Negative plate punching cutter die

Abstract

The utility model discloses a negative plate punching cutting die, and belongs to the technical field of lithium ion battery manufacturing. The negative plate punching cutting die comprises a cutting die plate; the cutter template is provided with a plurality of pole piece punching cutter cavities, buffer layers and anti-deformation layers which are matched with the cross sections of the cutter cavities in shape are sequentially arranged in the pole piece punching cutter cavities from bottom to top, and the buffer layers are adhered to the inner surfaces of the pole piece punching cutter cavities; the Shore A hardness of the buffer layer is smaller than that of the anti-deformation layer, and the thickness of the buffer layer is larger than that of the anti-deformation layer. The punching die can overcome deformation of materials in the punching process to the maximum extent, meanwhile, the cutter is protected, and the service life of the cutter is prolonged.

Description

Technical Field

[0001] This utility model relates to a technology in the field of lithium-ion battery manufacturing, specifically a negative electrode sheet punching die. Background Technology

[0002] Lithium-ion batteries have the characteristics of high voltage, high capacity, low consumption, no pollution, and small size, and have good application prospects.

[0003] Electrodes, as an important component of lithium-ion batteries, play a crucial role in maximizing battery performance. Lithium-ion battery production typically involves slitting the electrodes, with three main slitting processes: die-cutting, metal die-cutting, and laser die-cutting.

[0004] Die-cutting uses a die with the same design shape as the electrode sheet as the die-cutting device. Multiple blades are arranged at intervals to form multiple electrode sheets in one die-cutting process. In die-cutting, the electrode sheet tends to deform outward from the die. Due to differences in material type, foil thickness, ingredient ratio, and compaction density, negative electrode sheets are more flexible and have stronger shear resistance than positive electrode sheets. Therefore, negative electrode sheets are more likely to experience problems such as electrode deformation, wrinkles, difficulty in cutting at the tabs, and foil leakage, affecting the production quality and use of the product.

[0005] In order to solve the above-mentioned problems existing in the prior art, this utility model is thus developed. Utility Model Content

[0006] To address the aforementioned shortcomings of existing technologies, this invention proposes a negative electrode sheet punching die that can minimize the deformation of the negative electrode sheet during punching, while protecting the die and cutting tool and extending their service life.

[0007] This utility model relates to a negative electrode sheet punching die, including: a die template;

[0008] The die template is provided with several electrode punching cavities. From bottom to top, a buffer layer and an anti-deformation layer matching the cross-sectional shape of the die cavity are provided in the electrode punching cavity. The buffer layer is attached to the inner surface of the electrode punching cavity.

[0009] The Shore hardness of the buffer layer is less than that of the deformation-resistant layer, and the thickness of the buffer layer is greater than that of the deformation-resistant layer.

[0010] For some specific implementation schemes, the Shore A hardness of the buffer layer is 40-55, and the Shore D hardness of the deformation-resistant layer is 60-80.

[0011] Preferably, the buffer layer is made of EVA foam and the deformation-resistant layer is made of PVC.

[0012] In some specific implementation schemes, the thickness of the buffer layer is 85% to 88% of the groove depth, and the thickness of the anti-deformation layer is 10% to 15% of the thickness of the buffer layer.

[0013] Preferably, the thickness of the buffer layer is 2.5 mm and the thickness of the deformation-resistant layer is 0.25 mm.

[0014] Compared with the prior art, the present invention has the following technical effects:

[0015] 1) The anti-deformation layer is relatively hard and thin, which can suppress the movement of the negative electrode sheet during shearing and reduce dynamic friction loss; the buffer layer is relatively thick and has a certain compression and rebound space and is softer than the anti-deformation layer. Together with the anti-deformation layer, it acts on the negative electrode sheet and can compact the coating in advance, avoid the negative electrode sheet being suspended, and reduce the risk of delamination during cutting.

