Pole piece, roll core and battery
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN HIGHPOWER TECH CO LTD
- Filing Date
- 2025-07-17
- Publication Date
- 2026-08-07
AI Technical Summary
[0003]本实用新型提供了一种极片、卷芯及电池，以解决现有极片上压花虽能降低析锂的程度，但由于没有考虑压花区域中的压花槽的尺寸问题，还是会出现析锂现象的问题
[0018] The electrode sheet provided in this embodiment of the utility model has at least one embossed area on the electrode sheet, and each embossed area is located in the arc area of the core; each embossed area includes at least two embossed grooves; the depth and width of the embossed grooves are limited so that the ratio of the width to the depth of each embossed groove is greater than or equal to 0.01 and less than or equal to 0.05. This design can provide a suitable channel for the flow of electrolyte, avoid restricting the fluidity of electrolyte, solve the problem of arc lithium plating, and prevent the occurrence of arc lithium plating.
Smart Images
Figure CN224609859U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of electrode technology, and in particular to an electrode, a core, and a battery. Background Technology
[0002] Electrode embossing is a commonly used process technology. By embossing the electrode at the arc position of the core to a certain extent to form an embossed area, the channel for electrolyte flow at the arc can be increased. Although this can reduce the degree of lithium plating, lithium plating will still occur because the size of the embossing groove in the embossed area is not taken into account. Summary of the Invention
[0003] This invention provides an electrode sheet, a winding core, and a battery to solve the problem that although embossing on existing electrode sheets can reduce the degree of lithium plating, lithium plating still occurs because the size of the embossing grooves in the embossing area is not taken into account.
[0004] An electrode sheet, wherein the electrode sheet is a positive electrode sheet or a negative electrode sheet in a winding core, and the electrode sheet is provided with at least one embossed area, each of the embossed areas being located in the arc area of the winding core;
[0005] Each of the embossed areas includes at least two embossed grooves;
[0006] The ratio of the width to the depth of each embossed groove is greater than or equal to 0.01 and less than or equal to 0.05.
[0007] Preferably, the width of each embossing groove is 0.5-2.0 mm, and the depth of each embossing groove is 20-100 μm.
[0008] Preferably, the total area of all the embossed areas accounts for 10%-40% of the arc area of the core.
[0009] Preferably, the embossing groove is any one of the following shapes: arc, triangle, rectangle, and trapezoid.
[0010] Preferably, the opening of the embossing groove faces the inside of the electrode sheet.
[0011] A winding core includes a positive electrode sheet, a negative electrode sheet, and a separator; at least one of the positive electrode sheet and the negative electrode sheet is an electrode sheet as described above.
[0012] The positive electrode, the separator, and the negative electrode are formed into a core by a winding process;
[0013] The embossed area is located in the arc area of the core.
[0014] Preferably, the positive electrode, the separator, and the negative electrode are arranged alternately, with the separator located between the positive electrode and the negative electrode;
[0015] In the winding direction, the length of the separator is greater than the length of the negative electrode, and the length of the negative electrode is greater than the length of the positive electrode.
[0016] A battery, comprising a battery casing and the said winding core;
[0017] The winding core is installed inside the battery casing.
[0018] The electrode sheet provided in this embodiment of the utility model has at least one embossed area on the electrode sheet, and each embossed area is located in the arc area of the core; each embossed area includes at least two embossed grooves; the depth and width of the embossed grooves are limited so that the ratio of the width to the depth of each embossed groove is greater than or equal to 0.01 and less than or equal to 0.05. This design can provide a suitable channel for the flow of electrolyte, avoid restricting the fluidity of electrolyte, solve the problem of arc lithium plating, and prevent the occurrence of arc lithium plating. Attached Figure Description
[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0020] Figure 1 This is a cross-sectional view of the core in one embodiment of the present invention;
[0021] Figure 2 This is a cross-sectional view of the arc region of the core in one embodiment of this utility model.
[0022] Among them, 1 is the electrode sheet; 11 is the positive electrode sheet; 12 is the negative electrode sheet; 13 is the embossed area; 131 is the embossed groove; 14 is the non-embossed area; and 2 is the separator. Detailed Implementation
[0023] To make the technical problems, technical solutions, and beneficial effects solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.
[0024] In the description of this application, it should be understood that the terms "longitudinal," "radial," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. In the description of this application, unless otherwise stated, "a plurality of" means two or more.
