Negative current collector and full-tab cylindrical lithium-ion battery comprising the same
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIANGSU RELIANCE ENERGY TECHNOLOGY CO LTD
- Filing Date
- 2025-07-18
- Publication Date
- 2026-07-10
Smart Images
Figure CN224481150U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of lithium-ion battery technology, and in particular to a negative electrode current collector and a cylindrical lithium-ion battery with full tabs including the negative electrode current collector. Background Technology
[0002] The all-tab cylindrical lithium-ion battery is a key development direction for power batteries. It is made by pre-leaving blank positive and negative electrode foils at both ends of the core, then radially extruding the foils and flattening the end faces, then laser welding the current collector to the end faces of the foils, and finally electrically connecting the current collector to the electrode post on the cover plate to obtain the all-tab cylindrical lithium-ion battery.
[0003] However, the existing current collector welding process is complex and the current collector alignment is difficult, which causes misalignment when welding the cover plate to the shell, resulting in micro-deformation of the shell, which in turn leads to leakage during the welding process and renders the battery unusable.
[0004] In addition, in practical applications, it is necessary to reduce the space occupied by the current collector in the height direction to improve the energy density of the cylindrical battery cell, and to ensure that the welding position of the current collector is firmly welded to avoid the current collector's solder marks tearing or falling off, which could lead to an open circuit inside the cell and affect long-term reliability. Furthermore, during the welding process, vibration will be generated in the welding area, and the vibration will be transmitted and spread to each other, affecting the cell performance.
[0005] Therefore, it is both necessary and urgent to research and develop a negative electrode current collector that can effectively alleviate problems such as alignment difficulties, welding vibration, and weld tearing or detachment during the welding process of existing current collectors.
[0006] In view of the above, this utility model is hereby proposed. Utility Model Content
[0007] The primary objective of this invention is to provide a negative current collector that can effectively alleviate the problems of alignment difficulties, welding vibration, and solder mark tearing or falling off in existing current collector welding, which can lead to open circuits inside the battery cell and affect the long-term reliability of the battery cell.
[0008] The second objective of this invention is to provide a cylindrical lithium-ion battery with all tabs.
[0009] In order to achieve the above-mentioned objectives of this utility model, the following technical solution is adopted:
[0010] The present invention provides a negative electrode current collector, including a negative electrode current collector body, wherein the negative electrode current collector body has a welding position A on the side facing the negative end of the battery core, and a welding position B on the side facing the battery shell.
[0011] The negative electrode current collector body is provided with a C-shaped groove between welding position A and welding position B;
[0012] The C-shaped groove is set at the same center as the negative electrode collector plate body, and the ratio of the radius of the C-shaped groove to the radius of the collector plate body ranges from 0.2 to 0.23:1.
[0013] Furthermore, the arc α of the C-shaped groove is: 225° < α < 293°.
[0014] Furthermore, the arc α of the C-shaped groove is 270°.
[0015] Furthermore, the gap value L generated by the C-shaped groove on the negative electrode current collector body is:
[0016] 0 < L ≤ 0.05 mm.
[0017] Furthermore, the distance between the center of the C-shaped groove and the center of the battery casing is 0~0.01mm.
[0018] Furthermore, the ratio of the radius of the C-shaped groove to the radius of the center hole of the battery core is 4:3.
[0019] Furthermore, the thickness of the negative electrode current collector body is 0.1~0.35mm.
[0020] Furthermore, the negative electrode current collector body is covered with a nickel plating layer.
[0021] Furthermore, the ratio of the thickness of the nickel plating layer to the thickness of the negative electrode current collector body is 0.006~0.033:1.
[0022] This utility model provides a cylindrical lithium-ion battery with all tabs, wherein the cylindrical lithium-ion battery with all tabs includes the aforementioned negative electrode current collector.
[0023] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0024] The negative electrode current collector provided by this utility model has a welding position A on the side of the negative electrode current collector body facing the negative end of the battery core, and a welding position B on the side of the negative electrode current collector body facing the battery shell. A C-shaped groove is provided between the welding position A and the welding position B. At the same time, the C-shaped groove is concentric with the negative electrode current collector body, and the ratio of the radius of the C-shaped groove to the radius of the current collector body is in the range of 0.2~0.23:1. This invention utilizes a C-shaped groove to create a welding passage between the internal area of the C-shaped groove and the metal casing, while forming a core welding area on the outside. This reduces the heat impact of the two welds and prevents poor welding. Simultaneously, the gap created by the C-shaped groove facilitates electrolyte penetration and gas release in the event of a short circuit or thermal runaway within the battery. When the cell undergoes thermal runaway expansion, the pressure generated can compress the negative electrode current collector, causing the C-shaped groove on the negative electrode current collector to open or deform. This opening or deformation allows for better release of the cell's expansion pressure. Furthermore, the aforementioned C-shaped groove can also be used for positioning.
