Lithium battery

Abstract

The present application discloses a lithium battery, comprising: a case, a jelly roll, a negative electrode cover plate, a positive electrode cover plate, a positive electrode busbar disc, and a support member. An accommodating space is formed in the case; the jelly roll is arranged in the accommodating space; the negative electrode cover plate is arranged on a first end of the case; the positive electrode cover plate is arranged on a second end of the case; the positive electrode busbar disc is arranged on the side of the positive electrode cover plate close to the jelly roll; and the support member is arranged between the positive electrode cover plate and the positive electrode busbar disc, and the support member abuts against the positive electrode busbar disc.

Description

lithium battery

[0001] This application claims priority to Chinese patent application filed on October 31, 2023, with application number 202322944619.5. The entire contents of the above application are incorporated herein by reference. Technical Field

[0002] The present application relates to the technical field of lithium batteries, and in particular to a lithium battery. Background Art

[0003] In the prior art, the positive and negative electrode covers of aluminum-cased lithium batteries typically transmit electricity through a bent busbar. To install the busbar between the cover and the winding core, the busbar needs to be bent once or twice, resulting in an R angle during assembly.

[0004] Currently, the metal used for the positive busbar is aluminum, and the metal used for the negative busbar is copper. Due to the different metallic properties of aluminum and copper, the positive busbar requires a larger thickness than the negative busbar, resulting in a larger R angle of the positive busbar; since the core in the aluminum-shell lithium battery is a wrapped structure, the safety margin on the positive side of the aluminum-shell lithium battery is smaller than the safety margin on the negative side. After the positive cover is closed, the positive busbar will squeeze the core, resulting in increased pressure on the core at a local position, causing an internal short circuit in the positive electrode of the aluminum-shell lithium battery. SUMMARY OF THE INVENTION

[0005] An embodiment of the present application provides a lithium battery, which aims to improve the technical problem of excessive internal pressure in the lithium battery caused by the positive busbar squeezing the winding core, resulting in a short circuit inside the lithium battery.

[0006] In a first aspect, an embodiment of the present application provides a lithium battery, comprising:

[0007] a housing, wherein a receiving space is formed in the housing;

[0008] a winding core, the winding core being arranged in the accommodating space;

[0009] a negative electrode cover plate, the negative electrode cover plate being disposed at the first end of the housing;

[0010] a positive electrode cover plate, the positive electrode cover plate being arranged at the second end of the shell, the first end and the second end of the shell being opposite to each other;

[0011] A positive busbar, the positive busbar being arranged on a side of the positive cover plate close to the winding core and being fixedly connected to the winding core;

[0012] A support component is provided between the positive electrode cover plate and the positive electrode bus bar, and the support component abuts against the positive electrode bus bar.

[0013] In a second aspect, an embodiment of the present application provides a battery module, which includes the above-mentioned lithium battery. Beneficial effects

[0014] In an embodiment of the present application, a lithium battery is provided, comprising: a shell, a winding core, a negative electrode cover plate, a positive electrode cover plate, a positive electrode bus plate and a supporting component; a accommodating space is formed in the shell; the winding core is arranged in the accommodating space; the negative electrode cover plate is arranged at a first end of the shell; the positive electrode cover plate is arranged at a second end of the shell, and the first end of the shell is opposite to the second end; the positive electrode bus plate is arranged on a side of the positive electrode cover plate close to the winding core, and the positive electrode bus plate is fixedly connected to the winding core; the supporting component is arranged between the positive electrode cover plate and the positive electrode bus plate, and the supporting component abuts the positive electrode bus plate; by directly fixing the positive electrode bus plate to the winding core without bending the positive electrode bus plate, the bending R angle on the positive electrode bus plate is eliminated, so that after the positive electrode cover plate is closed, the positive electrode bus plate will not squeeze the winding core, thereby improving the technical problem of excessive internal pressure of the lithium battery caused by the positive electrode bus plate squeezing the winding core, causing a short circuit inside the lithium battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIG1 is a structural diagram of a lithium battery of the present application;

[0016] FIG2 is a cross-sectional view of the lithium battery of the present application;

[0017] Figure 3 is an enlarged view of position A in Figure 2;

[0018] FIG4 is a structural diagram of the positive electrode busbar in the lithium battery of the present application;

[0019] FIG5 is a cross-sectional view of the positive busbar in the lithium battery of the present application;

[0020] FIG6 is a structural diagram of a supporting component in a lithium battery of the present application;

[0021] FIG7 is a cross-sectional view of a supporting component in the lithium battery of the present application.

