Pole core insulating film, battery, battery pack and electric equipment

Abstract

The utility model provides a pole core insulating film and a battery. The pole core insulating film comprises a first insulating layer and a second insulating layer which are sequentially stacked, the first insulating layer comprises a polyethylene glycol terephthalate layer or a biaxially oriented polypropylene layer; the first insulating layer comprises a polyethylene glycol terephthalate layer and / or a polypropylene layer, and the thickness of the first insulating layer is 0.05 mm to 0.15 mm. The pole core insulating film has strong foreign matter puncture resistance, can effectively avoid corrosion of a shell of the battery, improves the safety of the battery, prolongs the service life of the battery, and improves the assembly efficiency of the battery.

Description

Technical Field

[0001] The present application relates to the field of batteries. Specifically, the present application relates to a core insulation film, a battery, a battery pack, and an electrical device. Background Art

[0002] During the current production process of batteries, an insulation film needs to be coated before the core is inserted into the shell, which protects the core from being scratched by the hard shell during the assembly process, and at the same time ensures that the core is in an insulated coating state, avoiding contact with the shell and making the shell negatively charged, thereby avoiding the problem of shell corrosion of aluminum shell batteries under low potential conditions and improving the safety performance of the batteries.

[0003] In the prior art, the insulation film is usually made by calendering or casting processes. The insulation film is prone to the defect of self - contained micropores, which causes the problem of shell corrosion during the use of the battery. Moreover, the existing insulation film is easily pierced by foreign objects, resulting in insulation failure and ultimately also causing shell corrosion.

[0004] Therefore, the current core insulation film urgently needs to be improved. Summary of the Utility Model

[0005] The present utility model aims to solve at least one of the technical problems in the related art to some extent. For this purpose, an object of the present utility model is to provide a core insulation film, a battery, and an electrical device. The core insulation film of the present utility model has strong foreign object puncture resistance, can effectively avoid the shell corrosion of the battery, and improve the safety, service life, and assembly efficiency of the battery.

[0006] The present utility model provides a core insulation film, which includes a first insulation layer and a second insulation layer stacked in sequence; the first insulation layer includes a polyethylene terephthalate layer and / or a polypropylene layer, and the thickness of the first insulation layer is 0.05 mm - 0.15 mm.

[0007] The battery insulation film of the present utility model has two insulation layers, which can effectively avoid the micropore defects of a single - layer film and prevent the shell corrosion of the battery. Using a polyethylene terephthalate layer and / or a polypropylene layer as the structural composition of the first insulation film and meeting the above - mentioned first insulation layer thickness condition can improve the foreign object puncture resistance of the core insulation film, avoid the damage of the core diaphragm or insulation layer due to the presence of foreign objects during the battery assembly or use process, and improve the safety, service life, and assembly efficiency of the battery.

[0008] In some embodiments, the first insulation layer includes a polyethylene terephthalate layer.

[0009] In some embodiments, in the first insulation layer, the polypropylene layer is a biaxially oriented polypropylene layer.

[0010] In some embodiments, the second insulating layer includes a polypropylene layer.

[0011] In some embodiments, the thickness of the first insulating layer is greater than that of the second insulating layer.

[0012] In some embodiments, the thickness of the second insulating layer is 0.03 mm to 0.10 mm.

[0013] In some embodiments, the puncture strength of the first insulating layer is 1.3 kgf to 3.0 kgf.

[0014] In some embodiments, a thermosensitive adhesive layer is laminated on a side of the second insulating layer facing away from the first insulating layer.

[0015] In some embodiments, the thickness of the thermosensitive adhesive layer is 5 μm to 15 μm.

[0016] In some embodiments, the electrode core insulating film further includes an adhesive layer laminated between the first insulating layer and the second insulating layer.

[0017] In some embodiments, the adhesive layer includes an acrylate adhesive layer.

[0018] In some embodiments, the thickness of the adhesive layer is 2 μm to 10 μm.

[0019] In some embodiments, the electrode core includes a positive electrode, a separator, and a negative electrode laminated together.

[0020] In some embodiments, the second insulating layer is adapted to be closer to the electrode core relative to the first insulating layer.

[0021] The present utility model also provides a battery, which includes: an electrode core and the above-mentioned electrode core insulating film, and the electrode core insulating film covers at least part of the surface of the electrode core. Thus, the battery of this utility model has all the features and advantages of the foregoing electrode core insulating film, which will not be elaborated herein. Generally speaking, it has at least the advantages of high safety, long service life, and high assembly efficiency.

