Novel diaphragm for lithium ion battery

Abstract

The utility model relates to the technical field of diaphragms for batteries, in particular to a novel diaphragm for a lithium ion battery, which comprises a membrane group, the membrane group comprises a base membrane, ceramic slurry layers are fixedly connected to the front side and the back side of the base membrane respectively, and solid electrolyte layers are fixedly connected to the outer surfaces of the ceramic slurry layers respectively. According to the novel diaphragm for the lithium ion battery, the diaphragm can be directly used after being made into the battery, a liquid injection process is not needed, and the two sides are coated with ceramic powder layers with the thickness of 1 micron, so that the puncture strength of the diaphragm is greatly improved, and the safety of the battery is enhanced. Even under the action of external force, the diaphragm can be effectively prevented from being punctured, a layer of PVDF glue with mass concentration is coated, binding power is generated after heating, the structure of each layer is more stable, meanwhile, new impurity materials are not introduced, the consistency and the cycle life of the battery are ensured, and the two ceramic slurry layers and the two solid electrolyte layers are coated on the base membrane, so that the service life of the battery is prolonged. And the performance of the diaphragm is further enhanced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of battery separator, specifically, a new type of lithium ion battery separator. BACKGROUND

[0002] Lithium ion battery separator is one of the key components of lithium ion battery, which separates the positive and negative electrodes of lithium ion battery, prevents the positive and negative electrodes from directly contacting and short circuiting, ensures the safety of the battery during charging and discharging, provides a channel for lithium ion migration between the positive and negative electrodes, enables the battery to realize normal charging and discharging function, and lithium ion can shuttle between the positive and negative electrodes through the micropores on the separator to complete the electrochemical process of the battery.

[0003] The traditional battery separator may have the problem of insufficient puncture strength, and when the battery is subjected to external impact or internal pressure change, it is easy to be pierced, resulting in positive and negative short circuit and causing safety accidents. Moreover, some traditional separators may introduce impurities, affecting the consistency and cycle life of the battery. The traditional lithium ion battery still needs to be injected before use, increasing the production cost.

[0004] Therefore, there is an urgent need for a new type of lithium ion battery separator to improve the shortcomings of the prior art. UTILITY MODEL CONTENT

[0005] The utility model aims at providing a new type of lithium ion battery separator to solve the problems in the background art.

[0006] To achieve the above-mentioned purpose, the utility model provides a new type of lithium ion battery separator, which comprises a film group, the film group comprises a base film, the front and back surfaces of the base film are fixedly connected with ceramic slurry layers respectively, and the outer surfaces of the ceramic slurry layers are fixedly connected with solid electrolyte layers respectively.

[0007] As a further improvement of the technical scheme, the base film is made of polyethylene material.

[0008] As a further improvement of the technical scheme, the base film is coated with a ceramic powder layer on both sides, and the ceramic powder layer is used to improve the puncture strength of the base film.

[0009] As a further improvement of the technical scheme, the surface of the solid electrolyte layer is attached with a PVDF glue layer.

[0010] As a further improvement of the technical scheme, the thickness of the ceramic powder layer is 1um.

[0011] Compared with the prior art, the utility model has the advantages of:

[0012] The new lithium ion battery separator, the separator is made into a battery which can be directly used without liquid injection process, double-sided coating of 1um thick ceramic powder layer greatly improves the puncture strength of the separator, enhances the safety of the battery. Even when subjected to external force, the separator can be effectively prevented from being punctured, and a layer of high-quality PVDF glue is coated, which generates adhesive force after heating, making the structure more stable, at the same time, without introducing new impurity materials, the consistency and cycle life of the battery are ensured, two layers of ceramic slurry layer and two layers of solid electrolyte layer are coated on the base film, which further strengthens the performance of the separator. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 The whole structure of the embodiment is shown in the schematic view.

[0014] The meanings of various numbers in the figure are:

[0015] 1, film group; 10, base film; 11, ceramic slurry layer; 12, solid electrolyte layer. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0017] Please refer to Figure 1 The embodiment provides a new lithium ion battery separator, which comprises a film group 1, and the film group 1 comprises a base film 10, the front and back surfaces of the base film 10 are respectively fixedly connected with ceramic slurry layers 11, and the outer surfaces of the ceramic slurry layers 11 are respectively fixedly connected with solid electrolyte layers 12.

