Connecting piece and battery cell structure

Abstract

The utility model relates to the technical field of batteries, and discloses a connecting piece and a battery cell structure. The second connecting part is arranged on one side of the first connecting part along the first direction, and the second connecting part is suitable for being welded with the pole; the third connecting part is arranged on the other side, in the first direction, of the first connecting part, and the third connecting part is suitable for being welded to the tab; a reinforcing rib is arranged on the third connecting part, is arranged in the second direction and is suitable for keeping the third connecting part in a flat state. According to the connecting piece provided by the utility model, the reinforcing rib is arranged on the third connecting part, so that the connecting piece can still keep a flat state even if the connecting piece is subjected to the pulling force of the tab after being welded with the tab, the phenomenon that a pole group diaphragm is punctured due to the bending of the connecting piece is avoided, and the safety of a battery cell is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a connecting piece and a battery cell structure. Background Art

[0002] With the increasing maturity of lithium-ion battery technology, lithium-ion batteries are widely used as power batteries in electric vehicles and energy storage fields, and the requirements for the use performance and safety of lithium-ion batteries are increasing day by day.

[0003] In the existing lithium-ion battery, electric energy is led out of the battery to the outside through a connecting piece between the electrode group and the cover plate. However, after the connecting piece is welded to the tab, the connecting piece is easily bent under the pulling force of the tab. After the connecting piece is bent, it is easy to pierce the separator of the electrode group, resulting in a short circuit inside the battery cell and risks such as thermal runaway. Summary of the Utility Model

[0004] In view of this, the utility model provides a connecting piece and a battery cell structure to solve the problem that the connecting piece of the existing lithium-ion battery is easily bent under the pulling force of the tab after being welded to the tab.

[0005] In a first aspect, the utility model provides a connecting piece, comprising:

[0006] A first connecting portion;

[0007] A second connecting portion, arranged on one side of the first connecting portion along a first direction, and the second connecting portion is adapted to be welded to a pole column;

[0008] A third connecting portion, arranged on the other side of the first connecting portion along the first direction, and the third connecting portion is adapted to be welded to a tab;

[0009] Reinforcing ribs are arranged on the third connecting portion, the reinforcing ribs are arranged along a second direction, and the reinforcing ribs are adapted to keep the third connecting portion in a flat state.

[0010] Advantageous Effects: The connecting piece provided by the utility model mainly comprises a first connecting portion, a second connecting portion and a third connecting portion. The first connecting portion is arranged between the second connecting portion and the third connecting portion, and the first connecting portion is adapted to connect the second connecting portion and the third connecting portion. The first connecting portion is a bent part; by arranging reinforcing ribs on the third connecting portion, after the connecting piece is welded to the tab, it can still keep a flat state even under the pulling force of the tab, avoiding piercing the separator of the electrode group due to the bending of the connecting piece and ensuring the safety of the battery cell.

[0011] In an optional embodiment, the second connecting portion and the third connecting portion have a first state in which they are unfolded relative to the first connecting portion and a second state in which they are oppositely arranged after being folded at the position of the first connecting portion.

[0012] Beneficial effects: In the first state, the second connecting portion, the third connecting portion, and the first connecting portion are in an unfolded state to reduce the processing difficulty and ensure the structural strength of the connecting piece. During the assembly process, after the second connecting portion and the pole column and the third connecting portion and the tab are welded, the connecting piece can be bent so that the second connecting portion and the third connecting portion are oppositely arranged after being folded at the position of the first connecting portion, causing the connecting piece to switch from the first state to the second state to facilitate the assembly of the battery cell.

[0013] In an optional embodiment, a fourth connecting portion is formed by bending between the second connecting portion and the first connecting portion. When the second connecting portion is in the second state, a sunken groove is formed by enclosing the side of the second connecting portion away from the third connecting portion and the side of the fourth connecting portion along the thickness direction of the second connecting portion itself, and the pole column is adapted to be received in the sunken groove.

[0014] Beneficial effects: Thus, more accommodation space is saved for the electrode group in the battery cell housing, which is beneficial to improving the volumetric energy density of the battery cell.

[0015] In an optional embodiment, the third connecting portion includes a first surface and a second surface oppositely arranged along the thickness direction of the third connecting portion itself, and the first surface is adapted to be welded to the tab.

[0016] The reinforcing rib is recessed from the first surface along the thickness direction of the third connecting portion towards the second surface and protrudes from the second surface.

