CN215119060U

CN215119060U - Battery with a battery cell

Info

Publication number: CN215119060U
Application number: CN202121044686.6U
Authority: CN
Inventors: 潘芳芳; 许久凌; 齐彬伟; 张勇杰
Original assignee: CALB Technology Co Ltd
Priority date: 2021-05-14
Filing date: 2021-05-14
Publication date: 2021-12-10
Anticipated expiration: 2031-05-14

Abstract

The disclosure relates to the technical field of batteries, and discloses a battery, which comprises a shell, a battery core and a welding connection part; the shell is provided with a first opening and a second opening and comprises a first shell and a second shell, the first shell is provided with a first flange edge, the second shell is provided with a second flange edge, and the first flange edge and the second flange edge are arranged oppositely; the battery cell is arranged in the shell and comprises a positive tab and a negative tab, the positive tab extends out of the shell through the first opening, a thermoplastic sealing layer is arranged between the positive tab and a first flange edge and a second flange edge at the first opening, the negative tab extends out of the shell through the second opening, and a thermoplastic sealing layer is arranged between the negative tab and the first flange edge and the second flange edge at the second opening; the welding connection part connects the first flange edge and the second flange edge in a welding mode, the end part of the welding connection part is connected with the thermoplastic sealing layer to form an annular sealing ring, and the width of the two end parts of the welding connection part is larger than that of the middle part of the welding connection part. The battery has good sealing performance, low process difficulty and high production efficiency.

Description

Battery with a battery cell

Technical Field

The disclosure relates to the technical field of batteries, in particular to a battery.

Background

In recent years, with the increasing environmental pollution, the new energy industry is receiving more and more attention. The lithium ion power battery has better safety performance, energy density, cycle life and other performances, and is widely popularized and used, so that the lithium ion power battery draws wide attention.

The lithium ion power battery comprises a battery core and a shell, wherein the battery core is arranged in the shell, and the shell plays a role in insulating and protecting the battery core, so the tightness of the shell is particularly important, but the tightness of the shell is poor at present.

It is to be noted that the information disclosed in the above background section is only for enhancement of understanding of the background of the present disclosure, and thus may include information that does not constitute prior art known to those of ordinary skill in the art.

SUMMERY OF THE UTILITY MODEL

The purpose of this disclosure is to overcome the above-mentioned shortcoming of the prior art poor leakproofness, provides a better battery of leakproofness.

According to an aspect of the present disclosure, there is provided a battery including:

the shell is provided with a first opening and a second opening and comprises a first shell and a second shell, the first shell is provided with a first flange edge, the second shell is provided with a second flange edge, and the first flange edge is opposite to the second flange edge;

the battery cell is arranged in the shell and comprises a positive tab and a negative tab, the positive tab extends out of the shell through the first opening, a thermoplastic sealing layer is arranged between the positive tab and the first flange edge and the second flange edge at the first opening, the negative tab extends out of the shell through the second opening, and a thermoplastic sealing layer is arranged between the negative tab and the first flange edge and the second flange edge at the second opening;

and the welding connection part is used for welding the first flange edge and the second flange edge, the end parts of the welding connection part are connected with the thermoplastic sealing layer to form an annular sealing ring, and the width of the two end parts of the welding connection part is greater than that of the middle part of the welding connection part.

According to the battery disclosed by the invention, the thermoplastic sealing layer is arranged between the positive electrode lug and the first flange edge and the second flange edge at the first opening, the thermoplastic sealing layer is arranged between the negative electrode lug and the first flange edge and the second flange edge at the second opening, and the positive electrode lug and the first flange edge and the second flange edge as well as the negative electrode lug and the first flange edge and the second flange edge are sealed through the thermoplastic sealing layer; the welding connection part is used for welding and connecting the first flange edge and the second flange edge, and two ends of the welding connection part are connected with the thermoplastic sealing layer to form an annular sealing ring to seal the whole battery; the widths of the two end parts of the welding connection part are larger than the width of the middle part of the welding connection part, so that the contact area between the thermoplastic sealing layer and the welding connection part is increased, and the sealing performance of the whole battery is improved; moreover, the width of the part, close to the thermoplastic sealing layer, of the welding connection part is wide, so that the thermoplastic sealing layer can easily flow to the welding connection part to be in contact connection with the welding connection part to form an annular sealing ring, the process difficulty is reduced, and the efficiency is improved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and together with the description, serve to explain the principles of the disclosure. It is to be understood that the drawings in the following description are merely exemplary of the disclosure, and that other drawings may be derived from those drawings by one of ordinary skill in the art without the exercise of inventive faculty.

