CN217641468U

CN217641468U - Lithium battery with reduced thickness

Info

Publication number: CN217641468U
Application number: CN202221252321.7U
Authority: CN
Inventors: 林国罗; 洪春林; 纪荣进; 陈杰; 其他发明人请求不公开姓名
Original assignee: Huizhou Liwinon Energy Technology Co Ltd
Current assignee: Huizhou Liwinon Energy Technology Co Ltd
Priority date: 2022-05-21
Filing date: 2022-05-21
Publication date: 2022-10-21
Anticipated expiration: 2032-05-21

Abstract

The utility model discloses a lithium cell of thickness attenuate relates to lithium cell technical field. A lithium battery with reduced thickness comprises a naked electric core and a shell, wherein the naked electric core is wrapped by the shell and is connected to the shell through a bonding adhesive tape; the adhesive tape at least comprises a first adhesive layer and a second adhesive layer which are arranged in a stacked mode. This lithium cell of thickness attenuate adopts the bonding adhesive tape of no substrate to come naked electric core and shell bonding together, gets rid of the restriction of substrate thickness, realizes the thickness attenuate of lithium cell, enlarges the range of application of lithium cell.

Description

Lithium battery with reduced thickness

Technical Field

The utility model relates to a lithium cell technical field specifically, relates to a lithium cell of thickness attenuate.

Background

With the common application of polymer lithium batteries in daily life, for example, a series of electronic products such as notebook computers, mobile phones and charge pal have the problem of fire and explosion caused by careless falling in the using process, so that the falling of the battery is a very core index for evaluating the safety performance of the lithium battery.

The battery is heavier and heavier when the 5G era comes, the anti-falling safety risk is also emphasized, the current falling failure reasons mainly include diaphragm turning, aluminum foil tearing and the like, wherein the aluminum foil tearing risk is the largest, and the aluminum foil tearing risk causes a series of failure phenomena such as internal short circuit, diaphragm turning, tab breakage, aluminum plastic film breakage and the like.

Naked electric core and plastic-aluminum membrane are bonded through hot melt double faced adhesive tape to the industry main at present, prevent relative movement, and then reduce the torn risk of aluminium foil. However, the existing hot-melt double faced adhesive tape is composed of an adhesive layer, a base material and an adhesive layer, and the thickness of the lithium battery cannot be reduced due to the limitation of the thickness of the base material, so that the application of the lithium battery is limited, and meanwhile, the energy density of the lithium battery is influenced to a certain extent, and the performance of the lithium battery is influenced.

SUMMERY OF THE UTILITY MODEL

Not enough to prior art, the utility model provides a lithium cell of thickness attenuate.

The utility model discloses a lithium battery with reduced thickness, which comprises a naked electric core and a shell, wherein the naked electric core is wrapped by the shell and is connected with the shell through at least one adhesive tape;

the adhesive tape at least comprises a first adhesive layer and a second adhesive layer which are arranged in a stacked mode.

According to an embodiment of the present invention, the thickness of the first adhesive layer is 3 to 50 μm, and the thickness of the second adhesive layer is 3 to 50 μm.

According to an embodiment of the present invention, the first adhesive layer and the second adhesive layer are attracted and bonded by van der waals force and covalent bond thereof.

According to an embodiment of the present invention, the first adhesive layer has viscosity at high temperature, and the first adhesive layer is used for bonding with the housing.

According to the utility model discloses an embodiment, the second adhesive linkage has viscidity under normal atmospheric temperature, and the second adhesive linkage is used for the bonding with naked electric core.

According to the utility model discloses an embodiment, the quantity of bonding adhesive tape is at least two, and bonding adhesive tape is and sets up side by side.

According to an embodiment of the present invention, the first adhesive layer has one of a dot shape, a linear shape, a mesh shape, and a continuous coating layer, and the second adhesive layer has one of a dot shape, a linear shape, a mesh shape, and a continuous coating layer.

According to an embodiment of the present invention, the main component of the first adhesive layer and the main component of the second adhesive layer are both styrene-based block copolymers.

According to an embodiment of the present invention, the main component of the first adhesive layer and the main component of the second adhesive layer are isomers.

According to an embodiment of the present invention, the density of the first adhesive layer is higher than the density of the second adhesive layer.

