Pole piece
By setting coating layers and adjustment layers with unequal distances in the electrode structure and adjusting the gap between the rollers, the problem of instantaneous damage when the coating layers come into contact is solved, thereby reducing foil damage and improving cell quality.
Patent Information
- Application Number
- CN202511538879.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-24
- Publication Date
- 2026-01-16
AI Technical Summary
During the electrode production process, when the coating layer comes into contact with the roller, a sudden change in the roller gap can cause damage to the foil, affecting the quality of subsequent electrode production and battery cells.
The electrode structure is designed such that the distance between the first coating layer and the short side is not equal to the distance between the second coating layer and the short side. By setting the first and second distance adjustment layers, the gap between the rollers is gradually adjusted to avoid instantaneous large forces.
This effectively reduces the instantaneous force exerted by the rollers on the electrode sheets, minimizes foil damage, and improves the quality stability of the sheets and cells.
Smart Images
Figure CN121355166A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of electrode manufacturing technology, and in particular to an electrode. Background Technology
[0002] Electrodes require a rolling process during production, specifically involving rolling the electrode (such as...) into a roll. Figure 1 As shown in A) to the two rollers (as shown in A) Figure 1 Between (as shown in B), two rollers are used to pass the foil (such as...) Figure 1 The coating layers on both sides of (as shown in C) Figure 1 Roll pressing is performed as shown in D in the figure.
[0003] Before the two coating layers come into contact with the two rollers, the distance between the two rollers is relatively small. When the two rollers come into contact with the two coating layers, the gap between the two rollers will be subjected to increased force. The increased gap will be smaller than the thickness of the unpressed electrode sheet, so the coating layers will be rolled.
[0004] The problem with the existing technology is that, because there is a height difference between the edge of the coating layer and the foil, and the coating layers on both sides of the foil are overlapped, the gap between the two rollers changes abruptly when the roller contacts the coating layer. This instantaneous force can easily cause damage to the foil, which can lead to foil breakage during subsequent wafer winding and cell recycling. Summary of the Invention
[0005] This invention provides an electrode sheet to solve the problem that when the rollers come into contact with the coating layer, the gap between the two rollers changes abruptly, which generates a large force at that moment and can easily damage the foil.
[0006] The present invention discloses an electrode sheet, comprising: a foil having a short side located on one side of the foil along its length; a first coating layer disposed on one side of the foil along its thickness; and a second coating layer disposed on the other side of the foil along its thickness; wherein the distance between the first coating layer and the short side is different from the distance between the second coating layer and the short side.
[0007] Optionally, it further includes a first distance adjustment layer disposed on one side of the foil in the thickness direction and located on the side of the first coating layer near the short side; the thickness of the first distance adjustment layer decreases in the direction away from the first coating layer.
[0008] Optionally, a second distance adjustment layer is further included, which is disposed on the other side of the foil in the thickness direction and located on the side of the second coating layer near the short side; the thickness of the second distance adjustment layer decreases in the direction away from the second coating layer.
[0009] Optionally, the projection of the first distance adjustment layer and the projection of the second distance adjustment layer are misaligned in the thickness direction of the foil.
[0010] Optionally, the width of the first distance adjustment layer is greater than or equal to 12 mm.
[0011] Optionally, the first distance adjustment layer is a layer of adhesive tape.
[0012] Optionally, the difference between the distance between the first coating layer and the short side and the distance between the second coating layer and the short side is less than or equal to 60 mm.
[0013] Optionally, the distance between the first distance adjustment layer and the first coating layer is greater than 0 mm and less than or equal to 0.5 mm.
[0014] Optionally, the thickness of the first distance adjustment layer on the side close to the first coating layer is 10 um to 20 um less than the thickness of the first coating layer.
