Bent tab, pole group and battery cell

Abstract

The utility model discloses a bending tab, which comprises an extending part and two bending parts, the two bending parts are respectively positioned on two sides of the same end part of the extending part, one end of each bending part is connected with the extending part, and the other end of each bending part extends towards the direction far away from the extending part. According to the utility model, the problems of insufficient welding of the tabs and welding cracks of the tabs on the outermost layer caused by the fact that the number of layers of the pole pieces is large and the welding capability cannot be achieved are solved, and the welding quality of the battery cell is improved. The utility model also discloses a pole group and a battery cell.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a bent pole ear, a pole group and a battery core. Background Art

[0002] As the requirements for electric vehicle mileage become higher and higher, the requirements for battery energy density are also getting higher and higher. Generally, the method of improving battery energy density includes improving the space utilization of the battery after it becomes a pole group, which makes the volume of the single battery larger and larger, so that the battery has a thicker thickness. However, the battery cell of the ultra-thick battery is welded by stacking multiple layers of pole ears, which is prone to the risk of cold welding, and the outermost fake pole ear is easy to be welded or even broken, causing the battery cell to be scrapped. Utility Model Content

[0003] In order to overcome the shortcomings and deficiencies in the prior art, the purpose of the utility model is to provide a bent pole ear, pole group and battery cell, to improve the problems of pole ear cold welding and outermost pole ear cracking caused by a large number of pole sheet layers and insufficient welding capacity, and to improve the welding quality of the battery cell.

[0004] The purpose of the utility model is achieved through the following technical solutions:

[0005] A bent pole ear comprises a protruding portion and two bent portions, wherein the two bent portions are respectively located on both sides of the same end of the protruding portion, one end of the bent portion is connected to the protruding portion, and the other end of the bent portion extends in a direction away from the protruding portion.

[0006] In one embodiment, the protruding portion has a length direction and a thickness direction, and the two bending portions are located at the same end of the protruding portion in the length direction and are respectively located at two sides of the protruding portion in the thickness direction.

[0007] In one embodiment, along the length direction of the protruding portion, the two bent portions are arranged in sequence and connected to one end portion of the protruding portion.

[0008] In one embodiment, along the length direction of the protruding portion, the two bent portions are aligned and connected to one end of the protruding portion.

[0009] In one embodiment, the bent portion and the protruding portion form an angle at a connection point, and the angle ranges from 30° to 120°.

[0010] In one embodiment, an insulating glue is provided on the protruding portion near the bending portion.

[0011] The utility model also provides a pole group, comprising the bent pole ear as described above and two bare battery cells, wherein the two bare battery cells are electrically connected to the bent pole ear respectively.

[0012] In one embodiment, the two bare cells are respectively a first bare cell and a second bare cell, and both of the bare cells include a fake pole ear, one of the bent portions of the bent pole ear is connected to the fake pole ear of the first bare cell, and the other bent portion of the bent pole ear is connected to the fake pole ear of the second bare cell, and the two fake pole ears connected to the same bent pole ear have the same polarity.

[0013] In one embodiment, each of the dummy tabs is bent in a direction away from the protruding portion.

[0014] In one embodiment, the pole group has a thickness direction, and each of the bent portions is parallel to the thickness direction of the pole group.

[0015] The utility model also provides a battery core, comprising the pole group and an external shell as described above, wherein the pole group is arranged in the shell.

[0016] The beneficial effect of the utility model is that by arranging bending parts on both sides of the protruding part, the two bending parts are respectively connected to a bare battery cell, so that two bare battery cells are electrically connected to the two bending parts of the bent pole ears to form a pole group, the number of welding layers is reduced, the problem of poor welding or scrapping caused by excessively thick battery cell pole ears is solved, and the welding quality of the battery cell is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a schematic structural diagram of a bent pole ear in one embodiment of the utility model;

[0019] Figure 2 yes Figure 1 A schematic diagram of the structure from another angle;

[0020] Figure 3 It is a schematic structural diagram of a bent pole ear of another embodiment of the utility model;

[0021] Figure 4 yes Figure 3 A schematic diagram of a structure in which two bending parts are separated;

[0022] Figure 5 yes Figure 1 A schematic diagram of a structure in which a bent pole ear is welded to a bare battery cell;

[0023] Figure 6 yes Figure 3 A schematic diagram of a structure in which a bent pole ear is welded to a bare battery cell;

[0024] Figure 7 This is a schematic diagram of the two bare battery cells with their fake tabs placed offset from each other;

[0025] Figure 8 It is a schematic diagram of the fake tabs of two bare cells being aligned with each other;

[0026] Fig. 9 yes Figure 1 The bent tabs and Figure 7 Schematic diagram of two bare battery cells welded together;

[0027] Fig.10 yes Figure 3 The bent tabs and Figure 8 Schematic diagram of two bare battery cells welded together;

[0028] Fig.11 yes Fig. 9 A schematic diagram of the structure of the pole group formed by bending the false pole ear;

[0029] Fig.12 yes Fig.11 Schematic diagram of the structure assembled into a battery cell.

