A pole piece

Abstract

This invention relates to the field of electrode manufacturing technology, specifically to an electrode. The electrode includes an electrode foil, a first coating layer, and a second coating layer. The foil includes a short side located on one side of the foil's length direction. The first coating layer is disposed on one side of the foil's thickness direction, and the second coating layer is disposed on the other side of the foil's thickness direction. 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. This prevents the two rollers from simultaneously contacting the first and second coating layers. Instead, one roller contacts one of the first and second coating layers first, and the other roller contacts the other. This causes the gap between the two rollers to change twice, but the degree of change is relatively small each time. This effectively reduces the instantaneous force exerted on the electrode by the rollers, thereby achieving the technical effect of reducing the probability of foil damage.

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 projections of the first distance adjustment layer and 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 an adhesive tape layer.

[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 closer to the first coating layer is 10 μm to 20 μm less than the thickness of the first coating layer.

[0015] Optionally, the widths of the first distance adjustment layer and the second distance adjustment layer are 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 spacing 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 spacing 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 closer to the first coating layer is 10 μm to 20 μm less than the thickness of the first coating layer, and the thickness of the second distance adjustment layer on the side closer to the second coating layer is 10 μm to 20 μm less than the thickness of the second coating layer.

[0016] The beneficial effects of the electrode sheet provided in this embodiment of the invention are as follows: The electrode sheet provided in this embodiment of the invention includes an electrode foil, a first coating layer, and a second coating layer. The foil includes a short side located on one side of the foil's length direction. The first coating layer is disposed on one side of the foil's thickness direction, and the second coating layer is disposed on the other side of the foil's thickness direction. 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. With this arrangement, the two rollers will not contact the first coating layer and the second coating layer simultaneously. Instead, one roller contacts one of the first and second coating layers first, and the other roller contacts the other one of the first and second coating layers later. In this way, the gap between the two rollers will change twice, but the degree of change each time will be relatively small. This can effectively reduce the instantaneous force exerted by the rollers on the electrode sheet, thereby achieving the technical effect of reducing the probability of foil damage. Attached Figure Description

[0017] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0018] Figure 1 This is a simplified diagram of the structure in the existing technology where the electrode sheet is about to enter between two rollers; Figure 2 This is a simplified structural diagram of the electrode sheet provided in an embodiment of the present invention; Figure 3 This is one of the simplified structural diagrams of the electrode sheet provided in another embodiment of the present invention; Figure 4 This is a second simplified structural diagram of the electrode provided in another embodiment of the present invention.

[0019] The labels for the attached figures are as follows: 1000, Electrode; 100. Foil material; 110. Short side; 200. First coating layer; 300. Second coating layer; 400. First distance adjustment layer; 500, Second Distance Adjustment Layer. Detailed Implementation

[0020] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0021] This invention provides an electrode 1000, such as... Figures 2-4 As shown, the electrode 1000 includes a foil 100, a first coating layer 200, and a second coating layer 300. The foil 100 includes a short side 110, which is located along the length of the foil 100 (see reference). Figure 2 On one side of the foil 100 (in the X direction), the short side 110 is the edge that first enters between the two rollers, hence it is named short side 110. The first coating layer 200 is disposed in the thickness direction of the foil 100 (refer to the thickness direction). Figure 2 On one side of the foil 100 in the Z direction, the second coating layer 300 is disposed on the other side in 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] Table 1: Comparison of Experimental Data Between Existing Technology and This Embodiment

[0026] 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.

[0027] 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.

[0028] refer to Figure 3 In a specific embodiment, the electrode 1000 further includes a second distance adjustment layer 500, which is disposed on the other side of the foil 100 in the thickness direction and 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 second coating layer 300 (see reference). Figure 3 (In the Y direction) decreases.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] Table 2: Comparison of Experimental Data Between Existing Technology and This Embodiment

[0036] refer to Figure 3 In some embodiments, the width of the first distance adjustment layer 400 (refer to...) Figure 3 a) is greater than or equal to 12 mm.

[0037] 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.

[0038] 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 2 b) is less than or equal to 60 mm.

[0039] 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.

[0040] refer to Figure 3 In some embodiments, the distance between the first distance adjustment layer 400 and the first coating layer 200 (reference) Figure 3 C) is greater than or equal to 0 mm and less than or equal to 0.5 mm.

[0041] 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.

[0042] 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.

[0043] In some embodiments, the first distance adjustment layer 400 is an adhesive tape layer.

[0044] 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.

[0045] 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...) Figure 4 e) should be as thin as possible to minimize the instantaneous force generated when the roller comes into contact with the adhesive paper.

[0046] refer to Figures 2-4 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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. An electrode sheet, characterized in that, include: A foil material, including a short side located on one side along the length of the foil material; A first coating layer is disposed on one side of the foil in the thickness direction; A second coating layer is disposed on the other side of the foil in the thickness direction; A first distance adjustment layer is disposed on one side of the foil in the thickness direction and is 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; The first distance adjustment layer and the first coating layer are spaced apart; the thickness of the first distance adjustment layer on the side closer to the first coating layer is less than the thickness of the first coating layer; 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 an adhesive paper layer; 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.

2. The electrode sheet according to claim 1, characterized in that, It also includes a second distance adjustment layer, 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.

3. The electrode sheet according to claim 2, characterized in that, In the thickness direction of the foil, the projections of the first distance adjustment layer and the second distance adjustment layer are misaligned.

4. The electrode sheet according to claim 1, characterized in that, The width of the first distance adjustment layer is greater than or equal to 12mm.

5. The electrode sheet according to any one of claims 1-4, characterized in that, 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.

6. The electrode sheet according to any one of claims 1-4, characterized in that, The thickness of the first distance adjustment layer on the side closer to the first coating layer is 10µm to 20µm less than the thickness of the first coating layer.

7. The electrode sheet according to claim 3, characterized in that, The widths of the first and second distance adjustment layers are 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 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 closer to the first coating layer is 10 μm to 20 μm less than the thickness of the first coating layer, and the thickness of the second distance adjustment layer on the side closer to the second coating layer is 10 μm to 20 μm less than the thickness of the second coating layer.

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