[0022] 100-housing; 200-winding core, 210-second opening; 300-negative electrode cover; 400-positive electrode cover; 500-positive electrode busbar, 510-first base, 511-first opening, 512-third opening, 520-side wall, 521-guide portion, 522-vertical portion, 530-mounting groove; 600-support component, 610-second base, 620-first annular support portion, 630-second annular support portion. Modes for Carrying Out the Invention

[0023] In the prior art, the positive and negative electrode covers of aluminum-cased lithium batteries typically transmit electricity through a bent busbar. To install the busbar between the cover and the winding core, the busbar needs to be bent once or twice, resulting in an R angle during assembly.

[0024] Currently, the metal used for the positive busbar is aluminum, and the metal used for the negative busbar is copper. Due to the different metal properties of aluminum and copper, the positive busbar requires a larger thickness than the negative busbar, resulting in a larger R angle of the positive busbar. Since the winding core in the aluminum shell lithium battery is a wrapped structure, the safety margin on the positive side of the aluminum shell lithium battery is smaller than the safety margin on the negative side. After the positive cover is closed, the positive busbar will squeeze the winding core, resulting in increased pressure on the winding core at a local position, causing an internal short circuit in the positive electrode of the aluminum shell lithium battery. Therefore, the present application provides a battery module, the battery module includes a lithium battery, with reference to Figures 1 and 2, the lithium battery includes: a shell 100, a winding core 200, a negative cover 300, a positive cover 400, a positive busbar 500 and a support component 600.

[0025] Specifically, a accommodating space is formed in the outer shell 100; the winding core 200 is arranged in the accommodating space; the negative electrode cover plate 300 is arranged at the first end of the outer shell 100; the positive electrode cover plate 400 is arranged at the second end of the outer shell 100, and the first end of the outer shell 100 is opposite to the second end; the positive electrode bus plate 500 is arranged on the side of the positive electrode cover plate 400 close to the winding core 200, and the positive electrode bus plate 500 is fixedly connected to the winding core 200; the support component 600 is arranged between the positive electrode cover plate 400 and the positive electrode bus plate 500, and the support component 600 abuts the positive electrode bus plate 500.

[0026] By directly connecting the positive busbar 500 to the winding core 200 without bending the positive busbar 500, the bending R angle on the positive busbar 500 is eliminated, so that after the positive cover 400 is closed, the positive busbar 500 will not squeeze the winding core 200, thereby improving the technical problem of excessive internal pressure of the lithium battery caused by the positive busbar 500 squeezing the winding core 200, causing a short circuit inside the lithium battery; at the same time, due to the elimination of the positive busbar 50 0 is bent, so that the positive bus tray 500 does not need to be bent during production, thereby solving the problem that the R angle bending amount of the positive bus tray 500 is poor in production accuracy and the R angle bending angle is difficult to accurately control, thereby ensuring that the process consistency of the aluminum shell lithium battery during production can be higher; and since the support component 600 is provided, the support component 600 can support the positive bus tray 500, thereby preventing the positive bus tray 500 from being deformed due to being squeezed by the winding core 200.

[0027] In this embodiment, the positive busbar 500 is fixedly connected to both the positive cover plate 400 and the side wall of the housing 100. The positive busbar 500 is fixedly connected to both the positive cover plate 400 and the housing 100 by laser welding.

[0028] In this embodiment, the material of the housing 100 is aluminum, the material of the positive busbar 500 is aluminum, and the material of the supporting component 600 is plastic.

[0029] In this embodiment, the positive electrode cover plate 400 , the support component 600 and the positive electrode bus plate 500 are all circular; and the sizes of the positive electrode cover plate 400 , the support component 600 and the positive electrode bus plate 500 are consistent with the area of ​​the opening on the housing 100 .

[0030] 4 and 5 , in this embodiment, the positive busbar 500 includes: a first base 510 and a side wall 520 ; the first base 510 is fixedly connected to the winding core 200 ; the side wall 520 extends from the four edges of the first base 510 toward the positive cover plate 400 , and a mounting groove 530 is formed between the side wall 520 and the first base 510 , wherein a support component 600 is located in the mounting groove 530 , and the support component 600 abuts the first base 510 . By providing the positive electrode busbar 500 with a first base portion 510 and a side wall portion 520, and the side wall portion 520 is provided to extend from the four edges of the first base portion 510 toward the positive electrode cover plate 400, so that a mounting groove 530 is formed between the side wall portion 520 and the first base portion 510, when installing the support component 600, the support component 600 can be directly set in the mounting groove 530, making the overall structure of the lithium battery more compact, thereby reducing the volume of the lithium battery.

[0031] 2-4 , in this embodiment, a first opening 511 is provided in the middle area of ​​the first base 510 , and a second opening 210 is provided on a side of the winding core 200 close to the positive busbar 500 , and the second opening 210 is connected to the first opening 511 .

