CN113451631B

CN113451631B - Battery structure and electronic device using same

Info

Publication number: CN113451631B
Application number: CN202010230901.5A
Authority: CN
Inventors: 戴志芳; 龙海
Original assignee: Ningde Amperex Technology Ltd
Current assignee: Ningde Amperex Technology Ltd
Priority date: 2020-03-27
Filing date: 2020-03-27
Publication date: 2022-12-13
Anticipated expiration: 2040-03-27
Also published as: CN113451631A

Abstract

A battery structure comprises a battery core and an adhesive structure. The battery core comprises an end face, and the adhesive structure is arranged on the end face. The adhesive structure comprises a base material, a first adhesive layer and a second adhesive layer. The substrate comprises a first surface and a second surface which are opposite to each other, the first surface is opposite to the battery core, the first surface comprises a first area and two second areas which are arranged at intervals, the first area is connected with the two second areas and is positioned between the two second areas, and the second surface comprises a third area corresponding to the first area. The first glue layer is arranged in the second area or arranged in the first area and the second area simultaneously. One side of the second adhesive layer is arranged in the third area, the other side of the second adhesive layer is bonded with the end face, and the adhesive structure is favorable for improving the failure condition of the battery core in the falling process and is also favorable for improving the safety of the battery. The application also provides an electronic device applying the battery structure.

Description

Battery structure and electronic device using same

Technical Field

The present disclosure relates to battery devices, and particularly to a battery structure and an electronic device using the same.

Background

With the mature application of consumer electronics, customers pay more and more attention to the risk of the whole machine application. For example, the demand for drop resistance of electronic products is increasing. The battery, as an important component of electronic products, also has a demand for resistance to dropping. When the battery falls along with an electronic product, the battery cell contained in the battery packaging film easily bursts the top seal or the side seal of the packaging film, so that the safety and the service life of the battery are influenced.

Disclosure of Invention

In view of the above, it is desirable to provide a battery structure with improved safety and improved failure, and an electronic device using the battery structure.

The application provides a battery structure, including electric core and sticky structure. The battery core comprises an end face, and the adhesive structure is arranged on the end face. The adhesive structure comprises a base material, a first adhesive layer and a second adhesive layer. The substrate comprises a first surface and a second surface which are opposite to each other, the first surface faces away from the battery cell, the first surface comprises a first area and two second areas which are arranged at intervals, the first area is connected with the two second areas and is positioned between the two second areas, and the second surface comprises a third area corresponding to the first area. The first adhesive layer is arranged in the second area or simultaneously arranged in the first area and the second area. One side of the second adhesive layer is arranged in the third area, the other side of the second adhesive layer is bonded with the end face to support the battery cell, the possibility of failure of the battery structure when the battery structure receives impact is reduced, after the first adhesive layer and other elements are bonded, the battery cell and other elements are displaced when the battery structure is impacted by external force, the adhesive structure is stretched, the impact force applied to the battery cell is buffered by the stretched adhesive structure, and the possibility of failure of the battery structure when the battery structure is impacted is further reduced.

As a scheme of this application, electric core still includes another terminal surface and utmost point ear, utmost point ear is along keeping away from the direction of terminal surface extends another terminal surface.

As a scheme of this application, electric core includes first pole piece, second pole piece and diaphragm, the second glue film bonds the part that the diaphragm is located terminal surface department.

As an aspect of the present application, the first adhesive layer is disposed at a distance from a peripheral edge of the substrate.

As a scheme of this application, first glue film is the hot melt adhesive, the viscidity increases after the inviscid and be heated under the first glue film normal atmospheric temperature.

As a scheme of this application, electric core still includes first side and second side, first side with the second side sets up relatively, the end connection first side with the second side, the second is regional to be located first side deviates from one side of second side reaches the second side deviates from one side of first side, adhesive structure still includes the third glue film, the third glue film set up in the second surface with the fourth region that the second region corresponds, just the viscidity of third glue film is less than the viscidity of second glue film. The first side and the second side of electric core are bonded to the third glue film, and because the viscosity of the third glue film is smaller than that of the second glue film, the impact force on the electric core can be reduced when the battery structure is impacted, and the outermost pole piece of the electric core is prevented from being torn.