Fig. 1 is a schematic diagram of an explosive structure of an exemplary embodiment of a battery of the present disclosure.

Fig. 2 is a schematic structural diagram of a first exemplary embodiment of a battery of the present disclosure.

Fig. 3 is a schematic structural diagram of a second exemplary embodiment of the disclosed battery.

Fig. 4 is a schematic structural diagram of a third exemplary embodiment of the disclosed battery.

Fig. 5 is a schematic structural diagram of a fourth example embodiment of the disclosed battery.

Fig. 6 is a schematic structural diagram of a fifth exemplary embodiment of the battery of the present disclosure.

Fig. 7 is a schematic structural diagram of a sixth exemplary embodiment of the disclosed battery.

Fig. 8 is a schematic structural diagram of a seventh exemplary embodiment of the battery of the present disclosure.

Fig. 9 is a schematic structural diagram of an eighth example embodiment of the battery of the present disclosure.

Description of reference numerals:

10. a first housing; 11. a first flanged edge; 12. a first housing body;

20. a second housing; 21. a second flanged edge; 22. a second housing body;

30. welding the connecting part; 31. a first weld; 32. a second weld; 321. a first sub-weld; 322. a second sub-weld;

40. a second accommodating chamber;

50. an electric core; 51. a cell main body; 52. a positive tab; 53. a negative tab;

60. a pole assembly;

70. a glue overflow groove; 71. a first groove; 72. a second groove;

80. a thermoplastic sealing layer; 81. a thermoplastic sealing strip.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus their detailed description will be omitted. Furthermore, the drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale.

Although relative terms, such as "upper" and "lower," may be used in this specification to describe one element of an icon relative to another, these terms are used in this specification for convenience only, e.g., in accordance with the orientation of the examples described in the figures. It will be appreciated that if the device of the icon were turned upside down, the element described as "upper" would become the element "lower". When a structure is "on" another structure, it may mean that the structure is integrally formed with the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure via another structure.

The terms "a," "an," "the," "said," and "at least one" are used to indicate the presence of one or more elements/components/parts/etc.; the terms "comprising" and "having" are intended to be inclusive and mean that there may be additional elements/components/etc. other than the listed elements/components/etc.; the terms "first," "second," and "third," etc. are used merely as labels, and are not limiting on the number of their objects.

The disclosed embodiment provides a battery, as shown in fig. 1 to 9, which may include a case, a battery cell 50, and two welding connection portions 30; the shell is provided with a first opening and a second opening and comprises a first shell 10 and a second shell 20, wherein the first shell 10 is provided with a first flange edge 11, the second shell 20 is provided with a second flange edge 21, and the first flange edge 11 and the second flange edge 21 are arranged oppositely; the battery cell 50 is arranged in the shell, the battery cell 50 comprises a positive tab 52 and a negative tab 53, the positive tab 52 extends out of the shell through a first opening, a thermoplastic sealing layer 80 is arranged between the positive tab 52 and a first flange edge 11 and a second flange edge 21 at the first opening, the negative tab 53 extends out of the shell through a second opening, and the thermoplastic sealing layer 80 is arranged between the negative tab 53 and the first flange edge 11 and the second flange edge 21 at the second opening; the welding connection part 30 connects the first flange edge 11 and the second flange edge 21 by welding, the end parts of the welding connection part 30 are connected with the thermoplastic sealing layer 80 to form an annular sealing ring, and the width of the two end parts of the welding connection part 30 is larger than that of the middle part.