[0017] Beneficial effects: So that the protruding direction of the reinforcing rib is oppositely arranged with respect to the tab welding surface of the third connecting portion, thereby avoiding interference of the reinforcing rib with the tab welding.

[0018] In an optional embodiment, a first welding area and a second welding area are provided on the first surface, and the first welding area and the second welding area are oppositely arranged along the first direction.

[0019] A notch is provided on the third connecting portion, and the notch is located between the first welding area and the second welding area.

[0020] Beneficial effects:

[0021] In an optional embodiment, reinforcing ribs are provided on both sides of the first welding area and the second welding area along the first direction away from the notch.

[0022] Beneficial effects: By providing a notch on the third connecting portion, the first welding area and the second welding area of the third connecting portion are independently arranged, thereby avoiding mutual influence due to vibration when the first welding area and the second welding area are welded to the tab, ensuring the welding yield. At the same time, by providing reinforcing ribs on the third connecting portion, deformation and collapse of the third connecting portion near the notch are prevented, thereby ensuring the flat state of the third connecting portion.

[0023] In an alternative embodiment, both the first welding area and the second welding area are disposed on a side of the third connecting portion away from the second connecting portion along the second direction.

[0024] Advantageous effect: Thus, interference between the second connecting portion and the tab is avoided.

[0025] In a second aspect, the present utility model further provides a battery cell structure, including:

[0026] A cover plate, on which a pole column is provided;

[0027] A pole group module, disposed opposite to the cover plate, and tabs are provided on a side of the pole group module close to the cover plate;

[0028] And a connecting piece as described above, the connecting piece is disposed between the pole group module and the cover plate, the second connecting portion of the connecting piece is welded to the pole column, and the third connecting portion of the connecting piece is welded to the tab.

[0029] Advantageous effect: The battery cell structure in the second aspect includes the connecting piece in the first aspect. Therefore, the battery cell structure in the second aspect includes all the advantageous effects of the connecting piece in the first aspect.

[0030] In an alternative embodiment, the pole group module includes a plurality of pole group units, and tabs are provided on each pole group unit; the pole group units and the connecting pieces are both provided in pairs;

[0031] The connecting pieces are respectively welded to the pole column and the tabs of the pole group units in a first state, and after welding is completed, the connecting pieces are switched from the first state to a second state by bending, so that the pole group units are combined to form an integral pole group module.

[0032] Advantageous effect: During the manufacturing process, when each pair of connecting pieces is in the first state, first, the second connecting portions are simultaneously welded to the pole column, then the third connecting portions are respectively welded to the tabs of the two pole group units, and then the connecting pieces are switched from the first state to the second state. At this time, each pair of pole group units are mutually attached along the first direction, and two pairs of pole group units can be combined to form an integral pole group module, thereby realizing the assembly of the connecting piece with the cover plate and the pole group module.

[0033] In an alternative embodiment, the tab of each pole group unit includes a first welding portion and a second welding portion, the first welding portion and the second welding portion are spaced apart from each other along the width direction, the first welding portion is adapted to be welded to the first welding area of the third connecting portion, and the second welding portion is adapted to be welded to the second welding area of the third connecting portion.

[0034] Advantageous effect: Thus, vibration isolation is performed between the first welding area and the second welding area, and mutual influence due to vibration is avoided, ensuring the welding yield. Description of the Drawings

[0035] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0036] Figure 1 A perspective view of a connecting piece in the first state according to an embodiment of the present invention;

[0037] Figure 2 A cross-sectional view of a connecting piece in the second state according to an embodiment of the present invention;

[0038] Figure 3 An assembly drawing of a connecting piece of a battery cell structure in the first state and a cover plate according to an embodiment of the present invention;

[0039] Figure 4 A cross-sectional view of a single pole group unit and a pole ear of a battery cell structure according to an embodiment of the present invention;

[0040] Figure 5 An assembly drawing of a connecting piece of a battery cell structure in the second state and a pole group module according to an embodiment of the present invention;

[0041] Figure 6 For Figure 5 A partial enlarged schematic view at P in

[0042] Figure 7 An assembly drawing of a connecting piece of a battery cell structure in the second state and a pole column and a pole group module according to an embodiment of the present invention;

[0043] Figure 8 For Figure 7 A partial enlarged schematic view at Q in

[0044] Explanation of reference numerals:

[0045] 11. First connecting portion; 12. Second connecting portion; 13. Third connecting portion; 131. First surface; 1311. First welding area; 1312. Second welding area; 132. Second surface; 133. Notch; 14. Reinforcing rib; 15. Fourth connecting portion; 16. Sunk groove;

[0046] 20. Cover plate; 21. Pole column;

[0047] 30. Pole group module; 31. Pole group unit;

[0048] 40. Pole ear; 41. First welding portion; 42. Second welding portion. Detailed embodiments

[0049] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative efforts belong to the scope of protection of the present utility model.