[0032] 4 , the first base portion 510 is further provided with a plurality of third openings 512, which are arranged around the first opening 511. The provision of the plurality of third openings 512 allows the electrolyte to penetrate the winding core 200 more quickly.

[0033] In this embodiment, the third openings 512 are set to 3, and the 3 third openings 512 are evenly arranged on the first base 510; or, in order to further improve the efficiency of the core 200 in wetting, the third openings 512 are set to 4, 5 or more, and the specific number of the third openings 512 is adjusted according to the area size of the first substrate.

[0034] In this embodiment, the third opening 512 is a bar-shaped through hole, a circular through hole, a polygonal through hole, or an irregularly shaped through hole.

[0035] 6 and 7 , in this embodiment, the support member 600 includes: a second base portion 610, a first annular support portion 620, and a second annular support portion 630; the second base portion 610 is connected to the positive electrode cover plate 400; the first annular support portion 620 extends from the second base portion 610 toward the first base portion 510, and the first annular support portion 620 is close to the center of the second base portion 610; the second annular support portion 630 extends from the second base portion 610 toward the first base portion 510, and the second annular support portion 630 is close to the edge of the second base portion 610, and the second annular support portion 630 is arranged around the first annular support portion 620. By providing a first annular support portion 620 and a second annular support portion 630, with the first annular support portion 620 positioned near the middle area of ​​the second base portion 610 and the second annular support portion 630 positioned near the edge area of ​​the second base portion 610, the first annular support portion 620 can support the middle area of ​​the second base portion 610, while the second annular support portion 630 can support the edge area of ​​the second base portion 610. This ensures that the force on the positive busbar 500 is more uniform, preventing deformation caused by excessive compression in different areas of the positive busbar 500. Both the first annular support portion 620 and the second annular support portion 630 are annular protrusions.

[0036] In this embodiment, the first annular support portion 620 includes a plurality of annular ridges arranged at intervals, and a gap is formed between two adjacent annular ridges.

[0037] In this embodiment, a connecting portion is further provided between the first annular support portion 620 and the second annular support portion 630, one end of the connecting portion is connected to the first annular support portion 620, and the other end of the connecting portion is connected to the second annular support portion 630. The connecting portion is a connecting bar.

[0038] In this embodiment, the supporting component 600 includes: a second base 610 and multiple support bars; the multiple support bars are arranged in sequence from the first side of the second base 610 toward the second side of the second base 610, and the first side of the second base 610 is opposite to the second side.

[0039] In this embodiment, the length of the support bar gradually decreases from the edge area to the middle area of ​​the second base 610; or, the length of the support bar gradually increases and then gradually decreases from the edge area to the middle area of ​​the second base 610.

[0040] Referring to Figure 4, in this embodiment, in order to better weld the positive busbar 500 to the side wall of the housing 100, it is necessary to ensure that the area of ​​the positive busbar 500 is consistent with the area of ​​the opening on the housing 100. Although this makes it easier to weld the busbar to the side wall of the housing 100, it also increases the difficulty of assembling the positive busbar 500 into the accommodation space. Therefore, the side wall portion 520 is provided to include a guide portion 521, which is connected to the first base 510 and is bent toward the center of the first base 510; so that the area of ​​the positive busbar 500 close to the winding core 200 is smaller, so that when producing lithium batteries, the positive busbar 500 can be more conveniently assembled into the accommodation space. Among them, the cross-section of the guide portion 521 is arc-shaped.

[0041] Referring to Figure 5 , in this embodiment, the sidewall portion 520 further includes a vertical portion 522 extending from the guide portion 521 in a direction away from the first base portion 510. A guide angle α is formed at the junction of the vertical portion 522 and the guide portion 521. The guide angle α is in the range of 0-50°. By setting the guide angle α formed at the junction of the vertical portion 522 and the guide portion 521 to 0-50°, the positive busbar 500 can be more easily assembled into the accommodating space.

[0042] In this embodiment, the vertical portion 522 is welded integrally with the positive electrode cover plate 400 and the housing 100. In this embodiment, the vertical portion 522 is welded to the edge of the positive electrode cover plate 400 and the sidewall of the housing 100 simultaneously by laser welding.

[0043] In this embodiment, the length of the vertical portion 522 is 0.3 mm to 2 mm. Setting the length of the vertical portion 522 to 0.3 mm to 2 mm ensures the strength of the welding between the positive busbar 500, the positive electrode cover plate 400, and the sidewall of the housing 100. Preferably, the length of the vertical portion 522 is 0.5 mm, 1 mm, or 1.6 mm.

