Current collecting tab, and cylindrical battery and assembly method therefor

Abstract

A current collecting tab, and a cylindrical battery and an assembly method therefor. The current collecting tab comprises a case welding area and a wing part extending out of at least one end of the case welding area; the wing part is used for being welded to a full tab of a jelly roll; the wing part is provided with a first side edge; an included angle is formed at the joint of the first side edge and the case welding area; and the formation of the included angle allows for elastic deformation between the wing part and the case welding area. In the present application, when the wing part is welded to the full tab of the jelly roll, and the case welding area is welded to the bottom wall of a case, elastic deformation can occur between the case welding area and the wing part to release generated stress, thereby avoiding direct pulling of the position where the wing part is welded to the full tab. In addition, due to vibration of a vehicle in which an assembled cylindrical battery is mounted and other factors, the jelly roll jumps and the wing part is driven to jump together, elastic deformation can also occur between the case welding area and the wing part to release impact stress, thereby avoiding the risk of open circuit at the position where the case welding area is welded to the bottom wall of the case, and improving the anti-vibration performance of the cylindrical battery.

Description

Current collecting sheet, cylindrical battery and assembly method thereof Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a current collector, a cylindrical battery, and an assembly method thereof. Background Art

[0002] Currently, lithium-ion / sodium-ion cylindrical batteries are becoming the mainstream products in the new energy industry due to their high energy density, good capacity consistency, and ability to support high-rate charge and discharge. More and more manufacturers are continuously pursuing structural compactness optimization of cylindrical batteries to increase energy density. However, cylindrical batteries currently have the following problems with the current collector:

[0003] (1) The current collectors commonly used in cylindrical batteries are more complex in design and use more metal materials, resulting in higher battery production costs.

[0004] (2) For the newly emerged current collector with a minimalist rectangular strip structure, when it is first laser welded to the full-pole tab of the winding core and then the middle part of the current collector is welded to the bottom wall of the shell by resistance welding, the full-pole tab welding position will be pulled. In addition, due to the rigid connection between the full-pole tab and the current collector, and the current collector and the bottom of the shell, when the vehicle is vibrated (the larger winding core inside jumps), the winding core will directly impact the welding position, which is easy to fall off, resulting in the risk of open circuit failure of the cylindrical battery.

[0005] Summary of the Invention

[0006] The purpose of this application is to provide a current collecting sheet and a cylindrical battery that can solve at least one technical problem mentioned in the background technology.

[0007] In order to achieve the above-mentioned purpose, the present application provides a current collecting plate, including a shell welding area and a wing extending from at least one end of the shell welding area, the wing being used to be welded to the full pole ear of the winding core, the wing having a first side edge, and the first side edge forming an angle with the connection between the shell welding area, the formation of the angle enables the wing and the shell welding area to be elastically deformed.

[0008] Optionally, the shell welding area includes an adjacent second side and a third side, the wing extends from the second side, the first side of the wing is connected to the third side, and the connection between the first side and the third side forms the angle, which is an obtuse angle.

[0009] Optionally, the angle is between 110° and 160°.

[0010] Optionally, the shell welding area includes a second side, the wing extends from the second side, one end of the second side exceeds the starting position of the wing and forms the angle with the connection with the first side of the wing, and the angle is an acute angle.

[0011] Optionally, the angle is between 30° and 70°.

[0012] Optionally, at least one welding track is formed on the wing portion, and the welding track is configured to conduct all the tabs of each layer from the inner ring to the outer ring of the winding core.

[0013] Optionally, wings extend from both opposite ends of the shell welding area.

[0014] Optionally, the wing portion extends out in a strip shape, and / or the current collecting piece as a whole is in a bent strip shape.

[0015] In order to achieve the above-mentioned purpose, the present application also provides a cylindrical battery, comprising a roll core, a shell and a current collecting sheet as described above, wherein the roll core is placed in the shell, the current collecting sheet is arranged between the roll core and the bottom wall of the shell, the shell welding area is arranged corresponding to the through hole of the roll core and welded to the bottom wall of the shell, the wing is welded to the full pole ear of the roll core, and when the wing vibrates with the roll core, elastic deformation is generated between the wing and the shell welding area to release stress.

