Lithium ion battery composite diaphragm

Abstract

The utility model discloses a lithium ion battery composite diaphragm, which relates to the technical field of lithium ion batteries and comprises a diaphragm layer body, a conductive coating is arranged on one side or two sides of the diaphragm layer body, a ceramic thermal insulation layer is arranged on one side of the conductive coating, and a coating layer is arranged on one side of the ceramic thermal insulation layer far away from the conductive coating. A reinforcing layer is arranged on the side, away from the ceramic heat insulation layer, of the coating layer, and an anti-static layer is arranged on the side, away from the coating layer, of the reinforcing layer. The diaphragm is subjected to heat insulation treatment by the heat insulation layer shell, so that the use safety of the lithium ion battery is improved, the tensile strength of the composite diaphragm of the lithium ion battery can be improved by the reinforcing layer, the safety performance of the composite diaphragm of the lithium ion battery is further improved, the electronic conductivity of the diaphragm is improved by the antistatic layer, and the problem of static electricity of a coating film is eliminated.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium ion batteries, in particular to a lithium ion battery composite diaphragm. Background Art

[0002] In the structure of lithium-ion batteries, the separator is a key internal component. The performance of the separator determines the battery's interface structure and internal resistance, directly affecting characteristics such as capacity, cycle life, and safety. A high-performance separator is crucial for improving the battery's overall performance. Due to its critical role in lithium-ion batteries, the separator is often called the "third electrode" of the battery. However, existing lithium-ion battery composite separators have limited high-temperature resistance and strength.

[0003] Therefore, a lithium-ion battery composite separator is proposed. Utility Model Content

[0004] Technical problems solved

[0005] The purpose of the utility model is to remedy the deficiencies of the prior art and provide a lithium ion battery composite diaphragm.

[0006] Technical Solution

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a lithium-ion battery composite diaphragm, comprising a diaphragm layer body, a conductive coating is provided on one or both sides of the diaphragm layer body, a ceramic insulation layer is provided on one side of the conductive coating, a coating layer is provided on the side of the ceramic insulation layer away from the conductive coating, a strengthening layer is provided on the side of the coating layer away from the ceramic insulation layer, an antistatic layer is provided on the side of the strengthening layer away from the coating layer, the insulation layer shell performs thermal insulation treatment on the diaphragm, thereby improving the safety of lithium batteries, the strengthening layer can increase the tensile strength of the lithium-ion battery composite diaphragm, further improving the safety performance of the lithium-ion battery composite diaphragm, and improving the electronic conductivity of the diaphragm through the antistatic layer, thereby eliminating the static electricity problem of the coating.

[0008] Preferably, the thickness of the conductive coating is 2-3.5 μm.

[0009] Preferably, the ceramic heat-insulating layer is composed of a plurality of ceramic particles, and the diameter of the ceramic particles is 0.05-0.9 μm.

[0010] Preferably, the strengthening layer is made of polyvinylidene fluoride and has a thickness of 0.5-2 μm.

[0011] Preferably, the diaphragm layer body adopts a porous base film, and the thickness of the diaphragm layer body 1 is 2-15 μm.

[0012] Preferably, the conductive coating comprises a single-ion conductive polymer and a binder, and the pore size of the conductive coating is 1-12 nm.

[0013] Preferably, the antistatic layer is made of carbon material.

[0014] Beneficial effects:

[0015] Compared with the existing technology, the lithium-ion battery composite separator has the following beneficial effects:

[0016] The thermal insulation layer shell of the utility model performs thermal insulation treatment on the diaphragm, thereby improving the safety of lithium battery use. The strengthening layer can increase the tensile strength of the lithium-ion battery composite diaphragm, further improving the safety performance of the lithium-ion battery composite diaphragm. The electronic conductivity of the diaphragm is improved through the antistatic layer, eliminating the static electricity problem of the coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0018] Figure 1 This is a schematic structural diagram of the first embodiment of the present utility model;

[0019] Figure 2 This is a structural diagram of the second embodiment of the present utility model.

