Heat dissipation film structure for power battery

Abstract

The embodiment of the utility model provides a heat dissipation film structure for a power battery, which comprises a composite film, a release film and a bonding layer, the bonding layer is arranged between the composite film and the release film, the composite film comprises an outer base material layer, a heat dissipation layer, an insulating layer, a heat conduction layer and an inner base material layer, the heat dissipation layer, the insulating layer and the heat conduction layer are arranged between the outer base material layer and the inner base material layer, and the bonding layer is arranged between the outer base material layer and the inner base material layer. The upper surface of the inner base material layer is provided with an insulating layer, the upper surface of the insulating layer is provided with a heat dissipation layer, the lower surface of the insulating layer is provided with a heat conduction layer, and the lower end face of the inner base material layer is connected with a bonding layer. The design of the film layer reduces the thermal resistance of the protective film, prevents heat from being accumulated on the surface of the battery, improves the uniformity of heat dissipation, does not damage the voltage / capacity balance, and in addition, the arrangement of the outer base material layer, the insulating layer and the inner base material layer enables the electrical insulation performance of the heat dissipation film not to be reduced, and enhances the mechanical strength at the same time.

Description

TECHNICAL FIELD

[0001] The utility model discloses an embodiment relates to the field of power battery, especially relates to a heat dissipation film structure for power battery. BACKGROUND

[0002] Power battery such as lithium battery, as a kind of cyclically charged energy storage equipment, is applied to industry, transportation and other fields, in the process of lithium battery manufacturing, protective film is used to protect the internal battery cell, and in the process of use, the temperature of battery pack is too high due to internal resistance heat and chemical reaction heat and other factors in the cyclic charging and discharging process, leading to battery capacity attenuation, even causing thermal runaway;

[0003] The existing technical means generally adopts the protective film of power battery to prepare liquid cooling system or optimize battery arrangement (such as reserving heat dissipation channel etc.), but the existing technical means generally makes uneven heat dissipation, leading to faster aging of local overheated area in battery pack, easily destroying voltage / capacity balance. INVENTION CONTENTS

[0004] (1) technical problem to be solved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the utility model provides a heat dissipation film structure for power battery, which solves the technical problem that uneven heat dissipation of power battery leads to faster aging of local overheated area in battery pack, easily destroying voltage / capacity balance.

[0006] (2) technical scheme

[0007] The utility model discloses a heat dissipation film structure for power battery, which comprises a composite film, a release film and an adhesive layer, the adhesive layer is arranged between the composite film and the release film, the composite film comprises an outer base material layer, a heat dissipation layer, an insulating layer, a heat conduction layer and an inner base material layer, the heat dissipation layer, the insulating layer and the heat conduction layer are arranged between the outer base material layer and the inner base material layer, the upper surface of the insulating layer is provided with the heat dissipation layer, the lower surface of the insulating layer is provided with the heat conduction layer, and the lower end surface of the inner base material layer is connected with the adhesive layer.

[0008] Preferably, the outer base material layer is a PET film with one side release and one side corona.

[0009] Preferably, the heat dissipation layer and the heat conduction layer are graphene materials.

[0010] Preferably, the material of the insulating layer is one of polypropylene, polyethylene terephthalate, polyethylene and biaxially oriented polypropylene.

[0011] Preferably, the inner base material layer is a PET film with two sides corona.

[0012] Preferably, the adhesive layer is a heat-resistant ultra-thin double-sided tape.

[0013] Preferably, the thickness of the composite film is 15 to 25 um.

[0014] (III) Beneficial effects

[0015] By improving the close fit of the composite film in the power battery package and the battery pack, the heat is transferred to the external heat dissipation system by using the heat dissipation layer in the composite film in cooperation with the heat dissipation layer, the design of the film layer reduces the thermal resistance of the protective film itself, avoids the accumulation of heat on the surface of the battery, improves the uniformity of heat dissipation, and does not damage the voltage / capacity balance, in addition, the setting of the outer base material layer, the insulating layer and the inner base material layer makes the electrical insulation performance of the heat dissipation film not reduced, and the mechanical strength is enhanced. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings are used to provide a further understanding of the technical scheme of the present application, and constitute a part of the specification, and are used together with the embodiments of the present application to explain the technical scheme of the present application, and do not constitute a limitation on the technical scheme of the present application.