[0015] Optionally, the width of the first distance adjustment layer and the second distance adjustment layer is greater than or equal to 12 mm; the difference between the distance between the first coating layer and the short side and the distance between the second coating layer and the short side is greater than or equal to 40 mm and less than or equal to 60 mm; the distance between the first distance adjustment layer and the first coating layer is greater than 0 mm and less than or equal to 0.5 mm, and the distance between the second distance adjustment layer and the second coating layer is greater than or equal to 0 mm and less than or equal to 0.5 mm; the thickness of the first distance adjustment layer on the side close to the first coating layer is 10 um to 20 um less than the thickness of the first coating layer, and the thickness of the second distance adjustment layer on the side close to the second coating layer is 10 um to 20 um less than the thickness of the second coating layer.
[0016] The pole piece provided by the embodiments of the present application has the beneficial effects that the pole piece includes a pole foil, a first coating layer, and a second coating layer. The foil includes a short side located on one side in the length direction of the foil. The first coating layer is arranged on one side in the thickness direction of the foil, and the second coating layer is arranged on the other side in the thickness direction of the foil. The distance between the first coating layer and the short side is different from the distance between the second coating layer and the short side. In this way, two rollers do not simultaneously contact the first coating layer and the second coating layer, but one roller first contacts one of the first coating layer and the second coating layer, and the other roller later contacts the other of the first coating layer and the second coating layer. The gap between the two rollers changes twice, but the degree of each change is relatively small, which can effectively reduce the instantaneous force on the pole piece caused by the rollers, thereby achieving the technical effect of reducing the damage probability of the foil. BRIEF DESCRIPTION OF DRAWINGS
[0017] The technical solutions of the present application will be further described in detail below in combination with the drawings and embodiments, in which: Figure 1 is a structure diagram of an existing technology in which the pole piece is about to enter between two over rollers; Figure 2 is a structure diagram of a pole piece provided by an embodiment of the present application; Figure 3 is a structure diagram of a pole piece provided by another embodiment of the present application; Figure 4 is a structure diagram of a pole piece provided by another embodiment of the present application.
[0018] In the drawings, the various reference signs are as follows: 1000, pole piece; 100, foil; 110, short side; 200, first coating layer; 300, second coating layer; 400, first distance adjusting layer; 500, second distance adjusting layer. DETAILED DESCRIPTION
[0019] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The preferred embodiments of the present application will be described in detail in combination with the drawings.
[0020] An embodiment of the present application provides a pole piece 1000, as shown in the drawings, the pole piece 1000 comprises a foil 100, a first coating layer 200 and a second coating layer 300, the foil 100 comprises a short side 110, the short side 110 is located on one side of the length direction (referring to the X direction in the drawings) of the foil 100, the short side 110 is the edge that enters between two over rollers first, so it is named as the short side 110. The first coating layer 200 is arranged on one side of the thickness direction (referring to the Z direction in the drawings) of the foil 100, the second coating layer 300 is arranged on the other side of the thickness direction of the foil 100, wherein the distance between the first coating layer 200 and the short side 110 is different from the distance between the second coating layer 300 and the short side 110. Figures 2-4 Figure 2 Figure 2
[0021] This invention illustrates an embodiment where the first coating layer 200 and the second coating layer 300 do not completely overlap. Specifically, the distance between the first coating layer 200 and the short side 110 is different from the distance between the second coating layer 300 and the short side 110. "The distance between the first coating layer 200 and the short side 110 is different from the distance between the second coating layer 300 and the short side 110" means that the distance between the first coating layer 200 and the short side 110 is less than the distance between the second coating layer 300 and the short side 110, or the distance between the first coating layer 200 and the short side 110 is greater than the distance between the second coating layer 300 and the short side 110. This embodiment is not limited to this.
[0022] With this configuration, the two rollers will not simultaneously contact the first coating layer 200 and the second coating layer 300. Instead, one roller contacts one of the first coating layer 200 and the second coating layer 300 first, and the other roller contacts the other one of the first coating layer 200 and the second coating layer 300 later. This causes the gap between the two rollers to change twice, but the degree of change each time is relatively small, effectively reducing the instantaneous force exerted by the rollers on the electrode 1000. Therefore, compared to the prior art where the distance between the first coating layer 200 and the second coating layer 300 and the short side 110 is the same, implementing this embodiment can reduce the instantaneous force exerted by the rollers on the electrode 1000, thereby achieving the technical effect of reducing the probability of damage to the foil 100.
