Current collector, cylindrical battery and battery pack

Abstract

The utility model belongs to the technical field of battery assemblies, and particularly discloses a current collector, a cylindrical battery and a battery pack. The current collector comprises a current collector body; the longest size of the current collector body is the length of the current collector body, and the linear direction of the longest size is a first direction; the direction perpendicular to the first direction is a second direction; the maximum size of the current collector body in the second direction is the width of the current collector body, and the length-width ratio of the current collector body is 2-12. The width of the current collector body is far smaller than the radius of the roll core, so that the area of the current collector body covering the roll core is reduced; compared with the prior art, the area, which is not covered by the current collector, of the end face of the roll core is increased, so that the seepage effect is improved, the seepage time is shortened, and when thermal runaway occurs to the battery cell, the area, which is not covered by the end face of the roll core, is increased, so that internal gas flows more smoothly, bursting is not easy to occur, and the use is safer; and meanwhile, the current collector needs fewer materials, so that the material cost is saved.

Description

Technical Field

[0001] The utility model relates to the technical field of battery components, in particular to a current collector, a cylindrical battery and a battery pack. Background Art

[0002] At present, the current collectors of existing cylindrical batteries are mostly approximately circular, and their area is too large. The area of the internal core end surface covered by the current collector is too large, which affects the leakage of the electrolyte and the smoothness of the gas flow when the battery suffers thermal runaway. It is easy for the gas to accumulate and then explode instantly, causing the shell to burst. Utility Model Content

[0003] The purpose of the present utility model is to provide a current collector, a cylindrical battery and a battery pack to solve the technical problem in the prior art that the area of the core end surface covered by the current collector is too large, which affects the leakage of the electrolyte and the smoothness of the gas flow when the battery suffers thermal runaway.

[0004] In order to achieve the above-mentioned objectives, the first aspect of the present invention provides a current collector for welding to the core of a cylindrical battery, comprising: a current collector body; the longest dimension of the current collector body is the length of the current collector body, and the straight line direction of the longest dimension is a first direction; the direction perpendicular to the first direction is a second direction; the maximum dimension of the current collector body in the second direction is the width of the current collector body, and the aspect ratio of the current collector body is 2 to 12.

[0005] Preferably, it further comprises: a current collector tab; the current collector tab is connected to the current collector body.

[0006] Preferably, the shape of the current collector body is rectangular or trapezoidal.

[0007] Preferably, the current collector body is provided with a through hole corresponding to the center of the winding core.

[0008] Preferably, the current collector body is provided with a protrusion for welding with the winding core of the cylindrical battery.

[0009] The second aspect of the present invention provides a cylindrical battery, which includes a winding core and a current collector as described above; the winding core is welded to the current collector body, and the current collector body is fitted and covered on the winding core, and the first direction of the current collector body passes through the central axis of the winding core.

[0010] Preferably, the length H of the weld mark between the winding core and the current collector body is ≥0.6R, where R is the radius of the winding core.

[0011] Preferably, a central hole is provided at the center of the winding core, and the current collector is provided with a through hole corresponding to the central hole of the winding core.

[0012] A third aspect of the present invention provides a battery pack, which includes a box and the cylindrical battery as described above, wherein the cylindrical battery is arranged in the box.

[0013] The current collector, cylindrical battery and battery pack provided by the present invention have the following beneficial effects: the current collector body is not circular, and the aspect ratio of the current collector body is 2 to 12, so the width of the current collector body is much smaller than the radius of the core, thereby reducing the area of the core covered by the current collector body; compared with the prior art, the area of the core end surface not covered by the current collector is increased to improve the seepage effect and shorten the seepage time, and when the battery cell suffers thermal runaway, the increased area of the core end surface not covered can make the internal gas flow smoother, less likely to burst, and safer to use; at the same time, when producing cylindrical batteries of the same size, less material is required for the current collector, saving material costs.

[0014] Additional aspects and advantages of the present invention will be given in part in the following description and will become apparent from the following description or learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic structural diagram of a current collector according to an embodiment of the present invention;

[0016] Figure 2 Schematic diagram of the planar structure of the current collector according to an embodiment of the present invention;

[0017] Figure 3 This is a schematic structural diagram of a current collector provided with through holes in an embodiment of the present utility model;

[0018] Figure 4 This is a schematic diagram of the connection structure between the current collector and the winding core, in which the current collector of an embodiment of the present invention is provided with a current collector body, through holes, and current collector tabs.