[0050] The following will describe the embodiments of the present utility model in conjunction with Figures 1 to 8 , the embodiments of the present utility model will be described.

[0051] According to an embodiment of the present utility model, on the one hand, a connecting piece is provided, including:

[0052] A first connecting portion 11;

[0053] A second connecting portion 12, disposed on one side of the first connecting portion 11 along a first direction, and the second connecting portion 12 is adapted to be welded to the pole column 21;

[0054] A third connecting portion 13, disposed on the other side of the first connecting portion 11 along the first direction, and the third connecting portion 13 is adapted to be welded to the tab 40;

[0055] A reinforcing rib 14 is provided on the third connecting portion 13, the reinforcing rib 14 is disposed along a second direction and penetrates through the welding area of the third connecting portion 13 with the tab 40, and the reinforcing rib 14 is adapted to keep the third connecting portion 13 in a flat state.

[0056] The connecting piece provided by the present utility model mainly includes a first connecting portion 11, a second connecting portion 12, and a third connecting portion 13. The first connecting portion 11 is disposed between the second connecting portion 12 and the third connecting portion 13. The first connecting portion 11 is adapted to connect the second connecting portion 12 and the third connecting portion 13. The first connecting portion 11 is a bent portion; by providing the reinforcing rib 14 on the third connecting portion 13, even after the connecting piece is welded to the tab 40, it can still maintain a flat state under the action of the pulling force of the tab 40, avoiding piercing the cell diaphragm due to the bending of the connecting piece and ensuring the safety of the battery cell.

[0057] Furthermore, the connecting piece is an integrally formed structure, and the connecting piece can be formed into the first connecting portion 11, the second connecting portion 12, and the third connecting portion 13 by stamping.

[0058] Furthermore, ultrasonic welding can be used between the second connecting portion 12 and the pole column 21 and between the third connecting portion 13 and the tab 40.

[0059] In some embodiments, please also combine Figure 1 andFigure 2 As shown, the second connecting portion 12 and the third connecting portion 13 have a first state in which they are unfolded relative to the first connecting portion 11 and a second state in which they are oppositely arranged after being folded at the position of the first connecting portion 11.

[0060] It should be noted that, please refer to Figure 1 As shown, the connecting piece can be formed into the first state by stamping. In the first state, the second connecting portion 12, the third connecting portion 13 and the first connecting portion 11 are in an unfolded state to reduce the processing difficulty and at the same time ensure the structural strength of the connecting piece; please refer to Figure 2 As shown, during the assembly process, after the welding between the second connecting portion 12 and the pole column 21 and between the third connecting portion 13 and the pole tab 40 is completed, the connecting piece can be bent so that the second connecting portion 12 and the third connecting portion 13 are oppositely arranged after being folded at the position of the first connecting portion 11, so that the connecting piece is switched from the first state to the second state to facilitate the assembly of the battery cell.

[0061] In some embodiments, please refer to Figure 1 、 Figure 2 and Figure 8 As shown, a fourth connecting portion 15 is bent between the second connecting portion 12 and the first connecting portion 11; when the second connecting portion 12 is in the second state, a sunken groove 16 is formed by enclosing one side of the second connecting portion 12 away from the third connecting portion 13 and one side of the fourth connecting portion 15 along the thickness direction of the second connecting portion 12 itself. The pole column 21 is adapted to be received in the sunken groove 16, so as to save more accommodation space for the electrode group in the battery cell housing, which is beneficial to improving the volume energy density of the battery cell.

[0062] In some embodiments, please refer to Figure 2 As shown, the third connecting portion 13 includes a first surface 131 and a second surface 132 that are oppositely arranged along the thickness direction of the third connecting portion 13 itself, and the first surface 131 is adapted to be welded to the pole tab 40;

[0063] The reinforcing rib 14 is recessed from the first surface 131 along the thickness direction of the third connecting portion 13 itself toward the second surface 132 and protrudes from the second surface 132, so that the protruding direction of the reinforcing rib 14 is opposite to the pole tab welding surface of the third connecting portion 13, thereby avoiding interference of the reinforcing rib 14 with the pole tab welding.