In the battery disclosed by the invention, the thermoplastic sealing layer 80 is arranged between the positive tab 52 and the first flange edge 11 and the second flange edge 21 at the first opening, the thermoplastic sealing layer 80 is arranged between the negative tab 53 and the first flange edge 11 and the second flange edge 21 at the second opening, and the positive tab 52 and the first flange edge 11 and the second flange edge 21 as well as the negative tab 53 and the first flange edge 11 and the second flange edge 21 are sealed through the thermoplastic sealing layer 80; the welding connection part 30 connects the first flange edge 11 and the second flange edge 21 in a welding way, and two ends of the welding connection part 30 are connected with the thermoplastic sealing layer 80 to form an annular sealing ring to seal the whole battery; the widths of the two end parts of the welding connection part 30 are larger than the width of the middle part, namely the width of the part, close to the thermoplastic sealing layer 80, of the welding connection part 30 is larger than the width of the part, far away from the thermoplastic sealing layer 80, of the welding connection part 30, so that the contact area between the thermoplastic sealing layer 80 and the welding connection part 30 is increased, the sealing performance of the whole battery is improved, moreover, because the width of the part, close to the thermoplastic sealing layer 80, of the welding connection part 30 is wide, the thermoplastic sealing layer 80 can easily flow to the welding connection part 30 to be in contact connection with the welding connection part 30 to form an annular sealing ring, the process difficulty is reduced, and the efficiency is improved.

In the present example embodiment, the housing may have a cavity and first and second openings communicating with the cavity. The first opening and the second opening may be oppositely disposed, for example, the first opening and the second opening may be located at opposite ends of the housing in a length direction. Of course, the first opening and the second opening may be located at opposite ends of the housing in the width direction. In addition, the first opening and the second opening may not be disposed oppositely, and may be disposed on the same side of the housing.

The housing may include a first case 10 and a second case 20. The first housing 10 may include a first housing body 12, and the first housing body 12 may be formed by shallow stamping. Specifically, the first case body 12 may include a bottom plate and a side plate connected around the bottom plate, the bottom plate and the side plate forming a first receiving cavity. A circle of first flange edges 11 are arranged around the first shell body 12, namely the first flange edges 11 are connected to one side of the side plate far away from the bottom plate, and the first flange edges 11 extend to one side far away from the first accommodating cavity. The first flange 11 may be a circumferentially closed structure, although it is not excluded that the first flange 11 is a circumferentially open structure.

The second housing 20 may include a second housing body 22, and the second housing body 22 may be formed by drawing. Specifically, the second housing body 22 may also include a bottom plate and a side plate connected around the bottom plate, the bottom plate and the side plate form a second accommodating cavity 40, and the depth of the second accommodating cavity 40 is greater than that of the first accommodating cavity. A circle of second flange edges 21 is arranged around the second shell body 22, namely the second flange edges 21 are connected to the side of the side plate far away from the bottom plate, and the second flange edges 21 extend to the side far away from the second accommodating cavity. The second flange 21 may be a circumferentially closed structure, although it is not excluded that the second flange 21 is a circumferentially open structure.

The width of the first flange edge 11 is greater than or equal to 0.1mm and less than or equal to 10mm, and the width of the second flange edge 21 is greater than or equal to 0.1mm and less than or equal to 10 mm.

Note that, the housing chamber may be provided only in the first casing 10 or the second casing 20, and the housing chamber may not be provided in the other casing, and may be provided only in a plate shape. It is also possible that the depth of the second receiving chamber is equal to the depth of the first receiving chamber.

After the first housing 10 and the second housing 20 are fastened, the first housing cavity and the second housing cavity 40 are combined into a cavity of the housing, the first flange 11 of the first housing 10 and the second flange 21 of the second housing 20 are oppositely arranged, and the first flange 11 and the second flange 21 do not form a housing space for the battery.

In the present exemplary embodiment, a battery cell 50 is disposed in the cavity, a positive tab 52 is disposed at one end of the battery cell 50, and a negative tab 53 is disposed at the opposite end of the battery cell 50, that is, the positive tab 52 and the negative tab 53 are disposed at opposite ends of the battery cell 50.

