Lithium battery protection film and lithium battery

Abstract

The utility model belongs to the technical field of lithium batteries, particularly relates to a lithium battery protection film and a lithium battery, and aims to solve the problems that the durability and the functionality of the lithium battery protection film need to be improved, the high temperature spreading speed between battery cells of the lithium battery is relatively high, and the service life is easily shortened due to expansion and shrinkage generated in the charging and discharging processes of the battery cells. According to the scheme, the lithium battery protection film comprises a lithium battery protection film body, and the lithium battery protection film body is formed by sequentially bonding a heat sealing layer, a blocking layer and a base material layer through an adhesive from inside to outside. Through the combination of a multi-layer structure, the lithium battery protection film provides all-around protection, effectively prevents the damage of the external environment to the battery core, prolongs the service life of the lithium battery, and effectively solves the problems of high temperature and volume change possibly generated in the charging and discharging process of the lithium battery due to the design of the buffer heat insulation piece, so that the service life of the lithium battery is prolonged. And the safety and the reliability of the lithium battery are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, in particular to a lithium battery protective film and a lithium battery. Background Art

[0002] A lithium battery is a battery that uses lithium metal or a lithium alloy as the negative electrode material and a non-aqueous electrolyte solution. They are widely used in portable electronic devices, electric vehicles, and energy storage systems due to their high energy density, long cycle life, and low self-discharge rate. Lithium batteries are mainly divided into two categories: lithium-ion batteries (Li-ion) and lithium metal batteries. Lithium-ion batteries use embedded lithium compounds as the positive electrode material, while lithium metal batteries use lithium metal or its alloy as the negative electrode.

[0003] Among them, the lithium battery protective film is a thin film material used to protect lithium battery components. It can prevent the battery from being physically damaged, chemically corroded, or affected by electrochemical reactions during manufacturing, transportation, storage, and use. Currently, the durability and functionality of lithium battery protective films need to be improved, and the high-temperature spread rate between lithium battery cells is relatively fast. The expansion and contraction generated during the charging and discharging process of the battery cells are likely to reduce the service life.

[0004] In view of the above problems, the present utility model document proposes a lithium battery protective film and a lithium battery. Summary of the Utility Model

[0005] The utility model provides a lithium battery protective film and a lithium battery, which solve the disadvantages in the prior art that the durability and functionality of the lithium battery protective film need to be improved, the high-temperature spread rate between lithium battery cells is relatively fast, and the expansion and contraction generated during the charging and discharging process of the battery cells are likely to reduce the service life.

[0006] The utility model provides the following technical solutions:

[0007] A lithium battery protective film, comprising:

[0008] A lithium battery protective film body, the lithium battery protective film body is sequentially bonded together by a heat-sealing layer, a barrier layer, and a substrate layer from the inside to the outside through an adhesive;

[0009] A surface treatment layer for improving wear resistance and a functional coating for improving thermal stability and barrier performance are provided on the surface of the substrate layer.

[0010] In a possible design, the heat-sealing layer is made of ethylene-vinyl acetate copolymer, which has excellent heat-sealing performance and low-temperature resistance. It can maintain the stability of the structure when the temperature changes and effectively prevent the leakage of substances such as electrolyte. The barrier layer is made of polyvinylidene chloride, and with its excellent barrier performance, it effectively isolates harmful substances such as moisture and oxygen in the external environment, thus protecting the lithium battery from external erosion. The substrate layer is made of polyimide. Due to its excellent heat resistance and mechanical properties, it provides strong structural support for the protective film and ensures stability even under extreme temperature conditions.

[0011] In a possible design, the surface treatment layer is an ultraviolet-curing coating, which is quickly cured by ultraviolet irradiation to form a hard and wear-resistant surface, effectively resisting external mechanical friction and chemical corrosion.

[0012] In a possible design, the functional coating is a ceramic coating. The ceramic coating further improves the wear resistance and heat insulation performance of the protective film with its high hardness and excellent thermal stability.

