CN212113952U

CN212113952U - Composite multilayer graphite film and lithium ion battery

Info

Publication number: CN212113952U
Application number: CN202020835865.0U
Authority: CN
Inventors: 黄志伟; 宗彦震
Original assignee: Zhuhai Cosmx Power Co Ltd
Current assignee: Zhuhai Cosmx Power Co Ltd
Priority date: 2020-05-19
Filing date: 2020-05-19
Publication date: 2020-12-08
Anticipated expiration: 2030-05-19

Abstract

A composite, multi-layered graphite film comprising: a graphite layer; the bonding layers are arranged on the surfaces of the two sides of the graphite layer; and the aromatic polyester amine high-molecular insulating layer is arranged on the outer surface of the bonding layer. Can with the utility model discloses a lithium ion battery is applied to compound multilayer graphite membrane, set up in the surface of electric core body, and/or the circuit board surface of protection shield circuit, and/or on the metal center of electric core body. The utility model discloses a compound multilayer graphite membrane uses high extension adhesive linkage and aromatic polyester amine polymer insulating layer to compound, the electric conductivity of graphite has been overcome, make compound multilayer graphite membrane possess heat conductivity and good insulating properties, can carry out the soaking to the inside consumption component of battery, the heat dissipation, it is whole or spread the battery outside to the battery with the balanced battery of some heat source of excessive concentration, make the whole temperature of battery keep in acceptable scope, the inside heat effect problem of rechargeable battery has been solved, the security performance of battery has been improved, the life of battery has been prolonged.

Description

Composite multilayer graphite film and lithium ion battery

Technical Field

The utility model belongs to the technical field of lithium ion battery, concretely relates to heat conduction graphite membrane for lithium ion battery is last.

Background

Lithium ion batteries are the most common energy storage devices in electronic products. With the development of science and technology, the performance of electronic products is continuously improved, and the energy consumption of the products is continuously increased. In order to solve the problem of high energy consumption of electronic products, a rapid charging technology represented by QC3.0, MaxCharge and the like is more and more widely applied. However, when the quick charging technology is used for charging, the high voltage and the large current can aggravate the heat effect of the charging loop, the battery can be accelerated to age when working in a high-temperature environment for a long time, and the battery can be burnt and exploded when being serious. In order to solve the problem of temperature rise of the battery, it is proposed in the industry to increase the copper plating thickness of the circuit board of the protection board circuit of the battery to reduce the resistance and increase the current-carrying capacity of the circuit board to reduce the heat generation of the circuit. However, the solution can only solve the heat dissipation problem of the circuit board, and has no way to reduce the temperature rise problem of high-power loss components such as ICs and MOS, and still has room for improvement.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a compound multilayer graphite membrane for high power component heat conduction.

In order to achieve the above object, the present invention adopts the following technical solutions:

a composite, multi-layered graphite film comprising: a graphite layer; the bonding layers are arranged on the surfaces of the two sides of the graphite layer; and the aromatic polyester amine high-molecular insulating layer is arranged on the outer surface of the bonding layer.

More specifically, the thickness of the graphite layer is 20-50 um

More specifically, the thickness of adhesive linkage is 20 ~ 30 um.

More specifically, the thickness of the aromatic polyester amine high polymer insulating layer is 40-50 um.

Further, the bonding layer covers the side edge of the graphite layer.

Further, the aromatic polyester amine insulating layer further comprises an outer side adhesive layer arranged on the outer side surface of the aromatic polyester amine high polymer insulating layer.

The utility model also provides a lithium ion battery, include: the battery cell comprises a battery cell body and a protection board circuit, wherein the composite multilayer graphite film is arranged on the surface of the battery cell body and/or the surface of a circuit board of the protection board circuit and/or a metal middle frame of the battery cell body.