[0044] When assembling the lithium battery, the negative electrode cover plate 300 is fixed to the first end of the shell 100, the winding core 200 is fixed in the shell 100, and the positive electrode busbar 500 is placed on the winding core 200, and the positive electrode busbar 500 is welded to the winding core 200 by laser welding to realize the electrical connection between the positive electrode busbar 500 and the winding core 200. Then, the supporting component 600 and the positive electrode cover plate 400 are installed on the positive electrode busbar 500 in turn, and it is ensured that the edge area of ​​the positive electrode cover plate 400, the side wall at the opening of the shell 100 and the vertical part 522 on the side wall part 520 of the positive electrode busbar 500 can correspond to each other. Then, the edge area of ​​the positive electrode cover plate 400, the side wall at the opening of the shell 100 and the vertical part 522 on the side wall part 520 of the positive electrode busbar 500 are welded together by laser welding to complete the closing of the positive electrode cover plate 400 and realize the assembly of the lithium battery.

Claims

1. A lithium battery comprising: A housing, wherein a receiving space is formed in the housing; A winding core, wherein the winding core is arranged in the accommodating space; A negative electrode cover plate, the negative electrode cover plate being disposed at the first end of the housing; A positive electrode cover plate, the positive electrode cover plate is arranged at the second end of the shell, and the first end of the shell is opposite to the second end; A positive busbar, the positive busbar being arranged on a side of the positive cover plate close to the winding core, and the positive busbar being fixedly connected to the winding core; A support component is disposed between the positive electrode cover plate and the positive electrode busbar, and the support component abuts against the positive electrode busbar.

2. The lithium battery according to claim 1, wherein The positive busbar comprises: a first base portion, the first base portion being fixedly connected to the winding core; A side wall portion extends from the four edges of the first base portion toward the positive electrode cover plate, and a mounting groove is formed between the side wall portion and the first base portion, wherein the support component is located in the mounting groove and abuts against the first base portion.

3. The lithium battery according to claim 2, wherein: A first opening is provided in the middle area of ​​the first base, and a second opening is provided on one side of the winding core close to the positive busbar, and the second opening is connected to the first opening.

4. The lithium battery according to claim 3, wherein: The first base is also provided with a plurality of third openings, and the plurality of third openings are arranged around the first opening.

5. The lithium battery according to claim 4, wherein: The third opening is a strip-shaped through hole, a circular through hole, a polygonal through hole or a through hole of an irregular shape.

6. The lithium battery according to claim 4, wherein: The number of the third openings is set to one of 3, 4 or 5.

7. The lithium battery according to any one of claims 2 to 6, wherein: The supporting member comprises: a second base portion, the second base portion being connected to the positive electrode cover plate; A first annular support portion, the first annular support portion extending from the second base portion toward the first base portion, the first annular support portion being close to a center area of ​​the second base portion; The second annular support portion extends from the second base portion toward the first base portion, the second annular support portion is close to the edge of the second base portion, and the second annular support portion is arranged around the first annular support portion.

8. The lithium battery according to claim 7, wherein: The first annular support portion includes a plurality of annular convex strips, the plurality of annular convex strips are arranged at intervals, and a gap is formed between two adjacent annular convex strips.

9. The lithium battery according to claim 7, wherein: A connecting portion is further provided between the first annular support portion and the second annular support portion, one end of the connecting portion is connected to the first annular support portion, and the other end of the connecting portion is connected to the second annular support portion.

10. The lithium battery according to claim 2, wherein: The side wall portion includes a guide portion connected to the first base portion and bent toward a center direction of the first base portion.

11. The lithium battery according to claim 10, wherein: The side wall portion further comprises a vertical portion, which extends from the guide portion in a direction away from the first base portion. A guide angle α is formed at a connection between the vertical portion and the guide portion, and the guide angle α is 0-50°.

12. The lithium battery according to claim 11, wherein: The vertical portion is welded integrally with the positive electrode cover plate and the outer shell.

13. The lithium battery according to claim 12, wherein: The vertical portion is welded to the edge area of ​​the positive electrode cover plate and the side wall of the shell simultaneously by laser welding.

14. The lithium battery according to claim 12, wherein: The length of the vertical portion is 0.3 mm-2 mm.

15. The lithium battery according to claim 14, wherein: The length of the vertical portion is one of 0.5 mm, 1 mm or 1.6 mm.

16. The lithium battery according to claim 10, wherein: The cross section of the guide portion is arc-shaped.

17. The lithium battery according to claim 1, wherein: The sizes of the positive electrode cover plate, the support component and the positive electrode busbar are consistent with the area size of the opening on the housing.

18. The lithium battery according to claim 17, wherein: The positive electrode cover plate, the support component and the positive electrode busbar are all circular.

19. The lithium battery according to claim 1, wherein: The material of the shell is aluminum, and the material of the positive electrode busbar is aluminum.

20. A battery module, comprising the lithium battery according to any one of claims 1 to 19.

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