[0025] Therefore, by setting the above-mentioned C-shaped groove, this utility model effectively alleviates the problems of alignment difficulties, welding vibration, and weld tearing or falling off in the existing current collector welding, which lead to open circuits inside the battery cell and affect the long-term reliability of the battery cell. Attached Figure Description
[0026] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0027] Figure 1 A schematic diagram of the negative electrode current collector body provided by this utility model; Figure 1 In the diagram, R1 is the radius of the negative electrode current collector body 100; R2 is the radius of the C-shaped groove 200; and H is the thickness of the negative electrode current collector body 100.
[0028] Figure 2 A schematic diagram of the gap generated on the negative electrode current collector body by the C-shaped groove provided by this utility model; Figure 2 L in the middle represents the gap created by the C-shaped groove 200.
[0029] Icons: 100 - Negative current collector body; 200 - C-shaped groove. Detailed Implementation
[0030] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model. To help to better understand this utility model, specific embodiments will now be described in detail.
[0031] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model 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 utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0032] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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 of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0033] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.
[0034] Figure 1 A schematic diagram of the structure of the negative electrode current collector body 100 provided by this utility model.
[0035] Figure 1 In the diagram, R1 is the radius of the negative electrode current collector body 100; R2 is the radius of the C-shaped groove 200; and H is the thickness of the negative electrode current collector body 100.
[0036] According to one aspect of the present invention, a negative electrode current collector includes a negative electrode current collector body 100, wherein the negative electrode current collector body 100 has a welding position A on the side facing the negative end of the battery core, and a welding position B on the side facing the battery casing, and a C-shaped groove 200 is provided between the welding position A and the welding position B.
[0037] The C-shaped groove 200 is set at the same center as the negative electrode collector plate body 100, and the ratio of the radius of the C-shaped groove 200 to the radius of the collector plate body is in the range of 0.2~0.23:1.
[0038] The negative electrode current collector provided by this utility model has a welding position A on the side of the negative electrode end of the battery core facing the negative electrode, and a welding position B on the side of the negative electrode current collector body 100 facing the battery casing. A C-shaped groove 200 is provided between welding positions A and B. The C-shaped groove 200 is concentric with the negative electrode current collector body 100, and the ratio of the radius of the C-shaped groove 200 to the radius of the current collector body is in the range of 0.2~0.23:1. This utility model provides a C-shaped groove 200 between the welding position at the negative electrode end of the battery core and the welding position of the current collector body on the battery casing. By setting the aforementioned C-shaped groove 200, a passage is formed between the internal area of the C-shaped groove 200 and the metal shell for welding, while the external area forms a core welding zone. This reduces the heat impact of the two welds and avoids welding defects. Simultaneously, the gap created by the C-shaped groove 200 is suitable for electrolyte penetration and gas discharge in the event of a short circuit or thermal runaway causing significant gas production inside the battery. When the battery cell undergoes thermal runaway expansion, the pressure generated can compress the negative electrode current collector, causing the C-shaped groove 200 on the negative electrode current collector to open or deform. After the C-shaped groove 200 opens or deforms, the expansion pressure of the battery cell can be better released. Furthermore, the aforementioned C-shaped groove 200 can also be used for positioning. Therefore, this invention, through the setting of the aforementioned C-shaped groove 200, effectively alleviates the problems of alignment difficulties, welding vibration, and weld tearing or detachment that exist in existing current collector welding, leading to open circuits inside the battery cell and affecting the long-term reliability of the battery cell.
[0039] It should be noted that the ratio of the radius of the C-shaped groove 200 to the radius of the collector plate body is in the range of 0.2~0.23:1, that is: the radius of the collector plate body is R1, and the radius of the C-shaped groove 200 is R2, satisfying 0.2<R2 / R1<0.23.
[0040] The relationship between the radius of the aforementioned C-shaped groove 200 and the radius of the collector plate body can effectively ensure the welding effect. If the radius R2 is too small, it is easy to detach during welding. Conversely, if R2 is too large, its surface flatness will be poor and its fit with the inner surface of the shell bottom will be poor.
[0041] In a preferred embodiment of this utility model, the arc α of the C-shaped groove 200 is 225° < α < 293°. Preferably, the arc α of the C-shaped groove 200 is 270°.