[0025] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0026] This utility model embodiment provides an electrode 1, referring to... Figure 1 and Figure 2 The electrode 1 is either the positive electrode 11 or the negative electrode 12 in the core. The electrode 1 has at least one embossed area 13, and each embossed area 13 is located in the arc area of the core. Each embossed area 13 includes at least two embossed grooves 131. The ratio of the width to the depth of each embossed groove 131 is greater than or equal to 0.01 and less than or equal to 0.05.
[0027] As an example, electrode 1 is either a positive electrode 11 or a negative electrode 12 in a core. Electrode 1 has at least one embossed region 13 and at least two non-embossed regions 14. Each embossed region 13 is located within the arc region of the core. Each embossed region 13 includes at least two embossed grooves 131. The width-to-depth ratio of each embossed groove 131 is S. When S is greater than 0.05, meaning the width of the embossed groove 131 is too large or the depth is too small, there are fewer channels for electrolyte flow, which fails to improve the electrolyte retention capacity of the arc region and thus cannot improve the electrolyte balance. Lithium; when S is less than 0.01, that is, the width of the embossing groove 131 is too small or the depth is too large, the channel for electrolyte flow is too narrow or too deep, the fluidity of the electrolyte is restricted, and the circular lithium deposition cannot be improved; therefore, it is necessary to limit the depth and width of the embossing groove 131 so that the ratio of the width to the depth of each embossing groove 131 is greater than or equal to 0.01 and less than or equal to 0.05. This design can provide a suitable channel for electrolyte flow, avoid restricting the fluidity of the electrolyte, solve the problem of circular lithium deposition, and prevent the occurrence of circular lithium deposition.
[0028] The following are the parameters for the example:
[0029] Example 1: The width of the embossing groove 131 is 1.0 mm, the depth of the embossing groove 131 is 40 μm, and the ratio of the width to the depth of the embossing groove 131 is 0.025;
[0030] Example 2: The width of the embossing groove 131 is 1.0 mm, the depth of the embossing groove 131 is 20 μm, and the ratio of the width to the depth of the embossing groove 131 is 0.05;
[0031] Example 3: The width of the embossing groove 131 is 1.0 mm, the depth of the embossing groove 131 is 100 μm, and the ratio of the width to the depth of the embossing groove 131 is 0.01;
[0032] Example 4: The width of the embossing groove 131 is 2.0 mm, the depth of the embossing groove 131 is 80 μm, and the ratio of the width to the depth of the embossing groove 131 is 0.025;
[0033] Comparative Example 1: Unpressed flower groove 131;
[0034] Comparative Example 2: The width of the embossing groove 131 is 1.5 mm, the depth of the embossing groove 131 is 20 μm, and the ratio of the width to the depth of the embossing groove 131 is 0.075.
[0035] Comparative Example 3: The width of the embossing groove 131 is 0.5 mm, the depth of the embossing groove 131 is 100 μm, and the ratio of the width to the depth of the embossing groove 131 is 0.005.
[0036] The battery cell was charged at 3C constant current and constant voltage to 4.5V, cut off at 0.05C, and discharged at 0.5C. After 1600 cycles, the battery was disassembled to check the lithium plating on the electrodes, which was divided into no lithium plating, slight lithium plating, moderate lithium plating, and severe lithium plating.
[0037] Comparison of battery cell test performance:
[0038] Example 1: The number of cycles was 1600, and no lithium deposition occurred in the arc-shaped area;
[0039] Example 2: The number of cycles was 1600, and no lithium deposition occurred in the arc-shaped area;
[0040] Example 3: The number of cycles was 1600, and no lithium deposition occurred in the arc-shaped area;
[0041] Example 4: After 1600 cycles, no lithium deposition was observed in the circular arc area.
[0042] Comparative Example 1: After 500 cycles, the lithium deposition at the arc was considered severe.
[0043] Comparative Example 2: After 700 cycles, the lithium deposition at the arc was moderate.
[0044] Comparative Example 3: The number of cycles was 800, and the lithium deposition in the arc was moderate.
[0045] In one embodiment, reference is made to Figure 1 and Figure 2 The width of each embossing groove 131 is 0.5-2.0 mm, and the depth of each embossing groove 131 is 20-100 μm.