[0064] In some embodiments, please refer to Figure 1 As shown, a first welding area 1311 and a second welding area 1312 are provided on the first surface 131, and the first welding area 1311 and the second welding area 1312 are oppositely arranged along the first direction;

[0065] A notch 133 is formed on the third connecting portion 13, and the notch 133 can be a "U" - shaped structure, and the notch 133 is located between the first welding area 1311 and the second welding area 1312.

[0066] In this embodiment, by providing a notch 133 in the third connecting portion 13, the first welding area 1311 and the second welding area 1312 of the third connecting portion 13 are independently arranged, thereby avoiding the mutual influence caused by vibration when the first welding area 1311 and the second welding area 1312 are welded to the tab 40, and ensuring the welding yield. At the same time, by providing a reinforcing rib 14 on the third connecting portion 13, deformation and collapse of the third connecting portion 13 near the notch 133 are prevented, thereby ensuring the flat state of the third connecting portion 13.

[0067] In some embodiments, please refer to Figure 1 As shown, reinforcing ribs 14 are provided on one side of the first welding area 1311 and the second welding area 1312 away from the notch 133 in the first direction, so that after the third connecting portion 13 is welded to the tab 40, it can still maintain a flat state even under the pulling force of the tab 40, effectively preventing deformation and collapse of the third connecting portion 13 near the notch 133, and avoiding piercing the separator of the electrode group due to deformation and bending of the third connecting portion 13.

[0068] In some embodiments, please also refer to Figure 1 and Figure 6 As shown, the first welding area 1311 and the second welding area 1312 are both arranged on one side of the third connecting portion 13 away from the second connecting portion 12 in the second direction.

[0069] It should be noted that, as shown in Figure 6 The tab 40 is an "L"-shaped structure. One side of the third connecting portion 13 in the second direction is arranged between the tab 40 and the electrode group. The first welding area 1311 and the second welding area 1312 are attached to one side of the tab 40 close to the electrode group along its own thickness direction, and then the first welding area 1311 and the second welding area 1312 are ultrasonically welded to the tab 40. Since the second connecting portion 12 is welded to the pole post 21 and the second connecting portion 12 and the third connecting portion 13 need to be folded at the first connecting portion 11, by arranging the first welding area 1311 and the second welding area 1312 on one side of the third connecting portion 13 away from the second connecting portion 12 in the second direction, interference between the second connecting portion 12 and the tab 40 is avoided.

[0070] According to an embodiment of the present invention, on the other hand, a battery cell structure is also provided, including:

[0071] A cover plate 20, on which a pole post 21 is provided;

[0072] An electrode group module 30, disposed opposite to the cover plate 20, and a tab 40 is provided on one side of the electrode group module 30 close to the cover plate 20;

[0073] and the connecting piece as described above, the connecting piece is disposed between the electrode group module 30 and the cover plate 20, the second connecting portion 12 of the connecting piece is welded to the electrode post 21, and the third connecting portion 13 of the connecting piece is welded to the tab 40.

[0074] The battery cell structure in this embodiment includes the connecting piece as described above. Therefore, the battery cell structure in this embodiment includes all the beneficial effects of the connecting piece as described above.

[0075] In some embodiments, the electrode group module 30 includes a plurality of electrode group units 31. Please refer to Figure 4 as shown, a tab 40 is disposed on each electrode group unit 31; please refer to Figure 5 as shown, the electrode group units 31 and the connecting pieces are both arranged in pairs;

[0076] The connecting piece is welded to the electrode post 21 and the tab 40 of the electrode group unit 31 respectively in the first state. After welding is completed, the connecting piece is switched from the first state to the second state by bending, so that the electrode group units 31 are combined to form an integral electrode group module 30.

[0077] It should be noted that, please refer to Figure 3 as shown, the connecting pieces are arranged in pairs, and each pair of connecting pieces is symmetrically arranged along the first direction; in the manufacturing process, when each pair of connecting pieces is in the first state, first, the second connecting portion 12 is simultaneously welded to the electrode post 21, and then the third connecting portion 13 is welded to the tabs 40 of the two electrode group units 31 respectively, and then the connecting piece is switched from the first state to the second state. Please refer to Figure 7 as shown, at this time, each pair of electrode group units 31 are attached to each other along the first direction. Please also refer to Figure 5 as shown, two pairs of electrode group units 31 can be combined to form an integral electrode group module 30, so as to realize the assembly of the connecting piece with the cover plate 20 and the electrode group module 30.

