Electrolyte-resistant aluminum plastic film for battery

Abstract

The utility model discloses an electrolyte-resistant aluminum plastic film for a battery, which comprises an aluminum foil layer clamped between a wear-resistant protective layer and a heat sealing layer; the heat sealing surface of the heat sealing layer is provided with containing grooves, the adjacent containing grooves are arranged at intervals, the containing grooves are provided with electrolyte adsorption layers, the adsorption surface of each electrolyte adsorption layer is flush with the heat sealing surface, and the adsorption surface is provided with an adsorption concave part. The electrolyte-resistant aluminum-plastic film for the battery is reasonable in structure, and the contact area between an adsorption surface and electrolyte is increased through the electrolyte adsorption layer and the adsorption sunken parts on the adsorption surface of the electrolyte adsorption layer, so that the adsorbability of the aluminum-plastic film to the electrolyte of the battery is improved; and the adjacent accommodating grooves are arranged at intervals, so that the heat sealing tightness of the heat sealing layer is ensured.

Description

Technical Field

[0001] This utility model relates to the field of battery packaging technology, and in particular to an electrolyte-resistant aluminum-plastic film for batteries. Background Technology

[0002] The packaging film used for soft-pack batteries is usually composed of aluminum foil with high water vapor barrier properties and a polymer film material with chemical resistance, good heat sealing and flexibility. For example, the structure of conventional aluminum-plastic film consists of a nylon (PA) layer, an aluminum foil layer and a polypropylene (PP) layer in sequence. When wrapping, the aluminum-plastic film uses the PP layer as the heat sealing layer. However, the PP layer has poor adsorption of the battery electrolyte and cannot effectively "lock" the electrolyte, which may lead to poor sealing. Especially under long-term use or extreme conditions, it increases the risk of electrolyte leakage.

[0003] Therefore, it is necessary to improve the electrolyte-resistant aluminum-plastic film for batteries in the existing technology. Utility Model Content

[0004] The purpose of this invention is to overcome the defects in the existing technology and provide an electrolyte-resistant aluminum-plastic film for batteries. The electrolyte-resistant aluminum-plastic film for batteries has a reasonable structure. Through the electrolyte adsorption layer and the adsorption depression of the adsorption surface, the contact area between the adsorption surface and the electrolyte is increased, thereby improving the adsorption of battery electrolyte by the aluminum-plastic film. The adjacent receiving tanks are spaced apart to ensure the heat sealing tightness of the heat sealing layer.

[0005] To achieve the above-mentioned technical effects, the technical solution of this utility model is: an electrolyte-resistant aluminum-plastic film for batteries, comprising:

[0006] An aluminum foil layer is sandwiched between a wear-resistant protective layer and a heat-sealing layer;

[0007] The heat-sealing layer has a receiving groove on its heat-sealing surface, with adjacent receiving grooves spaced apart. Each receiving groove has an electrolyte adsorption layer, the adsorption surface of which is flush with the heat-sealing surface, and the adsorption surface has an adsorption recess.

[0008] A preferred technical solution is that the receiving grooves are distributed in a dotted pattern on the heat-sealing surface; or they are distributed in a strip pattern extending along a first direction and arranged side by side on the heat-sealing surface, with the strip-shaped receiving grooves in the same extending direction being segmented.

[0009] A preferred technical solution is that the electrolyte adsorption layer is an ethylene-vinyl acetate copolymer layer or an ethylene-methacrylic acid copolymer layer.

[0010] A preferred technical solution is that the ratio of the depth of the receiving groove to the thickness of the heat-sealing layer is (0.2~0.5):1.

[0011] A preferred technical solution is that the ratio of the area of ​​the adsorption surface to the total area of ​​the heat-sealing surface is (0.3~0.4):1.

[0012] The preferred technical solution is that the heat-sealing layer is a polypropylene film, and the wear-resistant protective layer is a composite layer of a copolymer nylon layer and an ethylene-vinyl alcohol copolymer layer.

[0013] The preferred technical solution is that the wear-resistant protective layer is a laminated structure of copolynylon layer / ethylene-vinyl alcohol copolymer layer / copolynylon layer.

[0014] A preferred technical solution is that the aluminum foil layer and the heat-sealing layer, as well as the aluminum foil layer and the wear-resistant protective layer, are connected by an adhesive layer, wherein the adhesive layer is one of urethane adhesive, epoxy resin adhesive, acrylic resin adhesive, or TPU hot melt adhesive.

[0015] The preferred technical solution is that the thickness of the aluminum foil layer is 25-50 μm, the thickness of the heat-sealing layer is 20-40 μm, and the thickness of the wear-resistant protective layer is 20-40 μm.