Compared with the prior art, the utility model discloses a lithium cell of thickness attenuate has following advantage:

the utility model discloses a thickness attenuate's lithium cell, its bonding adhesive tape that adopts no substrate comes naked electric core and shell bonding together, gets rid of the restriction of substrate thickness, realizes the thickness attenuate of lithium cell, enlarges the range of application of lithium cell.

In addition, the adhesive tape is of a multi-layer adhesive structure, so that the adhesive performance is improved, the stress is uniform, the anti-drop performance of the lithium battery is improved, and the energy density and the safety performance of the lithium battery are further improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

FIG. 1 is a schematic structural diagram of a lithium battery with a reduced thickness in an embodiment;

FIG. 2 is a schematic structural diagram of an adhesive tape and a bare cell in the embodiment;

FIG. 3 is a sectional view showing the structure of an adhesive tape in the embodiment.

Description of the reference numerals:

1. naked electric core; 2. a housing; 3. a tab; 4. bonding adhesive tapes; 41. a first adhesive layer; 42. and a second adhesive layer.

Detailed Description

In the following description, numerous implementation details are set forth in order to provide a more thorough understanding of the present invention. It should be understood, however, that these implementation details should not be used to limit the invention. That is, in some embodiments of the invention, details of these implementations are not necessary. In addition, some conventional structures and components are shown in simplified schematic form in the drawings.

In addition, the descriptions related to "first", "second", etc. in the present invention are only for description purposes, not specifically referring to the order or sequence, and are not intended to limit the present invention, but only to distinguish the components or operations described in the same technical terms, and are not to be construed as indicating or implying any relative importance or implicit indication of the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions in the embodiments may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should not be considered to exist, and is not within the protection scope of the present invention.

Referring to fig. 1 and 2, fig. 1 is a schematic structural diagram of a lithium battery, and fig. 2 is a schematic structural diagram of a bonding adhesive tape bonded with a bare cell. This embodiment discloses a lithium cell of thickness attenuate, including naked electric core 1, shell 2 and utmost point ear 3, utmost point ear 3 sets up on naked electric core 1, and shell 2 wraps up naked electric core 1. Wherein, naked electric core 1 is connected in shell 2 through an at least bonding adhesive tape 4, and the shell generally adopts the plastic-aluminum membrane.

Referring to fig. 3, fig. 3 is a structural sectional view of the adhesive tape. The adhesive tape 4 includes a first adhesive layer 41 and a second adhesive layer 42, the first adhesive layer 41 and the second adhesive layer 42 are arranged in a stacked manner, and the first adhesive layer 41 and the second adhesive layer 42 are bonded to each other by van der waals force and covalent bond attraction. In this embodiment, the quantity of bonding adhesive tape 4 is two, and two bonding adhesive tape 4 are and set up side by side, and single bonding adhesive tape 4 sets up along naked electric core 1's length direction, and of course, according to the difference of bonding strength, the bonding adhesive tape also can set up to three or four or more.

The first adhesive layer 41 has a thickness of 3 to 50 μm, and the second adhesive layer 42 has a thickness of 3 to 50 μm.

Further, the first adhesive layer 41 has adhesiveness at high temperature, and the first adhesive layer 41 is used for adhesion with the case 2. The second adhesive layer 42 has adhesiveness at normal temperature, and the second adhesive layer 42 is used for adhering to the bare cell 1. Wherein, the high temperature is higher than the normal temperature, and the high temperature range is 45-85 ℃.

Further, the shape of the first adhesive layer 41 is one of a dot shape, a line shape, a mesh shape, and a continuous coating layer, and the shape of the second adhesive layer 42 is one of a dot shape, a line shape, a mesh shape, and a continuous coating layer. In this embodiment, when preparing the adhesive tape 4, the first adhesive layer 41 is coated on the release film by the micro-gravure coating method, and after drying, the second adhesive layer 42 is coated on the surface of the first adhesive layer 41 by the same method.