As a scheme of this application, the third glue film still set up in the second glue film with between the third region.

As an aspect of the present application, the substrate is bonded to the first side and the second side through the third adhesive layer.

As one scheme of the application, the thickness of the first adhesive layer is 1-20 μm, the thickness of the second adhesive layer is 1-20 μm, and the thickness of the third adhesive layer is less than 20 μm.

As a scheme of this application, the battery structure still including the encapsulation electric core reaches the packaging film of gluing the structure, wherein, set up in first glue film on the second area deviates from one side bonding of electric core the packaging film. When receiving external force and assaulting, the adhesive structure can effectively prevent to take place great displacement between electric core and the encapsulation membrane to prevent that battery top side seal from being washed out and leading to electrolyte to reveal, simultaneously, the adhesive structure is stretched and provides certain cushion force, has reduced the impact force that electric core received, thereby has further reduced the possibility that the battery structure became invalid when receiving the impact.

The application also provides an electronic device, which comprises the battery structure.

Drawings

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

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

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

Fig. 4 is a schematic cross-sectional view of a gluing structure according to an embodiment of the present application.

Fig. 5 is a schematic cross-sectional view of a gluing structure according to an embodiment of the present application.

Fig. 6 is a schematic cross-sectional view of a gluing structure according to an embodiment of the present application.

Fig. 7 is a schematic cross-sectional view of a battery structure according to an embodiment of the present application.

Fig. 8 is a schematic cross-sectional view of a gluing structure according to an embodiment of the present application.

Fig. 9 is a schematic cross-sectional view of a gluing structure according to an embodiment of the present application.

Fig. 10 is a schematic cross-sectional view of a battery structure according to an embodiment of the present application.

Fig. 11 is a schematic cross-sectional view of a gluing structure according to an embodiment of the present application.

Fig. 12 is a schematic cross-sectional view of a gluing structure according to an embodiment of the present application.

Fig. 13 is a schematic cross-sectional view of a battery structure according to an embodiment of the present application.

Fig. 14 is a schematic cross-sectional view of a gluing structure according to an embodiment of the present application.

Fig. 15 is a schematic cross-sectional view of a battery structure according to an embodiment of the present application.

Fig. 16 is a schematic cross-sectional view of a gluing structure according to an embodiment of the present application.

Description of the main elements

Battery structure 100

Battery cell 10

First side 11

Second side 13

End face 15

Adhesive structure 30

Substrate 31

First surface 311

First region 311a

Second region 311b

Second surface 313

Third region 313a

Fourth region 313b

First adhesive layer 33

Second adhesive layer 35

Encapsulation film 50

Accommodating cavity 501

First inner wall 51

Second inner wall 53

Third adhesive layer 37

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 are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all embodiments. 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 are described in detail below. The features of the following examples/embodiments and examples/embodiments may be combined with each other without conflict.

Referring to fig. 1 to 16, the present embodiment provides a battery structure 100, which includes a battery core 10 and an adhesive structure 30.

Referring to fig. 2 and 3, the battery cell 10 includes a first side surface 11, a second side surface 13, and an end surface 15. The first side surface 11 is opposite to the second side surface 13, and the end surface 15 connects the first side surface 11 and the second side surface 13.

The adhesive structure 30 includes a substrate 31, a first adhesive layer 33 and a second adhesive layer 35.

Referring to fig. 2 and 3, the substrate 31 includes a first surface 311 and a second surface 313 opposite to each other. The first surface 311 includes a first region 311a and two spaced second regions 311b, wherein the first region 311a connects the two second regions 311b and is located between the two second regions 311b. The second surface 313 includes a third region 313a and a fourth region 313b. The third region 313a corresponds to the first region 311a, and the fourth region 313b corresponds to the second region 311b. In some embodiments, the width of the first region 311a, i.e., the distance separating the two second regions 311b, may be 4mm to 30mm.