According to the technical scheme provided by the utility model, the utility model discloses a compound multilayer graphite membrane uses high extension adhesive linkage and aromatic polyester amine polymer insulating layer to compound, has overcome the electric conductivity of graphite for compound multilayer graphite membrane has possessed heat conductivity and good insulating properties, and has increased the intensity of product, has improved the security level of product. Will the utility model discloses a when compound multilayer graphite membrane is applied to lithium ion battery, utilize the outstanding heat conductivility of graphite, carry out soaking, heat dissipation to the inside consumption component of battery, the point heat source that will excessively concentrate is balanced to the battery wholly or is diffused to the battery outside, makes the battery bulk temperature keep at acceptable scope, has solved the inside fuel effect problem of filling the battery soon, has improved the security performance of battery, has prolonged the life of battery, has improved user experience.

Drawings

In order to illustrate the embodiments of the present invention more clearly, the drawings that are needed in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings can be obtained by those skilled in the art without inventive effort.

Fig. 1 is an exploded schematic view of a composite multilayer graphite film according to an embodiment of the present invention;

fig. 2a is a schematic view of an application of the composite multilayer graphite film in a fast-charging lithium ion battery with low calorific value according to an embodiment of the present invention;

FIG. 2b is a schematic diagram of a fast-charging lithium ion battery;

fig. 3 is a schematic diagram of an application of the composite multilayer graphite film in a fast-charging lithium ion battery with a high calorific value according to the embodiment of the present invention.

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings, wherein for convenience of illustration, the drawings showing the structure of the device are not to scale and are partially enlarged, and the drawings are only examples, which should not limit the scope of the invention. It should be noted that the drawings are in simplified form and are not to precise scale, which is only used for the purpose of facilitating and clearly assisting in the description of the embodiments of the present invention.

As shown in fig. 1, the composite multilayer graphite film of the present embodiment includes a graphite layer 1, an adhesive layer 2, and an aromatic polyester amine polymer insulating layer 3. Graphite layer 1 can be made by artificial graphite or graphite alkene, and graphite layer 1's thickness can be 20 ~ 50 um. This embodiment adopts the artificial graphite that polymer carbonization, sintering formed to prepare graphite layer 1, and graphite layer 1's thickness is 25 um. The graphite material has unique crystal grain orientation and molecular structure and excellent heat conducting performance, so that the graphite layer 1 can play a good heat conducting role in the composite multilayer structure. The graphite material has a high thermal conductivity coefficient of 1200-1500W/(m.K) in a horizontal direction, and has a low thermal conductivity coefficient of 5-20W/(m.K) between vertical direction surfaces, and when the composite multilayer graphite film is attached to the surface of a heating device by utilizing anisotropy of the thermal conductivity coefficient, local heat sources and heat in an attaching area can be rapidly transferred in the graphite film, but the heat cannot penetrate through the graphite film, and the heat can be rapidly diffused in the horizontal direction before being transferred to the other side of the heat source, so that heat balance is achieved, and heat dissipation and heat insulation effects are achieved.

Set up adhesive linkage 2 on graphite layer 1's both sides surface, adhesive linkage 2's thickness can be 20 ~ 30 um. The adhesive layer 2 of this embodiment is made of a modified acrylic glue using high elongation PET as a base material, and has a thickness of 30 um. The adhesive layer 2 can also be made of pure acrylic glue. The adhesive layers 2 are arranged on the surfaces of the two sides of the graphite layer 1, the tensile strength of the adhesive layers 2 can reach 20N/mm, and the fracture elongation rate reaches 50%, so that the strength of the composite multilayer graphite film can be improved, and graphite leakage caused by the fact that the graphite layer is punctured by a sharp object is avoided. Further, the adhesive layer 2 can cover the side edges of the graphite layer 1, i.e. the adhesive layer 2 is used for edge covering (180-degree adhesive stripping force of 5N/cm) of the graphite layer 1, and graphite leakage at the edges is prevented.

