CN211350702U

CN211350702U - Packaging structure of battery cell

Info

Publication number: CN211350702U
Application number: CN202020356865.2U
Authority: CN
Inventors: 杨洪战
Original assignee: Ningde Amperex Technology Ltd
Current assignee: Ningde Amperex Technology Ltd
Priority date: 2020-03-19
Filing date: 2020-03-19
Publication date: 2020-08-25
Anticipated expiration: 2030-03-19

Abstract

A packaging structure of a battery cell comprises a sealant and a packaging bag, wherein the packaging bag comprises a containing space and a sealing edge for sealing the containing space, the direction of a tab extending from the containing space to the outer side of the packaging bag is defined as a first direction, the tab comprises a first area, a second area and a third area which are sequentially connected, the first area is electrically connected with an electrode assembly in the containing space, the third area is exposed out of the packaging bag, the sealant surrounds the second area, and the second area is arranged in the sealing edge; the sealing edge comprises a first surface and a second surface which are oppositely arranged, the first surface is provided with a protruding portion at a position corresponding to the sealant, the second surface is a flat surface, the first surface comprises a first sealing area and a non-sealing area which are sequentially connected along a first direction, the second surface comprises a second sealing area, the width of the first sealing area is n, the width of the second sealing area is m, and n is less than m. The packaging structure of the battery cell is beneficial to improving the reliability of the battery cell.

Description

Packaging structure of battery cell

Technical Field

The application relates to the field of batteries, in particular to a packaging structure of a battery core.

Background

The battery has the advantages of large specific energy, high working voltage, low self-discharge rate, small volume, light weight and the like, and is widely applied to daily life. The product in the market at present mainly packages a packaging film, a tab and another packaging film by hot pressing of a heat sealing head at two sides, and grooves are arranged at the positions corresponding to the tab at the two sides of the sealing head to accommodate redundant glue overflow. However, after the battery cell is packaged in the prior art, the battery cell can have an obvious protruding part on the surface of the battery cell seal, and the protruding part occupies a certain thickness, so that the installation of the battery cell, particularly the ultra-thin battery cell later-stage protection plate, is not facilitated. In addition, the unevenness of the seal can also affect the fixation of the battery cell when the battery cell is placed into the equipment end, and further affect the reliability of the battery cell.

SUMMERY OF THE UTILITY MODEL

In view of the above, it is necessary to provide a package structure of a battery cell that solves the above problems.

A packaging structure of a battery cell comprises an electrode assembly, a tab, a sealant and a packaging bag, wherein the tab is electrically connected with the electrode assembly, the packaging bag forms an accommodating space for accommodating the electrode assembly, the packaging bag comprises a sealing edge for sealing the accommodating space, the direction of the tab extending from the accommodating space to the outer side of the packaging bag is defined as a first direction, the tab comprises a first area, a second area and a third area which are sequentially connected, the first area is electrically connected with the electrode assembly, the third area is exposed out of the packaging bag, the sealant surrounds the second area, and the second area is arranged in the sealing edge; the sealing edge comprises a first surface and a second surface which are arranged oppositely, the first surface is provided with a protruding portion, the protruding portion is arranged at the position corresponding to the sealing glue, the second surface is a flat surface, the first surface comprises a first sealing area and a non-sealing area which are sequentially connected in the first direction, the second surface comprises a second sealing area, the width of the first sealing area is n, the width of the second sealing area is m, and n is less than m.

This application packaging structure of electric core, the bellying set up in the first surface, just width n in first seal district is less than the width m in second seal district, when having guaranteed the reliability of encapsulation, has still guaranteed the planarization on the second surface of the sealed limit after the encapsulation to be favorable to the installation of follow-up protection shield.

Drawings

Fig. 1 is a schematic structural diagram of a cell packaging structure according to an embodiment of the present application.

Fig. 2 is a schematic cross-sectional view of a package structure of a battery cell according to an embodiment of the present application along a direction II-II.

Fig. 3 is a schematic cross-sectional view of a package structure of a battery cell according to an embodiment of the present application along a direction III-III.