In some embodiments, the substrate 31 is selected from, but not limited to, a polypropylene film (PP), a polyethylene film (PE), a polyethylene terephthalate film (PET), a polyimide film (PI), a polyvinyl chloride film (PVC), a multilayer co-extruded polyolefin heat shrinkable film (POF), or a combination thereof. The thickness of the substrate 31 may be selected from 6 μm to 30 μm. If the thickness of the substrate 31 is too low, the process requirements are higher and it is more difficult to achieve. If the thickness of the base material 31 is too high, the overall thickness of the adhesive structure 30 is affected, and thus the overall thickness and energy density of the battery structure 100 are affected. Preferably, the thickness of the substrate 31 is 8 μm to 12 μm.

In the present embodiment, the substrate 31 may have a single-layer structure. In other embodiments, the base substrate 31 may also be a multilayer composite structure, for example, the base substrate 31 is composed of two base layers disposed one above the other. Wherein, the material of each substrate layer can be selected from polypropylene film (PP), polyethylene film (PE), polyethylene terephthalate film (PET), polyimide film (PI), polyvinyl chloride film (PVC) or multilayer co-extruded polyolefin heat shrinkable film (POF), and the material of the two substrate layers can be the same or different. The two substrate layers can be bonded by an adhesive layer or can be combined by melting.

In some embodiments, referring to fig. 2, 4 and 5, the first adhesive layer 33 is adhered to the second region 311b of the first surface 311, and the second adhesive layer 35 is adhered to the third region 313a of the second surface 313. Preferably, the projection of the second glue layer 35 on the first surface 311 does not overlap the first glue layer 33 (as shown in fig. 2).

Referring to fig. 2 and fig. 3, the adhesive structure 30 bonds the end surface 15 of the battery cell 10 through a side of the second adhesive layer 35 away from the third region 313a. The first surface 311 faces away from the battery cell 10.

The second region 311b is located on a side of the first side 11 facing away from the second side 13 and on a side of the second side 13 facing away from the first side 11.

The thickness of the first adhesive layer 33 may be 1 μm to 20 μm, which is beneficial to reducing the overall thickness of the adhesive structure 30 while ensuring the adhesive force, thereby reducing the influence on the energy density of the battery structure.

The first adhesive layer 33 may be made of hot melt adhesive. The first adhesive layer 33 has no adhesiveness at normal temperature and has increased adhesiveness when heated, wherein the adhesiveness after heated is more than 60N/m. Based on the above-mentioned characteristics of the first glue layer 33, it is convenient to initially adjust the relative position between the bonding structure 30 and the object to be bonded with the first glue layer 33, and bond the object under heat and/or pressure after adjustment.

Preferably, in some embodiments, referring to fig. 6, the first adhesive layer 33 is spaced from the periphery of the substrate 31, so as to prevent the adhesive from overflowing from the periphery of the substrate 31 and adhering to the cell surface when the first adhesive layer 33 is applied, and also prevent the subsequent first adhesive layer 33 from overflowing from the periphery of the substrate 31 and adhering to the cell surface of another object when the first adhesive layer is adhered to another object under the conditions of heating and/or pressurization, thereby reducing the risk of the pole piece in the cell 10 being torn. Wherein the periphery of an element refers to the peripheral edge of the element. More specifically, in the present application, the periphery of the substrate 31 refers to the edge of the periphery of the substrate 31 or the edge of the first surface 311 of the substrate 31. Preferably, the first glue layer 33 may be spaced from the periphery of the substrate 31 by a distance of 1mm to 10mm.

The thickness of the second adhesive layer 35 may be 1 μm to 20 μm, which is beneficial to reducing the overall thickness of the adhesive structure 30 while ensuring the adhesive force, thereby reducing the influence on the energy density of the battery structure. Preferably, the thickness of the second glue layer 35 is 4 μm to 6 μm.

The viscosity of the second glue layer 35 at normal temperature is more than 100N/m. In some embodiments, the material of the third adhesive layer 37 can be selected from, but not limited to, polyacrylate, epoxy, rubber, hot melt adhesive, silicone, or a combination thereof.