The positive lug 52 extends out of the shell through the first opening, a thermoplastic sealing layer 80 is arranged between the positive lug 52 and the first flange edge 11 and the second flange edge 21 at the first opening, and the positive lug 52 at the first opening is sealed and insulated from the first flange edge 11 and the second flange edge 21 at the first opening through the thermoplastic sealing layer 80. The thermoplastic sealing layer 80 is formed not only on the surface of the positive tab 52 near the first flange edge 11 and the second flange edge 21, but also on both sides of the positive tab 52, i.e., the thermoplastic sealing layer 80 forms a circle around the positive tab 52. The negative electrode lug 53 extends out of the shell through the second opening, and a thermoplastic sealing layer 80 is arranged between the negative electrode lug 53 and the first flange edge 11 and the second flange edge 21 at the second opening; the negative electrode tab 53 at the second opening is sealed and insulated from the first flange 11 and the second flange 21 at the second opening by the thermoplastic sealing layer 80. The thermoplastic sealing layer 80 is formed not only on the surface of the negative electrode tab 53 near the first and

second flanges

11, 21 but also on both sides of the negative electrode tab 53, i.e., the thermoplastic sealing layer 8 is formed once around the negative electrode tab 53.

In the case where the positive tab 52 and the negative tab 53 are not disposed opposite to each other, the first opening and the second opening are not disposed opposite to each other, and the positive tab 52 needs to protrude out of the housing through the first opening, so that the position of the first opening needs to correspond to the position of the positive tab 52; the negative electrode tab 53 needs to protrude out of the case through the second opening, and thus, the position of the second opening needs to correspond to the position of the negative electrode tab 53.

In the present exemplary embodiment, the first flange 11 and the second flange 21 may be used for the connection of the first case 10 and the second case 20, that is, the connection of the first case 10 and the second case 20 is achieved by welding the first flange 11 and the second flange 21.

The first flange 11 and the second flange 21 are welded to form a welded connection 30 connected between the first flange 11 and the second flange 21. Because the welding is not carried out at the first opening part and the second opening part, two welding connection parts 30 are formed between the first opening part and the second opening part, the two welding connection parts 30 are connected with two thermoplastic sealing layers 80 at two ends of the two welding connection parts to form an annular sealing ring, namely the welding connection parts 30, the thermoplastic sealing layers 80, the welding connection parts 30 and the thermoplastic sealing layers 80 are connected end to form the annular sealing ring, and the interior of the battery is sealed.

The width of the part, close to the thermoplastic sealing layer 80, of the welding connection part 30 is larger than that of the part, far away from the thermoplastic sealing layer 80, so that the contact area of the welding connection part 30 and the thermoplastic sealing layer 80 is increased, and the sealing performance of the battery is improved; moreover, because the width of the part of the welding connection part 30 close to the thermoplastic sealing layer 80 is wider, the thermoplastic sealing layer 80 is easily contacted and connected with the welding connection part 30 to form an annular sealing ring, the process difficulty is reduced, and the efficiency is improved.

The specific structure of the welded connection 30 is as follows: each welded connection 30 may comprise one first weld 31 and two second welds 32, the first weld 31 being arranged along the first flange 11 and the second flange 21, the two second welds 32 being connected to an end of the first weld 31 adjacent to the thermoplastic sealing layer 80, at least part of the second welds 32 being connected to the thermoplastic sealing layer 80.

Referring to fig. 2, first weld 31 extends from the first opening to the second opening, first weld 31 extends from positive tab 52 to negative tab 53; the first weld 31 has two corners corresponding to the corners of the first flange 11 and the second flange 21, i.e. the first weld 31 is arranged along the first flange 11 and the second flange 21; second weld 32 is connected to both ends of first weld 31 near the first and second openings, that is, second weld 32 is connected to both ends of first weld 31 near positive tab 52 and negative tab 53. In the case of an oppositely arranged first and second opening, the two first weld seams 31 of the two welded connections 30 are identical.

The extending direction of the second weld 32 is consistent with the direction in which the positive electrode tab 52 protrudes out of the first opening or the direction in which the negative electrode tab 53 protrudes out of the second opening, that is, the extending direction of the second weld 32 intersects with the extending direction of the portion of the first weld 31 close to the first opening or the second opening; in the case where the first opening is disposed opposite the second opening, the direction in which the positive electrode tab 52 protrudes through the first opening coincides with the direction in which the negative electrode tab 53 protrudes through the second opening. The second weld 32 may extend across the width of the first flange 11 and the second flange 21. The first weld 31 may be connected to an end of the second weld 32 close to the cell body 51, so that the first weld 31 and the second weld 32 form an L-shaped connection structure. The length of the second welding seam 32 is the width of the part of the welding connection part 30 close to the thermoplastic sealing layer 80, the second welding seam 32 can be in contact connection with the thermoplastic sealing layer 80 in a whole, namely, line contact connection is formed, and compared with the point contact connection formed by only the contact connection of the end part of the first welding seam 31 and the thermoplastic sealing layer 80, the contact connection area is increased in a geometric series manner, so that the sealing reliability is improved.