Fig. 4 is a schematic cross-sectional view of a package structure of a battery cell according to an embodiment of the present application in a direction IV-IV.

Fig. 5 is a schematic cross-sectional view illustrating that a cell is encapsulated by a sealing head according to an embodiment of the present application.

Description of the main elements

Packaging structure 100 of battery cell

Electrode assembly 10

Tab 20

Sealing glue 30

Packaging bag 40

Accommodating space 41

Sealing edge 43

First direction X

First region 21

Second region 23

Third zone 25

First surface 431

Second surface 433

Convex part 430

First seal area 434

Non-seal area 435

Second seal area 436

Second direction Y

First encapsulation film 401

Second encapsulation film 403

First resin layer 401a

First metal layer 401b

Second resin layer 401c

Third resin layer 403a

Second metal layer 403b

Fourth resin layer 403c

First end socket 51

Second end socket 53

The following detailed description will further illustrate the present application in conjunction with the above-described figures.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

Some embodiments of the present application will be described in detail below with reference to the accompanying drawings. The embodiments described below and the features of the embodiments can be combined with each other without conflict.

Referring to fig. 1 to 4, a package structure 100 of a battery cell includes an electrode assembly 10, a tab 20, a sealant 30, and a packaging bag 40. Wherein the tabs 20 are electrically connected to the electrode assembly 10. The envelope 40 includes a receiving space 41 and a sealing edge 43 sealing the receiving space 41. The electrode assembly 10 is accommodated in the accommodation space 41. The direction in which the tab 20 extends from the accommodating space 41 to the outside of the packaging bag 40 is defined as a first direction X, along which the tab 20 includes a first region 21, a second region 23, and a third region 25, which are connected in sequence, wherein one end of the first region 21, which is away from the second region 23, is electrically connected to the electrode assembly 10, and the third region 25 is exposed out of the packaging bag 40. The second region 23 is disposed in the sealing edge 43, and the sealant 30 surrounds the second region 23 to bond the second region 23 and the sealing edge 43.

Referring to fig. 2, the sealing edge 43 includes a first surface 431 and a second surface 433 which are opposite to each other. Referring to fig. 3, the first surface 431 is provided with a protrusion 430 corresponding to the sealant 30. Referring to fig. 2, the first surface 431 includes a first sealing region 434 and a non-sealing region 435 sequentially connected along the first direction X. In the first direction X, the width of the first seal region 434 is n.

In some embodiments, the width n of the first sealing region 434 may be 0.5mm to 10 mm.

In the first direction X, the width of the sealing adhesive 30 may be greater than the width n of the first sealing region 434. In the present embodiment, in the first direction X, the width of the sealant 30 is greater than the sum of the width of the first sealing region 434 and the width of the non-sealing region 435.

The second surface 433 is a flat surface including a second seal area 436. In the first direction X, the width of the second seal region 436 is m, where n < m.

In the present embodiment, the orthographic projection of the first seal region 434 on the second surface 433 all falls into the second seal region 436. Further, the orthographic projection of the non-sealed region 435 on the second surface may also fall entirely into the second sealed region 436.

In some embodiments, m and n further satisfy the following relationship: m-n is more than 0 and less than or equal to 2 mm.

A second direction Y is defined, and the second direction Y is perpendicular to the second surface 433. The thickness of the package structure 100 of the battery cell in the second direction Y is T, where m, n, and T may further satisfy the following relation: n is more than 0.2T and less than m and less than 0.8T.

In the first direction X, the width of the sealing adhesive 30 may be greater than the width m of the second sealing region 436.

In some embodiments, the width of the sealant 30 exposed from the sealing edge 43 to the outside of the packaging bag 40 along the first direction X is greater than or equal to 0.1 mm. Further, along the first direction X, the width of the sealant 30 exposed from the sealing edge 43 to the outside of the package bag 40 is 0.1mm to 3 mm.

The packaging bag 40 includes a first packaging film 401 and a second packaging film 403 disposed opposite to the first packaging film 401, and the first packaging film 401 and the second packaging film 403 are sealed together to form the accommodating space 41 and the sealing edge 43.