The battery cell 10 includes a first pole piece (not shown), a second pole piece (not shown), and a separation film (not shown) located between the first pole piece and the second pole piece. The separator is typically longer than the first and second pole pieces, i.e. protrudes from the ends of the first and second pole pieces. When the second adhesive layer 35 is used for bonding the end face 15 of the battery cell 10, the second adhesive layer 35 is used for bonding the part of the isolating film, which is located at the end face 15 of the battery cell 10, so that the isolating film is prevented from being heated and shrunk to cause short circuit in contact with the positive and negative pole pieces.

Referring to fig. 1 and 3, the battery structure 100 may further include an encapsulation film 50 encapsulating the battery cell 10 and the adhesive structure 30. The encapsulation film 50 includes a receiving cavity 501, and the receiving cavity 501 includes a first inner wall 51 and a second inner wall 53 oppositely disposed, wherein the first side 11 of the battery cell 10 faces the first inner wall 51, and the second side 13 of the battery cell 10 faces the second inner wall 53. The first adhesive layer 33 on the second area 311b of the first side surface 11 facing away from the second side surface 13 is bonded to the first inner wall 51 after hot pressing, and the first adhesive layer 33 on the second area 311b of the second side surface 13 facing away from the first side surface 11 is bonded to the second inner wall 53 after hot pressing.

In the above embodiment, the first adhesive layer 33 is not disposed in the first region 311a, which is beneficial to providing a buffering effect for the battery cell 10 when the battery structure 100 falls due to deformation of the substrate 31.

In some embodiments, referring to fig. 7, fig. 8 and fig. 9, the first adhesive layer 33 may also be disposed on the first region 311a and the second region 311b of the first surface 311 at the same time.

In some embodiments, referring to fig. 10, fig. 11, fig. 12, fig. 13 and fig. 14, the adhesive structure 30 may further include a third adhesive layer 37, and the third adhesive layer 37 is disposed in the fourth region 313b of the second surface 313. Wherein the third glue layer 37 has a lower viscosity than the second glue layer 35. The third glue layers 37 may be connected to the second glue layers 35 or may be spaced apart.

Referring to fig. 10 and 13, when the adhesive structure 30 simultaneously bonds the battery cell 10 and the encapsulation film 50, the base material 31 is bonded to the first side surface 11 and the second side surface 13 through the third adhesive layer 37, so that the risk of damage to the adhesive structure 30 caused by stress concentration between the battery cell 10 and the adhesive structure 30 when the battery structure 100 is dropped can be reduced.

The third glue layer 37 has a viscosity of less than 40N/m at room temperature. In some embodiments, the material of the third adhesive layer 37 can be selected from, but not limited to, polyacrylate, epoxy, rubber, hot melt adhesive, silicone, or a combination thereof.

Preferably, as shown in fig. 10, 11, 13 and 14, the thickness of the third glue layer 37 corresponds to the thickness of the second glue layer 35.

In some embodiments, referring to fig. 15 and 16, the third adhesive layer 37 may be disposed on the third region 313a and the fourth region 313b of the second surface 313 simultaneously. The second glue layer 35 is disposed on a side of the third glue layer 37 of the third area 313a, which is away from the first area 311 a.

The present application will be specifically described below by way of comparative examples and examples. It should be understood that the parameters in the present application are not limited to the contents described in the comparative examples and examples, and can be specifically selected according to actual needs.

30 sets of the battery structures of the examples of the first embodiment shown in fig. 13 were prepared as in table 1 below, and the battery structures of the 30 sets of the examples were identical except for the parameters in the table. The battery structures of the above-described groups of examples were subjected to drop tests, and the corresponding drop results were recorded in table 1 below. The distance between the first glue layer and the periphery of the base material is called the 'margin distance'. The specific method of the drop test comprises the following steps: the battery is dropped 18 times from the height of 1.8m in a way that the upper and lower surfaces of the battery are grounded or four corners of the battery are grounded, if the pressure drop of the battery is less than 15mV and the phenomena of liquid leakage, fire, smoke generation and tearing of aluminum foil in a battery core do not exist, the battery passes the test, 10 batteries are respectively tested in each group of examples, and the passing ratio is the dropping result.

