Collector plate for cylindrical power battery and cylindrical power battery

Abstract

The utility model discloses a current collector plate for a cylindrical power battery and the cylindrical power battery, the current collector plate comprises a main body part, an extension part and a bending part, the extension part faces the main body part and is integrally connected to the edge of the main body part through the bending part, the current collector plate comprises a first metal layer and a second metal layer, the second metal layer is a nickel layer, and the first metal layer is a metal layer. The resistivity of the first metal layer is lower than that of the nickel layer, and the nickel layer is arranged on the side, back on to the main body part, of the extension part and is configured to face the roll core through hole so that a welding pin can make contact. When the collector plate and the shell bottom are welded, the welding needle penetrates through the roll core through hole and then directly makes contact with the nickel layer of the extending part, and then the needle sticking problem caused by contact between the first metal layer and the welding needle can be avoided.

Description

Technical Field

[0001] The present application relates to the technical field of power batteries, and in particular to a current collecting plate for a cylindrical power battery and a power battery. Background Art

[0002] At present, cylindrical power batteries such as lithium-ion / sodium-ion batteries have gradually become mainstream products in the new energy vehicle and energy storage industries due to their high energy density, good capacity consistency, and support for high-rate charging and discharging. More and more manufacturers continue to pursue the optimization of the compactness of cylindrical power battery structures to improve energy density.

[0003] However, the current collector of cylindrical power batteries currently has the following problems:

[0004] When resistance welding is performed on the collector plate, if a pure nickel collector plate is used, the price is relatively expensive and the resistance is relatively high (resulting in a large temperature rise during current flow, bringing safety risks). If an aluminum-nickel composite strip or a copper-nickel composite strip collector plate is used, the problem of needle sticking cannot be avoided when the aluminum or copper surface is facing up and in contact with the welding needle. Utility Model Content

[0005] The purpose of the present application is to provide a current collecting plate for a cylindrical power battery and a cylindrical power battery, which can solve the problem of needle sticking when the current collecting plate is subjected to resistance welding.

[0006] In order to achieve the above-mentioned objectives, the present application provides a current collecting plate for a cylindrical power battery, comprising a main body, an extension portion and a bending portion, wherein the extension portion faces the main body and is integrally connected to the edge of the main body through the bending portion, the current collecting plate comprises a first metal layer and a second metal layer, the second metal layer is a nickel layer, the resistivity of the first metal layer is lower than the resistivity of the nickel layer, the side of the extension portion facing away from the main body is the nickel layer and is configured to face the core through-hole for contact by a welding pin.

[0007] Optionally, the extension portion is at least partially in contact with the main body in an area corresponding to the welding pin.

[0008] Optionally, the extension portion is in contact with the main body at least in an area corresponding to the welding pin.

[0009] Optionally, the main body is formed with a full-tab welding area and a shell bottom welding area sunken relative to the full-tab welding area, the bent portion is connected to one side of the shell bottom welding area, and the extension portion is located in a space formed by the sinking of the shell bottom welding area.

[0010] Optionally, the upper surface of the extension portion is flush with or lower than the upper surface of the full-tab welding area.

[0011] Optionally, opposite sides of the shell bottom welding area are respectively connected to the full-tab welding area.

[0012] Optionally, a spacing groove is formed between the shell bottom welding area and the full-tab welding area. By setting the spacing groove, an elastically deformable position is formed between the shell bottom welding area and the full-tab welding area to release the stress transmitted from the shell bottom welding area and the full-tab welding area through elastic deformation.

[0013] Optionally, the spacing groove is roughly L-shaped, including a first branch groove that partially separates the shell bottom welding area and the full-pole lug welding area and penetrates outward, and a second branch groove that divides the full-pole lug welding area into a connecting arm and an extension portion, one end of the connecting arm is connected to the shell bottom welding area, and the other end of the connecting arm is connected to an end of the extension portion away from the shell bottom welding area. Due to the separation of the first branch groove, the other end of the extension portion is a free end, and the full-pole lug welding area is welded to the full-pole lug of the winding core through the extension portion.

[0014] Optionally, the first metal layer is a copper layer or an aluminum layer.

[0015] In order to achieve the above-mentioned objectives, the present application also provides a cylindrical power battery, comprising a winding core, a shell and a current collecting plate as described above, wherein the winding core is sleeved in the shell, and the current collecting plate is welded between the full pole ear of the winding core and the shell bottom of the shell, wherein the extension portion faces the winding core through hole for contact by the welding needle, and the main body is welded to the full pole ear of the winding core through the first metal layer.