[0019] In the figure, 100, current collector body; 110, through hole; 120, welding area; 130, current collector tab; 140, protrusion; 200, winding core; 210, center hole. DETAILED DESCRIPTION

[0020] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0021] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0022] In the description of this utility model, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and is not to be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0023] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0024] Please also refer to Figures 1 to 4 The current collector provided by the embodiment of the present invention is now described. The current collector of this embodiment is used for welding with the tab of the winding core 200 of the cylindrical battery.

[0025] Reference Figures 1 to 2 The current collector includes a current collector body 100; the longest dimension of the current collector body 100 is the length of the current collector body 100, and the linear direction of the longest dimension is a first direction; the direction perpendicular to the first direction is a second direction; the maximum dimension of the current collector body 100 in the second direction is the width of the current collector body 100, which is denoted as W. The aspect ratio L / W of the current collector body 100 is 2 to 12. That is, the current collector body 100 is not circular, and the length of the current collector body 100 is denoted as L. The length of L is less than the diameter of the winding core 200, so that the current collector can be placed in the cylindrical battery casing for installation.

[0026] Since the current collector body 100 is not circular and the aspect ratio of the current collector body 100 is 2 to 12, the width of the current collector body 100 is much smaller than the radius of the core 200. Therefore, there is a gap between the edge of the current collector body 100 and the outer edge of the core 200 in the second direction with a total width of at least the radius of the core 200, which can reduce the area of the core 200 covered by the current collector body 100; compared with the prior art, the area of the core 200 covered by the current collector body 100 can be reduced, thereby increasing the area of the end face of the core 200 not covered by the current collector, so as to improve the seepage effect and shorten the seepage time, and when the battery cell has thermal runaway, the area of the end face of the core 200 not covered increases, which can make the internal gas flow smoother, less likely to burst, and more practical and safer; at the same time, when producing cylindrical batteries of the same size, less material is required for the current collector, saving material costs.

[0027] In some embodiments of the present invention, the current collector body 100 has a rectangular or trapezoidal shape to facilitate processing and welding during assembly. Rectangular or trapezoidal current collectors can be easily processed using stamping equipment or mechanisms, saving production costs. However, due to processing errors, the shape of the current collector body 100 may also approximate a rectangle or trapezoid.

[0028] In some embodiments of the present invention, the current collector body 100 is provided with a through hole 110 corresponding to the center of the winding core 200. The through hole 110 corresponds to the center of the winding core 200 so that the electrolyte can pass through the through hole 110 of the current collector body 100 for liquid permeation.

[0029] It should be noted that cylindrical batteries generally have a positive electrode current collector and a negative electrode current collector. In one embodiment, Figures 1 to 4 As shown, the positive electrode current collector may not be provided with the through hole 110 , while the negative electrode current collector may be provided with the through hole 110 .

[0030] In some embodiments of the present invention, specifically, the current collector may further include a current collector tab 130, which is connected to the current collector body 100. The current collector tab 130 is bendable and welded to other components of the battery. Specifically, in this embodiment, the current collector tab 130 is arranged on the negative electrode current collector so that the negative electrode current collector is welded to the cover plate of the cylindrical battery through the tab 130.

[0031] In some embodiments of the present invention, the current collector body 100 is provided with protrusions 140 for welding to the core of a cylindrical battery. When welded to the core, protrusions 140, i.e., weld marks, are located on protrusions 140, which allow the current collector to fit more closely to the core, facilitating welding. Protrusions 140 also act as reinforcing ribs, making the current collector less susceptible to deformation.

[0032] Reference Figure 4 This embodiment also provides a cylindrical battery, which includes a core 200 and the current collector described above. The core 200 is welded to the current collector body 100, and the current collector body 100 is laminated and covered on the core 200. The first direction of the current collector body 100 passes through the central axis of the core 200. The current collector body 100 can pass through the center of the core 200 and extend to the outside of the core 200 in the first direction, so that the current collector body 100 can span and cover the core 200, ensuring that the current collector body 100 and the core 200 have sufficient space for laminating and connecting, ensuring a stable connection. That is, the current collector and the core 200 are welded and installed in the cylindrical battery housing to form a cylindrical battery.