An aromatic polyester amine polymer insulating layer 3 such as a polyester film, a polynaphthalene film, a polyimide film, a polytetrafluoroethylene film, or the like is provided on the outer surface of the adhesive layer 2. The thickness of the aromatic polyester amine polymer insulating layer 3 can be 40-50 um, and the thickness of the aromatic polyester amine polymer insulating layer 3 of the embodiment is 30 um. The utility model discloses an aromatic polyester amine macromolecular material preparation insulating layer compares with conventional PET insulating material, and aromatic polyester amine macromolecular material heat resistance, stability are good, can increase the insulation stability of compound multilayer graphite membrane, make it possess H level insulation level, 19KV/mm dielectric strength. And the aromatic polyester amine high polymer material also has wear resistance, high temperature resistance and flame retardance, is beneficial to improving the strength of the composite multilayer graphite film, can avoid aging caused by water vapor and temperature in the use process, and ensures the insulation effect.

In addition, as the utility model discloses an embodiment, in the in-service use process, can also set up outside adhesive linkage 4 in the outside of aromatic polyester amine polymer insulating layer 3 as required for the convenience is attached on the hot area surface that needs the heat dissipation with compound multilayer graphite membrane. The outside adhesive linkage 4 can adopt modified acrylic acid glue or pure acrylic acid glue to make, and thickness can be 30 ~ 50um, and the thickness of the outside adhesive linkage 4 of this embodiment is 30um, only sets up in the outside of one deck aromatic polyester amine polymer insulating layer 3.

The utility model discloses a compound multilayer graphite membrane possesses high thermal conductivity and high insulating nature simultaneously, can attach on the source that generates heat of lithium ion battery protection shield circuit, carries out battery PACK equipment to carry out high voltage, heavy current charge-discharge in-process at the battery, utilize compound multilayer graphite membrane to carry out soaking and heat conduction, with the temperature that reduces the components and parts that generate heat, make the battery wholly reach thermal balance.

The utility model discloses a when compound multilayer graphite membrane was used on lithium ion battery, can set up according to actual demand is nimble. For example, for a fast-charging lithium ion battery with a low calorific value, the composite multilayer graphite film S may be attached to the surface of the battery cell body 10 and the surface of the circuit board of the protection board circuit 11 in the lithium ion battery, as shown in fig. 2 a. Attaching the composite multilayer graphite film S on the surface of the circuit board of the protection board circuit 11, wherein the composite multilayer graphite film S corresponds to a heating area A (figure 2b) of a current collector of a component, and can utilize the thermal capacity of copper sheets and base materials of the circuit board to uniformly heat MOS, IC, FUSE and other heating components in the circuit by matching with the composite multilayer graphite film; the composite multilayer graphite film S is attached to the surface of the battery cell body 10, and the thermal capacity of the battery cell body can be utilized to uniformly heat the inside of the battery, the tabs and the like in cooperation with the composite multilayer graphite film. For the fast-charging lithium ion battery with larger calorific value, a composite multilayer graphite film (figure 3) can be further attached to a heat radiator which is contacted with the external air, such as a metal middle frame 12 of the battery, so that the heat in the battery can be rapidly diffused in a heat convection mode.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A composite multilayer graphite film, comprising:

a graphite layer;

the bonding layers are arranged on the surfaces of the two sides of the graphite layer;

and the aromatic polyester amine high-molecular insulating layer is arranged on the outer surface of the bonding layer.

2. The composite, multi-layered graphite film of claim 1, wherein: the thickness of graphite layer is 20 ~ 50 um.

3. The composite, multi-layered graphite film of claim 1, wherein: the thickness of adhesive linkage is 20 ~ 30 um.

4. The composite, multi-layered graphite film of claim 1, wherein: the thickness of the aromatic polyester amine high polymer insulating layer is 40-50 um.

5. The composite, multi-layered graphite film of claim 1, wherein: the bonding layer covers the side edge of the graphite layer.

6. The composite, multi-layered graphite film of claim 1, wherein: the aromatic polyester amine high polymer insulation layer is characterized by further comprising an outer side adhesive layer arranged on the outer side surface of the aromatic polyester amine high polymer insulation layer.

7. A lithium ion battery comprising: the battery cell body and the protection board circuit, further comprising the composite multilayer graphite film according to any one of claims 1 to 6, wherein the composite multilayer graphite film is disposed on a surface of the battery cell body, and/or a surface of a circuit board of the protection board circuit, and/or a metal middle frame of the battery cell body.