable range for the slurry. The depth c of the first groove 5 is less than half of the width d of the bottom plate 1.

[0029] A second groove 4 is provided at the edge of the side plate 2 close to the bottom plate 1, and the thickness of the second groove 4 is less than half the thickness of the side plate 2. The second groove 4 is a right triangle, and the length of the two right angle sides is 2-5 mm, which is convenient for processing, and the increased coating width due to the existence of the second groove 4 is thinned and used for waste scraps after slitting, which can save slurry and reduce scrap.

[0030] In this embodiment, the bottom plate 1 and the side plate 2 are both provided with a circular mounting hole 3 penetrating the plate body for mounting the coating gasket.

[0031] The working principle of the utility model is:

[0032] like Figure 2 As shown, the coating gasket is installed between the upper die head 7 and the lower die head 6, and a discharge port is formed between the bottom plate 1 and the first groove 5 and the two side plates 2. When the slurry flows into the cavity 8 formed between the upper die head 7, the lower die head 6 and the gasket, it is blocked by the steps formed between the first grooves 5, and the slurry flows toward the first groove 5, causing the pressure on both sides of the first groove 5 to increase, so that the slurry on both sides of each first groove 5 is thinned; at the same time, when the slurry flows at the side plate 2, the existence of the second groove 4 can widen the coating width and have a thinning effect, solving the problem of thinning only on both sides of the coating and no thinning in other material areas, so that the positive and negative electrode sheets can be randomly matched in the winding or lamination process without lithium precipitation and Safety risks, increase battery capacity, and improve production efficiency; in addition, the thickness of the first groove 5 is the same as the thickness of the bottom plate 1, and the thickness of the second groove 4 is less than the thickness of the side plate 2, which is adapted to the characteristic that the surface density trend of the slurry is a parabola opening downward, so that the coating sides and other material areas are evenly thinned, which is convenient for the positive and negative electrodes in the winding or stacking process, and can be randomly matched without lithium precipitation and safety risks; at the same time, due to the increased coating width thinning of the second groove 4, it is used for the waste scraps after slitting, which can save slurry, reduce scrap and reduce costs.

[0033] Example 2

[0034] like Figure 2As shown, this embodiment provides a coating die head, including an upper die head 7, a lower die head 6 and the coating gasket described in Example 1, wherein the coating gasket is arranged between the upper die head 7 and the lower die head 6. The lower die head 6 is provided with a cavity 8, and the cavity 8 is connected with a feed port 9, and a discharge port is formed between the bottom plate 1 and the first groove 5 and the two side plates 2.

[0035] Example 3

[0036] This embodiment provides a coating device equipped with the coating gasket described in Example 1 or the coating die head described in Example 2.

[0037] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A coated gasket, characterized in that: Including bottom plate and side plate; The bottom plate is provided with a first groove, and the thickness of the first groove is the same as the thickness of the bottom plate; The side plates are symmetrically connected to the two sides of the bottom plate. A second groove is provided at the edge of the side plate close to one side of the bottom plate. The thickness of the second groove is smaller than the thickness of the side plate.

2. The coated gasket according to claim 1, characterized in that: The bottom plate and the side plate are rectangular plates with the same thickness, and the bottom plate and the side plate are an integrally formed structure.

3. The coated gasket according to claim 1, characterized in that: The distance between two adjacent first grooves is 10-20 mm, and the distance between the first groove at the edge of the bottom plate and the side plate is 5-10 mm.

4. The coated gasket according to claim 1, characterized in that: The depth of the first groove is less than half of the width of the bottom plate.

5. The coated gasket according to claim 1, characterized in that: The first groove is an arc-shaped groove recessed inward from the side of the bottom plate.

6. The coated gasket according to claim 1, characterized in that: The thickness of the second groove is less than half of the thickness of the side plate.

7. The coated gasket according to claim 2, characterized in that: The second groove is a right triangle, and the lengths of the two right-angled sides are 2-5 mm.

8. The coated gasket according to claim 1, characterized in that: The bottom plate and the side plate are both provided with mounting holes penetrating the plate body.

9. A coating die head, characterized in that: It comprises an upper die head, a lower die head and 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.

10. A coating device, characterized in that: It comprises the coating gasket according to any one of claims 1 to 8 or the coating die head according to claim 9.

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