Note that the width direction of the first flange 11 and the second flange 21 is a direction perpendicular to the edges of the first casing 10 and the second casing 20.

In other example embodiments of the present disclosure, referring to fig. 3, the embodiment shown in fig. 3 differs from the embodiment shown in fig. 2 mainly in that: the first welding seam 31 is connected to the middle of the second welding seam 32, so that the first welding seam 31 and the second welding seam 32 form a T-shaped connecting structure.

In other example embodiments of the present disclosure, referring to fig. 4, the embodiment shown in fig. 4 differs from the embodiment shown in fig. 2 mainly in that: the first welding seam 31 is connected to the end of the second welding seam 32 far away from the cell main body 51, so that the first welding seam 31 and the second welding seam 32 still form an L-shaped connection structure, which is only opposite to the bending direction in fig. 2.

In other example embodiments of the present disclosure, as shown in fig. 5, the structure of the first weld 31 is the same as that shown in fig. 2, and thus, a detailed description thereof is omitted. Second weld 32 may include a first sub-weld 321 and a second sub-weld 322; one end of the first sub-weld 321 is connected to the first weld 31, specifically to the end of the first weld 31; the first sub-welding line 321 extends to a side close to the cell main body 51; one end of the second sub-weld 322 is connected to the first weld 31, in particular to the end of the first weld 31; the second sub-weld 322 extends toward the side away from the cell main body 51. The first sub-weld 321 and the second sub-weld 322 form an included angle of less than 180 degrees. The first weld 31 is connected with the first sub-weld 321 and the second sub-weld 322 to form a three-pronged structure. The distance between the end of the first sub-welded joint 321 remote from the first welded joint 31 and the end of the second sub-welded joint 322 remote from the first welded joint 31 is the width of the end of the welded connection 30.

In other example embodiments of the present disclosure, as shown in fig. 6, the structure of the first weld 31 is the same as that shown in fig. 2, and thus, a detailed description thereof is omitted. Second weld 32 may include a first sub-weld 321 and a second sub-weld 322; the first sub-weld 321 is parallel to the portion of the first weld 31 adjacent to the thermoplastic sealing layer 80; the second sub-welding seam 322 is parallel to the first sub-welding seam 321, and is located on two opposite sides of the first welding seam 31 from the first sub-welding seam 321. Of course, in other example embodiments of the present disclosure, the second weld 32 may also include a third sub-weld, a fourth sub-weld, and so on. The distance between the edge of the first sub-weld 321 remote from the first weld 31 and the edge of the second sub-weld 322 remote from the first weld 31 is the width of the end of the welded connection 30.

In the present specification, the term "parallel" is not completely parallel but has a certain error, and may mean, for example, a state in which an angle formed by two straight lines is-10 ° or more and 10 ° or less, and therefore, includes a state in which the angle is-5 ° or more and 5 ° or less. The term "perpendicular" is not completely perpendicular but has a certain error, and may mean, for example, a state in which an angle formed by two straight lines is 80 ° or more and 100 ° or less, and thus includes a state in which an angle is 85 ° or more and 95 ° or less.

It should be noted that the structure of the second bead 32 is not limited to the above description, and any structure that can increase the width of the end of the welded connection portion 30 is within the scope of the present disclosure.

In the present exemplary embodiment, the battery may further include an adhesive overflow groove 70, the adhesive overflow groove 70 may be disposed on the first casing 10, when the battery is assembled, the first casing 10 is generally located below, the second casing 20 is generally located above the first casing 10, and the hot melt adhesive sealant may flow into the adhesive overflow groove 70 on the first casing 10 to form a thermoplastic sealing strip 81. Of course, in other exemplary embodiments of the present disclosure, the glue overflow groove 70 may also be disposed on the second casing 20, as in this case, when assembling the battery, the second casing 20 is generally located below, the first casing 10 is generally located above the second casing 20, and the hot melt sealant may flow into the glue overflow groove 70 on the second casing 20 to form the thermoplastic sealing strip 81. In addition, the glue overflow groove 70 may also be disposed on the first casing 10 and the second casing 20, and the glue overflow groove 70 disposed on the first casing 10 and the glue overflow groove 70 disposed on the second casing 20 are disposed opposite to each other, so as to form a glue overflow groove with a larger accommodating space.

