Flexible current collector
By designing flexible current collectors and dispersing the deformation of the battery cell using the three-dimensional space elastic deformation current collectors, the problem of insufficient deformation during the charging and discharging of traditional current collectors is solved, and the stability and safety of the battery are improved.
Patent Information
- Application Number
- CN202420414132.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-04
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2034-03-04
AI Technical Summary
The traditional rigid current collector disk cannot match the deformation of the battery cell during the charging and discharging of lithium batteries, resulting in damage to the solder joint, increasing internal resistance and posing safety hazards. The existing arc arm design is not enough to completely solve the problem, especially in the The two-dimensional elasticity is insufficient when the battery size increases.
Design a flexible current collector, including a center current collector head and multiple three-dimensional space elastic deformation current collectors. The current collector protrudes from the side of the current collector head and is connected to the current collector head for use with the all-pole ear Welding, through the coil spring structure and the arch elastic structure, dispersing deformation to three dimensions, reducing the deformation demand within a unit area.
It effectively reduces the deformation demand of flexible current collectors when the battery cell shape changes, improves elastic adaptability, reduces the risk of solder joint damage, and enhances the safety and performance of the battery.
Smart Images
Figure CN222190796U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of secondary batteries (such as lithium batteries), and in particular to a flexible current collector in a secondary battery. Background Art
[0002] Currently, most large cylindrical batteries on the market are designed with collector plates to connect multiple or all pole ears to increase the electron path.
[0003] However, during the charge and discharge process of the battery, the volume of the battery cell will change. Since the traditional collector plate is mostly a rigid structure, the deformation of the traditional collector plate cannot match the deformation of the battery cell during charge and discharge, resulting in excessive stress and damage to the welding point of the collector plate, which in turn causes desoldering. This not only increases the internal resistance of the battery, but also poses certain safety hazards.
[0004] In order to overcome the rigid structure of the collector plate, although there are designs such as arc arms on the market to obtain elasticity to reduce desoldering, if deformation occurs between adjacent welding points, only the metal ductility of the material on the plane can accommodate the deformation of the battery cell, which is not necessarily sufficient. Especially if the battery is further enlarged in size, it may be insufficient to provide elasticity in only two-dimensional directions.
[0005] Therefore, a flexible current collector is provided to overcome one or more of the above-mentioned drawbacks. Utility Model Content
[0006] The utility model aims to provide a flexible current collector which can disperse the deformation required by the morphological change of the battery core into three dimensions to reduce the deformation per unit area.
[0007] To achieve the above purpose, the flexible current collector of the utility model includes a current collector head at a central position and a plurality of current collector hands arranged around the current collector head and capable of three-dimensional elastic deformation. The current collector hands protrude from the side of the current collector head and are connected to the current collector head, and the current collector hands are configured to be welded to the full tab.
[0008] Compared with the prior art, since the flexible current collector of the utility model also includes a plurality of current collector hands which are arranged separately around the current collector head, can be elastically deformed in three-dimensional space and are used for welding with the full pole ear, the flexible current collector of the utility model uses the current collector hands to cater to the deformation required by the morphological change of the battery cell, and disperses the deformation into three dimensions, thereby effectively reducing the deformation required by the flexible current collector and current collector plate of the utility model per unit area.
[0009] Preferably, all the current collecting hands are arranged radially with the current collecting head as the center.
[0010] Preferably, the current collector is a coil spring structure.
[0011] Preferably, the current collecting head branches out laterally from current collecting branch strips which penetrate through the spiral spring structure.
[0012] Preferably, each of the coil spring structures corresponds to a current collecting branch strip, and each of the current collecting branch strips is connected to a corresponding coil spring structure.
[0013] Preferably, the current collecting hand includes a current collecting branch strip branching laterally from the current collecting head and a plurality of arched elastic structures arranged on the current collecting branch strip and arranged spaced apart along the length direction of the current collecting branch strip, all of the arched elastic structures are arched relative to the current collecting branch strip in the same direction, and the arched elastic structure is configured for welding with the full pole ear.
[0014] Preferably, the arched elastic structure is semicircular, and the end of the arched elastic structure is welded to the current collecting and branching strips, or the end of the arched elastic structure and the current collecting and branching strips together form an integrated structure.
[0015] Preferably, the collecting and branching strips are provided with hollow spaces extending along the length direction of the collecting and branching strips, and each of the arched elastic structures spans across the hollow spaces.
[0016] Preferably, the flexible current collector of the present invention further comprises an outer ring structure arranged around the current collecting head, and the ends of all the current collecting branch strips away from the current collecting head are connected to the outer ring structure.
[0017] Preferably, the current collecting head is a disc structure. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 It is a plan view of the flexible current collector according to the first embodiment of the utility model.