Further, the main component of the first adhesive layer 41 and the main component of the second adhesive layer 42 are each a styrene-based block copolymer. Styrenic block copolymers are one of the common materials used in hot melt adhesives, and the components of the first adhesive layer 41 and the second adhesive layer 42 will be described below by way of example, but are not limited thereto. For example, the first adhesive layer 41 is prepared by reacting 45 parts of styrenic block copolymer SEPS G1657 (Kraton), 15 parts of amorphous α -olefin copolymer Vestoplast 508 (Evonik), 39 parts of hydrogenated petroleum resin ARKON P115 (Arakawa), and 1 part of antioxidant Irganox1076, and the second adhesive layer 42 is prepared by reacting 42 parts of styrenic block copolymer SEPS G1657 (Kraton), 42 parts of amorphous α -olefin copolymer Vestoplast 508 (Evonik), 15 parts of hydrogenated petroleum resin ARKON P140 (Arakawa), and 1 part of antioxidant Irganox 1076.

Further, the main component of the first adhesive layer 41 and the main component of the second adhesive layer 42 are isomers, and the density of the first adhesive layer 41 is higher than that of the second adhesive layer 42. Because the difference of the functional groups determines the property difference of the two adhesive layers, the density of the first adhesive layer 41 is higher than that of the second adhesive layer 42, which is more favorable for resisting the electrolyte corrosion, thereby ensuring that the electrolyte resistance effect is better.

The effect of reducing the thickness of the lithium battery will be described below by way of example, but the present invention is not limited thereto. Under the condition of the naked electric core of the same thickness and the shell of the same thickness to and, under the same condition of the use quantity of adhesive tape, survey the thickness of lithium cell. Preparing a first lithium battery by using the hot-melt double-sided adhesive tape in the prior art, wherein the thickness of the first lithium battery is 4.378mm; and the second lithium battery is prepared by using the adhesive tape without the base material in the embodiment, the thickness of the second lithium battery is 4.344mm, and the thickness of the second lithium battery is reduced by 0.034mm compared with that of the first lithium battery. Such a reduced thickness is considerable for lithium batteries.

In conclusion, this thickness attenuate's lithium cell adopts the bonding adhesive tape of no substrate to come naked electric core and shell bonding together, gets rid of the restriction of substrate thickness, realizes the thickness attenuate of lithium cell, enlarges the range of application of lithium cell. In addition, the adhesive tape is of a multi-layer adhesive structure, so that the adhesive performance is improved, the stress is uniform, the anti-drop performance of the lithium battery is improved, and the energy density and the safety performance of the lithium battery are further improved.

The above description is only an embodiment of the present invention, and is not intended to limit the present invention. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. The utility model provides a lithium cell of thickness attenuate, its characterized in that, includes naked electric core and shell, the shell parcel said naked electric core, and just naked electric core is connected in through at least one bonding adhesive tape in the shell;

the adhesive tape at least comprises a first adhesive layer and a second adhesive layer, and the first adhesive layer and the second adhesive layer are arranged in a stacked mode.

2. The lithium battery with reduced thickness as claimed in claim 1, wherein the first adhesive layer has a thickness of 3 to 50 μm and the second adhesive layer has a thickness of 3 to 50 μm.

3. The lithium battery of claim 1, wherein the first adhesive layer and the second adhesive layer are attracted to each other by van der waals forces and covalent bonds.

4. The lithium battery of claim 1, wherein the first adhesive layer is adhesive at high temperature, the first adhesive layer for bonding to the housing.

5. The lithium battery with reduced thickness according to claim 1, wherein the second adhesive layer has adhesiveness at normal temperature, and the second adhesive layer is used for adhering to the bare cell.

6. The lithium battery with reduced thickness as claimed in claim 1, wherein the number of the adhesive strips is at least two, and the adhesive strips are arranged side by side.

7. The lithium battery with reduced thickness as claimed in any one of claims 1 to 6, wherein the first adhesive layer is in the shape of one of a dot, a line, a grid and a continuous coating, and the second adhesive layer is in the shape of one of a dot, a line, a grid and a continuous coating.

8. The lithium battery according to any one of claims 1 to 6, wherein the main component of the first adhesive layer and the main component of the second adhesive layer are each a styrene-based block copolymer.

9. The lithium battery of claim 8, wherein a main component of the first adhesive layer and a main component of the second adhesive layer are isomers.

10. The lithium battery of claim 9, wherein the first adhesive layer has a higher density than the second adhesive layer.