A lithium battery current collector structure

Abstract

This invention belongs to the field of battery technology and discloses a lithium battery current collector structure, which includes multiple battery cells, a busbar, and at least one copper bar. The multiple battery cells are arranged side-by-side in sequence. The multiple battery cells are disposed on the back side of the busbar. The copper bar includes a bonding portion connected to the front side of the busbar. The tabs of the battery cells extend from the back side of the busbar to the front side, bond, and bypass the bonding portion before bending and entering the busbar. The tabs are bonded to the bonding portion of the copper bar, enabling series and parallel connection of multiple battery cells. The tabs extending from the busbar, bending, bypassing the bonding portion, and then entering the busbar avoids the requirement for precise tab length, thereby effectively reducing the difficulty of lithium battery design and manufacturing processes.

Description

Technical Field

[0001] This invention belongs to the field of battery technology, and particularly relates to a current collector structure for lithium batteries. Background Technology

[0002] To achieve high energy density and long cycle life in lithium-ion batteries, the internal structure of lithium batteries for new energy vehicles is constructed using a series-parallel connection method in the actual design process. However, if the positive and negative tabs of the battery cell are too long or too short, it will cause process risks. If the tabs are too long, the positive and negative tabs may overlap, eventually leading to poor soldering. If the tabs are too short, it will be difficult to press the welding copper nozzle tightly, making the welding process difficult to implement.

[0003] Existing technologies mainly include two types: bent tabs and non-bent tabs. The former requires ensuring the accuracy of cell cutting and tab length, while the latter requires designing a connector for the tabs to ensure the implementation of series and parallel connections, which increases the design workload and requires analysis of the spatial area of ​​the connector, making the design and manufacturing process more difficult.

[0004] Therefore, there is an urgent need for a lithium battery current collector structure to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to propose a current collector structure for lithium batteries, which solves the technical problem of high design and manufacturing difficulty of lithium batteries due to the high requirements for the dimensional accuracy of the tabs in the prior art.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] A lithium battery current collector structure, comprising:

[0008] Multiple battery cells are arranged side by side in sequence;

[0009] A busbar, with multiple battery cells disposed on the back side of the busbar;

[0010] At least one copper bar includes a bonding portion connected to the front side of the busbar. The electrode of the battery cell extends from the back side of the busbar to the front side, is bonded, and passes around the bonding portion before being bent and inserted into the busbar.

[0011] As a preferred technical solution of the above-mentioned lithium battery current collector structure, the copper bar includes a plurality of bonding portions and at least one connecting portion. The plurality of bonding portions are arranged in sequence at intervals, and each pair of adjacent bonding portions is connected by at least one connecting portion. Each bonding portion is provided with a corresponding tab.

[0012] As a preferred technical solution of the above-mentioned lithium battery current collector structure, the copper bar includes two bonding parts and two connecting parts. The two connecting parts are arranged at intervals. The two ends of each connecting part are respectively connected to the two bonding parts. The two bonding parts and the two connecting parts form a through groove. Each bonding part is provided with a corresponding tab. The two tabs corresponding to the same copper bar pass through the through groove.

[0013] As a preferred technical solution of the above-mentioned lithium battery current collector structure, the two tabs corresponding to the same copper bar are respectively bypassed from the opposite sides of the two bonding parts, and then bent towards the direction of mutual approach before being inserted into the through groove.

[0014] As a preferred technical solution of the above-mentioned lithium battery current collector structure, the busbar is provided with at least one copper bar mounting part, each copper bar mounting part is connected to a copper bar, each copper bar mounting part has an insertion groove and two exit grooves, the two tabs corresponding to the same copper bar respectively pass out from the two exit grooves, and after bending towards each other, they simultaneously pass into the through groove and the insertion groove in sequence.

[0015] As a preferred technical solution of the above-mentioned lithium battery current collector structure, a through groove is provided on the copper mounting part, a rectangular frame is provided in the through groove, the inner groove of the rectangular frame is the insertion groove, a plurality of mutually spaced ribs are connected between the outer wall of the rectangular frame and the inner wall of the through groove, and the two exit grooves are respectively located on opposite sides of the through groove.

[0016] As a preferred technical solution of the above-mentioned lithium battery current collector structure, the two tabs corresponding to the same copper bar simultaneously emerge from the through groove and bypass the two bonding parts respectively, and then enter the busbar from the opposite sides of the two bonding parts respectively.

[0017] As a preferred technical solution of the above-mentioned lithium battery current collector structure, the busbar is provided with at least one copper bar mounting part, each copper bar mounting part is connected to a copper bar, each copper bar mounting part has two insertion slots and two exit slots, the two tabs corresponding to the same copper bar are respectively inserted into the insertion slots through the two exit slots, and after passing through the insertion slots, they are bent in opposite directions and respectively inserted into the two insertion slots.