[0016] In the present application, the current collecting disk includes a nickel layer and a first metal layer with a resistivity lower than that of the nickel layer, which can avoid the problem of the high price and high resistance of the pure nickel current collecting disk. Moreover, the present application forms an extension portion of the main body facing the current collecting disk by bending, and the side of the extension portion facing away from the main body is a nickel layer. When the first metal layer is welded to the full-pole ear of the winding core, the nickel layer of the extension portion faces the through hole of the winding core to facilitate contact with the welding needle. When the current collecting disk and the shell bottom are welded, the welding needle will directly contact the nickel layer of the extension portion after passing through the through hole of the winding core, thereby avoiding the problem of needle sticking caused by the contact between the first metal layer and the welding needle. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the three-dimensional structure of the collecting plate of the embodiment of the present application.

[0018] Figure 2 It is a schematic diagram of the cross-sectional structure of the cylindrical power battery of the embodiment of the present application. DETAILED DESCRIPTION

[0019] In order to explain the technical content, structural features, and achieved effects of the present application in detail, the following is a detailed description in conjunction with the implementation methods and the accompanying drawings.

[0020] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0021] See also Figure 1 and Figure 2 The embodiment of the present application discloses a current collecting plate 1 for a cylindrical power battery. The cylindrical power battery includes a winding core 7 and a shell 8 sleeved with the winding core 7, and the current collecting plate 1 is welded between the full pole ear of the winding core 7 and the shell bottom 81 of the shell 8.

[0022] The collector plate 1 includes a main body 10, an extension 20 and a bend 30, wherein the extension 20 faces the main body 10 and is integrally connected to the edge of the main body 10 through the bend 30, and the collector plate 1 includes a first metal layer 40 and a second metal layer 50, wherein the second metal layer 50 is a nickel layer 50, and the resistivity of the first metal layer 40 is lower than that of the nickel layer 50, and the side of the extension 20 facing away from the main body 10 is the nickel layer 50 and is configured to face the winding core through hole 71 for contact with the welding pin. The main body 10 is welded to the full-pole ear of the winding core 7 through the first metal layer 40. The main body 10 can be welded to the shell bottom 81 through the nickel layer 50.

[0023] In the present application, the current collecting disk 1 includes a nickel layer 50 and a first metal layer 40 with a resistivity lower than that of the nickel layer 50, which can avoid the problem of using a pure nickel current collecting disk 1 that is expensive and has a high resistance. Moreover, the present application forms an extension portion 20 facing the main body 10 of the current collecting disk 1 by bending, and the side of the extension portion 20 facing away from the main body 10 is the nickel layer 50. When the first metal layer 40 is welded to the full-pole ear of the winding core 7, the nickel layer 50 of the extension portion 20 faces the winding core through hole 71 to facilitate contact with the welding needle. When the current collecting disk 1 and the shell bottom 81 are welded, the welding needle will directly contact the nickel layer 50 of the extension portion 20 after passing through the winding core through hole 71, thereby avoiding the problem of needle sticking caused by the contact between the first metal layer 40 and the welding needle.

[0024] Specifically, the first metal layer 40 is a copper layer or an aluminum layer.

[0025] In the example shown in the drawings, the number of the extension portion 20 and the bending portion 30 is only one, but the present invention is not limited thereto. For example, two adjacent extension portions 20 may be formed on the same side of the main body 10, and each extension portion 20 at least partially corresponds to the winding core through hole 71; or extension portions 20 may be bent and extended from opposite sides of the main body 10 and attached to the main body 10, and each extension portion 20 at least partially corresponds to the winding core through hole 71.

[0026] It can be understood that in order to perform resistance welding on the collecting plate 1 and the shell bottom 81, in some embodiments, the extension portion 20 is at least partially in contact with the main body 10 in the area corresponding to the welding pin, so that when resistance welding is performed, the extension portion 20, the main body 10 and the shell bottom 81 can be welded together.

[0027] Specifically, the extension portion 20 is in contact with the main body 10 at least in the area corresponding to the welding pin. Since the extension portion 20 is in contact with the main body 10 at least in the area corresponding to the welding pin, stable welding is achieved during resistance welding.

[0028] Furthermore, the extension portion 20 is integrally attached to the main body 10 .

[0029] It is understandable that, in order to perform resistance welding on the current collecting plate 1 and the shell bottom 81, the extension portion 20 does not necessarily need to be directly attached to the main body 10. For example, in other embodiments, the extension portion 20 may be defined as a first extension portion, which includes a second extension portion in addition to the first extension portion, and the second extension portion is connected to different edges of the main body portion through a second bending portion, the second extension portion is attached to the main body portion, and the first extension portion is attached to the second extension portion, and when welding with a welding needle, the welding needle contacts the first extension portion, and the first extension portion, the second extension portion, the main body portion and the shell bottom are welded.