[0023] To more clearly demonstrate the beneficial effects of implementing this embodiment, this embodiment also provides a comparison table of experimental data between the prior art and this embodiment.
[0024] Table 1: Comparison of Experimental Data Between Existing Technology and This Embodiment
[0025] refer to Figure 3 In a specific embodiment, the electrode 1000 further includes a first distance adjustment layer 400. The first distance adjustment layer 400 is disposed on one side of the foil 100 in the thickness direction and is located on the side of the first coating layer 200 near the short side 110. The thickness of the first distance adjustment layer 400 is directed away from the first coating layer 200 (see reference). Figure 3 (In the Y direction) decreases.
[0026] Specifically, due to the thickness of the first distance adjustment layer 400 moving away from the first coating layer 200 (refer to...) Figure 3The gap between the two rollers gradually increases as the roller passes through the first distance adjustment layer 400. Before the roller contacts the first coating layer 200, the gap has already increased, so that when the roller contacts the first coating layer 200, it does not exert a large instantaneous force on the electrode 1000. Therefore, compared to a technical solution without the first distance adjustment layer 400, implementing this embodiment can further reduce the instantaneous force exerted by the roller on the electrode 1000, thereby achieving the technical effect of further reducing the probability of damage to the foil 100.
[0027] refer to Figure 3 In a specific embodiment, the electrode 1000 further includes a second distance adjustment layer 500. The second distance adjustment layer 500 is disposed on the other side of the foil 100 in the thickness direction and is located on the side of the second coating layer 300 near the short side 110. The thickness of the second distance adjustment layer 500 is directed away from the first coating layer 300 (see reference). Figure 3 (In the Y direction) decreases.
[0028] Specifically, due to the thickness of the second distance adjustment layer 500 moving away from the second coating layer 300 (refer to...) Figure 3 The gap between the two rollers gradually increases as the roller passes through the second distance adjustment layer 500. Before the roller contacts the second coating layer 300, the gap has already increased, so that when the roller contacts the second coating layer 300, it will not exert a large instantaneous force on the electrode 1000. Therefore, compared to the technical solution without the second distance adjustment layer 500, implementing this embodiment can further reduce the instantaneous force exerted by the roller on the electrode 1000, thereby achieving the technical effect of further reducing the probability of damage to the foil 100.
[0029] It is worth mentioning that the thickness of the second distance adjustment layer 500 on the side closest to the short side 110 should be as thin as possible, so as to minimize the instantaneous force generated when the roller comes into contact with the second distance adjustment layer 500.
[0030] It should be noted that when the foil 100 is provided with both the first distance adjustment layer 400 and the second distance adjustment layer 500, the gap between the two rollers will increase before the rollers come into contact with the first coating layer 200 and the second coating layer 300. Therefore, the entire rolling process will not bring a large instantaneous force to the electrode 1000, thus reducing the probability of damage to the foil 100.
[0031] refer to Figure 3In a specific embodiment, the projections of the first distance adjustment layer 400 and the second distance adjustment layer 500 are misaligned in the thickness direction of the foil 100.
[0032] Specifically, the misalignment of the projections of the first distance adjustment layer 400 and the second distance adjustment layer 500 along the thickness direction of the foil 100 means that there is no overlapping area between the projections of the first distance adjustment layer 400 and the second distance adjustment layer 500 along the thickness direction of the foil 100. If there is an overlapping area between the projections of the first distance adjustment layer 400 and the second distance adjustment layer 500 along the thickness direction of the foil 100, it means that when one roller is in contact with the first distance adjustment layer 400, the other roller is in contact with the second distance adjustment layer 500. This results in a large change in the gap between the two rollers per unit time, which is not conducive to reducing the force exerted by the rollers on the electrode 1000. Therefore, it is best to adjust the gap between the two rollers using one of the first distance adjustment layers 400 and 500, and then use the other of the first distance adjustment layers 400 and 500 to adjust the gap between the two rollers again.
