Pole piece and battery cell
By limiting the range of the width and thickness ratio of the thinning zone, the problem of lithium deposition at the edge of the active material layer in lithium batteries is solved, thus improving the safety and stability of the cell.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-23
- Publication Date
- 2026-03-10
AI Technical Summary
In existing lithium batteries, the width of the thinned area of the active material layer is too large and the thickness is too small, which makes it easy for lithium to be deposited at the edges, affecting the safety of the cell.
By limiting the ratio range of the width w of the thinning zone to the thickness h2 of the active material layer (1mm≤w≤10mm, 0.85≤h1/h2≤1), the width of the thinning zone corresponds to the thickness, thus preventing lithium plating.
It effectively prevents lithium deposition at the edges of the active material layer, improving the safety and stability of the battery cell.
Smart Images
Figure CN223986571U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of new energy technology, specifically providing an electrode sheet and a battery cell. Background Technology
[0002] With increasing environmental pollution and growing environmental awareness, the new energy industry, including lithium batteries, is developing at a rapid pace.
[0003] Traditional lithium batteries consist of a casing and a cell housed within the casing. The cell includes a separator, electrodes on either side of the separator, a current collector, and an active material layer coated on the current collector. However, to prevent bulging at the edges of the active material layer during coating, the edges are typically thinned to form a thinned zone. Existing thinned zones are too wide and too thin, making lithium plating at the edges of the active material layer more likely, posing a safety hazard to the battery cell.
[0004] Therefore, a new technical solution is needed in this field to solve the above problems. Utility Model Content
[0005] The present invention aims to solve the above-mentioned technical problems, namely, to solve the technical problem of bulging in the thinning area of the existing active material layer.
[0006] In a first aspect, the present invention provides an electrode sheet comprising a current collector and an active material layer disposed on the current collector. The edge of the active material layer is provided with a thinning region, and a point is provided on the outer surface of the thinning region. The distance between the point and the outer edge of the thinning region is w, and the distance between the point and the current collector is h1. The thickness of the active material layer is h2. When 1 mm ≤ w ≤ 10 mm, 0.85 ≤ h1 / h2 ≤ 1.
[0007] By adopting the above technical solution and limiting the above ratio range, not only is the width of the thinning area too large, but also the thickness of the thinning area is prevented from being too small, so as to achieve a correlation between the width and thickness of the thinning area, effectively preventing the occurrence of lithium plating at the edge of the active material layer and improving the safety of the battery cell.
[0008] In the preferred embodiment of the above electrode, the outer surface of the thinning region is an arc surface that convexes away from the current collector.
[0009] In the preferred technical solution of the above electrode, when 1mm≤w≤2mm, 0.85≤h1 / h2≤0.9.
[0010] In the preferred technical solution of the above electrode, when 2mm<w≤5mm, 0.92≤h1 / h2≤0.95.
[0011] In the preferred technical solution of the above electrode, when 5mm < w ≤ 10mm, 0.95 ≤ h1 / h2 ≤ 1.
[0012] In the preferred embodiment of the above-mentioned electrode, the thinning region is disposed at both ends of the active material layer.
[0013] In the preferred embodiment of the above-mentioned electrode, the active material layer is provided in two parts and disposed on both sides of the current collector.
[0014] In the preferred technical solution of the above-mentioned electrode, when the electrode is a positive electrode, 86μm≤h2≤93.5μm.
[0015] In the preferred technical solution of the above-mentioned electrode, when the electrode is a negative electrode, 57.5μm≤h2≤65μm.
[0016] In a second aspect, the present invention also provides a battery cell, the battery cell comprising the aforementioned electrode plates. Attached Figure Description
[0017] The preferred embodiments of this utility model are described below with reference to the accompanying drawings, in which:
[0018] Figure 1 This is a top view of the electrode sheet of this utility model;
[0019] Figure 2 yes Figure 1 The figure shows a cross-sectional view of the electrode sheet of this utility model along line AA.
[0020] List of reference numerals in the attached diagram:
[0021] 100. Electrode; 1. Current collector; 2. Active material layer; 21. Thinning zone; 22. Outer edge. Detailed Implementation
[0022] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.