[0016] The present application also provides a method for assembling the cylindrical battery as described above, comprising:

[0017] Welding the wing of the current collecting sheet to the full tab of the winding core so that the shell welding area of ​​the current collecting sheet corresponds to the through hole of the winding core;

[0018] placing the winding core into the shell so that the current collecting sheet faces the bottom wall of the shell;

[0019] The shell welding area of ​​the current collecting sheet is welded to the bottom wall of the shell by utilizing the through hole of the winding core.

[0020] In the present application, the current collector is a simple sheet structure. On the basis of ensuring low material consumption and low cost, the angle between the shell welding area and the wing is set to allow the shell welding area and the wing to be elastically deformed. After the wing is welded to the full-pole ear of the winding core, when the shell welding area is welded to the bottom wall of the shell, elastic deformation can occur between the shell welding area and the wing to release the generated stress, avoiding direct pulling of the welding position between the wing and the full-pole ear. In addition, when the cylindrical battery is assembled and the winding core jumps due to loading vibration, etc. and drives the wing to jump together, elastic deformation can also occur between the shell welding area and the wing to release the impact stress, avoiding the risk of open circuit at the welding position of the shell welding area and the bottom wall of the shell, thereby improving the seismic performance of the cylindrical battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG1 is a schematic structural diagram of a current collecting sheet according to an embodiment of the present application.

[0022] FIG2 is a schematic diagram of the top view of the assembled current collecting sheet and winding core according to an embodiment of the present application.

[0023] FIG3 is a schematic diagram of the exploded structure of a cylindrical battery according to an embodiment of the present application.

[0024] 4 to 15 are schematic structural diagrams of current collecting sheets according to different embodiments of the present application.

[0025] FIG16 is a flow chart of a method for assembling cylindrical batteries according to an embodiment of the present application. DETAILED DESCRIPTION

[0026] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0027] Referring to Figures 1 to 15 , an embodiment of the present application discloses a current collector 1. The current collector 1 is used for a cylindrical battery, which also includes a winding core 2 and a shell 3. When assembled, the winding core 2 is sleeved within the shell 3, and the current collector 1 is located between the winding core 2 and the bottom wall 30 of the shell 3, and is welded to the full tab of the winding core 2 and the bottom wall 30 of the shell 3, respectively. The current collector 1 includes a shell welding area 11 for welding to the bottom wall 30 of the shell 3, and a wing 12 extending from at least one end of the shell welding area 11. The wing 12 is used to weld to the full tab of the winding core 2. The wing 12 has a first side 121. The connection between the first side 121 and the shell welding area 11 forms an angle a. The formation of the angle a enables elastic deformation between the wing 12 and the shell welding area 11.

[0028] It should be explained that the formation of angle a allows elastic deformation between the wing 12 and the shell welding area 11. This means that the wing 12 extends straight out from the shell welding area 11, and the connection between the shell welding area 11 and the wing 12 has no angle a (180 degrees, for example, the collector is a rectangular strip structure) or the angle a is 90 degrees, so that the shell welding area 11 and the wing 12 are rigidly connected. By forming angle a, the shell welding area 11 and the wing 12 can be elastically deformed, becoming an elastic connection. In this way, when the shell welding area 11 and the wing 12 are pulled or driven up and down, elastic deformation can occur to release stress. For example, after welding the wing 12 to the full tab of the winding core 2 and then welding the shell welding area 11 to the bottom wall 30 of the shell 3, elastic deformation can occur between the wing 12 and the shell welding area 11 to release the stress generated thereby; when the cylindrical battery causes the winding core 2 to jump due to loading vibrations and drives the wing 12 to jump together, elastic deformation can also occur between the wing 12 and the shell welding area 11 to release the impact stress.

[0029] In the present application, the current collector 1 is a simple sheet structure. On the basis of ensuring low material consumption and low cost, the angle a between the shell welding area 11 and the wing 12 is set, so that the shell welding area 11 and the wing 12 can be elastically deformed. After the wing 12 is welded to the full pole ear of the winding core 2, when the shell welding area 11 is welded to the bottom wall 30 of the shell 3, elastic deformation can occur between the shell welding area 11 and the wing 12 to release the generated stress, and avoid directly pulling the welding position of the wing 12 and the full pole ear. In addition, when the cylindrical battery is assembled and the winding core 2 jumps due to loading vibration, etc. and drives the wing 12 to jump together, elastic deformation can also occur between the shell welding area 11 and the wing 12 to release the impact stress, avoiding the risk of open circuit at the welding position of the shell welding area 11 and the bottom wall 30 of the shell 3, thereby improving the seismic performance of the cylindrical battery.