[0013] The present utility model also provides a lithium battery, including:

[0014] A lithium battery cell and the above-mentioned lithium battery protective film;

[0015] The heat-sealing layer uniformly covers the surface of the lithium battery cell. A buffer and heat-insulating member is arranged between two adjacent lithium battery cells, which is used to effectively block the spread of high temperature between adjacent cells and provide a buffer space for the expansion and contraction generated during the charging and discharging process of the cells, thereby improving the service life.

[0016] In a possible design, the buffer and heat-insulating member includes a rubber frame arranged between two adjacent lithium battery cells, and an adiabatic core material is embedded in the rubber frame. Both sides of the adiabatic core material are hot-pressed and bonded with a polymer film.

[0017] In a possible design, the adiabatic core material is aerogel felt. Aerogel felt has excellent heat insulation performance and low thermal conductivity, which can effectively block the transfer of heat. The polymer film is made of polybenzimidazole, which has good high-temperature resistance and chemical stability, and can enhance the high-temperature resistance and service life of the adiabatic core material.

[0018] It should be understood that the above general description and the following detailed description are only exemplary and do not limit the present utility model.

[0019] The present utility model has the following beneficial effects:

[0020] Through the combination of multi-layer structures, the lithium battery protective film of the present utility model provides all-round protection, effectively preventing damage to the battery core from the external environment and extending the service life of the lithium battery. Among them, the application of high-performance materials such as ethylene-vinyl acetate copolymer, polyvinylidene chloride, and polyimide further enhances the heat resistance, barrier property, and mechanical properties of the protective film; the introduction of ultraviolet curing coating and ceramic coating improves the wear resistance and thermal stability of the protective film, making it more adaptable to various complex working environments.

[0021] In the present utility model, the design of the buffer and heat insulation component effectively solves the problems of high temperature and volume change that may occur during the charging and discharging process of the lithium battery, improving the safety and reliability of the lithium battery. Among them, the application of aerogel felt as the heat insulation core material and the polymer film made of polybenzimidazole further enhances the heat insulation effect and mechanical properties of the buffer and heat insulation component, providing more comprehensive protection for the lithium battery. Brief Description of the Drawings

[0022] Figure 1 It is a front view structural schematic diagram of a lithium battery protective film and a lithium battery provided by an embodiment of the present utility model;

[0023] Figure 2 It is a disassembled structural schematic diagram of the lithium battery protective film body provided by an embodiment of the present utility model;

[0024] Figure 3 It is a structural schematic diagram of the assembly of two adjacent lithium battery cores provided by an embodiment of the present utility model;

[0025] Figure 4 It is a disassembled structural schematic diagram of the buffer and heat insulation component provided by an embodiment of the present utility model.

[0026] Reference Signs: 1. Lithium battery protective film body; 2. Lithium battery core; 3. Heat-sealing layer; 4. Barrier layer; 5. Substrate layer; 6. Surface treatment layer; 7. Functional coating; 8. Rubber frame; 9. Heat insulation core material; 10. Polymer film. Detailed Description of the Embodiment

[0027] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

[0028] In the description of the present utility model, it should be understood that terms such as "opening", "upper", "middle", "length", "inner", etc. indicating orientation or positional relationships are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the referred components or elements must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model.

[0029] To keep the following description of the embodiments of the present utility model clear and concise, detailed descriptions of known functions and known components are omitted.

[0030] Embodiment 1

[0031] Please refer to Figure 1-2 , a lithium battery protective film, comprising:

[0032] The lithium battery protective film body 1, the lithium battery protective film body 1 is sequentially adhered together by a heat-sealing layer 3, a barrier layer 4 and a substrate layer 5 from the inside to the outside through an adhesive. The heat-sealing layer 3 is made of ethylene-vinyl acetate copolymer material, which has good heat-sealing performance and flexibility, and can ensure the close fitting between the lithium battery protective film and the battery cell. The barrier layer 4 is made of polyvinylidene chloride material, which has good gas barrier property and chemical stability, and can effectively prevent the gas leakage inside the lithium battery and the intrusion of external gas, thus ensuring the safety performance of the lithium battery. The substrate layer 5 is made of polyimide material, and polyimide has excellent high temperature resistance, chemical corrosion resistance and mechanical strength, and can ensure that the lithium battery protective film maintains good structure and performance during use;