[0023] It should be noted that in the description of this utility model, terms such as "inner," "outer," "upper," "lower," "top," "bottom," "left," "right," "front," and "rear," which indicate direction or positional relationships, are based on the direction or positional relationships shown in the accompanying drawings. These are used merely for ease of description and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0024] Furthermore, it should be noted that in the description of this utility model, unless otherwise explicitly specified and limited, the terms "set," "connect," and "install" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0025] Specifically, first refer to Figure 1 and Figure 2 , Figure 1 This is a top view of the electrode sheet of this utility model. Figure 2 yes Figure 1 The figure shows a cross-sectional view of the electrode sheet of this utility model along line AA.
[0026] In one embodiment, the present invention provides an electrode 100, including a current collector 1 and an active material layer 2 disposed on the current collector 1. The edge of the active material layer 2 is provided with a thinning region 21, and a point B is provided on the outer surface of the thinning region 21. The distance between the point B and the outer edge 22 of the thinning region 21 is w, the distance between the point B and the current collector 1 is h1, and the thickness of the active material layer 2 is h2. When 1mm≤w≤10mm, 0.85≤h1 / h2≤1.
[0027] Preferably, the current collector 1 can be aluminum foil, copper foil, etc., and the specific material can be set as needed, without being specifically limited here. Furthermore, the current collector 1 can be cuboid, polygonal, circular, or other geometric shapes, without being specifically limited here.
[0028] More preferably, the active material layer 2 is disposed on the current collector 1. The active material layer 2 may be one and located on one side of the current collector 1, or two and located on both sides of the current collector, or multiple and arranged at intervals on the current collector 1, so as to meet different needs.
[0029] More preferably, the active material layer 2 can be rectangular, circular or other geometric shapes, which can be set as needed and are not specifically limited here; furthermore, the active material layer 2 is formed on the current collector 1 by coating, or other connection methods, etc., which are not specifically limited here.
[0030] Preferably, the thinning region 21 is disposed at the edge of the active material layer 2, such as at the edge of the width direction or the edge of the length direction of the active material layer 2. It can be disposed as needed and is not specifically limited here. Furthermore, the thinning region 21 can be one, two and located on both sides of the active material layer 2, or multiple, etc. The specific number can be disposed as needed and is not specifically limited here.
[0031] More preferably, the thickness h2 of the active material layer 2 is the maximum distance between its two end faces in the thickness direction, such as... Figure 2 As shown, it represents the thickness of the thickest region of the active material layer 2, which is generally the thickness of the middle region of the active material layer 2.
[0032] Furthermore, point B is located on the outer surface of the thinning region 21, and it can be any point on the outer surface of the thinning region 21, without any specific limitation here.
[0033] Furthermore, the outer surface of the thinning region 21 is connected to both ends of the active material layer 2 in the thickness direction, and the outer edge 22 of the thinning region 21 is the outermost part of its outer surface in the length or width direction, such as... Figure 2 As shown. The distance w between point B and the outer edge 22 of the thinning region 21 is the distance between the two in the length direction or the width direction; further, the distance h1 between point B and the current collector 1 is the distance between point B and the surface of the current collector 1 near the active material layer 2 in the thickness direction of the active material layer 2, as shown. Figure 2 As shown, it actually represents the thickness of the thinning zone 21 at the location of point B.
[0034] Furthermore, when 1mm ≤ w ≤ 10mm, 0.85 ≤ h1 / h2 ≤ 1. Specifically: First, w can be any value between 1mm and 10mm, such as 1mm, 1.5mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, etc. The specific value can be set as needed and is not specifically limited here. It should be noted that it is precisely the above limitation on w that prevents the thinning zone 21 from becoming too large; secondly, When w is any value between 1mm and 10mm, h1 / h2 can be any value between 0.85 and 1, such as 0.85, 0.86, 0.87, 0.88, 0.89, 0.9, 0.95, 1, etc. The specific value can be set as needed and is not specifically limited here. It should be noted that it is the above limitation of h1 / h2 that effectively prevents the occurrence of lithium plating at the edge of the active material layer 2 caused by the thinning zone 21 being too thin, thus ensuring the safety of the battery cell.
[0035] In one embodiment, the outer surface of the thinning region 21 is an arcuate surface that convexes toward the direction away from the current collector 1, such as... Figure 2 As shown.