[0019] Figure 2 It is a plan view of the flexible current collector according to the second embodiment of the present utility model.
[0020] Figure 3 yes Figure 2 Floor plan behind hidden collector.
[0021] Figure 4 It is a plan view of a flexible current collector according to the third embodiment of the present utility model.
[0022] Figure 5 yes Figure 4 A plan view of the current collector in the flexible current collector as viewed along its length.
[0023] Figure 6 It is a plan view of a flexible current collector according to a fourth embodiment of the present utility model.
[0024] Figure 7 is along Figure 6 Internal view cut along line AA.
[0025] Figure 8 It is a plan view of a flexible current collector according to a fifth embodiment of the present utility model. DETAILED DESCRIPTION
[0026] Embodiments of the present invention will now be described with reference to the accompanying drawings, in which like reference numerals represent like elements.
[0027] See also Figure 1 The flexible current collector 100a of the first embodiment includes a current collector head 10 at a central position and six current collector hands 20 arranged around the current collector head 10 and capable of three-dimensional elastic deformation. The current collector hands 20 protrude from the side of the current collector head 10 and are connected to the current collector head 10. The current collector hands 20 are configured to be welded to the full tab. Specifically, Figure 1 As an example, all the current collectors 20 are arranged radially with the current collector 10 as the center, so that the arrangement of the current collectors 20 on the current collector 10 is as uniform as possible, thereby effectively improving the elastic deformation capacity of the flexible current collector 100a in the three-dimensional space of the first embodiment; in addition, the current collector 10 is a disc structure, so as to facilitate the processing and manufacturing of the current collector 10. More specifically, Figure 1 In the figure, as an example, the current collector 20 is a coil spring structure to effectively improve the three-dimensional deformation ability of the current collector 20. It should be noted that due to the special structure of the coil spring structure 20, the deformation task is dispersed to more units, and there are more choices in the conductivity and ductility of the material. However, when welding, care should be taken not to weld the multiple layers of spirals in the coil spring structure 20 together, which makes the elasticity of the coil spring structure 20 lose its effect. In addition, according to the parameters of the welding equipment and the required current collecting effect, the spacing of each layer of the spiral of the coil spring structure 20 is selected to avoid welding the multiple layers of spirals in the coil spring structure 20 together, thereby weakening the expansion and contraction ability of the current collector 20. In addition, the material of the coil spring structure 20 is selected as soft, conductive and low-cost as possible. Finally, although Figure 1 The current collector 20 shown is six, and it is obvious that the number may be two, three, four, five or seven according to actual needs. Figure 1 Limits shown.
[0028] See also Figure 2 The structures of the flexible current collector 100b of the second embodiment are substantially the same as those of the flexible current collector 100a of the first embodiment, and the differences are as follows:
[0029] In the flexible current collector 100b of the second embodiment, the current collecting head 10 branches out laterally from the current collecting branch strips 11 which penetrate the spiral spring structure 20; Figure 2 and Figure 3 As an example, each coil spring structure 20 corresponds to a current collecting branch strip 11, and each current collecting branch strip 11 is connected to a corresponding coil spring structure 20, such as by welding. This design allows the current conducted from the coil spring structure 20 to be further collected to the current collecting head 10 through the current collecting branch strips 11.
[0030] In the flexible current collector 100 a of the first embodiment, the current collecting head 10 thereof is not provided with the current collecting branch strips 11 .
[0031] Apart from the above differences, the other aspects are the same and will not be elaborated here.
[0032] See also Figure 4 and Figure 5 The structures of the flexible current collector 100c of the third embodiment and the flexible current collector 100a of the first embodiment are basically the same, and the difference between the two lies in the current collector, which is as follows:
[0033] At Figure 4 and Figure 5 In the second embodiment, the current collector 20' in the flexible current collector 100c includes a current collecting branch strip 21' branched laterally from the current collecting head 10 and six arched elastic structures 22' arranged on the current collecting branch strip 21' and spaced apart along the length direction of the current collecting branch strip 21'. All the arched elastic structures 22' arch relative to the current collecting branch strip 21' in the same direction, and the arched elastic structures 22' are configured to be welded with the full pole ear; optionally, in Figure 5 In the embodiment, as an example, the arched elastic structure 22' is semicircular, so that the arched elastic structure 22' is a semi-spring structure, and the end of the arched elastic structure 22' is welded to the current collecting branch strip 21'; this design can solve the problem that the current collecting hand 20 occupies more space in the longitudinal direction of the battery when it is a spiral spring structure, and only one side of the current collecting branch strip 21' has strong ductility. In the flexible current collector 100a of the first embodiment, its current collecting hand 20 is a spiral spring structure.
[0034] Apart from the above differences, the other two are the same, so I will not go into details here.