[0018] The working principle is as follows: first, the base film 10 in the film group 1 serves as a core support structure, and the front and back surfaces thereof are respectively fixedly connected with ceramic slurry layers 11, the main role of the ceramic slurry layers 11 is to improve the puncture strength of the separator and enhance the mechanical properties of the separator, so as to prevent the separator from being punctured due to external force or internal pressure during the use of the battery, thereby avoiding direct contact between the positive and negative electrodes to cause short circuit and other safety problems, and the outer surfaces of the ceramic slurry layers 11 are fixedly connected with solid electrolyte layers 12, the solid electrolyte layers 12 provide a channel for the migration of lithium ions between the positive and negative electrodes, and due to the solid characteristics, the solid electrolyte layers 12 have higher safety and stability compared with the traditional liquid electrolyte, can effectively prevent electrolyte leakage and other problems, and are helpful to realize the design of the all-solid-state battery and improve the overall performance and safety of the battery.

[0019] In order to enhance stability, therefore, in the embodiment, the base film 10 is made of polyethylene material, which has good chemical stability and mechanical strength. The polyethylene material has good chemical stability and can remain stable in the working environment of the lithium ion battery without chemical reaction with the positive and negative electrode materials, electrolyte, etc. This ensures that the diaphragm will not be damaged by chemical reaction in the battery, thereby ensuring the performance and life of the battery.

[0020] In order to be able to pierce the strength, therefore, in the embodiment, the ceramic slurry layer 11 is made of ceramic powder, and the base film 10 is coated with 1um thick ceramic powder on both sides. The ceramic powder layer improves the puncture strength of the base film 10. The ceramic powder has very high hardness and rigidity, and can effectively block the invasion of the puncture object when the diaphragm is punctured by external force. The presence of the ceramic powder increases the thickness and strength of the diaphragm, so that the puncture object needs to overcome greater resistance to penetrate the diaphragm.

[0021] In order to improve the service life, therefore, in the embodiment, the solid-state electrolyte layer 12 is made of 1% mass concentration of PVDF adhesive layer. The PVDF adhesive layer generates adhesive force after heating, and the use of PVDF does not introduce new impurity materials to effectively prevent the improvement of battery consistency and cycle life.

[0022] The new diaphragm for lithium ion battery in the embodiment is used in specific use. First, the base film 10 in the film group 1 is used as the core support structure. The polyethylene material has good chemical stability and can remain stable in the working environment of the lithium ion battery without chemical reaction with the positive and negative electrode materials, electrolyte, etc. This ensures that the diaphragm will not be damaged by chemical reaction in the battery, thereby ensuring the performance and life of the battery. The ceramic slurry layer 11 is fixedly connected to the front and back surfaces of the base film 10. The main function of the ceramic slurry layer 11 is to improve the puncture strength of the diaphragm and enhance the mechanical properties of the diaphragm. It prevents the diaphragm from being punctured by external force or internal pressure during the use of the battery, thereby avoiding the direct contact of the positive and negative electrodes to cause short circuit and other safety problems. The solid-state electrolyte layer 12 is fixedly connected to the outer surface of the ceramic slurry layer 11. The ceramic powder layer has very high hardness and rigidity. When the diaphragm is punctured by external force, the ceramic powder layer can effectively block the invasion of the puncture object. The presence of the ceramic powder layer increases the thickness and strength of the diaphragm, so that the puncture object needs to overcome greater resistance to penetrate the diaphragm. The solid-state electrolyte layer 12 provides a channel for the migration of lithium ions between the positive and negative electrodes. Due to its solid-state characteristics, compared with the traditional liquid electrolyte, the PVDF adhesive layer generates adhesive force after heating, and the use of PVDF does not introduce new impurity materials to effectively prevent the improvement of battery consistency and cycle life, which has higher safety and stability, can effectively prevent electrolyte leakage and other problems, and is helpful to realize the design of all-solid-state battery, and improve the overall performance and safety of the battery.

[0023] The basic principle, main features and advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above examples, and the above examples and descriptions in the specification are only preferred examples of the present application and are not intended to limit the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A new type of separator for lithium-ion batteries, comprising a film group (1), characterized by: The film group (1) comprises a base film (10), the front and back surfaces of the base film (10) are fixedly connected with ceramic slurry layers (11) respectively, and the outer surfaces of the ceramic slurry layers (11) are fixedly connected with solid electrolyte layers (12) respectively.

2. The novel separator for lithium-ion batteries according to claim 1, characterized by: The base film (10) is made of polyethylene material.

3. The novel separator for lithium-ion batteries according to claim 1, characterized by: The base film (10) is coated with ceramic powder layers on both surfaces, and the ceramic powder layers are used for improving the puncture strength of the base film (10).

4. The novel separator for lithium-ion batteries according to claim 1, characterized by: A PVDF glue layer is attached to the surface of the solid electrolyte layer (12).

5. The novel separator for lithium-ion batteries according to claim 3, characterized by: The thickness of the ceramic powder layer is 1 um.

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