[0017] Figure 1 is a cross-sectional view of the heat dissipation film structure for power batteries;

[0018] Explanation of reference signs:

[0019] 1, composite film; 10, outer base material layer; 11, heat dissipation layer; 12, insulating layer; 13, heat conduction layer; 14, inner base material layer; 2, release film; 3, adhesive layer. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0021] The following will be combined with the drawings Figure 1, for further description, the utility model discloses a kind of heat dissipation film structures for power battery, including composite film 1, release film 2 and adhesive layer 3, adhesive layer 3 is set between composite film 1 and release film 2, composite film 1 includes outer base material layer 10, heat dissipation layer 11, insulating layer 12, heat conducting layer 13 and inner base material layer 14, heat dissipation layer 11, insulating layer 12 and heat conducting layer 13 are arranged between outer base material layer 10 and inner base material layer 14, the upper surface of insulating layer 12 is provided with heat dissipation layer 11, the lower surface of insulating layer 12 is provided with heat conducting layer 13, and ordinary modified acrylic adhesive is provided between outer base material layer 10, heat dissipation layer 11, insulating layer 12, heat conducting layer 13 and inner base material layer 14 two by two, composite between layer and layer by ordinary modified acrylic adhesive, the lower end surface of inner base material layer 14 is connected adhesive layer 3, and release film 2 can be used by tearing.

[0022] In the preferred embodiment, the outer base material layer 10 is a PET film with one side release and one side corona.

[0023] In the preferred embodiment, the heat dissipation layer 11 and the heat conducting layer 13 are both graphene materials in film shape.

[0024] In the preferred embodiment, the material of the insulating layer 12 is one of polypropylene, polyethylene terephthalate, polyethylene and biaxially oriented polypropylene.

[0025] In the preferred embodiment, the inner base material layer 14 is a PET film with two sides corona.

[0026] In the preferred embodiment, the adhesive layer 3 is a heat-resistant ultra-thin double-sided adhesive, such as high-adhesion modified acrylic adhesive.

[0027] In the preferred embodiment, the thickness of the composite film 1 is 15 to 25 um.

[0028] According to the above-mentioned embodiment, the following parameters can be tested:

[0029]

[0030] According to the above technical parameters, the heat dissipation film not only meets the heat dissipation requirements of the power battery, but also has good mechanical strength, which not only meets the heat dissipation conditions of the power battery during charging and discharging, but also protects the power battery from physical damage to a certain extent.

[0031] In summary, by improving the close fit of the composite film in the power battery package and the battery pack, the heat is transferred to the external heat dissipation system by the heat conduction layer in the composite film cooperating with the heat dissipation layer, the design of the film layer reduces the thermal resistance of the protective film itself, avoids the heat accumulation on the surface of the battery, improves the uniformity of heat dissipation, does not damage the voltage / capacity balance, in addition, the setting of the outer base material layer, the insulating layer and the inner base material layer makes the electrical insulation performance of the heat dissipation film not reduced, and the mechanical strength is enhanced.

[0032] Although the above has shown the embodiments of the present application, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application, and the ordinary skilled in the art can modify the above embodiments, but the modifications are included in the broad scope of the foregoing disclosure, drawings and claims.

Claims

1. A heat dissipation film structure for a power battery, comprising a composite film, a release film, and an adhesive layer, the adhesive layer being arranged between the composite film and the release film, characterized in that: The composite film comprises an outer base material layer, a heat dissipation layer, an insulating layer, a heat conduction layer and an inner base material layer, the heat dissipation layer, the insulating layer and the heat conduction layer are arranged between the outer base material layer and the inner base material layer, the upper surface of the insulating layer is provided with the heat dissipation layer, the lower surface of the insulating layer is provided with the heat conduction layer, and the lower end surface of the inner base material layer is connected with a bonding layer.

2. The heat dissipation film structure for power battery according to claim 1, characterized in that: The outer base material layer is a PET film with one side releasing and one side corona.

3. The heat dissipation film structure for power battery according to claim 1, characterized in that: The heat dissipation layer and the heat conduction layer are graphene materials.

4. The heat dissipation film structure for power battery according to claim 1, characterized in that: The material of the insulating layer is one of polypropylene, polyethylene terephthalate, polyethylene and biaxially oriented polypropylene.

5. The heat dissipation film structure for power battery according to claim 1, characterized in that: The inner base material layer is a PET film with two sides corona.

6. The heat dissipation film structure for power battery according to claim 1, characterized in that: The bonding layer is a heat-resistant ultra-thin double-sided adhesive tape.

7. The heat dissipation film structure for power battery according to claim 1, characterized in that: The thickness of the composite film is 15-25 um.

Images