[0030] In the figure: 100, pole group; 1, bent pole ear; 11, bending portion; 12, extending portion; 13, insulating glue; 14, welding area; 15, welding portion; 2, bare cell; 2A, first bare cell; 2B, second bare cell; 21, fake pole ear; 3, shell. DETAILED DESCRIPTION

[0031] The following will describe in detail a specific embodiment of the utility model in conjunction with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the utility model, rather than all the embodiments. Based on the description of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0032] In the description of the present utility model, unless otherwise clearly specified and limited, the terms "set", "install", "connection" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0033] The directions or positional relationships indicated by terms such as "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inside" and "outside" are based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the utility model product is usually placed when in use. They are only for the convenience of description and simplified description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the utility model.

[0034] The terms "first", "second", "third" and the like are merely used to distinguish elements of similar nature, and do not indicate or imply relative importance or a particular order.

[0035] The terms "comprises," "comprising," or any other variations thereof, are intended to cover a non-exclusive inclusion of the elements listed and may also include additional elements not expressly listed.

[0036] The utility model provides a bent pole ear 1, such as Figures 1 to 6 , Figures 9 to 11 As shown, it includes an extension portion 12 and two bent portions 11, the two bent portions 11 are respectively located on both sides of the same end of the extension portion 12, one end of the bent portion 11 is connected to the extension portion 12, and the other end of the bent portion 11 extends in a direction away from the extension portion 12, which is used to connect the bare battery cell 2, so that the two bare battery cells 2 are electrically connected to the two bent portions 11 of the bent pole ear 1 to form a pole group 100, reduce the number of welding layers of the pole ear, solve the problem of poor welding or scrapping caused by excessive thickness of the battery cell pole ear, and improve the welding quality of the battery cell. Specifically, the bent pole ear 1 has a bending portion 11 set in two different directions, and the two bending portions 11 are located on both sides of the extension portion 12, both extending in a direction away from the extension portion 12, so as to facilitate connection with the bare battery cell 2. Among them, the two bending portions 11 are arranged at the same horizontal position on both sides of one end of the extending portion 12. When the two bending portions 11 are respectively connected to a bare battery cell 2, the two bare battery cells 2 can be well overlapped and combined to form an electrode group 100; and the two bending portions 11 are connected to one end of the extending portion 12, so that when the two bare battery cells 2 are connected and combined into the electrode group 100, the extending portion 12 will not be clamped between the two bare battery cells 2, and there is no gap between the two bare battery cells 2, and the connection is tight.

[0037] As an implementation method, Figures 1 to 3 As shown, the extension portion 12 has a length direction L1 and a thickness direction D1 , and the two bending portions 11 are located at the same end of the extension portion 12 in the length direction L1 and are respectively located at two sides of the extension portion 12 in the thickness direction D1 .

[0038] As an implementation method, Figure 1 and Figure 2As shown, along the length direction L1 of the extension portion 12, the two bent portions 11 are arranged in sequence and connected to one end of the extension portion 12, that is, the two bent portions 11 are located on different sides of the extension portion 12 and are staggered. In this embodiment, the two bent portions 11 can be made of the same piece of metal foil, and one side of the bent tab 1 is cut and divided into parts of equal width, which are then bent in two directions to obtain two bent portions 11.

[0039] As an implementation method, Figure 3 As shown, along the length direction L1 of the extension portion 12, the two bent portions 11 are aligned and connected to one end of the extension portion 12. Figure 4 As shown, the two bending portions 11 are made of two L-shaped metal foils of different sizes. Specifically, the large L-shaped metal foil includes a bending portion 11 and a protruding portion 12. A welding area 14 is provided on the protruding portion 12 of the large L-shaped metal foil. The small L-shaped metal foil includes a bending portion 11 and a welding portion 15. By welding the welding portion 15 to the welding area 14, the two L-shaped metal foils are welded into a whole, forming a Figure 3 The bent pole ear 1 is shown.

[0040] As an embodiment, the bending portion 11 and the extension portion 12 form an angle at the connection, and the angle ranges from 30° to 120°, or 80° to 100°. The appropriate angle range helps to weld the bending portion 11 and the false pole ear 21 of the bare battery cell 2 together. The shape of the bending pole ear 1 includes but is not limited to Y-shape and T-shape; wherein, when the shape of the bending pole ear 1 is T-shape, the angle between the bending portion 11 and the extension portion 12 is 90°. The angle range of the two bending portions 11 and the extension portion 12 is 30° to 120°, and the angles between the two bending portions 11 and the extension portion 12 can be equal or unequal.