Referring to fig. 7 and 8, the number of the glue overflow grooves 70 may be four, two glue overflow grooves 70 are disposed at the first opening, and the other two glue overflow grooves 70 are disposed at the second opening; the corresponding thermoplastic sealing strips 81 are also provided in four. Specifically, one end of two of the glue overflow grooves 70 may extend to the first opening, and the other end of the two glue overflow grooves 70 may extend to two ends of the two welding connection parts 30 adjacent to the first opening; one ends of the other two glue overflow grooves 70 may extend to the second opening, and the other ends of the two glue overflow grooves 70 may extend to both end portions of the two welding connection parts 30 adjacent to the second opening.

In the present exemplary embodiment, the glue overflow groove 70 may include a first groove 71 and a second groove 72; the extending direction of the first groove 71 is consistent with the direction of the positive tab 52 protruding out of the first opening or the direction of the negative tab 53 protruding out of the second opening; namely, the extending direction of the first groove 71 arranged on one side of the positive tab 52 is consistent with the direction of the positive tab 52 extending out of the first opening; the extending direction of the first groove 71 disposed on the negative electrode tab 53 side coincides with the direction of the negative electrode tab 53 protruding out of the second opening. Two second grooves 72 are provided, two second grooves 72 are connected to both ends of the first groove 71, and the second grooves 72 extend toward the side near the positive electrode tab 52 or the negative electrode tab 53. To facilitate the flow of hot melt sealant, the junction of the second groove 72 and the first groove 71 may be provided as an arcuate corner.

The thermoplastic sealing tape 81 is formed by the hot melt adhesive flowing into the adhesive overflow groove 70, and therefore, the structure of the thermoplastic sealing tape 81 is the same as that of the adhesive overflow groove 70, and thus, the structure of the thermoplastic sealing tape 81 will not be described in detail.

At least a portion of the edge of second weld 32 is collinear with the edge of first groove 71 distal from either positive tab 52 or negative tab 53, forming a thermoplastic seal 81 to seal the connection with weld connection 30.

When the positive tab 52 and the first opening are subjected to hot melt sealing, the hot melt sealant flows into the two glue overflow grooves 70 on the two sides of the first opening, a thermoplastic sealing layer 80 and two thermoplastic sealing strips 81 are formed after cooling, and the thermoplastic sealing strips 81 are connected with the thermoplastic sealing layer 80 and the welding connection part 30 at the first opening; similarly, when the negative tab 53 and the second opening are hot-melted and sealed, the hot-melted sealant flows into the two glue overflow grooves 70 on the two sides of the second opening, and forms a thermoplastic sealing layer 80 and two thermoplastic sealing strips 81 after cooling, and the thermoplastic sealing strip 81 connects the thermoplastic sealing layer 80 and the welding connection portion 30 at the second opening. Finally, an annular sealing structure with the end-to-end connection of the thermoplastic sealing strip 81, the thermoplastic sealing layer 80, the thermoplastic sealing strip 81, the welding connection part 30, the thermoplastic sealing strip 81, the thermoplastic sealing layer 80, the thermoplastic sealing strip 81 and the welding connection part 30 is formed.

Referring to fig. 9, the number of the glue overflow grooves 70 may be two, wherein one glue overflow groove 70 is disposed at the first opening, and the other glue overflow groove 70 is disposed at the second opening; the corresponding thermoplastic sealing strips 81 are also provided in two. Specifically, one of the glue overflow grooves 70 penetrates through the first opening, and two ends of this glue overflow groove 70 may extend to two ends of the two welding connection portions 30 adjacent to the first opening; another glue overflow groove 70 penetrates through the second opening, and both ends of this glue overflow groove 70 may extend to both ends of the two welding connection parts 30 adjacent to the first opening.