[0016] A preferred technical solution is that the thickness of the adhesive layer is 2 to 6 μm.

[0017] The advantages and beneficial effects of this utility model are as follows:

[0018] The battery uses an electrolyte-resistant aluminum-plastic film with a reasonable structure. Through the electrolyte adsorption layer and the adsorption depressions on the adsorption surface, the contact area between the adsorption surface and the electrolyte is increased, thereby improving the adsorption capacity of the aluminum-plastic film for the battery electrolyte. The adjacent receiving tanks are spaced apart to ensure the heat sealing tightness of the heat sealing layer. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the electrolyte-resistant aluminum-plastic film for batteries according to this utility model;

[0020] Figure 2 This is a schematic diagram of the first type of receiving tank structure in the electrolyte-resistant aluminum-plastic film for batteries of this utility model;

[0021] Figure 3 This is a schematic diagram of the second type of receiving tank structure in the electrolyte-resistant aluminum-plastic film for batteries of this utility model.

[0022] In the diagram: 1. Aluminum foil layer; 2. Wear-resistant protective layer; 3. Heat-sealing layer; 11. Adhesive layer; 21. Copolymer nylon layer; 22. Ethylene-vinyl alcohol copolymer layer; 30. Heat-sealing surface; 31. Adsorption surface; 300. Receiving groove. Detailed Implementation

[0023] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solution of this utility model and should not be construed as limiting the scope of protection of this utility model.

[0024] The term "surface" is used with reference to the normal operating condition of the electrolyte-resistant aluminum-plastic film for batteries. It is used only for the convenience of describing this utility model and simplifying the description, and is not intended to indicate or imply that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0025] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0026] like Figures 1-3 As shown, the electrolyte-resistant aluminum-plastic film for batteries of this utility model includes an aluminum foil layer 1, a wear-resistant protective layer 2, and a heat-sealing layer 3. The aluminum foil layer 1 is sandwiched between the wear-resistant protective layer 2 and the heat-sealing layer 3. The heat-sealing layer 3 has a receiving groove 300 on its heat-sealing surface 300. Adjacent receiving grooves 300 are spaced apart. An electrolyte adsorption layer is provided in the receiving groove 300. The adsorption surface 31 of the electrolyte adsorption layer is flush with the heat-sealing surface 39. The adsorption surface 31 is provided with an adsorption recess (not shown).

[0027] The contact area between the adsorption surface 31 and the electrolyte is increased by the adsorption layer and the adsorption depression of its adsorption surface 31, thereby improving the adsorption of battery electrolyte by the aluminum-plastic film; the adjacent receiving tanks 300 are spaced apart to ensure the heat sealing tightness of the heat sealing layer 3.

[0028] like Figure 2 As shown, the structure and heat-sealing area of ​​the receiving tank are optimized to maintain the heat-sealing strength of the aluminum-plastic film while improving the adsorption of battery electrolyte. In some embodiments, the receiving tank 300 is distributed in a dotted pattern on the heat-sealing surface 30.

[0029] like Figure 3 As shown, in some other embodiments, the receiving grooves 300 are distributed in strips extending along a first direction and arranged side by side on the heat-receiving surface, and the strip-shaped receiving grooves 300 in the same extending direction are segmented.

[0030] Without significantly altering the basic properties of the heat-sealing layer, the polarity and hydrophilicity of the material surface are increased to improve the adsorption of electrolyte components. Furthermore, heat-sealing layer 3 is a polypropylene film, and the electrolyte adsorption layer is an ethylene-vinyl acetate copolymer layer or an ethylene-methacrylic acid copolymer layer. Polypropylene film (CPP) has a wide heat-sealing temperature range, meaning it can achieve reliable sealing under different temperature conditions, which is crucial for different types of battery production and assembly processes. CPP can achieve effective heat sealing at relatively low temperatures, which helps reduce the impact on other layer materials and lowers production costs. The ethylene-vinyl acetate copolymer layer (EVA) has excellent adhesion properties and can bond well with various materials, which helps improve the integrity and sealing effect of the composite structure. EVA is softer and more elastic than PP, which is particularly advantageous for applications that need to adapt to battery expansion and contraction. EVA can achieve effective heat sealing at lower temperatures, reducing processing difficulty and minimizing the impact on other layer materials. EVA exhibits good resistance to many organic solvents and electrolyte components, helping to maintain its physical properties. EMA contains carboxyl functional groups, which give it higher polarity and hydrophilicity, which is very helpful in improving the adsorption and compatibility with electrolyte components.