[0016] 2) The combination of the anti-deformation layer and the buffer layer can improve the punching efficiency and quality, ensure the consistency of the punching edge, and reduce the adhesion of the material area. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the negative electrode sheet punching die in Example 1;

[0018] Figure 2 for Figure 1 A partial structural diagram of the central cutting template;

[0019] Figure 3 for Figure 2 Schematic diagram of the longitudinal section of the AA direction;

[0020] In the diagram: 100, die template; 200, electrode punching cavity; 300, buffer layer; 400, anti-deformation layer. Detailed Implementation

[0021] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0022] Example 1

[0023] like Figure 1 , Figure 2 and Figure 3 As shown, this embodiment includes a blade template 100, which is provided with a plurality of electrode punching cavities 200;

[0024] For reference only. Figure 1 The CCP has set up 6 electrode punching cavities 200, arranged in two columns and three rows, symmetrically on the left and right. Among them, the electrode tab punching areas of the two columns of electrode punching cavities 200 are set away from the axis of symmetry, and are respectively set on the outer left and outer right sides of the blade template.

[0025] The electrode blanking cavity 200 is provided with a buffer layer 300 and an anti-deformation layer 400 that match the cross-sectional shape of the cavity from bottom to top. The buffer layer 300 is attached to the inner surface of the electrode blanking cavity 200. The buffer layer 300 is made of EVA foam and the anti-deformation layer 400 is made of PVC.

[0026] The blade cavity depth is 2.9 mm, the buffer layer has a Shore A hardness of 55 degrees and a thickness of 2.5 mm, and the deformation-resistant layer has a Shore A hardness of 60 degrees and a thickness of 0.25 mm.

[0027] In this invention, a buffer layer 300 and an anti-deformation layer 400 are sequentially arranged in the electrode punching cavity 200. During operation, the die template 100 is placed in the punching machine; then the negative electrode material is positioned above the electrode punching cavity 200; then a PVC board is placed on the negative electrode material. The PVC board has the same external dimensions as the die template and has PVC sub-modules with the same shape and size as the die cavity; finally, the punching machine operates, and the punch cuts to obtain the negative electrode.

[0028] In the above-mentioned process, the harder anti-deformation layer can suppress the movement of the negative electrode sheet during shearing, reducing dynamic friction loss; the softer buffer layer works together with the harder anti-deformation layer on the negative electrode sheet to pre-compact the coating, preventing the negative electrode sheet from being suspended and reducing a series of risks such as deformation and delamination of the negative electrode sheet during cutting; in addition to improving punching efficiency and quality, it can also protect the die template and the cutting tool, especially the cutting tool, thereby ensuring that the equipment has the expected service life; in addition, the PVC board has the same external dimensions as the die template, and the PVC board also has sub-modules with the same shape and size as the die cavity, so the die usage area can be clearly displayed, making it easier to align the material area with the die during manual operation. Alignment with the PVC board can reduce the situation of foil leakage or excessive material height due to misalignment; and the upper and lower PVC boards press the negative electrode sheet tightly, reducing lateral displacement during shearing, which can reduce the pressure required for punching, better protect the die, and improve punching quality.

[0029] It should be emphasized that the above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model in any way. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall still fall within the scope of the technical solution of the present utility model.

Claims

1. A negative electrode sheet punching die, characterized in that, include: Knife template; The blade template is provided with several electrode punching cavities. From bottom to top, a buffer layer and an anti-deformation layer matching the cross-sectional shape of the blade cavity are provided in the electrode punching cavity. The buffer layer is attached to the inner surface of the electrode punching cavity. The Shore hardness of the buffer layer is less than that of the deformation-resistant layer, and the thickness of the buffer layer is greater than that of the deformation-resistant layer.

2. The negative electrode sheet punching die according to claim 1, wherein The Shore A hardness of the buffer layer is 40-55, and the Shore D hardness of the anti-deformation layer is 60-80.

3. The negative electrode sheet punching die according to claim 2, characterized by The buffer layer is made of EVA foam, and the anti-deformation layer is made of PVC.

4. The negative electrode sheet punching die according to claim 1, wherein The thickness of the buffer layer is 85% to 88% of the groove depth, and the thickness of the anti-deformation layer is 10% to 15% of the thickness of the buffer layer.

5. The negative electrode sheet punching die according to claim 4, wherein The thickness of the buffer layer is 2.5 mm, and the thickness of the deformation-resistant layer is 0.25 mm.

6. The negative electrode sheet punching die according to claim 1, wherein The electrode punching cavity is provided in two rows, which are symmetrically arranged on the left and right sides of the die template.

7. The negative electrode sheet punching die according to claim 6, wherein The electrode blanking chamber is provided with an electrode tab blanking area, which is located away from the axis of symmetry.

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