[0042] As a preferred embodiment, the negative current collector of this utility model is used for conductive connection between the metal shell and the core electrode assembly, that is, to form a passage between the core electrode assembly, the negative current collector and the metal shell. Therefore, the C-shaped groove 200 cannot be completely cut off and needs to maintain a certain curvature.
[0043] In a preferred embodiment of this utility model, the gap value L generated by the C-shaped groove 200 on the negative electrode current collector body 100 is: 0 < L ≤ 0.05 mm.
[0044] Figure 2 A schematic diagram of the gap generated on the negative electrode current collector body 100 by the C-shaped groove 200 provided by this utility model. Figure 2 L in the middle represents the gap created by the C-shaped groove 200.
[0045] In a preferred embodiment of this utility model, the distance between the center of the C-shaped groove 200 and the center of the battery casing is 0~0.01mm;
[0046] The ratio of the radius of the C-shaped groove 200 to the radius of the center hole of the battery core is 4:3, that is, R2≈ the radius of the center hole of the core.
[0047] In a preferred embodiment, the distance between the center of the C-shaped groove 200 and the center of the battery casing is set so that it can smoothly pass through the opening of the metal casing and enter the inner cavity of the metal casing; at the same time, the diameter of the negative electrode current collector and the winding core is generally slightly smaller than the inner diameter of the metal casing.
[0048] In a preferred embodiment of this utility model, the thickness of the negative electrode current collector body 100 is 0.1~0.35.
[0049] As a preferred embodiment, the thickness of the negative electrode current collector body 100 is 0.1~0.35mm. If it is not within this range, the thickness is too small and the mechanical strength is insufficient, making it easy to deform. If the thickness is too large, it will increase the internal resistance of the battery and also occupy more longitudinal space.
[0050] In a preferred embodiment of this utility model, the negative electrode current collector body 100 is covered with a nickel plating layer. Preferably, the ratio of the thickness of the nickel plating layer to the thickness of the negative electrode current collector body 100 is 0.006~0.033:1.
[0051] As a preferred embodiment, the aforementioned nickel plating effectively improves corrosion resistance, with a nickel layer thickness h, where 0.006 < h / H ≤ 0.033. When the plating thickness is too thin, its corrosion resistance is low, and its hardness is insufficient. In the negative electrode current collector, except for the bending area which requires a softer material, the hardness of other areas can be appropriately increased, especially for the plate body that needs to be laser welded to the core. If this part is too soft, it is prone to deformation and cannot make good contact and flatness with the core, affecting the welding quality. When the plating thickness is too thick, it increases production costs, and the plating is prone to defects such as cracking and bubbling.
[0052] According to one aspect of the present invention, a cylindrical lithium-ion battery with all tabs is provided, the cylindrical lithium-ion battery with all tabs including the aforementioned negative electrode current collector.
[0053] This utility model provides a cylindrical lithium-ion battery with all tabs, which includes the aforementioned negative electrode current collector.
[0054] The technical solution of this utility model will be further described below with reference to the embodiments.
[0055] Example 1
[0056] Figure 1 A schematic diagram of the structure of the negative electrode current collector body 100 provided by this utility model;
[0057] Figure 2 A schematic diagram of the gap generated on the negative electrode current collector body 100 by the C-shaped groove 200 provided by this utility model.
[0058] See Figure 1 , Figure 2 A negative electrode current collector includes a negative electrode current collector body 100, wherein the negative electrode current collector body 100 has a welding position A on the side facing the negative end of the battery core, and a welding position B on the side facing the battery casing, and a C-shaped groove 200 is provided between the welding position A and the welding position B.
[0059] The C-shaped groove 200 is co-centered with the negative electrode current collector body 100, the radius of the C-shaped groove 200 is 2.1 mm, and the radius of the current collector body is 9.5 mm;
[0060] That is, in this embodiment, the ratio of the radius of the C-shaped groove 200 to the radius of the collector plate body is in the range of 0.2:1.
[0061] In this embodiment, the arc α of the C-shaped groove 200 is 270°.
[0062] In this embodiment, the gap value generated by the C-shaped groove 200 on the negative electrode current collector body 100 is 0.05.
[0063] In this embodiment, the distance between the center of the C-shaped groove 200 and the center of the battery casing is 0.01.
[0064] In this embodiment, the ratio of the radius of the C-shaped groove 200 to the radius of the center hole of the battery core is 4:3.
[0065] In this embodiment, the thickness of the negative electrode current collector body 100 is 0.1 mm.
[0066] In this embodiment, the negative electrode current collector body 100 is covered with a nickel plating layer, and the ratio of the thickness of the nickel plating layer to the thickness of the negative electrode current collector body 100 is 0.006:1.