In the present exemplary embodiment, the glue overflow groove 70 may include two first grooves 71 and two second grooves 72; two first grooves 71 are provided on both sides of the positive tab 52 or the negative tab 53. The extending direction of the first groove 71 is consistent with the direction of the positive tab 52 protruding out of the first opening or the direction of the negative tab 53 protruding out of the second opening; namely, the extending direction of the first groove 71 arranged on one side of the positive tab 52 is consistent with the direction of the positive tab 52 extending out of the first opening; the extending direction of the first groove 71 disposed on the negative electrode tab 53 side coincides with the direction of the negative electrode tab 53 protruding out of the second opening. The two second grooves 72 are connected to both ends of the two first grooves 71 and penetrate the thermoplastic sealing layer 80, and the two second grooves 72 are connected with the two first grooves 71 to form a rectangle. To facilitate the flow of hot melt sealant, the junction of the second groove 72 and the first groove 71 may be provided as an arcuate corner.

When the positive tab 52 and the first opening are subjected to hot-melt sealing, the hot-melt sealant flows into one glue overflow groove 70 at the first opening, and forms a thermoplastic sealing layer 80 and a thermoplastic sealing strip 81 after cooling, wherein the thermoplastic sealing strip 81 penetrates through the thermoplastic sealing layer 80 and connects two end parts of the two welding connection parts 30 at the first opening; similarly, when the negative tab 53 and the second opening are hot-melted and sealed, the hot-melted sealant flows into the glue overflow groove 70 at the second opening, and after cooling, a thermoplastic sealing layer 80 and a thermoplastic sealing strip 81 are formed, and the thermoplastic sealing strip 81 penetrates through the thermoplastic sealing layer 80 and connects the two ends of the two welding connection portions 30 at the second opening. Finally, an annular sealing structure is formed in which the thermoplastic sealing strip 81, the thermoplastic sealing layer 80, the thermoplastic sealing strip 81, the welded connection 30, the thermoplastic sealing strip 81, the thermoplastic sealing layer 80, the thermoplastic sealing strip 81, and the welded connection 30 are connected end to end, in which case the thermoplastic sealing strip 81 and the thermoplastic sealing layer 80 have overlapping portions.

The cross-sectional shape of the glue overflow groove 70 perpendicular to the first flange edge 11 may be an arc, a rectangle, a trapezoid, etc. The depth of the glue overflow groove 70 is more than or equal to 0.1mm and less than or equal to 3mm, and the width is more than or equal to 0.5mm and less than or equal to 5 mm.

Through overflowing gluey groove 70 can form hot plastic seal strip 81, further guarantee to be connected between welded connection portion 30 and the thermoplastic sealing layer 80 through hot plastic seal strip 81, guarantee to form annular seal structure, improve the sealing performance of battery.

The battery cell 50 can be a laminated battery cell 50, which is convenient to assemble and can be processed to obtain a battery with a longer length. The cell 50 has a first pole piece, a second pole piece opposite to the first pole piece, and a diaphragm disposed between the first pole piece and the second pole piece, such that a plurality of pairs of the first pole piece and the second pole piece are stacked to form the laminated cell 50.

Alternatively, the battery may be a wound battery.

In one embodiment, as shown in fig. 1, the battery cell 50 includes a cell main body 51 and a tab extending from a length direction of the cell main body 51.

The first casing 10 or the second casing 20 is provided with the pole assembly 60, and before the first casing 10 and the second casing 20 are welded, the tab is connected with the pole assembly 60, wherein the tab and the pole assembly 60 can be directly connected, that is, the tab and the pole assembly 60 can be directly welded, or the tab and the pole assembly 60 can be connected through a metal adapter plate, and the specific connection mode can be welding, riveting or other modes can not be excluded, and the connection mode is not limited here.

It should be noted that the electric core main body 51 includes more than two pole pieces, the tab includes more than two single-piece tabs, the single-piece tabs respectively extend from the pole pieces corresponding to the single-piece tabs, the width of the single-piece tabs is smaller than the width of the pole pieces, a plurality of single-piece tabs are stacked together to form the tab, and are connected with the pole assembly 60, wherein the tab can be welded with the pole assembly 60. Wherein the single tab is made of a metal foil having good electrical and thermal conductivity, such as aluminum, copper, nickel, or the like.