[0033] To more clearly demonstrate the beneficial effects of implementing this embodiment, this embodiment also provides a comparison table of experimental data between the prior art and this embodiment.
[0034] Table 2: Comparison of Experimental Data Between Existing Technology and This Embodiment
[0035] refer to Figure 3 In some embodiments, the width of the first distance adjustment layer 400 (refer to...) Figure 2 a) is greater than or equal to 12 mm.
[0036] Specifically, the smaller the width of the first distance adjustment layer 400, the faster the distance adjustment between the two rollers will be, and the greater the force acting on the electrode 1000 will be. Therefore, in order to avoid damage to the electrode 1000, this embodiment limits the width of the first distance adjustment layer 400 to a range of greater than or equal to 12 mm.
[0037] refer to Figure 2 In some embodiments, the difference between the distance between the first coating layer 200 and the short side 110 and the distance between the second coating layer 300 and the short side 110 (refer to...) Figure 3 b) is less than or equal to 60 mm.
[0038] Specifically, if the difference between the distance between the first coating layer 200 and the short side 110, and the difference between the distance between the second coating layer 300 and the short side 110, is too large, there will be less coating material, resulting in material waste and poorer parameters for the electrode 1000. Therefore, in this embodiment, the difference between the distance between the first coating layer 200 and the short side 110, and the difference between the distance between the second coating layer 300 and the short side 110, is limited to less than or equal to 60 mm.
[0039] refer to Figure 3 In some embodiments, the distance between the first distance adjustment layer 400 and the first coating layer 200 (reference) Figure 4 C) is greater than or equal to 0 mm and less than or equal to 0.5 mm.
[0040] Specifically, it is preferable that there is no gap between the first distance adjustment layer 400 and the first coating layer 200. However, if the processing is not done properly, the first distance adjustment layer 400 can easily overlap the first coating layer 200. In this case, the thickness of the electrode 1000 increases, the force during roller rolling is greater, and the foil 100 is more likely to be damaged. To avoid the above problems, there is a gap between the first distance adjustment layer 400 and the first coating layer 200 in this embodiment. However, since an excessive gap would cause material waste, this embodiment limits the distance between the first distance adjustment layer 400 and the first coating layer 200 to a range of greater than or equal to 0 mm and less than or equal to 0.5 mm.
[0041] refer to Figure 4 In some embodiments, the thickness of the first distance adjustment layer 400 on the side closest to the first coating layer 200 is 10µm to 20µm less than the thickness of the first coating layer 200, i.e. Figure 4 The thickness d is greater than or equal to 10 μm and less than or equal to 20 μm. This is because the roller needs to apply pressure to the first coating layer 200 to reduce its thickness. Therefore, the side of the first distance adjustment layer 400 closest to the first coating layer 200 cannot be thicker than the first coating layer 200. If the side of the first distance adjustment layer 400 closest to the first coating layer 200 is too thin, it will be detrimental to reducing the instantaneous force on the electrode 1000 when the roller contacts the first coating layer 200. Therefore, this embodiment constrains the thickness difference between the side of the first distance adjustment layer 400 closest to the first coating layer 200 and the thickness of the first coating layer 200. Specifically, the thickness of the side of the first distance adjustment layer 400 closest to the first coating layer 200 is 10 μm to 20 μm less than the thickness of the first coating layer 200.
[0042] In some embodiments, the first distance adjustment layer 400 is an adhesive tape layer.
[0043] Specifically, the adhesive layer is sticky and can be adhered to the foil 100, and the adhesive layer is insulating and will not increase the risk of short circuit.
[0044] refer to Figure 4 It is worth mentioning that the thickness of the gel layer on the side closest to the short side 110 (refer to...) Figures 2-4 e) should be as thin as possible to minimize the instantaneous force generated when the roller comes into contact with the adhesive paper.