TABLE 1

30 sets of the battery structures of the examples of the second embodiment shown in fig. 10 were prepared as in table 2 below, and the battery structures of the 30 sets of the examples were identical except for the parameters in the table. The battery structures of the above-described groups of examples were subjected to drop tests, and the corresponding drop results were recorded in table 2 below. The distance between the first glue layers on the two second areas is called as a reserved space. The specific method of the drop test is the same as the drop test method of the battery structure according to the first embodiment.

TABLE 2

45 sets of cell structures of examples of the third embodiment shown in fig. 13 were prepared according to the following table 3, and the cell structures of 30 sets of examples were identical except for the parameters in the table. The battery structures of the above-described groups of examples were subjected to drop tests, and the corresponding drop results were recorded in table 3 below. The width of the area of the second adhesive layer where the third adhesive layer is not arranged is called as the blank width. The specific method of the drop test is the same as the drop test method of the battery structure of the first embodiment.

TABLE 3

According to the following table 4, a glue layer is coated on one whole side of a substrate layer, the substrate layer is adhered to the surface of the battery cell (namely, the glue layer is combined with the first side surface, the end surface and the second side surface) in a conventional glue winding manner, and a battery structure with 3-pair proportion is prepared. Other parameters were the same between the 3-pair comparative cell structures, consistent with the parameters of the examples. Drop tests were performed on the battery structures of the above respective sets of comparative examples, and the corresponding drop results were recorded in table 4 below. The specific method of the drop test is the same as the drop test method of the battery structure of the first embodiment.

TABLE 4

Based on the dropping results of the above examples and comparative examples, it can be seen that the battery structure 100 of the present application can greatly improve the drop resistance of the battery, so that the battery structure is not prone to fail after dropping.

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. The utility model provides a battery structure, includes electric core, electric core includes the terminal surface, its characterized in that, battery structure still includes the adhesive structure, sets up on the terminal surface, the adhesive structure includes:

the battery cell comprises a substrate and a plurality of battery cells, wherein the substrate comprises a first surface and a second surface which are opposite to each other, the first surface faces away from the battery cell, the first surface comprises a first area and two second areas which are arranged at intervals, and the first area is connected with the two second areas and is positioned between the two second areas; the second surface includes a third region corresponding to the first region;

the first adhesive layer is only arranged in the second area or is arranged in the first area and the second area simultaneously; and

and one side of the second adhesive layer is only arranged in the third area, and the other side of the second adhesive layer is bonded with the end face.

2. The battery structure of claim 1, wherein the cell comprises a first pole piece, a second pole piece, and a separator, and the second glue layer bonds a portion of the separator at the end face.

3. The battery structure of claim 2, wherein the cell further comprises another end surface and a tab extending out of the another end surface in a direction away from the end surface.

4. The battery structure of claim 1, wherein the first glue layer is spaced from the periphery of the substrate.

5. The battery structure of claim 1, wherein the first adhesive layer is a hot melt adhesive that is non-tacky at room temperature and increases in tack when heated.

6. The battery structure of claim 1, wherein the battery core further comprises a first side surface and a second side surface, the first side surface and the second side surface are arranged oppositely, the end surface is connected with the first side surface and the second side surface, the second region is located on one side of the first side surface, which is far away from the second side surface, and one side of the second side surface, which is far away from the first side surface, the adhesive structure further comprises a third adhesive layer, the third adhesive layer is arranged on a fourth region of the second surface, which corresponds to the second region, and the viscosity of the third adhesive layer is smaller than that of the second adhesive layer.

7. The battery structure of claim 6, wherein the third glue layer is further disposed between the second glue layer and the third region.

8. The battery structure of claim 6, wherein the substrate is bonded to the first side and the second side by the third glue layer.

9. The battery structure of claim 6, wherein at least one of the following characteristics is satisfied:

the thickness of the first adhesive layer is 1-20 μm;

the thickness of the second adhesive layer is 1-20 μm;

the thickness of the third glue layer is less than 20 mu m.

10. The battery structure according to any one of claims 1 to 9, wherein the battery structure further comprises an encapsulation film encapsulating the battery cell and the adhesive structure, and a side of the first adhesive layer disposed on the second region, which side faces away from the battery cell, is bonded to the encapsulation film.

11. An electronic device, characterized in that the electronic device comprises a battery construction according to any of claims 1-10.