CN211350702U - Packaging structure of battery cell - Google Patents

Abstract

An encapsulation structure of an electric core comprises a sealant and an encapsulation bag, the encapsulation bag comprises a accommodating space and a sealing edge for sealing the accommodating space, and the direction in which the tabs extend from the accommodating space to the outside of the encapsulating bag is defined as a first direction, In the first direction, the tab includes a first area, a second area and a third area that are connected in sequence, the first area is electrically connected to the electrode assembly in the accommodating space, the third area is exposed to the packaging bag, and the sealant surrounds the second area, And the second area is arranged in the sealing edge; the sealing edge includes a first surface and a second surface that are oppositely arranged, the first surface is provided with a raised portion at a position corresponding to the sealant, the second surface is a flat surface, and the second surface is a flat surface. A surface includes a first sealing area and a non-sealing area connected in sequence along the first direction, and the second surface includes a second sealing area. In the first direction, the width of the first sealing area is n, and the width of the second sealing area is m, where n<m. The packaging structure of the battery cell is beneficial to improve the reliability of the battery cell.

Description

Cell packaging structure

technical field

The present application relates to the field of batteries, and in particular, to a packaging structure for a battery cell.

Background technique

Batteries have the advantages of large specific energy, high operating voltage, low self-discharge rate, small size and light weight, and are widely used in daily life. At present, the products on the market mainly encapsulate the packaging film, the tabs and the other packaging film by hot pressing the heat sealing heads on both sides, and set grooves on both sides of the sealing head corresponding to the positions of the tabs to accommodate excess glue. However, after the battery cells in the prior art are packaged, there will be obvious protrusions on the sealing surface of the battery cells, occupying a certain thickness, which is not conducive to the installation of the battery cells, especially the later protection boards of the ultra-thin battery cells. In addition, the unevenness of the seal will also affect the fixation of the battery cells when they are placed on the device side, thereby affecting the reliability of the battery cells.

Utility model content

In view of the above-mentioned situation, it is necessary to provide a packaging structure for a battery cell that solves the above-mentioned problems.

An encapsulation structure of a battery cell, comprising an electrode assembly, a tab electrically connected to the electrode assembly, a sealant, and an encapsulation bag, the encapsulation bag forms a accommodating space for accommodating the electrode assembly, and the encapsulation bag includes a sealing The sealing edge of the accommodating space defines the direction in which the tabs extend from the accommodating space to the outside of the packaging bag as a first direction. A first area, a second area and a third area, the first area is electrically connected to the electrode assembly, the third area is exposed to the packaging bag, the sealant surrounds the second area, and the first area is The second area is arranged in the sealing edge; the sealing edge includes a first surface and a second surface arranged oppositely, the first surface is provided with a raised portion, and the raised portion is arranged corresponding to the sealant The second surface is a flat surface at the position of the In the first direction, the width of the first seal area is n, and the width of the second seal area is m, where n<m.

In the packaging structure of the battery cell of the present application, the protruding portion is arranged on the first surface, and the width n of the first sealing area is smaller than the width m of the second sealing area, which ensures the reliability of the packaging and also The flatness of the second surface of the encapsulated sealing edge is ensured, thereby facilitating subsequent installation of the protection board.

Description of drawings

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

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

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

FIG. 4 is a schematic cross-sectional view of the packaging structure of the battery cell along the IV-IV direction according to an embodiment of the present application.

FIG. 5 is a schematic cross-sectional view of an embodiment of the present application for encapsulating a cell with a head.

Description of main component symbols

Cell packaging structure 100

Electrode assembly 10

Tab 20

Sealant 30

Packaging bag 40

accommodating space 41

sealing edge 43

first direction X

District 1 21

District 2 23

District 3 25

first surface 431

second surface 433

boss 430

First Seal Area 434

Unsealed Area 435

Second Sealed 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 header 51

Second Head 53

The following specific embodiments will further illustrate the present application in conjunction with the above drawings.

Detailed ways

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. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terms used herein in the specification of the application are for the purpose of describing specific embodiments only, and are not intended to limit 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 features in the embodiments may be combined with each other without conflict.

Referring to FIG. 1 to FIG. 4 , the packaging structure 100 of the battery cell includes an electrode assembly 10 , a tab 20 , a sealant 30 and a packaging bag 40 . Wherein, the tab 20 is electrically connected to the electrode assembly 10 . The packaging bag 40 includes an accommodating space 41 and a sealing edge 43 for sealing the accommodating space 41 . The electrode assembly 10 is accommodated in the accommodating space 41 . The direction in which the tabs 20 extend from the accommodating space 41 to the outside of the packaging bag 40 is defined as a first direction X, and along the first direction X, the tabs 20 include first regions 21 connected in sequence , a second area 23 and a third area 25 , wherein one end of the first area 21 facing away from the second area 23 is electrically connected to the electrode assembly 10 , and the third area 25 is exposed to 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 disposed opposite to each other. Please also refer to FIG. 3 , the first surface 431 has a protrusion 430 corresponding to the sealant 30 . Referring to FIG. 2 , the first surface 431 includes a first sealing area 434 and a non-sealing area 435 connected in sequence along the first direction X. In the first direction X, the width of the first sealing area 434 is n.