In some embodiments, the first encapsulation film 401 may include a first resin layer 401a, a first metal layer 401b, and a second resin layer 401c, which are sequentially stacked. The surface of the first resin layer 401a facing away from the first metal layer 401b is the outer surface of the package bag 40 exposed to the outside. The region of the second resin layer 401c corresponding to the sealing edge 43 corresponding to the protrusion 430 is bonded to the sealant 30. The area of the first packaging film 401 corresponding to the protruding portion 430 protrudes toward the side away from the tab 20 along the second direction Y to accommodate the sealant 30. The other region in the second resin layer 401c corresponding to the sealing edge 43 is bonded to the second encapsulation film 403 in the sealing edge 43.

The first resin layer 401a may be selected from, but not limited to, a nylon film layer, a polyethylene terephthalate film layer, or a combination thereof. The second resin layer 401c may be selected from, but not limited to, a random polypropylene film layer, a cast polypropylene resin film layer, or a combination of the two.

In some embodiments, the distance between the first metal layer 401b and any position of the tab 20 is greater than 15 μm.

The first metal layer 401b may be selected from, but not limited to, an aluminum foil, a stainless steel plate, or a combination thereof.

The sealant 30 includes at least one adhesive layer, and the melting point of the adhesive layer bonded to the second resin layer 401c is MP₁The melting point of the second resin layer is MP₂Wherein, | MP₁-MP₂The absolute value is less than or equal to 30 ℃. In some embodiments, 0 < MP₂-MP₁≤20℃。

In the present embodiment, as shown in fig. 3, the sealant 30 is formed of a single layer of glue. When the sealant 30 includes at least two layers of adhesive layers, the two layers may be made of the same or different materials. As shown in fig. 5, the sealant 30 includes three layers of adhesive layers, and the three layers of adhesive layers are sequentially stacked.

The sealant 30 may be selected from, but not limited to, at least one of a polypropylene film layer and a polyethylene film layer.

In the present embodiment, the second encapsulation film 403 may include a third resin layer 403a, a second metal layer 403b, and a fourth resin layer 403c, which are sequentially stacked. The surface of the third resin layer 403a facing away from the second metal layer 403b is the outer surface of the package bag 40 exposed to the outside. The region of the fourth resin layer 403c corresponding to the sealing edge 43, which corresponds to the sealant 30, is bonded to the sealant 30. The other region of the fourth resin layer 403c corresponding to the sealing edge 43 is bonded to the second resin layer 401c corresponding to the sealing edge 43.

The melting point of the glue layer of the sealant 30 bonded to the fourth resin layer 403c is MP₃The melting point of the fourth resin layer 403c is MP₄Wherein, | MP₃-MP₄The absolute value is less than or equal to 30 ℃. Further preferred, 0 < MP₄-MP₃≤20℃。

The third resin layer 403a may be selected from, but not limited to, a nylon film layer, a polyethylene terephthalate film layer, or a combination thereof. The fourth resin layer 403c may be selected from, but not limited to, a random polypropylene film layer, a cast polypropylene resin film layer, or a combination thereof.

In some embodiments, the distance between the second metal layer 403b and any position of the tab 20 is greater than 15 microns.

The second metal layer 403b may be selected from, but not limited to, an aluminum foil, a stainless steel plate, or a combination thereof.

When the sealing edge 43 is formed by sealing, the second resin layer 401c overflows toward the non-sealing region 435, so that the region of the first sealing film 401 corresponding to the non-sealing region 435 is tilted away from the tab 20 (as shown in fig. 2 and 4). When the sealing edge 43 is sealed, the fourth resin layer 403c overflows from the sealing edge 43 toward the outside of the package bag 40 to form an adhesive overflow portion a (as shown in fig. 2).