[0045] refer to Preferably, in the specific embodiment where the projections of the first distance adjustment layer 400 and the second distance adjustment layer 500 are misaligned in the thickness direction of the foil 100, the widths of the first distance adjustment layer 400 and the second distance adjustment layer 500 are greater than or equal to 12 mm; the difference between the distance between the first coating layer 200 and the short side 110 and the distance between the second coating layer 300 and the short side 110 is greater than or equal to 40 mm and less than or equal to 60 mm; the spacing between the first distance adjustment layer 400 and the first coating layer 200 is greater than 0 mm and less than or equal to 0.5 mm, and the spacing between the second distance adjustment layer 500 and the second coating layer 300 is greater than or equal to 0 mm and less than or equal to 0.5 mm; the thickness of the first distance adjustment layer 400 on the side closer to the first coating layer 200 is less than the thickness of the first coating layer 200 by 10 μm to 20 μm, and the thickness of the second distance adjustment layer 500 on the side closer to the second coating layer 300 is less than the thickness of the second coating layer 300 by 10 μm to 20 μm.
[0046] Firstly, the smaller the width of the first distance adjustment layer 400, the faster the distance adjustment between the two rollers will be, and the greater the force acting on the electrode 1000 will be. Therefore, in order to avoid damage to the electrode 1000, this embodiment limits the width of the first distance adjustment layer 400 to a range of greater than or equal to 12 mm.
[0047] Secondly, the smaller the width of the second distance adjustment layer 500, the faster the distance adjustment between the two rollers will be, and the greater the force acting on the electrode 1000 will be. Therefore, in order to avoid damage to the electrode 1000, this embodiment limits the width of the second distance adjustment layer 500 to a range of greater than or equal to 12 mm.
[0048] Thirdly, if the difference between the distance between the first coating layer 200 and the short side 110, and the difference between the distance between the second coating layer 300 and the short side 110, is too large, there will be less coating material, resulting in material waste and poorer parameters for the electrode 1000. Therefore, in this embodiment, the difference between the distance between the first coating layer 200 and the short side 110, and the difference between the distance between the second coating layer 300 and the short side 110, is limited to a range of greater than or equal to 40 mm and less than or equal to 60 mm.
[0049] Fourthly, it is preferable that there is no gap between the first distance adjustment layer 400 and the first coating layer 200. However, if the processing is not done properly, the first distance adjustment layer 400 can easily overlap the first coating layer 200. In this case, the thickness of the electrode 1000 increases, the force during roller rolling is greater, and the foil 100 is more likely to be damaged. To avoid the above problems, there is a gap between the first distance adjustment layer 400 and the first coating layer 200 in this embodiment. However, since an excessive gap would cause material waste, this embodiment limits the distance between the first distance adjustment layer 400 and the first coating layer 200 to a range greater than or equal to 0 mm and less than or equal to 0.5 mm.
[0050] Fifthly, it is preferable that there is no gap between the second distance adjustment layer 500 and the second coating layer 300. However, if the processing is not done properly, the second distance adjustment layer 500 can easily overlap the second coating layer 300. In this case, the thickness of the electrode 1000 increases, the force during roller rolling is greater, and the foil 100 is more likely to be damaged. To avoid the above problems, there is a gap between the second distance adjustment layer 500 and the second coating layer 300 in this embodiment. However, since an excessive gap would cause material waste, this embodiment limits the distance between the second distance adjustment layer 500 and the second coating layer 300 to a range greater than or equal to 0 mm and less than or equal to 0.5 mm.
[0051] Sixthly, the roller needs to apply pressure to the first coating layer 200 to reduce its thickness. Therefore, the side of the first distance adjustment layer 400 closest to the first coating layer 200 cannot be thicker than the first coating layer 200. If the side of the first distance adjustment layer 400 closest to the first coating layer 200 is too thin, it will be detrimental to reducing the instantaneous force on the electrode 1000 when the roller contacts the first coating layer 200. Therefore, this embodiment constrains the thickness difference between the side of the first distance adjustment layer 400 closest to the first coating layer 200 and the thickness of the first coating layer 200. Specifically, the thickness of the side of the first distance adjustment layer 400 closest to the first coating layer 200 is 10µm to 20µm less than the thickness of the first coating layer 200.