[0036] Preferably, the outer surface of the thinning region 21 is an arc surface and the arc surface protrudes in a direction away from the current collector 1, thereby effectively increasing the thickness of the thinning region 21 and preventing it from being too thin and affecting the safety of the battery cell.
[0037] It should be noted that the thinning zone 21 can also be a plane, a wave-like shape, or other geometric shapes, and no specific limitation is made here.
[0038] In one embodiment, when 1mm ≤ w ≤ 2mm, 0.85 ≤ h1 / h2 ≤ 0.9, such as... Figure 2 As shown.
[0039] Preferably, when w is between 1mm and 2mm, such as 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, etc., there is no specific limitation here. h1 / h2 is any value between 0.85 and 0.9, such as 0.85, 0.86, 0.87, 0.88, 0.89, 0.9, etc. The specific value can be set as needed and is not specifically limited here.
[0040] It should be noted that the simultaneous limitation of the range of values for w and h1 / h2 ensures the thickness of the edge region of the thinning region 21, prevents lithium plating in the edge region of the active material layer 2 due to excessively small thickness of the edge region of the thinning region 21, and ensures the safety of use.
[0041] In one embodiment, when 2mm < w ≤ 5mm, 0.92 ≤ h1 / h2 ≤ 0.95, such as... Figure 2 As shown.
[0042] Preferably, when w is between 2mm and 5mm, such as 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc., the specific value can be set as needed and is not specifically limited here. h1 / h2 is any value between 0.92 and 0.95, such as 0.92, 0.93, 0.94, 0.95, etc., the specific value can be set as needed and is not specifically limited here.
[0043] It should be noted that the simultaneous limitation of the range of values for w and h1 / h2 ensures the thickness of the central region of the thinning region 21, prevents lithium plating at the edge of the active material layer 2 due to excessively small thickness of the central region of the thinning region 21, and ensures the safety of use.
[0044] In one embodiment, when 5mm < w ≤ 10mm, 0.95 ≤ h1 / h2 ≤ 1, such as... Figure 2 As shown.
[0045] Preferably, when w is between 5mm and 10mm, such as 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, etc., the specific value can be set as needed and is not specifically limited here. h1 / h2 is any value between 0.95 and 1, such as 0.95, 0.96, 0.97, 0.98, 0.99, 1, etc., the specific value can be set as needed and is not specifically limited here.
[0046] It should be noted that the simultaneous limitation of the range of values for w and h1 / h2 ensures the thickness of the thinning region 21 at the end away from its outer edge 22, preventing the thinning region from being too thin and causing lithium plating in the edge region of the active material layer 2, thus ensuring the safety of use.
[0047] In summary, by dividing w into three segments and limiting the h1 / h2 ratio for each segment, the thickness of each corresponding region in the thinning zone is made relatively thick, and the width of each region in the thinning zone is correlated with its thickness, effectively preventing lithium plating and ensuring the safety of the battery cell.
[0048] In one embodiment, the thinning region 21 is disposed at both ends of the active material layer 2, such as...Figure 1 and Figure 2 As shown.
[0049] Preferably, two thinning regions 21 are provided and located at both ends of the active material layer 2, thereby effectively preventing lithium plating in the regions at both ends and ensuring the safety of the battery cell.
[0050] It should be noted that in other embodiments, the thinning zone 21 may also be set to one, three, four, etc., and the specific number can be set as needed, and no specific limitation is made here.
[0051] More preferably, the thinning region 21 can be disposed at both ends of the active material layer 2 in the length direction or at both ends of the active material layer 2 in the width direction. It can be disposed as needed and is not specifically limited here.
[0052] More preferably, the thinning region 21 can be disposed at the two adjacent ends of the active material layer 2, or at the two opposite ends of the active material layer 2, without specific limitation.
[0053] In one embodiment, the active material layer 2 is provided in two layers and disposed on both sides of the current collector 1, such as... Figure 2 As shown.
[0054] Preferably, there are two active material layers 2 located on both sides of the current collector 1 in the thickness direction, thereby achieving a stable connection between the active material layer 2 and the current collector 1, increasing the volume of the active material layer 2, and improving the electrical performance of the battery cell.