[0018] As a preferred technical solution of the above-mentioned lithium battery current collector structure, each of the copper bar mounting parts is provided with a positioning protrusion, the positioning protrusion is disposed between the two through slots, the positioning protrusion passes through the through slot, and its two ends respectively abut against the two opposite inner walls of the through slot.

[0019] The bonding part is provided with a hot riveting hole, and the busbar is provided with a hot riveting post, which is hot riveted into the hot riveting hole.

[0020] The beneficial effects of this invention are:

[0021] This invention provides a current collector structure for a lithium battery. The copper bus includes a bonding portion connected to the front side of the busbar. The tabs of the battery cells extend from the back side of the busbar to the front side, are bonded, and after passing around the bonding portion, are bent and inserted into the busbar. The tabs' bonding with the bonding portion of the copper busbar enables series and parallel connections of multiple battery cells. The tabs' extension through the busbar, bending around the bonding portion, and then inserting into the busbar eliminates the need for precise tab length requirements, thereby effectively reducing the design and manufacturing complexity of lithium batteries. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0023] Figure 1 This is a partial structural schematic diagram of the lithium battery current collector structure provided in Embodiment 1 of the present invention;

[0024] Figure 2 This is a schematic diagram of the structure of the electrode tab of the battery cell provided in Embodiment 1 of the present invention;

[0025] Figure 3 This is a schematic diagram of the copper bar provided in Embodiment 1 of the present invention;

[0026] Figure 4 This is a schematic diagram of the bus structure provided in Embodiment 1 of the present invention;

[0027] Figure 5 This is a top view of the bus provided in Embodiment 1 of the present invention;

[0028] Figure 6 This is a partial structural schematic diagram of the lithium battery current collector structure provided in Embodiment 2 of the present invention;

[0029] Figure 7 This is a schematic diagram of the structure of the electrode tab of the battery cell provided in Embodiment 2 of the present invention;

[0030] Figure 8 This is a schematic diagram of the bus structure provided in Embodiment 2 of the present invention;

[0031] Figure 9 This is a top view of the bus provided in Embodiment 2 of the present invention.

[0032] In the picture:

[0033] 1. Battery cell; 2. Busbar; 3. Copper busbar;

[0034] 11. Pole tab; 21. Insertion groove; 22. Exit groove; 23. Spacing part; 24. Rib; 25. Positioning plate; 26. Positioning protrusion; 27. Hot riveting post; 28. Extension frame; 31. Fitting part; 32. Connecting part; 33. Through groove;

[0035] 311. Hot riveting hole. Detailed Implementation

[0036] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0037] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "installed" should be interpreted broadly. For example, they can refer to a mounting connection or a detachable connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0038] In the description of this invention, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0039] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0040] Example 1

[0041] like Figures 1 to 5As shown, this embodiment provides a lithium battery current collector structure, which includes multiple battery cells 1, a busbar 2 and at least one copper bar 3. The multiple battery cells 1 are arranged side by side in sequence. The multiple battery cells 1 are disposed on the back side of the busbar 2. The copper bar 3 includes a bonding part 31, which is connected to the front side of the busbar 2. The tabs 11 of the battery cells 1 extend from the back side to the front side of the busbar 2, are bonded and bypass the bonding part 31, and then bend and pass into the busbar 2.

[0042] The lithium battery current collector structure provided in this embodiment includes a copper busbar 3 with a bonding portion 31 connected to the front of the busbar 2. The tab 11 of the battery cell 1 extends from the back to the front of the busbar 2, is bonded, and then bends and passes around the bonding portion 31 before entering the busbar 2. The tab 11 is bonded to the bonding portion 31 of the copper busbar 3, enabling the series and parallel connection of multiple battery cells 1. The tab 11's extension through the busbar 2, bending and passing around the bonding portion 31 before entering the busbar 2 avoids the requirement for precise length control of the tab 11, thereby effectively reducing the difficulty of lithium battery design and manufacturing processes.

[0043] Optionally, the copper bar 3 includes multiple bonding portions 31 and at least one connecting portion 32. The multiple bonding portions 31 are arranged sequentially at intervals, and each pair of adjacent bonding portions 31 is connected by at least one connecting portion 32. Each bonding portion 31 is provided with a corresponding tab 11. Multiple tabs 11 are connected on the same copper bar 3 to realize the series and parallel connection of multiple battery cells 1.