[0052] Seventhly, the roller needs to apply pressure to the second coating layer 300 to reduce its thickness. Therefore, the side of the second distance adjustment layer 500 closest to the second coating layer 300 cannot be thicker than the second coating layer 300. If the side of the second distance adjustment layer 500 closest to the second coating layer 300 is too thin, it will be detrimental to reducing the instantaneous force on the electrode 1000 when the roller contacts the second coating layer 300. Therefore, this embodiment constrains the thickness difference between the side of the second distance adjustment layer 500 closest to the second coating layer 300 and the thickness of the second coating layer 300. Specifically, the thickness of the side of the second distance adjustment layer 500 closest to the second coating layer 300 is 10µm to 20µm less than the thickness of the second coating layer 300.
[0053] It should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Those skilled in the art can modify the technical solutions described in the above embodiments, or make equivalent substitutions for some of the technical features; and all such modifications and substitutions should fall within the protection scope of the appended claims of the present invention.
Claims
1. A pole piece, characterized in that, The foil includes a short side located on one side of the length direction of the foil; a first coating layer disposed on one side of the thickness direction of the foil; and a second coating layer disposed on the other side of the thickness direction of the foil; wherein the distance between the first coating layer and the short side is different from the distance between the second coating layer and the short side. The first distance adjustment layer is disposed on one side of the thickness direction of the foil and located on the side of the first coating layer close to the short side; and the thickness of the first distance adjustment layer decreases in the direction away from the first coating layer. The second distance adjustment layer is disposed on the other side of the thickness direction of the foil and located on the side of the second coating layer close to the short side; and the thickness of the second distance adjustment layer decreases in the direction away from the first coating layer. The projection of the first distance adjustment layer and the projection of the second distance adjustment layer are misaligned in the thickness direction of the foil. The width of the first distance adjustment layer is greater than or equal to 12 mm.
2. The pole piece of claim 1, wherein The first distance adjustment layer is a layer of adhesive paper.
3. The pole piece of claim 2, wherein The difference between the distance between the first coating layer and the short side and the distance between the second coating layer and the short side is less than or equal to 60 mm.
4. The pole piece of claim 3, wherein The distance between the first distance adjustment layer and the first coating layer is greater than 0 mm and less than or equal to 0.5 mm.
5. The pole piece of claim 2, wherein The thickness of the side of the first distance adjustment layer close to the first coating layer is less than the thickness of the first coating layer by 10-20 um.
6. The pole piece of claim 2, wherein The width of the first distance adjustment layer and the second distance adjustment layer is greater than or equal to 12 mm; the difference between the distance between the first coating layer and the short side and the distance between the second coating layer and the short side is greater than or equal to 40 mm and less than or equal to 60 mm; the distance between the first distance adjustment layer and the first coating layer is greater than 0 mm and less than or equal to 0.5 mm, and the distance between the second distance adjustment layer and the second coating layer is greater than 0 mm and less than or equal to 0.5 mm; the thickness of the side of the first distance adjustment layer close to the first coating layer is less than the thickness of the first coating layer by 10-20 um, and the thickness of the side of the second distance adjustment layer close to the second coating layer is less than the thickness of the second coating layer by 10-20 um.
7. The pole piece of any of claims 1-6, wherein, 8. The pole piece of any of claims 2-6, wherein, 9. The pole piece of any of claims 2-6, wherein, 10. The pole piece of claim 4, wherein
Citation Information
Patent Citations
Negative pole piece, electrochemical device and electric equipment
CN118156409A
Pole piece coating structure
CN215600396U
Pole piece, battery cell and lithium ion battery
CN223181149U