[0022] In some embodiments, the electrode core insulating film covers at least part of the surface of at least the large surface of the electrode core.

[0023] In some embodiments, the battery further includes a housing, the housing forms a receiving space, the electrode core is received in the receiving space, and the electrode core insulating film is disposed between the electrode core and the housing.

[0024] In some embodiments, the housing includes a housing body and a cover body, and the housing body and the cover body jointly enclose the receiving space;

[0025] The battery further includes a separator for separating the electrode core from the cover body, and the electrode core insulating film at least partially covers the separator.

[0026] In some embodiments, the second insulating layer is closer to the electrode core than the first insulating layer.

[0027] The present utility model also provides a battery pack, including a battery pack box body and a plurality of the above-mentioned batteries, and the plurality of batteries are arranged in the battery pack box body.

[0028] The present utility model also provides an electrical equipment, which includes the above-mentioned battery or battery pack.

[0029] The additional aspects and advantages of the present utility model will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present utility model. Description of the Drawings

[0030] The above and / or additional aspects and advantages of the present utility model will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, wherein:

[0031] Figure 1 It shows a schematic structural diagram of the electrode core insulating film according to an embodiment of the present utility model;

[0032] Figure 2 It shows a sectional view of the battery according to an embodiment of the present utility model;

[0033] Figure 3 It shows a schematic structural diagram of the battery according to an embodiment of the present utility model.

[0034] Reference Signs:

[0035] 1: Battery; 10: Electrode core insulating film; 100: First insulating layer; 200: Second insulating layer; 300: Thermal adhesive layer; 400: Adhesive layer; 20: Electrode core; 30: Housing body; 40: Cover body; 50: Separator. Detailed Embodiments

[0036] The embodiments of the present utility model will be described in detail below. The described embodiments are exemplary and are only used to explain the present utility model, and should not be construed as a limitation to the present utility model. For those technologies or conditions not specified in the embodiments, they shall be carried out according to the technologies or conditions described in the literature in the field or according to the product specifications. For the reagents or instruments not specified for the manufacturers, they are all conventional products that can be obtained through commercial purchase.

[0037] In one aspect of the present utility model, the present utility model provides an electrode core insulating film. Refer to Figure 1, the electrode core insulating film 10 includes a first insulating layer 100 and a second insulating layer 200 which are stacked in sequence; the first insulating layer 100 includes a polyethylene terephthalate layer and / or a polypropylene layer, and the thickness of the first insulating layer 100 is 0.05 mm to 0.15 mm.

[0038] The battery insulating film 10 of the present utility model has two insulating layers. When micropores appear in a single-layer film, the probability that the micropores in different layers overlap in the film thickness direction is extremely low, so it is not easy for the composite film to have micropores penetrating in the thickness direction. Thus, the micropore defects in the single-layer film can be effectively avoided.

[0039] Due to the limited space in the electrode core, under the condition of limited thickness, if there are tiny foreign objects in the electrode core, there is a risk of being pierced by the foreign objects, resulting in insulation failure, and then bringing problems such as corrosion of the electrode core tab and the housing and abnormal battery performance due to low voltage. For this reason, since polyethylene terephthalate and polypropylene have puncture resistance, one or both of them are used as the structural components of the first insulating layer. Further, selecting to meet the above thickness condition of the first insulating layer can provide better insulation performance and puncture resistance against foreign objects, can avoid damage to the electrode core separator or insulating layer due to the presence of foreign objects during battery assembly or use, and can also provide the required mechanical properties for the electrode core insulating film, and can ensure that the structural form of the electrode core insulating film remains intact in most actual working conditions (for example: road vibration faced by the electrode core, expansion during charge and discharge, and extrusion of foreign objects between electrode cores, etc.), improving the safety, service life and assembly efficiency of the battery. Exemplarily, the thickness of the first insulating layer 100 is 0.05 mm, 0.06 mm, 0.08 mm, 0.10 mm, 0.12 mm, 0.14 mm, 0.15 mm or a range value formed by any two values as endpoint values.

[0040] In some embodiments of the present utility model, the puncture strength of the first insulating layer 100 is 1.3 kgf to 3.0 kgf. Exemplarily, the puncture strength can be 1.3 kgf, 1.4 kgf, 1.5 kgf, 1.6 kgf, 1.7 kgf, 1.8 kgf, 1.9 kgf, 2.0 kgf, 2.1 kgf, 2.2 kgf, 2.3 kgf, 2.4 kgf, 2.5 kgf, 2.6 kgf, 2.7 kgf, 2.8 kgf, 2.9 kgf, 3.0 kgf or a range value formed by any two values as endpoint values. Thus, the first insulating layer meeting the above conditions further has better puncture resistance.