[0078] In some embodiments, please refer to Figure 4 as shown, the tab 40 of each electrode group unit 31 includes a first welding portion 41 and a second welding portion 42, and the first welding portion 41 and the second welding portion 42 are spaced apart from each other along the width direction. Please also refer to Figure 1 and Figure 6 as shown, the first welding portion 41 is adapted to be welded to the first welding area 1311 of the third connecting portion 13, and the second welding portion 42 is adapted to be welded to the second welding area 1312 of the third connecting portion 13.

[0079] In this embodiment, during the manufacturing process, the first welding portion 41 is welded to the first welding area 1311, and the second welding portion 42 is welded to the second welding area 1312. An opening 133 is formed in the third connecting portion 13 to make the first welding area 1311 and the second welding area 1312 independent of each other with an interval therebetween. At the same time, by setting the tab 40 of each pole group unit 31 as the first welding portion 41 and the second welding portion 42, the first welding portion 41 and the second welding portion 42 are arranged at intervals relative to each other in the width direction, so as to isolate vibration between the first welding area 1311 and the second welding area 1312, avoid mutual influence due to vibration, and ensure the welding yield.

[0080] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A connecting sheet, characterized in that: include: a first connecting portion; A second connection portion, arranged at one side of the first connection portion along the first direction, the second connection portion being suitable for welding with the pole; A third connection portion, disposed on the other side of the first connection portion along the first direction, the third connection portion being suitable for welding with the tab; The third connection portion is provided with reinforcing ribs, the reinforcing ribs are arranged along the second direction, and the reinforcing ribs are suitable for maintaining a flat state of the third connection portion.

2. The connecting piece according to claim 1, characterized in that: The second connection portion and the third connection portion have a first state in which they are unfolded relative to the first connection portion and a second state in which they are folded relative to each other at the position of the first connection portion.

3. The connecting piece according to claim 2, characterized in that: The second connection part is bent with the first connection part to form a fourth connection part; when the second connection part is in the second state, the side of the second connection part away from the third connection part along its own thickness direction and the side of the fourth connection part together enclose a groove, and the groove is suitable for accommodating the pole.

4. The connecting sheet according to claim 2, characterized in that: The third connecting portion comprises a first surface and a second surface which are arranged opposite to each other along its thickness direction, and the first surface is suitable for welding with the tab; The reinforcing rib is formed by the first surface being recessed toward the second surface along the thickness direction of the third connecting portion and protruding from the second surface.

5. The connecting piece according to claim 4, characterized in that: A first welding area and a second welding area are arranged on the first surface, and the first welding area and the second welding area are arranged opposite to each other along a first direction; The third connecting portion is provided with a notch, and the notch is located between the first welding area and the second welding area.

6. The connecting piece according to claim 5, characterized in that: The reinforcing ribs are disposed on one side of the first welding area and the second welding area away from the notch along the first direction.

7. The connecting sheet according to claim 5, characterized in that: The first welding area and the second welding area are both arranged on a side of the third connecting portion away from the second connecting portion along the second direction.

8. A battery cell structure, characterized in that: include: a cover plate on which a pole is arranged; A pole group module is arranged opposite to the cover plate, and a pole ear is arranged on a side of the pole group module close to the cover plate; And a connecting piece as described in any one of claims 1 to 7 above, wherein the connecting piece is arranged between the pole group module and the cover plate, the second connecting portion of the connecting piece is welded to the pole column, and the third connecting portion of the connecting piece is welded to the pole ear.

9. The battery cell structure according to claim 8, characterized in that: The pole group module comprises a plurality of pole group units, each of which is provided with the pole lug; the pole group units and the connecting sheets are provided in pairs; The connecting piece is welded to the pole column and the pole ear of the pole group unit respectively in the first state. After welding, the connecting piece switches from the first state to the second state by bending, so that the pole group units are combined to form the integral pole group module.

10. The battery core structure according to claim 9, characterized in that: The pole ear of each pole group unit includes a first welding portion and a second welding portion, the first welding portion and the second welding portion are arranged relatively spaced apart in the width direction, the first welding portion is suitable for welding with the first welding area of ​​the third connecting portion, and the second welding portion is suitable for welding with the second welding area of ​​the third connecting portion.

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