[0030] In some embodiments, the bending portion 30 is U-shaped, but is not limited thereto. In addition, the U-shape here should not be understood in a narrow sense, such as the two arms of the U-shaped structure must be parallel. Various U-shaped structures should all belong to the U-shape referred to in this application. For example, the accompanying drawings provide an example of the bending portion 30 not being U-shaped in a narrow sense.

[0031] In some embodiments, the main body 10 is formed with a full-tab welding area 11 and a shell bottom welding area 12 that is sunken relative to the full-tab welding area 11, the bent portion 30 is connected to one side of the shell bottom welding area 12, and the extension portion 20 is located in the space formed by the sinking of the shell bottom welding area 12. In a specific example, the extension portion 20 is directly attached to the shell bottom welding area 12.

[0032] Specifically, the upper surface of the extension portion 20 is flush with or lower than the upper surface of the full-tab welding area 11. Since the upper surface of the extension portion 20 is flush with or lower than the upper surface of the full-tab welding area 11, reliable welding of the full-tab welding area 11 and the full-tab of the winding core 7 can be ensured.

[0033] Specifically, the opposite sides of the shell bottom welding area 12 are respectively connected with full-pole lug welding areas 11. It can be understood that the full-pole lug welding areas 11 of the collector plate 1 are not limited to being formed on both sides of the shell bottom welding area 12, and the number of full-pole lug welding areas 11 is not limited. The present application does not limit the specific form of the collector plate 1, as long as the above-mentioned extension portion 20 that can be contacted by the welding needle is formed by bending to perform resistance welding on the collector plate 1 and the shell bottom 81, it is within the protection scope of the present application.

[0034] Specifically, a spacing groove 13 is formed between the shell bottom welding area 12 and the full-pole lug welding area 11. By setting the spacing groove 13, an elastically deformable position is formed between the shell bottom welding area 12 and the full-pole lug welding area 11 to release the stress transmitted from the shell bottom welding area 12 and the full-pole lug welding area 11 through elastic deformation. It should be noted that the collector plate 1 is at least divided into the shell bottom welding area 12 and the full-pole lug welding area 11, but not all areas of the shell bottom welding area 12 and the full-pole lug welding area 11 are used for welding. An elastically deformable position is formed between the shell bottom welding area 12 and the full-pole lug welding area 11, which means that an elastically deformable position is formed between the actual welding area of ​​the shell bottom welding area 12 and the actual welding area of ​​the full-pole lug welding area 11, and the elastically deformable position can be located at the full-pole lug welding area 11, the shell bottom welding area 12 and / or the position where the two are connected.

[0035] Through this arrangement, after the full-pole lug welding area 11 is welded to the full-pole lug of the winding core 7, when the shell bottom welding area 12 is welded to the shell bottom 81, the elastically deformable position can be elastically deformed to release possible stress and avoid direct pulling of the welding position between the full-pole lug welding area 11 and the full-pole lug. In addition, when the assembled cylindrical power battery causes the winding core 7 to jump due to loading vibration and drives the full-pole lug welding area 11 to jump together, the elastically deformable position will also be elastically deformed to release impact stress and avoid the risk of open circuit at the welding position between the shell bottom welding area 12 and the shell bottom 81, thereby improving the seismic performance of the cylindrical power battery.

[0036] Specifically, the spacing groove 13 is roughly L-shaped, including a first branch groove 131 that partially separates the shell bottom welding area 12 and the full-pole ear welding area 11 and penetrates outward, and a second branch groove 132 that divides the full-pole ear welding area 11 into a connecting arm 111 and an extension portion 112. One end of the connecting arm 111 is connected to the shell bottom welding area 12, and the other end of the connecting arm 111 is connected to an end of the extension portion 112 away from the shell bottom welding area 12. Due to the separation of the first branch groove 131, the other end of the extension portion 112 is a free end, and the full-pole ear welding area 11 is welded to the full-pole ear of the winding core 7 through the extension portion 112.

[0037] In a specific example, two opposite sides of the shell bottom welding area 12 are symmetrically connected to two full-tab welding areas 11 , and accordingly, the number of the spacing grooves 13 is two.

[0038] Please combine Figure 1 and Figure 2 The present application also discloses a cylindrical power battery, comprising a winding core 7, a shell 8 and a current collecting plate 1 as described above, wherein the winding core 7 is sleeved in the shell 8, and the current collecting plate 1 is welded between the full pole ear of the winding core 7 and the shell bottom 81 of the shell 8, wherein the extension 20 faces the winding core through hole 71 for contact with the welding needle. The main body 10 is welded to the full pole ear of the winding core 7 through the first metal layer 40, and can be welded to the shell bottom 81 through the nickel layer 50.