[0044] Specifically, the copper bar 3 includes two fitting portions 31 and two connecting portions 32. The two connecting portions 32 are spaced apart from each other, and both ends of each connecting portion 32 are connected to the two fitting portions 31 respectively. The two fitting portions 31 and the two connecting portions 32 form a through groove 33. Each fitting portion 31 is provided with a corresponding tab 11, and both tabs 11 corresponding to the same copper bar 3 pass through the through groove 33. In this embodiment, one copper bar 3 is connected to two tabs 11. The connection between the two fitting portions 31 and the two connecting portions 32 improves the structural strength of the copper bar 3.

[0045] Specifically, the two tabs 11 corresponding to the same copper bar 3 pass around from the opposite side of the two mating parts 31, and bend towards each other before passing through the groove 33.

[0046] More specifically, the busbar 2 is provided with at least one copper bar mounting part, and each copper bar mounting part is connected to a corresponding copper bar 3. Each copper bar mounting part has one insertion groove 21 and two exit grooves 22. The two tabs 11 corresponding to the same copper bar 3 pass out from the two exit grooves 22 respectively, and after bending towards each other, they simultaneously pass into the through groove 33 and the insertion groove 21 in sequence. In this embodiment, the insertion groove 21 is directly opposite the through groove 33 of the copper bar 3, and the copper bar 3 is located between the two exit grooves 22. The fitting part 31 of the copper bar 3 has a plate-like structure. After the tab 11 passes out from the exit groove 22, it is bent twice to form a U-shaped structure, which increases the fitting area between the tab 11 and the fitting part 31. In this embodiment, the busbar 2 is provided with three copper bars 3, and correspondingly, the busbar 2 is provided with three copper bar mounting parts. Of course, the busbar 2 can also be provided with other numbers of copper bar mounting parts for installing a corresponding number of copper bars 3.

[0047] Specifically, such as Figure 4 As shown, a through groove is provided on the copper busbar mounting section, and a rectangular frame is set inside the through groove. The inner groove of the rectangular frame is a through groove 21. Multiple spaced ribs 24 are connected between the outer wall of the rectangular frame and the inner wall of the through groove. Two through grooves 22 are located on opposite sides of the through groove. This design ensures the structural strength of the busbar 2 while reducing the amount of material used.

[0048] More specifically, a positioning plate 25 is provided on the front side of the busbar 2, protruding between the through slot 22 and the through slot, and the copper bar 3 abuts between the two positioning plates 25. The two positioning plates 25 play a positioning role for the copper bar 3.

[0049] Furthermore, each copper bar mounting part is provided with a positioning groove, and a through groove is provided at the bottom of the positioning groove. The copper bar 3 is placed in the positioning groove, with its back abutting against the bottom of the positioning groove and the rib 24, and its side abutting against the inner wall of the positioning groove. The positioning groove further serves to position the copper bar 3.

[0050] Specifically, the bonding portion 31 is provided with a hot riveting hole 311, and the busbar 2 is provided with a hot riveting post 27, which is hot-riveted into the hot riveting hole 311. The hot riveting post 27 and the hot riveting hole 311 cooperate to connect the copper bar 3 to the busbar 2. In this embodiment, each bonding portion 31 is provided with a corresponding hot riveting post 27.

[0051] Specifically, the back of the busbar 2 is provided with a plurality of spacers 23 spaced apart from each other, with one spacer 23 between every two battery cells 1. The spacers 23 can separate the battery cells 1 arranged side by side.

[0052] Optionally, the battery cell 1 can be packaged using a three-side seal or a four-side seal.

[0053] Example 2

[0054] Figures 6 to 9 Embodiment 2 is shown, wherein the same or corresponding structures as in Embodiment 1 are referred to by the same reference numerals. For the sake of simplicity, only the differences from Embodiment 1 are described below. The difference is that the two tabs 11 corresponding to the same copper bar 3 simultaneously pass out from the through groove 33 and bypass the two fitting parts 31 respectively, and then pass into the busbar 2 from the opposite sides of the two fitting parts 31.

[0055] Specifically, the busbar 2 is provided with at least one copper bar mounting part, and each copper bar mounting part is connected to a corresponding copper bar 3. Each copper bar mounting part has two insertion slots 21 and two exit slots 22. The two tabs 11 corresponding to the same copper bar 3 pass through the two exit slots 22 and into the through slots 33 respectively. After passing through the through slots 33, they are bent in opposite directions and pass into the two insertion slots 21 respectively. In this embodiment, the two exit slots 22 are located between the two insertion slots 21, and the two exit slots 22 are simultaneously facing the through slots 33. The fitting part 31 of the copper bar 3 has a plate-like structure. After the tabs 11 pass through the exit slots 22, they are bent twice to form a U-shaped structure, which increases the contact area between the tabs 11 and the fitting part 31.