In some embodiments, as shown in fig. 5, an area between the first encapsulation film 401 and the second encapsulation film 403 where the tab 20 is disposed is encapsulated by a first sealing head 51 and a second sealing head 53, wherein a groove is formed on a surface of the first sealing head 51 acting on the first encapsulation film 401 facing the first encapsulation film 401, corresponding to the sealant 30, and a surface of the second sealing head 53 acting on the second encapsulation film 403 facing the second encapsulation film 403 is a flat plane, so that an area of the sealing edge 43 corresponding to the sealant 30 after sealing is only protruded toward one side. In addition, in the first direction X, the width of the first sealing head 51 is smaller than the width of the second sealing head 53.

The packaging structure 100 of the battery core of the application, the protruding portion 430 is arranged on the first surface 431, the width n of the first sealing area 434 is smaller than the width m of the second sealing area 436, the reliability of the package is guaranteed, and meanwhile the flatness of the second surface 433 of the sealing edge 43 after the package is guaranteed, so that the subsequent installation of the protection board is facilitated.

In addition, it is obvious to those skilled in the art that other various corresponding changes and modifications can be made according to the technical idea of the present application, and all such changes and modifications should fall within the protective scope of the present application.

Claims

1. A packaging structure of a battery cell comprises an electrode assembly, a tab, a sealant and a packaging bag, wherein the tab is electrically connected with the electrode assembly, the packaging bag forms an accommodating space for accommodating the electrode assembly, the packaging bag comprises a sealing edge for sealing the accommodating space, the direction of the tab extending from the accommodating space to the outer side of the packaging bag is defined as a first direction, the tab comprises a first area, a second area and a third area which are sequentially connected, the first area is electrically connected with the electrode assembly, the third area is exposed out of the packaging bag, the sealant surrounds the second area, and the second area is arranged in the sealing edge;

the sealing edge comprises a first surface and a second surface which are oppositely arranged, the first surface is provided with a protruding portion, the protruding portion is arranged at a position corresponding to the sealing glue, the second surface is a flat surface, the first surface comprises a first sealing area and a non-sealing area which are sequentially connected along a first direction, the second surface comprises a second sealing area, the width of the first sealing area is n, the width of the second sealing area is m, and n is less than m.

2. The cell packaging structure of claim 1, wherein m and n further satisfy the following relationship: m-n is more than 0 and less than or equal to 2 mm.

3. The cell encapsulation structure of claim 1, wherein a thickness direction of the cell is defined as a second direction, the second direction is perpendicular to the first direction, the cell has a thickness T in the second direction, and n, m, and T further satisfy the following relationship: n is more than 0.2T and less than m and less than 0.8T.

4. The cell encapsulation structure of claim 1, wherein a width n of the first sealing region in the first direction is 0.5mm to 10 mm.

5. The cell packaging structure of claim 1, wherein in the first direction, the width of the sealant is greater than the width of the first sealing region.

6. The cell encapsulation structure of claim 5, wherein along the first direction, the width of the sealant outside the sealing edge is greater than or equal to 0.1 mm.

7. The battery cell packaging structure of claim 1, wherein the packaging bag includes a first packaging film and a second packaging film disposed opposite to the first packaging film, the first packaging film and the second packaging film are sealed together to form the accommodating space and the sealing edge, the first packaging film includes a first resin layer, a first metal layer and a second resin layer, which are sequentially stacked, the second resin layer is combined with the sealant, and a distance between the first metal layer and any position of the tab is greater than 15 μm.

8. The cell packaging structure of claim 7, wherein the sealant comprises at least one adhesive layer, and the melting point of the adhesive layer combined with the second resin layer is MP₁The melting point of the second resin layer is MP₂Wherein, MP is more than or equal to 0₁-MP₂|≤30℃。

9. The cell packaging structure of claim 8, wherein 0 < MP₂-MP₁≤20℃。

10. The packaging structure of the battery cell of claim 8, wherein the first resin layer is selected from a nylon film layer, a polyethylene terephthalate film layer, or a combination thereof; the first metal layer is selected from an aluminum foil, a stainless steel plate or a combination of the two, the second resin layer is selected from a random polypropylene film layer, a cast polypropylene resin film layer or a combination of the two, and the adhesive layer is selected from a polypropylene film layer, a polyethylene film layer or a combination of the two.