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

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

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

In this embodiment, the orthographic projections of the first sealing area 434 on the second surface 433 all fall into the second sealing area 436 . Further, the orthographic projection of the non-sealing area 435 on the second surface may also all fall into the second sealing area 436 .

In some embodiments, the above m and n also satisfy the following relationship: 0<m-n≤2mm.

A second direction Y is defined, and the second direction Y is perpendicular to the second surface 433 . The thickness of the packaging structure 100 of the cell in the second direction Y is T, wherein the m, n and T may also satisfy the following relational formula: 0.2T<n<m<0.8T.

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

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

The packaging bag 40 includes a first packaging film 401 and a second packaging film 403 opposite to the first packaging film 401 , and the first packaging film 401 and the second packaging film 403 are jointly sealed to form the receiving 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 laminated. Wherein, the surface of the first resin layer 401a facing away from the first metal layer 401b is that the outer surface of the packaging bag 40 is exposed to the outside. A region of the second resin layer 401 c corresponding to the sealing edge 43 corresponding to the raised portion 430 is combined with the sealant 30 . The region of the first encapsulation 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 . Other regions in the second resin layer 401 c corresponding to the sealing edge 43 are combined with the second packaging film 403 in the sealing edge 43 .

The first resin layer 401a can be selected from, but not limited to, a nylon film layer, a polyethylene terephthalate film layer, or a combination of the above two. 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 above two.

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

The first metal layer 401b can be selected from, but not limited to, aluminum foil, stainless steel plate, or a combination of the above two.

The sealant 30 includes at least one adhesive layer, the melting point of the adhesive layer bonded with the second resin layer 401c is MP ₁ , and the melting point of the second resin layer is MP ₂ , wherein |MP ₁ − MP ₂ |≤30℃. In some embodiments, 0<MP2 _{- MP1≤20} °C.

In this embodiment, as shown in FIG. 3 , the sealant 30 is composed of an adhesive layer. When the sealant 30 includes at least two adhesive layers, the materials of any two adhesive layers may be the same or different. As shown in FIG. 5 , the sealant 30 includes three layers of adhesive layers, and the three layers of adhesive layers are stacked in sequence.

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

In this embodiment, the second encapsulation film 403 may include a third resin layer 403a, a second metal layer 403b and a fourth resin layer 403c that are stacked in sequence. Wherein, the surface of the third resin layer 403a facing away from the second metal layer 403b is that the outer surface of the packaging bag 40 is exposed to the outside. The region corresponding to the sealant 30 in the fourth resin layer 403 c corresponding to the sealing edge 43 is combined with the sealant 30 . Other regions in the fourth resin layer 403 c corresponding to the sealing edge 43 are combined with the second resin layer 401 c corresponding to the sealing edge 43 .

The melting point of the adhesive layer in the sealant 30 bonded to the fourth resin layer 403c is MP ₃ , and the melting point of the fourth resin layer 403c is MP ₄ , where |MP ₃ -MP ₄ |≤30°C . More preferably, 0<MP ₄ -MP ₃ ≤ 20°C.

The third resin layer 403a can be selected from, but not limited to, a nylon film layer, a polyethylene terephthalate film layer, or a combination of the above two. The fourth resin layer 403c can be selected from, but not limited to, a random polypropylene film layer, a cast polypropylene resin film layer, or a combination of the above two.

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 can be selected from, but not limited to, aluminum foil, stainless steel plate, or a combination of the above two.

When the sealing edge 43 is formed by sealing, the second resin layer 401c overflows toward the non-sealing area 435, so that the area of the first packaging film 401 corresponding to the non-sealing area 435 faces away from the pole The direction of the ear 20 is raised (as shown in FIGS. 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 packaging bag 40 to form an overflow portion A (as shown in FIG. 2 ).

In some embodiments, as shown in FIG. 5 , the first sealing head 51 and the second sealing head 53 may cover the area between the first packaging film 401 and the second packaging film 403 where the tabs 20 are provided packaging, wherein the surface of the first sealing head 51 acting on the first packaging film 401 facing the first packaging film 401 is provided with a groove corresponding to the sealant 30 and acting on the second packaging The surface of the second sealing head 53 on the film 403 facing the second packaging film 403 is a flat plane, so that the area of the sealing edge 43 corresponding to the sealant 30 only protrudes to one side after sealing. In addition, in the first direction X, the width of the first head 51 is smaller than the width of the second head 53 .

In the packaging structure 100 of the battery cell of the present application, the protruding portion 430 is disposed on the first surface 431 , and the width n of the first sealing area 434 is smaller than the width m of the second sealing area 436 , which ensures the reliability of the packaging. At the same time, the flatness of the second surface 433 of the encapsulated sealing edge 43 is also ensured, thereby facilitating the subsequent installation of the protection board.

In addition, for those of ordinary skill in the art, various other corresponding changes and deformations can be made according to the technical concept of the present application, and all these changes and deformations should belong to the protection scope of the present application.

Claims (10)

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.

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