[0033] The current collector body 100 of the cylindrical battery is not circular, and the aspect ratio of the current collector body 100 is 2 to 12. The radius of the current collector body 100 is much smaller than the radius of the core 200, thereby reducing the area of the core 200 covered by the current collector body 100; compared with the prior art, the area of the end face of the core 200 not covered by the current collector is increased to improve the seepage effect and shorten the seepage time. Moreover, when the battery cell suffers from thermal runaway, the increased area of the end face of the core 200 not covered can make the internal gas flow smoother, the gas is less likely to explode, and it is safer to use; at the same time, when producing cylindrical batteries of the same size, less material is required for the current collector, saving material costs.

[0034] In some embodiments of the present invention, the length H of the weld mark between the core 200 and the current collector body 100 is ≥ 0.6R, where R is the radius of the core. The current collector body 100 and the core 200 are welded at the welding area 120, and the weld mark K is located on the welding area 120. A length of weld mark K greater than 0.6R ensures a more stable weld between the core 200 and the current collector body 100 and ensures electrical continuity between the core 200 and the current collector body 100. The direction of weld mark K is preferably parallel to the direction of the current collector body 100 to ensure a better, outside-to-inward welding of the current collector body 100 and the core 200, thereby ensuring the current collecting function of the current collector body 100.

[0035] In some embodiments of the present invention, the core 200 is provided with a central hole 210, and the current collector is provided with a through hole 110 corresponding to the central hole 210 of the core 200. The central hole 210 of the core 200 corresponds to the through hole 110 to allow electrolyte to pass through, thereby improving the liquid seepage efficiency.

[0036] This embodiment also provides a battery pack, which can provide electrical energy for electrical equipment. The battery pack includes a box and the cylindrical batteries as described above, and the cylindrical batteries are arranged in the box.

[0037] The battery pack uses cylindrical batteries as described above. The current collector body 100 of the cylindrical battery is not circular, and the aspect ratio of the current collector body 100 is 2 to 12. The width of the current collector body 100 is much smaller than the radius of the core 200, thereby reducing the area of the core 200 covered by the current collector body 100. Compared with the prior art, the area of the end face of the core 200 not covered by the current collector is increased to improve the seepage effect and shorten the seepage time. Moreover, when the battery cell suffers from thermal runaway, the increased area of the end face of the core 200 not covered can make the internal gas flow smoother, less likely to burst, and safer to use. At the same time, when producing cylindrical batteries of the same size, less material is required for the current collector, saving material costs.

[0038] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and replacements can be made without departing from the technical principles of the present invention. These improvements and replacements should also be regarded as the scope of protection of the present invention.

Claims

1. A current collector for welding to the core of a cylindrical battery, characterized in that: include: Current collector body; The longest dimension of the current collector body is the length of the current collector body, and the linear direction of the longest dimension is the first direction; A direction perpendicular to the first direction is a second direction; a maximum dimension of the current collector body in the second direction is a width of the current collector body, and an aspect ratio of the current collector body is 2 to 12.

2. The current collector according to claim 1, characterized in that Also includes: Current collector tab; The current collector tab is connected to the current collector body.

3. The current collector according to claim 1, characterized in that The shape of the current collector body is rectangular or trapezoidal.

4. The current collector according to claim 1, characterized in that The current collector body is provided with a through hole corresponding to the center of the winding core.

5. The current collector according to claim 1, characterized in that The current collector body is provided with a protrusion for welding with the winding core of the cylindrical battery.

6. A cylindrical battery, characterized in that: It comprises a winding core and the current collector according to any one of claims 1 to 3; the winding core is welded to the current collector body, and the current collector body is fitted and covered on the winding core, and the first direction of the current collector body passes through the central axis of the winding core.

7. The cylindrical battery according to claim 6, characterized in that: The length H of the weld mark between the winding core and the current collector body is ≥0.6R, where R is the radius of the winding core.

8. The cylindrical battery according to claim 6, characterized in that: A central hole is provided at the center of the winding core, and a through hole corresponding to the central hole of the winding core is provided on the current collector.

9. A battery pack, characterized in that: It comprises a box body and a cylindrical battery as claimed in any one of claims 6 to 8, wherein the cylindrical battery is arranged in the box body.

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