[0041] As an implementation method, Figures 1 to 6 , Fig.12 As shown, an insulating glue 13 is provided on the extension portion 12 near the bending portion 11 for tab packaging.

[0042] The utility model also provides a pole group 100, such as Fig.11 As shown, it includes the bent pole tab 1 as described above and two bare battery cells 2, and the two bare battery cells 2 are electrically connected to the bent pole tab 1 respectively.

[0043] As an implementation method, Figures 7 to 12As shown, the two bare cells 2 are respectively a first bare cell 2A and a second bare cell 2B, and both bare cells 2 include a dummy electrode 21, a bent portion 11 of the bent electrode 1 is connected to the dummy electrode 21 of the first bare cell 2A, and another bent portion 11 of the bent electrode 1 is connected to the dummy electrode 21 of the second bare cell 2B, and the two dummy electrodes 21 connected to the same bent electrode 1 have the same polarity. Specifically, as Figures 9 to 11 As shown, a bare cell 2 (first bare cell 2A) includes two fake pole ears 21, one fake pole ear 21 is positive polarity, and the other fake pole ear 21 is negative polarity, and another bare cell 2 (second bare cell 2B) also has two fake pole ears 21 with positive polarity and negative polarity respectively, and the two bent portions 11 of a bent pole ear 1 correspond to the two fake pole ears 21 with positive polarity of the two bare cells 2, and the two bent portions 11 of another bent pole ear 1 correspond to the two fake pole ears 21 with negative polarity of the two bare cells 2, forming a pole group 100.

[0044] As an implementation method, Fig.11 As shown, each dummy electrode tab 21 is bent in a direction away from the extension portion 12 , so that two bare battery cells 2 are tightly connected to form an electrode group 100 .

[0045] As an implementation method, Fig.11 As shown, the pole group 100 and the pole group 20 have a thickness direction D2 , and the two bending portions 11 are parallel to the thickness direction D2 of the pole group 100 .

[0046] As an implementation manner, the dummy electrode tab 21 and the bent portion 11 are connected by ultrasonic welding or laser welding.

[0047] The utility model further provides a battery core, comprising the pole group 100 and the shell 3 as described above, wherein the pole group 100 is arranged in the shell 3, and the shell 3 is provided with an electrolyte.

[0048] The utility model also provides a method for preparing a battery core, comprising the following steps:

[0049] S1, using the same size of positive electrode sheet, negative electrode sheet and separator, through lamination or winding process to make two bare cells 2; Figure 7 and Figure 8 As shown, the dummy tabs 21 with the same polarity in two bare cells 2 (the first bare cell 2A and the second bare cell 2B) are placed opposite to each other; Fig. 9 and Fig.10As shown, two bare cells 2 and the bent pole tab 1 are welded into a whole. For example, a bent portion 11 of a bent pole tab 1 is welded to the false pole tab 21 (positive polarity) of the first bare cell 2A as a whole, and another bent portion 11 is welded to the false pole tab 21 (positive polarity) of the second bare cell 2B as a whole; a bent portion 11 of another bent pole tab 1 is welded to the false pole tab 21 (negative polarity) of the first bare cell 2A as a whole, and another bent portion 11 is welded to the false pole tab 21 (negative polarity) of the second bare cell 2B as a whole, that is, the bent portions 11 of the two bent pole tabs 1 are connected to the false pole tabs 21 of the two bare cells 2 to form a pole group 100.

[0050] S2, such as Fig.11 As shown, the false tabs 21 of the two bare cells 2 are bent in a direction away from the extension 12 of the bent tab 1, and the two bare cells 2 are combined into a pole group 100. The thickness of the pole group 100 is the sum of the thicknesses of the two bare cells 2 (the first bare cell 2A and the second bare cell 2B). At this time, each bending portion 11 is parallel to the thickness direction D1 of the pole group 100;

[0051] S3, encapsulating the electrode group 100 into the housing 3 to form a battery cell.

[0052] In the above S1, the bent tab 1 used may be the bent tab 1 having two offset bent portions 11 (such as Figure 1 and Figure 2 As shown), it can also be a bent pole ear 1 with two aligned bent portions 11 (as shown Figure 3 shown);

[0053] The dummy pole ears 21 with the same polarity in the two bare cells 2 are placed in parallel opposite to each other. The two dummy pole ears 21 with the same polarity are placed head to head. The two dummy pole ears 21 with the same polarity can be aligned with each other (such as Figure 7 As shown), two dummy pole ears 21 of the same polarity may also be offset from each other (as shown Figure 6 shown).