[0020] In the picture:

[0021] 1. Diaphragm layer body; 2. Conductive coating; 3. Ceramic insulation layer; 4. Coating layer; 5. Strengthening layer; 6. Antistatic layer. DETAILED DESCRIPTION

[0022] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] For example 1, please refer to Figure 1As shown, the utility model provides a technical solution: a lithium-ion battery composite diaphragm, comprising a diaphragm layer body 1, a conductive coating 2 is provided on one side of the diaphragm layer body 1, a ceramic insulation layer 3 is provided on one side of the conductive coating 2, a coating layer 4 is provided on the side of the ceramic insulation layer 3 away from the conductive coating 2, a strengthening layer 5 is provided on the side of the coating layer 4 away from the ceramic insulation layer 3, and an antistatic layer 6 is provided on the side of the strengthening layer 5 away from the coating layer 4.

[0024] Example 2, please refer to Figure 2 A lithium-ion battery composite diaphragm includes a diaphragm layer body 1, conductive coatings 2 are provided on both sides of the diaphragm layer body 1, a ceramic thermal insulation layer 3 is provided on one side of the conductive coating 2, a coating layer 4 is provided on the side of the ceramic thermal insulation layer 3 away from the conductive coating 2, a strengthening layer 5 is provided on the side of the coating layer 4 away from the ceramic thermal insulation layer 3, and an antistatic layer 6 is provided on the side of the strengthening layer 5 away from the coating layer 4.

[0025] In both embodiments, the heat insulation layer 3 is used to insulate the diaphragm to improve the safety of lithium batteries. The strengthening layer 5 can increase the tensile strength of the lithium-ion battery composite diaphragm, further improving the safety performance of the lithium-ion battery composite diaphragm. The antistatic layer 6 improves the electronic conductivity of the diaphragm, eliminating the static problem of the coating.

[0026] In the two embodiments, the following features are the same: the thickness of the conductive coating 2 is 2-3.5 μm, the ceramic insulation layer 3 is composed of a plurality of ceramic particles, the diameter of the ceramic particles is 0.05-0.9 μm, the strengthening layer 5 is made of polyvinylidene fluoride and has a thickness of 0.5-2 μm, the diaphragm layer body 1 is made of a porous base film, the thickness of the diaphragm layer body 1 is 2-15 μm, and the porous base film is made of at least one material selected from polyethylene, polypropylene, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyimide, polyetherimide, polysulfone, polyethersulfone, polyamide, polyphenylene ether and polyphenylene sulfide; the conductive coating 2 includes a single-ion conductive polymer and a binder, the pore size of the conductive coating is 1-12 nm, the single-ion conductive polymer is a polybissulfonyl imide lithium-based single-ion conductive polymer, and the antistatic layer 6 is made of a carbon material, and the resistivity of the carbon material is 0.005-0.02 Ω·m.

[0027] Working principle: The heat insulation layer 3 provides heat insulation treatment to the diaphragm to improve the safety of lithium battery use. The strengthening layer 5 can increase the tensile strength of the lithium-ion battery composite diaphragm, further improving the safety performance of the lithium-ion battery composite diaphragm. The antistatic layer 6 improves the electronic conductivity of the diaphragm and eliminates the static electricity problem of the coating.

[0028] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "includes," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0029] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A lithium-ion battery composite diaphragm, comprising a diaphragm layer body (1), characterized in that: A conductive coating (2) is provided on one or both sides of the diaphragm layer body (1); a ceramic heat-insulating layer (3) is provided on one side of the conductive coating (2); a coating layer (4) is provided on the side of the ceramic heat-insulating layer (3) away from the conductive coating (2); a strengthening layer (5) is provided on the side of the coating layer (4) away from the ceramic heat-insulating layer (3); and an antistatic layer (6) is provided on the side of the strengthening layer (5) away from the coating layer (4).

2. A lithium-ion battery composite separator according to claim 1, characterized in that: The thickness of the conductive coating (2) is 2-3.5 μm.

3. The lithium-ion battery composite separator according to claim 1, characterized in that: The ceramic heat-insulating layer (3) is composed of a plurality of ceramic particles, and the diameter of the ceramic particles is 0.05-0.9 μm.

4. The lithium-ion battery composite separator according to claim 1, characterized in that: The strengthening layer (5) is made of polyvinylidene fluoride and has a thickness of 0.5-2 μm.

5. The lithium-ion battery composite separator according to claim 1, characterized in that: The diaphragm layer body (1) adopts a porous base film, and the thickness of the diaphragm layer body (1) is 2-15 μm.

6. The lithium-ion battery composite separator according to claim 1, characterized in that: The antistatic layer (6) is made of carbon material.

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