[0033] On the surface of the substrate layer 5, an ultraviolet-curable coating is provided as a surface treatment layer 6 to improve the wear resistance of the protective film. The ultraviolet-curable coating has the advantages of fast curing speed, good wear resistance, chemical corrosion resistance, etc., and can effectively extend the service life of the lithium battery protective film; and a ceramic coating is provided as a functional coating 7 to improve the thermal stability and barrier performance of the protective film. The ceramic coating has good thermal stability and barrier performance, can effectively prevent the thermal runaway of the lithium battery in a high temperature environment, and prevent the intrusion of external moisture and harmful substances.

[0034] Please refer to Figure 3-4 , and a lithium battery is also provided, which includes a lithium battery cell 2 and the above-described lithium battery protective film. The heat-sealing layer 3 uniformly covers the surface of the lithium battery cell 2, and the lithium battery protective film is closely adhered to the battery cell through a heat-sealing technique. A buffer and heat-insulating member is provided between two adjacent lithium battery cells 2 to effectively block the spread of high temperature between adjacent battery cells and provide a buffer space for the expansion and contraction generated during the charge and discharge process of the battery cells;

[0035] The specific structure of the buffer heat insulator includes a rubber frame 8, in which a heat-insulating core material 9 is embedded. The rubber frame 8 has good elasticity and sealing performance, which can effectively isolate adjacent battery cells and prevent the diffusion of heat and harmful substances. The heat-insulating core material 9 is made of aerogel felt, which has excellent heat-insulating performance and low thermal conductivity, and can effectively block the transfer of heat. On both sides of the heat-insulating core material 9, a polymer film 10 is hot-pressed and bonded. The polymer film 10 is made of polybenzimidazole material, which has good high-temperature resistance and chemical stability, and can enhance the high-temperature resistance performance and service life of the heat-insulating core material 9.

[0036] The above is only the specific implementation manner of the present utility model, but the protection scope of the present utility model is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present utility model can easily think of changes or substitutions, which should all be covered within the protection scope of the present utility model; without conflict, the embodiments of the present utility model and the features in the embodiments can be combined with each other. Therefore, the protection scope of the present utility model should be subject to the protection scope of the claims.

Claims

1. A lithium battery protective film, characterized in that: include: A lithium battery protective film body (1), wherein the lithium battery protective film body (1) is sequentially bonded from the inside to the outside by a heat sealing layer (3), a barrier layer (4) and a base layer (5) through an adhesive, the heat sealing layer (3) being made of ethylene-vinyl acetate copolymer, the barrier layer (4) being made of polyvinylidene chloride, and the base layer (5) being made of polyimide; The surface of the substrate layer (5) is provided with a surface treatment layer (6) and a functional coating (7); the surface treatment layer (6) is an ultraviolet light curing coating, and the functional coating (7) is a ceramic coating.

2. A lithium battery, characterized in that: include: A lithium battery cell (2) and a lithium battery protective film as claimed in claim 1; The heat sealing layer (3) is evenly covered on the surface of the lithium battery cell (2), and a buffer heat insulating member is provided between two adjacent lithium battery cells (2) to effectively prevent high temperature from spreading between adjacent cells and to provide a buffer space for expansion and contraction generated during the charging and discharging process of the cells, thereby increasing the service life.

3. A lithium battery according to claim 2, characterized in that: The buffer heat-insulating component comprises a rubber frame (8) arranged between two adjacent lithium battery cells (2), a heat-insulating core material (9) being embedded and installed in the rubber frame (8), and polymer films (10) being heat-pressed and bonded on both sides of the heat-insulating core material (9).

4. A lithium battery according to claim 3, characterized in that: The thermal insulation core material (9) is aerogel felt, and the polymer film (10) is made of polybenzimidazole.

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