[0046] As an example, if the width of the embossing groove 131 is too large or the depth is too small, there are fewer channels for electrolyte flow, which cannot improve the electrolyte retention capacity of the arc and thus cannot improve the arc lithium plating. If the width of the embossing groove 131 is too small or the depth is too large, the channel for electrolyte flow is too narrow or too deep, and the fluidity of the electrolyte is restricted, which also cannot improve the arc lithium plating. Therefore, it is necessary to limit the depth and width of the embossing groove 131, so that the width of each embossing groove 131 is 0.5-2.0 mm and the depth of each embossing groove 131 is 20-100 μm. This design can provide a suitable channel for electrolyte flow, avoid restricting the fluidity of the electrolyte, solve the problem of arc lithium plating, and prevent the occurrence of arc lithium plating.
[0047] In one embodiment, reference is made to Figure 1 and Figure 2 The total area of all embossed areas 13 accounts for 10%-40% of the arc area of the core.
[0048] As an example, when the total area of all embossed areas 13 accounts for less than 10% of the arc area of the core, there is no effect. When the total area of all embossed areas 13 accounts for more than 40% of the arc area of the core, it is easy to cause electrode damage and strip breakage. Therefore, it is necessary to limit the proportion of the total area of all embossed areas 13 in the arc area of the core. The proportion of the total area of all embossed areas 13 in the arc area of the core should be 10%-40%. Within this range, more electrolyte transport channels can be provided, the problem of lithium plating at the arc can be improved, and the cycle life of the cell can be extended.
[0049] In one embodiment, reference is made to Figure 1 and Figure 2 The embossing groove 131 can be any one of the following shapes: arc, triangle, rectangle and trapezoid.
[0050] As an example, the shape of the embossing groove 131 is introduced. The shape of the embossing groove 131 can be set to any one of arc, triangle, rectangle and trapezoid according to actual needs, so as to provide a suitable channel for electrolyte flow, avoid restricting the fluidity of electrolyte, solve the problem of arc lithium plating, and avoid the occurrence of arc lithium plating.
[0051] In one embodiment, reference is made to Figure 1 and Figure 2 The opening of the embossing groove 131 faces the inside of the electrode sheet.
[0052] As an example, the opening of the embossing groove 131 faces the inside of the electrode. This setting can provide a suitable channel for the flow of electrolyte, avoid restricting the fluidity of electrolyte, solve the problem of arc lithium plating, and prevent the occurrence of arc lithium plating.
[0053] This utility model embodiment provides a winding core, referring to... Figure 1 and Figure 2 It includes a positive electrode 11, a negative electrode 12 and a separator 2; at least one of the positive electrode 11 and the negative electrode 12 is the aforementioned electrode 1; the positive electrode 11, the separator 2 and the negative electrode 12 are made into a core by a winding process; the embossed area 13 is located in the arc area of the core.
[0054] As an example, the core includes a positive electrode 11, a negative electrode 12, and a separator 2; at least one of the positive electrode 11 and the negative electrode 12 is an electrode 1; the positive electrode 11, the separator 2, and the negative electrode 12 are formed into a core by a winding process; the electrode 1 is either the positive electrode 11 or the negative electrode 12 in the core, and at least one embossed area 13 and at least two non-embossed areas 14 are provided on the electrode 1, each embossed area 13 being located in the arc area of the core; each embossed area 13 includes at least two embossed grooves 131; the ratio of the width to the depth of each embossed groove 131 is S, and when S is greater than 0.05, that is, the width of the embossed groove 131 is too large or the depth is too small. The limited number of channels provided for electrolyte flow makes it impossible to improve the electrolyte retention capacity of the embossing groove 131, thus failing to improve the lithiation of the embossing groove. When S is less than 0.01, that is, the width of the embossing groove 131 is too small or the depth is too large, the channels for electrolyte flow are too narrow or too deep, restricting the fluidity of the electrolyte and failing to improve the lithiation of the embossing groove. Therefore, it is necessary to limit the depth and width of the embossing groove 131 so that the ratio of the width to the depth of each embossing groove 131 is greater than or equal to 0.01 and less than or equal to 0.05. This design can provide suitable channels for electrolyte flow, avoid restricting the fluidity of the electrolyte, solve the problem of lithiation of the embossing groove, and prevent the occurrence of lithiation of the embossing groove.