[0041] It should be noted that the polyethylene terephthalate layer (which can also be referred to as the "PET layer" in this text) and the polypropylene layer (which can also be referred to as the "PP film" in this text) with a puncture strength of 1.3 kgf to 3.0 kgf are well-known film materials in the art. It can be understood that the puncture strength can be tested using a steel needle with a radius of 0.5 mm and the tooling mentioned in the standard according to "GB / T 10004—2008 Plastic composite films and bags for packaging Dry lamination, extrusion lamination". Exemplarily, the polypropylene layer can be a biaxially oriented polypropylene layer (which can also be referred to as the "BOPP film" in this text).

[0042] In some embodiments of the present utility model, the first insulating layer 100 includes a polyethylene terephthalate layer, and the polyethylene terephthalate layer includes polyethylene terephthalate. The polyethylene terephthalate layer has a relatively high puncture strength. The first insulating layer 100 including the polyethylene terephthalate layer can further improve the mechanical strength of the electrode core insulating film, and improve the safety, service life and assembly efficiency of the battery.

[0043] In some embodiments of the present utility model, the second insulating layer 200 is adapted to be closer to the electrode core relative to the first insulating layer 100. When the polyethylene terephthalate layer is at a low potential (for an aluminum shell battery, there is often only one separator between the outermost negative electrode of the electrode core and the electrode core insulating film. If the polyethylene terephthalate layer is arranged close to the electrode core, when the outermost separator of the electrode core is damaged and the negative electrode is exposed, the polyethylene terephthalate layer will be in direct contact with the negative electrode and be at a low potential) and is infiltrated by the electrolyte, there is a risk of degradation and weakening of strength. Arranging the second insulating layer closer to the electrode core relative to the first insulating layer can avoid the polyethylene terephthalate layer being at a low potential and degrading and weakening in strength. In addition, the properties of polyethylene terephthalate are quite different from those of common separator materials of the electrode core, which is not conducive to the heat fusion fixation of the polyethylene terephthalate layer and the electrode core separator, and will bring difficulties to the assembly. Arranging the second insulating layer closer to the electrode core relative to the first insulating layer can use the second insulating layer to be heat fusion fixed with the electrode core separator, which is convenient for assembly.

[0044] In some embodiments of the present utility model, the second insulating layer 200 includes a polypropylene layer, and the polypropylene layer includes polypropylene. When only the first insulating layer with a high puncture strength is used, although the puncture strength is high, there is a risk of film degradation or weakening of strength under the conditions of a low potential (such as when the outermost separator of the electrode core is damaged and the electrode plate is exposed, the electrode plate and the housing are at a low potential) and being infiltrated by the battery electrolyte. The polypropylene layer (PP film) has good corrosion resistance to the electrolyte, which helps to maintain the integrity of the insulating film, and its mechanical strength is good, which can prevent mechanical damage during assembly and use. In addition, its electrochemical stability is strong, and it can remain stable within a wide range of voltages and temperatures, improving the safety of the battery.

[0045] In some embodiments of the present utility model, the thickness of the first insulating layer 100 is greater than that of the second insulating layer 200. Thus, after the first insulating layer 100 and the second insulating layer 200 are adhesively compounded, edge insulation warping of the film in the width direction of the film roll is avoided.

[0046] In some embodiments of the present utility model, the thickness of the second insulating layer 200 is 0.03 mm to 0.10 mm. In some embodiments, the thickness of the second insulating layer 200 is 0.03 mm, 0.05 mm, 0.06 mm, 0.08 mm, 0.10 mm, or a range value formed by any two values as end point values. Thus, better insulation performance, foreign object puncture resistance performance, and electrolyte resistance performance can be provided. Moreover, mechanical properties that meet the requirements can be provided for the electrode core insulating film, and the structural form of the electrode core insulating film can be ensured to be intact under most actual working conditions (for example, road vibrations faced by the electrode core, expansion during charge and discharge, and foreign object extrusion between electrode cores, etc.).