[0030] Optionally, the current collecting sheet 1 is made of copper, nickel, copper-nickel composite strip or aluminum. Of course, the current collecting sheet 1 can also be made of other materials.

[0031] In the examples of Figures 1 to 14 , the housing welding area 11 includes a second side 111 and a third side 112 adjacent to each other. The wing 12 extends from the second side 111. The first side 121 of the wing 12 is connected to the third side 112. The connection between the first side 121 and the third side 112 forms an obtuse angle a. Preferably, the angle a is between 110° and 160°.

[0032] Referring to Figures 1 to 3 , specifically, the housing welding area 11 is configured to align with the through-hole 21 of the winding core 2. After the current collector sheet 1 and the winding core 2 are assembled, the housing welding area 11 at least partially protrudes outward from the through-hole 21 of the winding core 2 to facilitate welding. Alternatively, the housing welding area 11 may entirely protrude outward from the through-hole 21 of the winding core 2, meaning that the projection of the through-hole 21 of the winding core 2 onto the current collector sheet 1 is located inwardly of the outer periphery of the housing welding area 11.

[0033] In the example of Figure 1, the shell welding area 11 is roughly rectangular, and the width L of the shell welding area 11 is greater than the diameter of the through hole 21 of the winding core 2. After the current collecting sheet 1 and the winding core 2 are assembled, the two ends of the shell welding area 11 extend outward beyond the through hole 21 of the winding core 2.

[0034] In the example of FIG. 1 , the shell welding area 11 is generally rectangular, but is not limited thereto.

[0035] In the example of FIG1 , at least one welding track 122 is formed on the wing portion 12. The welding track 122 is configured to conduct electricity from the inner ring to the outer ring of the winding core 2. The welding track 122 can have a straight or spiral appearance, etc., without limitation.

[0036] In the example of FIG1 , wings 12 extend from opposite ends of the shell welding area 11 , and the wings 12 at both ends can be welded to the full tabs on both sides of the through hole 21 of the winding core 2 . It is understood that the present application is not limited to this.

[0037] Specifically, in this example, the two wings 12 of the current collecting piece 1 located at both ends of the shell welding area 11 are bent toward the same side of the shell welding area 11. Of course, when wings 12 extend from both ends of the shell welding area 11, this is not limited to this. For example, FIG4 shows a current collecting piece 1 in which the two wings 12 located at both ends of the shell welding area 11 are bent toward different sides of the shell welding area 11.

[0038] Specifically, the wings 12 at opposite ends of the shell welding area 11 are symmetrically arranged, or may be asymmetrically arranged.

[0039] In the example of FIG1 , the wings 12 extend in a strip shape, meaning they extend a considerable distance relative to their overall width. Specifically, the wings 12 can be relatively regular strips with a uniform width, though this is not a limitation. More specifically, the width of the wings 12 is less than the radius of the winding core 2 .

[0040] In the example of Figure 1 , the current collecting sheet 1 is generally strip-shaped with a bend. Specifically, in this example, the current collecting sheet 1 has two bends, which define wing portions 12 at either end and a housing weld zone 11 located between the two wings 12. The bends form an angle a. Of course, while the current collecting sheet 1 is generally strip-shaped with a bend, it may also include only one bend, i.e., have a wing portion 12 that forms an angle a with the housing weld zone 11.

[0041] Specifically, in this example, the entire current collecting sheet 1 may have a uniform width, that is, the widths of the shell welding area 11 and the wing portion 12 are substantially the same. More specifically, the entire width of the current collecting sheet 1 is smaller than the radius of the winding core 2 .

[0042] FIG5 shows a different example of a current collecting piece 1. The main difference between the current collecting piece 1 in this example and the current collecting piece 1 shown in FIG1 is that only one end of the shell welding area 11 extends out of the wing portion 12.

[0043] Figure 6 shows a different example of a current collecting plate 1. The main difference between this example and the current collecting plate 1 shown in Figure 5 is the shape of the wings 12. In this example, the ends of the wings 12 have an arc-shaped structure. Of course, the wings 12 can also have other shapes, such as the example shown in Figure 7.

[0044] Figure 8 shows a different example of a current collecting piece 1. The main difference between this example and the current collecting piece 1 shown in Figure 5 is the shape of the shell welding area 11. In this example, the end of the shell welding area 11 away from the wing portion 12 has an arc structure. Of course, the shell welding area 11 can also have other shapes.