[0035] See also Figure 6 and Figure 7 The structures of the flexible current collector 100d of the fourth embodiment and the flexible current collector 100c of the third embodiment are basically the same, and the difference between the two lies in the current collecting branch strips, which are as follows:
[0036] In the flexible current collector 100d of the fourth embodiment, a hollow space 211 extending along the length direction of the current collecting branch strip 21' is provided on the current collecting branch strip 21', and each arched elastic structure 22' spans across the hollow space 211. Figure 7 As shown; in addition, the end of the arched elastic structure 22' and the current collecting branch plate 21' together form an integrated structure; such a design allows the current collecting hand 20' of the flexible current collector 100d of the fourth embodiment to be made by stamping and cutting, which solves the problem of welding difficulty and complex structure caused by welding the end of the arched elastic structure 22' and the current collecting branch plate 21' in the flexible current collector 100c of the third embodiment.
[0037] In addition, in the flexible current collector 100d of the third embodiment, the current collecting branch strips 21' thereof are not provided with hollow spaces 211.
[0038] Except for the above-mentioned differences, the structures of the other two are basically the same, so they will not be described here.
[0039] See also Figure 8 The flexible current collector 100e of the fifth embodiment has the same structure as the flexible current collector 100d of the fourth embodiment, and the only difference is that the flexible current collector 100e of the fifth embodiment also includes an outer ring structure 30 arranged around the current collecting head 10, and the ends of all the current collecting branch strips 21' away from the current collecting head 10 are connected to the outer ring structure 30. For example, the outer ring structure 30 also forms an integrated structure with the ends of all the current collecting branch strips 21' away from the current collecting head 10; such a design can be used to produce the flexible current collector 100e of the fifth embodiment by stamping and hollowing, thereby improving the functionality of the accessories without increasing the difficulty of production.
[0040] In the flexible current collector 100 d of the fourth embodiment, the outer ring structure 30 is not provided.
[0041] Except for the above differences, the structures of the other two are the same, so they will not be described here.
[0042] Compared with the prior art, since the flexible current collector 100a (100b, 100c, 100d, 100e) of the utility model also includes a plurality of current collector hands 20 (20') which are arranged in a spaced relationship around the current collector head 10, can be elastically deformed in three-dimensional space and are used for welding with the full pole ear, the flexible current collector 100a (100b, 100c, 100d, 100e) of the utility model uses the current collector hands 20 (20') to cater to the deformation required by the morphological change of the battery cell, and disperses the deformation into three dimensions, thereby effectively reducing the deformation required by the flexible current collector plate 100a (100b, 100c, 100d, 100e) of the utility model per unit area.
[0043] The above disclosure is only a preferred embodiment of the present invention, and certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.
Claims
1. A flexible current collector, comprising a current collector at a central position, characterized in that: The flexible current collector also includes a plurality of current collector arms which are spaced apart and arranged around the current collector head and can elastically deform in three dimensions. The current collector arms protrude from the sides of the current collector head and are connected to the current collector head. The current collector arms are configured to be welded to the full tabs.
2. The flexible current collector according to claim 1, characterized in that: All the current collecting hands are arranged radially with the current collecting head as the center.
3. The flexible current collector according to claim 1 or 2, characterized in that: The current collector is a spiral spring structure.
4. The flexible current collector according to claim 3, characterized in that: The current collecting head branches out laterally from current collecting branch strips which penetrate into the spiral spring structure.
5. The flexible current collector according to claim 4, characterized in that: Each of the coil spring structures corresponds to a current collecting branch strip, and each of the current collecting branch strip is connected to a corresponding coil spring structure.
6. The flexible current collector according to claim 1 or 2, characterized in that: The current collecting hand includes a current collecting branch strip branching laterally from the current collecting head and a plurality of arched elastic structures arranged on the current collecting branch strip and arranged spaced apart along the length direction of the current collecting branch strip, all of the arched elastic structures are arched relative to the current collecting branch strip in the same direction, and the arched elastic structure is configured for welding with the full pole ear.
7. The flexible current collector according to claim 6, characterized in that: The arched elastic structure is semicircular, and the end of the arched elastic structure is welded to the current collecting and branching strips, or the end of the arched elastic structure and the current collecting and branching strips together form an integrated structure.
8. The flexible current collector according to claim 6, characterized in that: The current collecting and branching strips are provided with hollow spaces extending along the length direction of the current collecting and branching strips, and each of the arched elastic structures spans across the hollow spaces.
9. The flexible current collector according to claim 6, characterized in that: It also includes an outer ring structure arranged around the current collecting head, and ends of all the current collecting branch strips away from the current collecting head are connected to the outer ring structure.
10. The flexible current collector according to claim 1, characterized in that: The current collecting head is a disc structure.