[0031] To optimize the adsorption effect of the adsorption layer on the battery electrolyte and reduce manufacturing costs, the ratio of the depth of the receiving tank 300 to the thickness of the heat-sealing layer 3 is (0.2~0.5):1. Furthermore, the ratio of the area of ​​the adsorption surface 31 to the total area of ​​the heat-sealing surface 30 is (0.3~0.4):1.

[0032] The wear-resistant protective layer 2 is a composite layer of copolymer nylon layer 21 and ethylene-vinyl alcohol copolymer layer 22. This composite layer enhances the barrier properties of the aluminum-plastic film. Through co-extrusion, the layers are directly fused together to form a whole, giving the aluminum-plastic film higher mechanical strength, impact resistance, and puncture resistance. Furthermore, the wear-resistant protective layer 2 has a laminated structure of copolymer nylon layer / ethylene-vinyl alcohol copolymer layer / copolymer nylon layer. The copolymer nylon layer 21, by introducing other monomers, reduces overall hygroscopicity, thereby improving dimensional stability and electrical insulation, enhancing flexibility and impact strength, and ultimately improving the puncture resistance, durability, and barrier properties of the aluminum-plastic film.

[0033] The aluminum foil layer 1 and the heat-sealing layer 3, as well as the aluminum foil layer 1 and the wear-resistant protective layer 2, are connected by an adhesive layer 11, which is one of urethane adhesive, epoxy resin adhesive, acrylic resin adhesive, or TPU hot melt adhesive.

[0034] The aluminum foil layer 1 has a thickness of 25–50 μm, the heat-sealing layer 3 has a thickness of 20–40 μm, the wear-resistant protective layer 2 has a thickness of 20–40 μm, and the adhesive layer 11 has a thickness of 2–6 μm.

[0035] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A battery electrolyte-resistant aluminum plastic film, comprising: an aluminum foil layer sandwiched between a wear-resistant protective layer and a heat-seal layer; characterized in that the heat-seal surface of the heat-seal layer is provided with accommodation grooves arranged at intervals between adjacent accommodation grooves, the accommodation grooves are provided with an electrolyte adsorption layer, the adsorption surface of the electrolyte adsorption layer is flush with the heat-seal surface, and the adsorption surface is provided with adsorption recesses.

2. The electrolyte-resistant aluminum laminate for a battery according to claim 1, characterized by, The accommodation grooves are distributed on the heat-seal surface in a dot shape; or are distributed on the heat-seal surface in a strip shape extending in a first direction and arranged side by side, and the strip-shaped accommodation grooves in the same extension direction are arranged in sections.

3. The electrolyte-resistant aluminum laminate for a battery according to claim 1 or 2, characterized in that, The electrolyte adsorption layer is an ethylene-vinyl acetate copolymer layer or an ethylene-methacrylic acid copolymer layer.

4. The electrolyte-resistant aluminum laminate for a battery according to claim 1 or 2, characterized by, The ratio of the groove depth of the accommodation grooves to the thickness of the heat-seal layer is (0.2-0.5):

1.

5. The electrolyte-resistant aluminum laminate for a battery according to claim 1 or 2, characterized in that, The ratio of the area of the adsorption surface to the total area of the heat-seal surface is (0.3-0.4):

1.

6. The electrolyte-resistant aluminum laminate for a battery according to claim 1, wherein The heat-seal layer is a polypropylene film, and the wear-resistant protective layer is a composite layer of a copolymer nylon layer and an ethylene-vinyl alcohol copolymer layer.

7. The electrolyte-resistant aluminum laminate for a battery according to claim 6, characterized by The wear-resistant protective layer has a laminated structure of a copolymer nylon layer / ethylene-vinyl alcohol copolymer layer / copolymer nylon layer.

8. The electrolyte-resistant aluminum laminate for a battery according to claim 1, wherein The aluminum foil layer and the heat-seal layer, and the aluminum foil layer and the wear-resistant protective layer are connected by an adhesive layer, and the adhesive layer is one of urethane adhesive, epoxy resin adhesive, acrylic resin adhesive, and TPU hot melt adhesive.

9. The electrolyte-resistant aluminum laminate for a battery according to claim 4, characterized by The thickness of the aluminum foil layer is 25-50 μm, the thickness of the heat-seal layer is 20-40 μm, and the thickness of the wear-resistant protective layer is 20-40 μm.

10. The electrolyte-resistant aluminum laminate for a battery according to claim 8, wherein The thickness of the adhesive layer is 2-6 μm.

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