[0047] In some embodiments of the present utility model, a thermosensitive adhesive layer 300 is laminated on the side of the second insulating layer 200 facing away from the first insulating layer 100. If an adhesive (such as epoxy resin) with an adhesive effect at normal temperature is used, it is easy to adhere to tiny foreign objects during battery assembly, and it is difficult to remove the tiny foreign objects through a dust removal device. Furthermore, during use, the diaphragm and the insulating film may be squeezed and broken due to the thermal expansion of the electrode core, and a low voltage may be formed between the electrode plate and the housing, causing housing corrosion. By laminating the thermosensitive adhesive layer 300 on the side of the second insulating layer 200 facing away from the first insulating layer 100, the thermosensitive adhesive layer 300 includes a thermosensitive adhesive. The thermosensitive adhesive is a solid and does not have adhesiveness when the temperature is lower than the melting viscosity temperature (for example, lower than 70 °C). When the temperature is higher than the melting viscosity temperature (for example, between 70 °C and 120 °C), it will be in a molten state and bond the electrode core 20 to the second insulating layer 200. When the use temperature returns to below the melting viscosity temperature, the thermosensitive adhesive is in a solid state and fixedly connects the electrode core 20 to the second insulating layer 200.

[0048] It should be noted that the "thermosensitive adhesive" is a well-known hot-melt resin material in the art, and specifically, it may include, for example, thermoplastic polyurethane elastomer (TPU) or rubber-like thermoplastic polymer materials, etc.

[0049] In some embodiments of the present utility model, the thickness of the thermosensitive adhesive layer 300 is 5 μm to 15 μm. In some embodiments, the thickness of the thermosensitive adhesive layer 300 is 5 μm, 6 μm, 8 μm, 10 μm, 12 μm, 14 μm, 15 μm, or a range value formed by any two values as end point values. Thus, the thermosensitive adhesive layer has better adhesion performance, and the second insulating layer can be stably adhered to the electrode core.

[0050] In some embodiments of the present utility model, the electrode core insulating film 10 further includes an adhesive layer 400 laminated between the first insulating layer 100 and the second insulating layer 200. The adhesive layer 400 is used to bond the first insulating layer 100 and the second insulating layer 200.

[0051] In some embodiments of the present utility model, the adhesive layer 400 includes an acrylate adhesive layer, and the acrylate adhesive layer includes acrylate. The acrylate can be quickly cured between the first insulating layer and the second insulating layer, and has advantages such as good adhesion performance and high temperature resistance.

[0052] In some embodiments of the present utility model, the thickness of the adhesive layer 400 is 2μm to 10μm. In some embodiments, the thickness of the adhesive layer 400 is 2μm, 4μm, 6μm, 8μm, 10μm or a range value formed by any two values as the end values. Thus, the adhesive layer 400 has better adhesion performance, and the first insulating layer 100 and the second insulating layer 200 can be stably adhered, and the increase of the battery thickness can be avoided, thereby reducing the volume energy density of the battery module.

[0053] In some embodiments of the present utility model, the electrode core includes a positive electrode, a separator and a negative electrode which are laminated.

[0054] In another aspect of the present utility model, the present utility model also proposes a battery. Refer to Figure 2 , the battery 1 includes: an electrode core 20 and the above-mentioned electrode core insulating film 10, and the electrode core insulating film 10 covers at least part of the surface of the electrode core 20. Thus, the battery of this utility model has all the features and advantages of the foregoing electrode core insulating film, which will not be elaborated here. Generally speaking, it has at least the advantages of high safety, long service life and high assembly efficiency.

[0055] In some embodiments of the present utility model, the electrode core insulating film 10 covers at least part of the surface of at least the large surface of the electrode core 20. It can be understood that the large surface of the electrode core 20 refers to the surface with the largest surface area of the electrode core; for example, the electrode core 20 is a substantially square structure, the electrode core 20 has a long side, a wide side and a thick side, the dimension of the long side is greater than or equal to the dimension of the wide side, and the dimension of the wide side is greater than or equal to the dimension of the thick side, and the large surface is the surface of the electrode core 20 perpendicular to the thick side direction, that is, the surface parallel to the long side and the wide side.

[0056] In some embodiments of the present utility model, the battery further includes a housing, the housing forms a receiving space, the electrode core 20 is received in the receiving space, and the electrode core insulating film 10 is disposed between the electrode core 20 and the housing.

[0057] In some embodiments of the present utility model, the housing includes a housing body 30 and a cover body 40, and the housing body 30 and the cover body 40 jointly enclose the receiving space.

[0058] In some embodiments of the present utility model, the battery 1 further includes a separator 50 for separating the electrode core 20 from the cover 40, and the electrode core insulating film 10 at least partially covers the separator 50. The separator 50 between the electrode core 20 and the cover 40 is usually an insulating material, which aims to prevent short circuit between the electrode core 20 and the cover 40, and may also have multiple functions such as support, sealing or protection. Exemplarily, the separator includes an inner spacer ring.