[0056] Specifically, each copper bar mounting section is provided with a positioning protrusion 26, which is located between two through slots 22 and passes through a through slot 33, with its two ends abutting against two opposing inner walls of the through slot 33. The positioning protrusion 26 serves to position the copper bar 3, allowing for pre-installation of the copper bar 3. Figure 8 As shown, the positioning protrusion 26 has a frame structure, which serves both a positioning function and saves materials.

[0057] More specifically, such as Figure 8 and Figure 9 As shown, an extension frame 28 protrudes from the back of the busbar 2 for each insertion slot 21, and the inner groove of the extension frame 28 is directly connected to the insertion slot 21. When the tab 11 is long, the tab 11 passes through the insertion slot 21 and enters the extension frame 28. The extension frame 28 provides extension space for the tab 11, preventing two adjacent tabs 11 from contacting each other after exiting from the back of the busbar 2, thus affecting the normal series and parallel connection between the cells 1.

[0058] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A lithium battery current collector structure, characterized in that, include: Multiple battery cells (1) are arranged side by side in sequence; Busbar (2), with a plurality of said cells (1) disposed on the back side of said busbar (2); At least one copper bar (3) includes a bonding part (31) connected to the front of the busbar (2). The tab (11) of the battery cell (1) extends from the back of the busbar (2) to the front, is bonded and bypasses the bonding part (31), bends and enters the busbar (2), and exits from the back of the busbar (2), reducing the requirement for the accuracy of the length of the tab (11).

2. The lithium battery current collector structure according to claim 1, characterized in that, The copper bar (3) includes a plurality of the bonding parts (31) and at least one connecting part (32). The plurality of bonding parts (31) are arranged in sequence at intervals. Each pair of adjacent bonding parts (31) is connected by at least one connecting part (32). Each bonding part (31) is provided with a corresponding tab (11).

3. The lithium battery current collector structure according to claim 1, characterized in that, The copper bar (3) includes two fitting parts (31) and two connecting parts (32). The two connecting parts (32) are spaced apart from each other. The two ends of each connecting part (32) are respectively connected to the two fitting parts (31). The two fitting parts (31) and the two connecting parts (32) form a through groove (33). Each fitting part (31) is provided with a corresponding tab (11). The two tabs (11) corresponding to the same copper bar (3) pass through the through groove (33).

4. The lithium battery current collector structure according to claim 3, characterized in that, The two tabs (11) corresponding to the same copper bar (3) pass around from the opposite side of the two mating parts (31), and bend toward each other before passing through the through groove (33).

5. The lithium battery current collector structure according to claim 4, characterized in that, The busbar (2) is provided with at least one copper bar mounting part, and each copper bar mounting part is connected to a copper bar (3). Each copper bar mounting part has an insertion groove (21) and two exit grooves (22). The two tabs (11) corresponding to the same copper bar (3) pass out from the two exit grooves (22) respectively, and after bending towards each other, they pass through the through groove (33) and the insertion groove (21) in sequence.

6. The lithium battery current collector structure according to claim 5, characterized in that, The copper bar mounting part is provided with a through groove, and a rectangular frame is provided in the through groove. The inner groove of the rectangular frame is the insertion groove (21). A plurality of mutually spaced ribs (24) are connected between the outer wall of the rectangular frame and the inner wall of the through groove. The two exit grooves (22) are located on opposite sides of the through groove.

7. The lithium battery current collector structure according to claim 3, characterized in that, Two tabs (11) corresponding to the same copper bar (3) simultaneously emerge from the through groove (33) and bypass the two fitting parts (31) respectively, and then enter the busbar (2) from the opposite side of the two fitting parts (31).

8. The lithium battery current collector structure according to claim 7, characterized in that, The busbar (2) is provided with at least one copper bar mounting part, and each copper bar mounting part is connected to a copper bar (3). Each copper bar mounting part has two insertion slots (21) and two exit slots (22). The two tabs (11) corresponding to the same copper bar (3) pass through the two exit slots (22) and enter the through slots (33) respectively. After passing through the through slots (33), they bend in opposite directions and pass through the two insertion slots (21) respectively.

9. The lithium battery current collector structure according to claim 8, characterized in that, Each of the copper bar mounting parts is provided with a positioning protrusion (26), the positioning protrusion (26) is disposed between the two through grooves (22), the positioning protrusion (26) passes through the through groove (33), and its two ends respectively abut against the two opposite inner walls of the through groove (33).

10. The lithium battery current collector structure according to any one of claims 1-9, characterized in that, The bonding part (31) is provided with a hot riveting hole (311), and the busbar (2) is provided with a hot riveting post (27), which is hot riveted into the hot riveting hole (311).

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