[0067] Example 2
[0068] A negative electrode current collector includes a negative electrode current collector body 100, wherein the negative electrode current collector body 100 has a welding position A on the side facing the negative end of the battery core, and a welding position B on the side facing the battery casing, and a C-shaped groove 200 is provided between the welding position A and the welding position B.
[0069] The C-shaped groove 200 is co-centered with the negative electrode current collector body 100, the radius of the C-shaped groove 200 is 2.1 mm, and the radius of the current collector body is 9.5 mm;
[0070] That is, in this embodiment, the ratio of the radius of the C-shaped groove 200 to the radius of the collector plate body is in the range of 0.23:1.
[0071] In this embodiment, the arc α of the C-shaped groove 200 is 225°.
[0072] In this embodiment, the gap value generated by the C-shaped groove 200 on the negative electrode current collector body 100 is 0.05.
[0073] In this embodiment, the distance between the center of the C-shaped groove 200 and the center of the battery casing is 0.01.
[0074] In this embodiment, the ratio of the radius of the C-shaped groove 200 to the radius of the center hole of the battery core is 4:3.
[0075] In this embodiment, the thickness of the negative electrode current collector body 100 is 0.35 mm.
[0076] In this embodiment, the negative electrode current collector body 100 is covered with a nickel plating layer, and the ratio of the thickness of the nickel plating layer to the thickness of the negative electrode current collector body 100 is 0.033:1.
[0077] Example 3
[0078] A negative electrode current collector includes a negative electrode current collector body 100, wherein the negative electrode current collector body 100 has a welding position A on the side facing the negative end of the battery core, and a welding position B on the side facing the battery casing, and a C-shaped groove 200 is provided between the welding position A and the welding position B.
[0079] The C-shaped groove 200 is co-centered with the negative electrode current collector body 100, the radius of the C-shaped groove 200 is 2.1 mm, and the radius of the current collector body is 9.5 mm;
[0080] That is, in this embodiment, the ratio of the radius of the C-shaped groove 200 to the radius of the collector plate body is in the range of 0.2:1.
[0081] In this embodiment, the arc of the C-shaped groove 200 is 293°.
[0082] In this embodiment, the gap value generated by the C-shaped groove 200 on the negative electrode current collector body 100 is 0.05.
[0083] In this embodiment, the distance between the center of the C-shaped groove 200 and the center of the battery casing is 0.01.
[0084] In this embodiment, the ratio of the radius of the C-shaped groove 200 to the radius of the center hole of the battery core is 4:3.
[0085] In this embodiment, the thickness of the negative electrode current collector body 100 is 0.25 mm.
[0086] In this embodiment, the negative electrode current collector body 100 is covered with a nickel plating layer, and the ratio of the thickness of the nickel plating layer to the thickness of the negative electrode current collector body 100 is 0.033:1.
[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model 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 or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.
Claims
1. A negative electrode current collector, comprising a negative electrode current collector body, characterized in that, The negative electrode current collector body has a welding position A on the side facing the negative end of the battery core, and the negative electrode current collector body has a welding position B on the side facing the battery casing. The negative electrode current collector body is provided with a C-shaped groove between welding position A and welding position B; The C-shaped groove is set at the same center as the negative electrode collector plate body, and the ratio of the radius of the C-shaped groove to the radius of the collector plate body ranges from 0.2 to 0.23:
1.
2. The negative electrode current collector according to claim 1, characterized in that, The arc α of the C-shaped groove is: 225° < α < 293°.
3. The negative electrode current collector according to claim 2, characterized in that, The arc α of the C-shaped groove is 270°.
4. The negative electrode current collector according to claim 1, characterized in that, The gap value L generated by the C-shaped groove on the negative electrode current collector body is: 0 < L ≤ 0.05 mm.
5. The negative electrode current collector according to claim 1, characterized in that, The distance between the center of the C-shaped groove and the center of the battery casing is 0~0.01mm.
6. The negative electrode current collector according to claim 1, characterized in that, The ratio of the radius of the C-shaped groove to the radius of the center hole of the battery core is 4:
3.
7. The negative electrode current collector according to claim 1, characterized in that, The thickness of the negative electrode current collector body is 0.1~0.35mm.
8. The negative electrode current collector according to claim 1, characterized in that, The negative electrode current collector body is covered with a nickel plating layer.
9. The negative electrode current collector according to claim 8, characterized in that, The ratio of the thickness of the nickel plating layer to the thickness of the negative electrode current collector body is 0.006~0.033:
1.
10. A cylindrical lithium-ion battery with multiple tabs, characterized in that, Includes the negative current collector as described in any one of claims 1 to 9.