[0055] In one embodiment, reference is made to Figure 1 and Figure 2 The positive electrode 11, the separator 2, and the negative electrode 12 are arranged alternately, with the separator 2 located between the positive electrode 11 and the negative electrode 12. In the winding direction, the length of the separator 2 is greater than the length of the negative electrode 12, and the length of the negative electrode 12 is greater than the length of the positive electrode 11.
[0056] As an example, during the fabrication of the core, the positive electrode 11, separator 2, and negative electrode 12 are arranged alternately, with the separator 2 located between the positive electrode 11 and the negative electrode 12. In the winding direction, the length of the separator 2 is greater than the length of the negative electrode 12. The longer separator 2 can better wrap the electrode sheet, making the winding process smoother and reducing problems such as misalignment and wrinkles of the electrode sheet during the winding process. The length of the negative electrode 12 is greater than the length of the positive electrode 11, which can increase the effective area of the negative electrode and the lithium-ion insertion sites, thereby improving the charge and discharge efficiency and cycle life of the battery.
[0057] This utility model provides a battery, including a battery casing and a winding core; the winding core is installed inside the battery casing.
[0058] As an example, the battery includes a battery casing and a core; the core includes a positive electrode 11, a negative electrode 12, and a separator 2; at least one of the positive electrode 11 and the negative electrode 12 is an electrode 1; the positive electrode 11, the separator 2, and the negative electrode 12 are formed into a core by a winding process; the electrode 1 is either the positive electrode 11 or the negative electrode 12 in the core, and at least one embossed area 13 and at least two non-embossed areas 14 are provided on the electrode 1, each embossed area 13 being located in the arc area of the core; each embossed area 13 includes at least two embossed grooves 131; the ratio of the width to the depth of each embossed groove 131 is S, and when S is greater than 0.05, that is, the width of the embossed groove 131 is too large... If the width or depth of the embossing groove 131 is too large or too small, there will be too few channels for electrolyte flow, which will not be able to improve the electrolyte retention capacity of the arc and thus cannot improve the arc lithium plating. When S is less than 0.01, that is, the width of the embossing groove 131 is too small or the depth is too large, the channel for electrolyte flow is too narrow or too deep, the fluidity of the electrolyte is restricted, and the arc lithium plating cannot be improved. Therefore, it is necessary to limit the depth and width of the embossing groove 131 so that the ratio of the width to the depth of each embossing groove 131 is greater than or equal to 0.01 and less than or equal to 0.05. This design can provide a suitable channel for electrolyte flow, avoid restricting the fluidity of the electrolyte, solve the problem of arc lithium plating, and prevent the occurrence of arc lithium plating.
[0059] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.
Claims
1. An electrode sheet, wherein the electrode sheet is a positive or negative electrode sheet in a wound core, characterized in that, The electrode sheet is provided with at least one embossed area, and each embossed area is located in the arc area of the core. Each of the embossed areas includes at least two embossed grooves; The ratio of the width to the depth of each embossed groove is greater than or equal to 0.01 and less than or equal to 0.
05.
2. The electrode sheet according to claim 1, characterized in that, The width of each embossing groove is 0.5-2.0 mm, and the depth of each embossing groove is 20-100 μm.
3. The electrode sheet according to claim 1, characterized in that, The total area of all the embossed areas accounts for 10%-40% of the arc area of the core.
4. The electrode sheet according to claim 1, characterized in that, The embossing groove can be any one of the following shapes: arc, triangle, rectangle, and trapezoid.
5. The electrode sheet according to claim 1, characterized in that, The opening of the embossed groove faces the inside of the electrode sheet.
6. A type of winding core, characterized in that, It includes a positive electrode, a negative electrode, and a separator; at least one of the positive electrode and the negative electrode is the electrode as described in any one of claims 1-5; The positive electrode, the separator, and the negative electrode are formed into a core by a winding process; The embossed area is located in the arc area of the core.
7. The winding core according to claim 6, characterized in that, The positive electrode, the separator, and the negative electrode are arranged alternately, with the separator located between the positive electrode and the negative electrode. In the winding direction, the length of the separator is greater than the length of the negative electrode, and the length of the negative electrode is greater than the length of the positive electrode.
8. A battery, characterized in that, Includes the battery casing and the winding core as described in any one of claims 6-7; The winding core is installed inside the battery casing.