[0055] In one embodiment, when the electrode 100 is a positive electrode, 86μm≤h2≤93.5μm, such as... Figure 2 As shown.
[0056] Preferably, the positive electrode is typically small in size, so that only a small adhesive force is required to achieve a stable connection between it and the separator 1, effectively preventing misalignment between the two.
[0057] More preferably, when the electrode 100 is a positive electrode, the thickness h2 of the active material layer can be any value between 86 μm and 93.5 μm, such as 86 μm, 86.1 μm, 86.2 μm, 86.3 μm, 86.4 μm, 86.5 μm, 86.6 μm, 86.7 μm, 86.8 μm, 86.9 μm, 87 μm, 87.5 μm, 88 μm, 88.5 μm, 89 μm, 89.5 μm, 90 μm, 90.5 μm, 91 μm, 91.5 μm, 92 μm, 92.5 μm, 93 μm, 93.5 μm, etc. The specific value can be set as needed and is not specifically limited here.
[0058] It should be noted that the above-mentioned limitation on the thickness h2 of the active material layer not only prevents the electrical performance from deteriorating due to insufficient active material caused by an insufficient thickness of the active material layer, but also prevents the structural stability from decreasing due to an excessive thickness of the active material layer, thus meeting the overall performance requirements of the battery cell.
[0059] In one embodiment, when the electrode 100 is a negative electrode, 57.5μm≤h2≤65μm, such as... Figure 2 As shown.
[0060] Preferably, when the electrode 100 is a negative electrode, the thickness of the electrode 100 can be set to be relatively small in order to meet the requirement of its firm adhesion to the separator 1.
[0061] More preferably, when the electrode 100 is a negative electrode, the thickness h2 of the active material layer can be 57.5μm, 58μm, 58.5μm, 59μm, 59.5μm, 60μm, 60.5μm, 61μm, 61.5μm, 62μm, 62.5μm, 63μm, 63.5μm, 64μm, 64.5μm, 65μm, etc., and the specific value can be set as needed, without being specifically limited here.
[0062] It should be noted that the above-mentioned limitation on the thickness h2 of the active material layer not only prevents the electrical performance from deteriorating due to insufficient active material caused by an insufficient thickness of the active material layer, but also prevents the structural stability from decreasing due to an excessive thickness of the active material layer, thus meeting the overall performance requirements of the battery cell.
[0063] In one embodiment, the present invention also provides a battery cell, the battery cell including the aforementioned electrode 100.
[0064] Those skilled in the art will understand that although some embodiments described herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, any of the claimed embodiments in the claims of this application can be used in any combination.
[0065] The technical solution of this utility model has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the protection scope of this utility model is obviously not limited to these specific embodiments. Without departing from the principle of this utility model, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of this utility model.
Claims
1. A pole piece, characterized in that, The electrode tab comprises a current collector, an active material layer disposed on the current collector, an edge of the active material layer is provided with a thinning area, an outer surface of the thinning area is provided with a point, a distance between the point and an outer edge of the thinning area is w, a distance between the point and the current collector is h1, a thickness of the active material layer is h2, when 1mm≤w≤10mm, 0.85≤h1 / h2≤1.
2. The pole piece of claim 1, wherein The outer surface of the thinning area is an arc surface protruding towards a direction away from the current collector.
3. The pole piece of claim 1, wherein When 1mm≤w≤2mm, 0.85≤h1 / h2≤0.
9.
4. The pole piece of claim 3, wherein When 2mm<w≤5mm, 0.92≤h1 / h2≤0.
95.
5. The pole piece of claim 4, wherein, When 5mm<w≤10mm, 0.95≤h1 / h2≤1.
6. The pole piece of claim 1, wherein The thinning area is disposed at two ends of the active material layer.
7. The pole piece of claim 6, wherein The active material layer is provided with two and disposed on both sides of the current collector.
8. The pole piece of any one of claims 1 to 5, wherein, When the electrode tab is a positive electrode tab, 86μm≤h2≤93.5μm.
9. The pole piece of any one of claims 1 to 5, wherein, When the electrode tab is a negative electrode tab, 57.5μm≤h2≤65μm.
10. An electric cell characterized by The electrode tab comprises the electrode tab of any one of claims 1 to 9.