[0045] FIG9 shows a different example of the current collecting piece 1. The main difference between the current collecting piece 1 in this example and the current collecting piece 1 shown in FIG5 is that the shape of the shell welding area 11 is different. In this example, the shell welding area 11 is roughly circular. Of course, the shell welding area 11 can also be other shapes. In this example, the first side 121 is a straight line, the third side 112 is an arc, and the angle a is the angle a formed between the tangents of the first side 121 and the third side 112 at the connection point. In the example given in FIG10, the shell welding area 11 is also roughly circular, the first side 121 is a straight line, the third side 112 is an arc, and the angle a is the angle a formed between the tangents of the first side 121 and the third side 112 at the connection point.

[0046] Figure 11 shows a different example of a current collecting plate 1. The main difference between this example and the current collecting plate 1 shown in Figure 5 is that the shell welding area 11 of the current collecting plate 1 in Figure 5 is rectangular, and the second side 111 of the extended wing portion 12 is a side of the rectangle. In Figure 11, the shell welding area 11 of the current collecting plate 1 is a rectangle with one corner cut off, and the second side 111 of the extended wing portion 12 is the side formed by the cut corner of the shell welding area 11.

[0047] Fig. 12 shows a different example of the current collecting piece 1. The main difference between the current collecting piece 1 in this example and the current collecting piece 1 shown in Fig. 11 is that the shape of the wing 12 is different. In this example, the end of the wing 12 has an arc structure.

[0048] FIG13 shows a different example of a current collecting piece 1. The main difference between the current collecting piece 1 in this example and the current collecting piece 1 shown in FIG11 is that the end of the shell welding area 11 away from the wing portion 12 has an arc structure.

[0049] 14 shows a different example of a current collecting piece 1. In this example, the shell welding area 11 of the current collecting piece 1 is roughly trapezoidal, the second side 111 of the extended wing portion 12 is the narrower bottom of the trapezoid, and the third side 112 is the height of the trapezoid.

[0050] The third side 112 in each of the above examples is substantially in a straight line or an arc shape, but is not limited thereto.

[0051] Figure 15 shows a different example of a current collector 1. In this example, the housing welding area 11 includes a second side 111, from which the wing 12 extends. One end of the second side 111 extends beyond the starting position of the wing 12 (i.e., where it meets the second side 111) and forms an acute angle a with the first side 121 of the wing 12. In this example, the second side 111 is a straight line, but this is not limiting and can also be other shapes, such as an arc.

[0052] Optionally, the angle a is between 30° and 70°.

[0053] It should be noted that, in this application, the shapes of the housing weld area 11 and the wing portion 12 are not limited to those in the above examples. The housing weld area 11 and the wing portion 12 can be designed into various shapes as needed. In the above examples, the first side 121 is substantially linear. Of course, the first side 121 is not limited to this and can also be curved or have other regular or irregular shapes, as long as the connection between the first side 121 and the housing weld area 11 forms an angle that allows elastic deformation between the housing weld area 11 and the wing portion 12.

[0054] Please refer to Figures 1 to 3. The present application also discloses a cylindrical battery, including a core 2, a shell 3 and the current collecting sheet 1 as described above. The core 2 is placed in the shell 3, and the current collecting sheet 1 is arranged between the core 2 and the bottom wall 30 of the shell 3. The shell welding area 11 is arranged corresponding to the through hole 21 of the core 2 and welded to the bottom wall 30 of the shell 3. The wing 12 is welded to the full tab of the core 2. When the wing 12 vibrates with the core 2, elastic deformation occurs between the wing 12 and the shell welding area 11 to release stress.

[0055] In the present application, the current collecting sheet 1 is a simple sheet structure. On the basis of ensuring low material consumption and low cost, the angle a between the shell welding area 11 and the wing 12 is set so that the shell welding area 11 and the wing 12 can be elastically deformed. Then, when the cylindrical battery after assembly is completed causes the winding core 2 to jump due to loading vibration, etc. and drives the wing 12 to jump together, elastic deformation can occur between the shell welding area 11 and the wing 12 to release the impact stress, thereby avoiding the risk of open circuit at the welding position of the shell welding area 11 and the bottom wall 30 of the shell 3, thereby improving the seismic performance of the cylindrical battery.

[0056] Specifically, the full tab welding of the wing portion 12 and the winding core 2 is performed by laser welding.

[0057] Specifically, the shell welding area 11 is welded to the bottom wall 30 of the shell 3 by resistance welding. Of course, it is not limited to this, for example, laser welding or penetration welding can also be used.