[0039] In the present application, the current collecting disk 1 includes a nickel layer 50 and a first metal layer 40 with a resistivity lower than that of the nickel layer 50, which can avoid the problem of using a pure nickel current collecting disk 1 that is expensive and has a high resistance. Moreover, the present application forms an extension portion 20 facing the main body 10 of the current collecting disk 1 by bending, and the side of the extension portion 20 facing away from the main body 10 is the nickel layer 50. When the first metal layer 40 is welded to the full-pole ear of the winding core 7, the nickel layer 50 of the extension portion 20 faces the winding core through hole 71 to facilitate contact with the welding needle. When the current collecting disk 1 and the shell bottom 81 are welded, the welding needle will directly contact the nickel layer 50 of the extension portion 20 after passing through the winding core through hole 71, thereby avoiding the problem of needle sticking caused by the contact between the first metal layer 40 and the welding needle.

[0040] The following describes an optional assembly process of the exemplary cylindrical power battery of the present application to facilitate understanding of the present application and should not be regarded as a limitation of the present application.

[0041] First, the full-tab welding area 11 (first metal layer 40) of the current collecting plate 1 is attached and welded to the full-tab of the winding core 7, and the nickel layer 50 of the extension portion 20 faces the winding core through hole 71;

[0042] Place the winding core 7 into the housing 8, with the collecting plate 1 located on the housing bottom 81;

[0043] A welding needle is used to pass through the winding core through hole 71 to contact the nickel layer 50 of the extension part 20 , and resistance welding is performed on the extension part 20 , the shell bottom welding area 12 and the shell bottom 81 .

[0044] The above disclosure is only a preferred example of the present application, and its role is to facilitate the technical personnel in this field to understand and implement it. Of course, it 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 collector for a cylindrical power battery, It is characterized in that It includes a main body, an extension part and a bending part, the extension part faces the main body and is integrally connected to the edge of the main body through the bending part, the collecting plate includes a first metal layer and a second metal layer, the second metal layer is a nickel layer, the resistivity of the first metal layer is lower than the resistivity of the nickel layer, the side of the extension part facing away from the main body is the nickel layer and is configured to face the core through hole for contact by the welding pin.

2. The collecting plate according to claim 1, It is characterized in that The extension portion is at least partially attached to the main body in an area corresponding to the welding pin.

3. The collecting plate according to claim 2, It is characterized in that The extension portion is in contact with the main body at least in a region corresponding to the welding pin.

4. The collecting plate according to any one of claims 1 to 3, It is characterized in that The main body is formed with a full-tab welding area and a shell bottom welding area sunken relative to the full-tab welding area, the bent portion is connected to one side of the shell bottom welding area, and the extension portion is located in a space formed by the sinking of the shell bottom welding area.

5. The collecting plate according to claim 4, It is characterized in that The upper surface of the extension portion is flush with or lower than the upper surface of the full-tab welding area.

6. The collecting plate according to claim 4, It is characterized in that The opposite sides of the shell bottom welding area are respectively connected to the full-tab welding area.

7. The collecting plate according to claim 4, It is characterized in that A spacing groove is formed between the shell bottom welding area and the full tab welding area. By setting the spacing groove, an elastically deformable position is formed between the shell bottom welding area and the full tab welding area to release the stress transmitted from the shell bottom welding area and the full tab welding area through elastic deformation.

8. The collecting plate according to claim 7, It is characterized in that The spacing groove is roughly L-shaped, including a first branch groove that partially separates the shell bottom welding area and the full-pole lug welding area and penetrates outward, and a second branch groove that divides the full-pole lug welding area into a connecting arm and an extension portion, one end of the connecting arm is connected to the shell bottom welding area, and the other end of the connecting arm is connected to an end of the extension portion away from the shell bottom welding area. Due to the separation of the first branch groove, the other end of the extension portion is a free end, and the full-pole lug welding area is welded to the full-pole lug of the winding core through the extension portion.

9. The collecting plate according to claim 1, It is characterized in that The first metal layer is a copper layer or an aluminum layer.

10. A cylindrical power battery, It is characterized in that It comprises a winding core, a shell and a current collecting disk as described in any one of claims 1 to 9, wherein the winding core is sleeved in the shell, and the current collecting disk is welded between the full pole ear of the winding core and the shell bottom of the shell, wherein the extension portion faces the through hole of the winding core for contact by the welding needle, and the main body is welded to the full pole ear of the winding core through the first metal layer.

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