In some embodiments, there may be two pole assemblies 60, two pole assemblies 60 are a positive pole assembly 60 and a negative pole assembly 60, and there are two tabs, two tabs are a positive tab 52 and a negative tab 53, respectively, the positive pole assembly 60 is connected to the positive tab 52, and the negative pole assembly 60 is connected to the negative tab 53.

When the battery is assembled, laser welding may be performed first, and after the laser welding is completed, two welding connection portions 30 are formed, and then hot-melt sealing is performed. In the case where the glue overflow groove 70 is provided, the laser welding needs to be welded to an end portion of the glue overflow groove 70. When in hot-melt sealing, a certain pressure can be applied to the first shell 10 or the second shell 20 for extrusion, so that the hot melt adhesive overflows into the adhesive overflow groove 70 and finally flows to the welding connection part 30; therefore, the hot melt adhesive after hot melting can overflow to the reserved position of the hot melt adhesive so as to realize the encapsulation of the battery shell, the selection of the sequence can simplify the process when the encapsulation is realized, and the molten glue can overflow until the molten glue is connected with the welding connection part 30 through hot melting and extrusion; if hot-melt sealing is carried out firstly and then laser welding is carried out, the contact position is easy to have welding explosion, and the process control is difficult.

The welded connection portion 30 may be formed by any one of laser welding, ultrasonic welding, and resistance welding.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

Claims

1. A battery, comprising:

the battery cell is arranged in the shell and comprises a battery cell main body, an anode lug and a cathode lug, the anode lug extends out of the shell through the first opening, a thermoplastic sealing layer is arranged between the anode lug and the first flange edge and the second flange edge at the first opening, the cathode lug extends out of the shell through the second opening, and a thermoplastic sealing layer is arranged between the cathode lug and the first flange edge and the second flange edge at the second opening;

2. The battery of claim 1, wherein the welded connection comprises:

a first weld disposed along the first flange and the second flange;

two second weld seams are arranged at one end of the first weld seam close to the thermoplastic sealing layer, and at least part of the second weld seams are connected with the thermoplastic sealing layer.

3. The battery of claim 2, wherein the second weld extends in a direction that coincides with a direction of the positive tab protruding out of the first opening or a direction of the negative tab protruding out of the second opening.

4. The battery of claim 3, wherein the first weld is connected to a middle portion of the second weld, or wherein the first weld is connected to an end of the second weld that is proximal to the cell body, or wherein the first weld is connected to an end of the second weld that is distal to the cell body.

5. The battery of claim 2, wherein the second weld comprises:

one end of the first sub-welding seam is connected to the first welding seam, and the first sub-welding seam extends towards one side close to the battery cell main body;

and one end of the second sub-welding line is connected to the first welding line, and the second sub-welding line extends towards one side far away from the battery cell main body.

6. The battery of claim 2, wherein the second weld comprises:

a first sub-weld parallel to a portion of the first weld proximate to the thermoplastic sealing layer;

and the second sub-welding seams are parallel to the first sub-welding seams and are positioned on two opposite sides of the first sub-welding seams.

7. The battery of claim 1, further comprising:

and the glue overflow groove is arranged on one or two of the first flange edge and the second flange edge, a thermoplastic sealing strip is arranged in the glue overflow groove, and the thermoplastic sealing strip is connected between the thermoplastic sealing layer and the welding connection part.

8. The battery of claim 7, wherein the glue overflow groove is provided in two, the thermoplastic sealing strip is provided in two, and the thermoplastic sealing strip penetrates through the thermoplastic sealing layer and is connected between the two welded connection portions.

9. The battery of claim 7, wherein the glue overflow slots are four in number and the thermoplastic sealing strips are four in number, each of the thermoplastic sealing strips being connected between the thermoplastic sealing layer and the welded connection.

10. The battery of claim 9, wherein the glue-overflow trough comprises:

the extending direction of the first groove is consistent with the direction of the positive electrode lug extending out of the first opening or the direction of the negative electrode lug extending out of the second opening;

the two second grooves are connected to two ends of the first groove, and extend towards one side close to the positive electrode lug or one side close to the negative electrode lug.