[0059] In some embodiments of the present utility model, the second insulating layer 200 is closer to the electrode core 20 than the first insulating layer 100.

[0060] Another aspect of the present utility model further provides a battery pack, which includes a battery pack box body and a plurality of batteries 1, and the plurality of batteries 1 are arranged in the battery pack box body.

[0061] Another aspect of the present utility model further provides an electrical device, and the electrical device includes the battery described above. The electrical device of this utility model has all the features and advantages of the aforementioned battery, which will not be elaborated here.

[0062] Batteries, battery modules, and battery packs can be used as the power source of an electrical device or as the energy storage unit of an electrical device. Electrical devices can include mobile devices (such as mobile phones, laptop computers, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships, energy storage systems, etc., but are not limited thereto.

[0063] As an electrical device, a battery, a battery module or a battery pack can be selected according to its usage requirements.

[0064] As an electrical device of an embodiment, it can be a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, etc. In order to meet the high power and high energy density requirements of the electrical device for the battery, a battery pack or a battery module can be adopted.

[0065] As an electrical device of another embodiment, it can be a mobile phone, a tablet computer, a laptop computer, etc. This electrical device usually requires thin and light design, and a battery can be used as the power source.

[0066] In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, "a plurality of" means two or more, unless otherwise clearly and specifically defined.

[0067] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by terms such as "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial direction", "radial direction", "circumferential direction", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model.

[0068] Although the embodiments of the present utility model have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as a limitation to the present utility model. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present utility model.

Claims

1. A core insulating film, characterized in that: It includes a first insulating layer and a second insulating layer which are stacked in sequence; The first insulating layer comprises a polyethylene terephthalate layer and / or a polypropylene layer; The thickness of the first insulating layer is 0.05 mm to 0.15 mm.

2. The core insulating film according to claim 1, characterized in that: The core insulating film satisfies at least one of the following (a), (b), and (c): (a) the first insulating layer comprises a polyethylene terephthalate layer; (b) In the first insulating layer, the polypropylene layer is a biaxially oriented polypropylene layer; (c) The second insulating layer comprises a polypropylene layer.

3. The pole core insulating film according to claim 1 or 2, characterized in that: The core insulating film satisfies at least one of the following (I), (II), and (III): (I) the thickness of the first insulating layer is greater than the thickness of the second insulating layer; and / or, (II) the thickness of the second insulating layer is 0.03 mm to 0.10 mm; and / or, (III) The puncture strength of the first insulating layer is 1.3 kgf to 3.0 kgf.

4. The core insulating film according to claim 1, characterized in that: A heat-sensitive adhesive layer is stacked on a side of the second insulating layer facing away from the first insulating layer.

5. The core insulating film according to claim 4, characterized in that: The thickness of the heat-sensitive adhesive layer is 5 μm to 15 μm.

6. The core insulating film according to claim 1, characterized in that: The core insulating film further includes an adhesive layer stacked between the first insulating layer and the second insulating layer.

7. The core insulating film according to claim 6, characterized in that: The adhesive layer includes an acrylate layer.

8. The core insulating film according to claim 6, characterized in that: The thickness of the adhesive layer is 2 μm to 10 μm.

9. The core insulating film according to claim 1, characterized in that: The pole core comprises a positive electrode, a separator and a negative electrode which are stacked.

10. The pole core insulating film according to claim 1 or 2, characterized in that: The second insulating layer is adapted to be closer to the pole core relative to the first insulating layer.

11. A battery, characterized in that: include: A pole core and the pole core insulating film according to any one of claims 1 to 10, wherein the pole core insulating film covers at least a portion of the surface of the pole core.

12. The battery according to claim 11, characterized in that The pole core insulating film at least covers at least a portion of the surface of the pole core large surface.

13. The battery according to claim 11 or 12, characterized in that: The battery further includes a shell, the shell is formed with an accommodation space, the pole core is accommodated in the accommodation space, and the pole core insulating film is disposed between the pole core and the shell.

14. The battery according to claim 13, characterized in that The shell comprises a shell body and a cover body, and the shell body and the cover body together enclose the accommodating space; The battery further includes an isolating member, which is used to separate the pole core from the cover, and the pole core insulating film at least partially covers the isolating member.

15. The battery according to claim 11, characterized in that The second insulating layer is closer to the pole core than the first insulating layer.

16. A battery pack, comprising a battery pack case and a plurality of batteries according to any one of claims 11 to 15, wherein the plurality of batteries are arranged in the battery pack case.

17. An electrical equipment, characterized in that: It comprises the battery according to any one of claims 11 to 15 or the battery pack according to claim 16.

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