[0054] In the above S2, the fake pole ears 21 of the two bare battery cells 2 are bent, and the bent places are places where the fake pole ears 21 are not involved in welding or places where welding is performed. The places where the fake pole ears 21 are not involved in welding are the better choice, because the foil material of the fake pole ears 21 is softer and easier to bend. The welded fake pole ears 21 are compounded with the bent pole ears 1, and the foil material of the bent pole ears is harder and not easy to bend.

[0055] Specifically, two types of bent tabs 1 can be used in the battery cell preparation method: one is to use the bent tab 1 with two bent portions 11 in opposite directions and offset to connect the bare battery cell 2 (such as Fig. 9 As shown), Figure 1 and Figure 2As shown, the two bent portions 11 are made of the same piece of metal foil. Specifically, one side of the bent pole ear 1 is cut and divided into parts of equal width, and then bent in opposite directions to obtain two bent portions 11; second, the bent pole ear 1 with two aligned bent portions 11 is used to connect the bare battery cell 2 (such as Fig.10 As shown), Figure 3 to Figure 4 As shown, the two bending parts 11 are made of two pieces of L-shaped metal foils of different sizes. Specifically, the large L-shaped metal foil includes a bending part 11 and an extension part 12. The extension part 12 of the large L-shaped metal foil is provided with a welding area 14. The small L-shaped metal foil includes a bending part 11 and a welding part 15. By welding the welding part 15 to the welding area 14, the two L-shaped metal foils are welded as a whole. The battery cell preparation method can significantly improve the problems of poor welding of the pole ear and welding cracks of the outermost pole ear caused by the large number of pole sheet layers and insufficient welding capacity. At the same time, separate welding reduces the equipment welding power, the degree of wear of the welding head and the base, and improves the service life of the equipment.

[0056] The utility model specially designs the pole ear into a bent structure so that it has a multi-position welding function, and at the same time divides a thicker battery cell into two thin bare battery cells 2 in parallel, and the fake pole ears 21 of the same polarity of the two thin bare battery cells 2 are respectively welded to different positions of the same bent pole ear 1, thereby reducing the number of welding layers and solving the problem of poor welding or scrapping caused by excessive thickness of the battery cell pole ear; the design method of the bent pole ear 1 can reduce the pole ear processing and manufacturing procedures, and is easier to mass produce.

[0057] The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with the profession can make some changes or modifications to the technical contents disclosed above without departing from the scope of the technical solution of the present invention, which are equivalent embodiments of equivalent changes. However, any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. A bent tab, characterized in that: It comprises an extension portion (12) and two bent portions (11), wherein the two bent portions (11) are respectively located on both sides of the same end of the extension portion (12), one end of the bent portion (11) is connected to the extension portion (12), and the other end of the bent portion (11) extends in a direction away from the extension portion (12).

2. The bent tab according to claim 1, characterized in that: The protruding portion (12) has a length direction (L1) and a thickness direction D1, and the two bent portions (11) are located at the same end of the protruding portion (12) in the length direction (L1) and are respectively located on both sides of the protruding portion (12) in the thickness direction D1.

3. The bent tab according to claim 2, characterized in that: Along the length direction (L1) of the protruding portion (12), the two bent portions (11) are arranged in sequence and connected to one end of the protruding portion (12).

4. The bent tab according to claim 2, wherein: Along the length direction (L1) of the protruding portion (12), the two bent portions (11) are aligned and connected to one end of the protruding portion (12).

5. The bent tab according to claim 1, wherein: The bent portion (11) and the protruding portion (12) form an angle at the connection point, and the angle ranges from 30° to 120°.

6. The bent tab according to claim 1, wherein: An insulating glue (13) is provided on the protruding portion (12) at a position close to the bent portion (11).

7. A pole group, characterized in that: It comprises a bent pole lug (1) as claimed in any one of claims 1 to 6 and two bare battery cells (2), wherein the two bare battery cells (2) are electrically connected to the bent pole lug (1) respectively.

8. The electrode group according to claim 7, characterized in that: The two bare cells (2) are respectively a first bare cell (2A) and a second bare cell (2B), and both bare cells (2) include a dummy pole lug (21), one of the bent portions (11) of the bent pole lug (1) is connected to the dummy pole lug (21) of the first bare cell (2A), and the other bent portion (11) of the bent pole lug (1) is connected to the dummy pole lug (21) of the second bare cell (2B), and the two dummy pole lugs (21) connected to the same bent pole lug (1) have the same polarity.

9. The pole group according to claim 8, characterized in that: Each of the dummy pole tabs (21) is bent in a direction away from the protruding portion (12).

10. The electrode group according to claim 9, characterized in that: The pole group (100) has a thickness direction D2, and each of the bent portions (11) is parallel to the thickness direction D2 of the pole group (100).

11. A battery cell, characterized in that: Comprising a pole group (100) as claimed in any one of claims 7 to 10 and an external shell (3) ， The pole group (100) is arranged in the housing (3).

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