[0058] Specifically, the shell welding area 11 at least partially extends outwardly beyond the through hole 21 of the winding core 2 to facilitate welding.

[0059] In the example shown in Figure 1, the shell welding area 11 is roughly rectangular, and the width L of the shell welding area 11 is greater than the diameter of the through hole 21 of the winding core 2. After the current collecting sheet 1 and the winding core 2 are assembled, the two ends of the shell welding area 11 extend outward beyond the through hole 21 of the winding core 2.

[0060] In conjunction with FIG. 1 to FIG. 3 and FIG. 16 , the present application further discloses a method for assembling the aforementioned cylindrical battery, comprising:

[0061] S1, welding the wing portion 12 of the current collecting sheet 1 to the full tab of the winding core 2, so that the shell welding area 11 of the current collecting sheet 1 corresponds to the through hole 21 of the winding core 2;

[0062] S2. Place the winding core 2 into the housing 3 so that the current collecting sheet 1 faces the bottom wall 30 of the housing 3;

[0063] S3 . Utilize the through hole 21 of the winding core 2 to weld the shell welding area 11 of the current collecting sheet 1 to the bottom wall 30 of the shell 3 .

[0064] After the wing 12 is welded to the full tab of the winding core 2, when the shell welding area 11 is welded to the bottom wall 30 of the shell 3, elastic deformation can occur between the wing 12 and the shell welding area 11 to release the stress generated thereby, thereby avoiding direct pulling of the welding position between the wing 12 and the full tab.

[0065] Specifically, before step S1 , the assembly method may further include a pre-processing step in which all tabs of the winding core 2 are flattened.

[0066] The above disclosure is only a preferred example of the present application, and its purpose is to facilitate the understanding and implementation of those skilled in the art. It certainly cannot be used to limit the scope of rights of the present application. Therefore, equivalent changes made according to the scope of the patent application of the present application still fall within the scope covered by the present application.

Claims

1. A current collecting sheet, characterized in that: It includes a shell welding area and a wing extending from at least one end of the shell welding area, wherein the wing is used for welding to the full pole ear of the winding core, and the wing has a first side edge, and the first side edge forms an angle with the connection of the shell welding area. The formation of the angle allows elastic deformation between the wing and the shell welding area.

2. The current collecting sheet according to claim 1, characterized in that: The shell welding area includes a second side and a third side adjacent to each other, the wing extends from the second side, the first side of the wing is connected to the third side, and the connection between the first side and the third side forms the angle, which is an obtuse angle.

3. The current collecting sheet according to claim 1, characterized in that: The angle is between 110° and 160°.

4. The current collecting sheet according to claim 1, characterized in that: The shell welding area includes a second side edge, the wing portion extends from the second side edge, one end of the second side edge exceeds the starting position of the wing portion and forms the angle at the connection with the first side edge of the wing portion, and the angle is an acute angle.

5. The current collecting sheet according to claim 4, characterized in that: The angle is between 30° and 70°.

6. The current collecting sheet according to claim 1, characterized in that: At least one welding track is formed on the wing portion, and the welding track is configured to conduct all the tabs of each layer from the inner circle to the outer circle of the winding core.

7. The current collecting sheet according to claim 1, characterized in that: The wings extend from opposite ends of the shell welding area.

8. The current collecting sheet according to any one of claims 1 to 7, characterized in that: The wing portion extends out in a strip shape, and / or the current collecting piece is in a bent strip shape as a whole.

9. A cylindrical battery, characterized in that: It includes a winding core, a shell and a current collecting sheet as described in any one of claims 1 to 8, the winding core is placed in the shell, the current collecting sheet is arranged between the winding core and the bottom wall of the shell, the shell welding area is arranged corresponding to the through hole of the winding core and welded to the bottom wall of the shell, the wing is welded to the full pole ear of the winding core, and when the wing vibrates with the winding core, elastic deformation is generated between the wing and the shell welding area to release stress.

10. A method for assembling a cylindrical battery as claimed in claim 9, characterized in that: include: Welding the wing of the current collector to the full tab of the winding core so that the shell welding area of ​​the current collector corresponds to the through hole of the winding core; Put the winding core into the shell so that the current collecting sheet faces the bottom wall of the shell; The shell welding area of ​​the current collecting sheet is welded to the bottom wall of the shell by utilizing the through hole of the winding core.

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