Composite membrane and electrochemical device

A technology of composite diaphragm and polymer film, which is applied in the direction of electrochemical generators, circuits, electrical components, etc., can solve the problem of thermal bonding coating, shrinkage performance and interface bonding performance of the diaphragm, and it is difficult to take into account the high energy density of the battery And high safety, reduce battery energy density and other issues, to achieve the effect of improving interface adhesion, high strength, and increasing energy density

Pending Publication Date: 2022-04-15
ZHUHAI COSMX BATTERY CO LTD
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the existence of heat-resistant coating and bonding coating thickens the thickness of the separator, which will reduce the energy density of the battery
Further, the thickness of the separator is reduced by combining the bonding coating and the heat-resistant coating, thereby increasing the energy density. It is greatly reduced, which affects the safety performance of the battery. Therefore, it is often difficult to balance the high energy density and high safety of the battery with the separator of the prior art.

Method used

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  • Composite membrane and electrochemical device
  • Composite membrane and electrochemical device
  • Composite membrane and electrochemical device

Examples

Experimental program
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preparation example Construction

[0034] The method of preparing the composite diaphragm provided by the present invention, comprising: mixing inorganic particles and organic particles to form a mixed coating, coating the mixed coating on at least one surface of the polymer film, after drying, forming a functional coating to obtain a composite diaphragm .

[0035] In the specific implementation process of the present invention, the inorganic particles are first dispersed in the solvent to form a first mixture; the organic particles are dispersed in the solvent to form a second mixture; and then the first mixture and the second mixture The stirring is uniform, form a third mixture; the third mixture is evenly applied to at least one surface of the polymer film, and the functional coating is formed after drying, and the composite diaphragm is obtained.

[0036] Specifically, the coating method includes a gravure coating, a wire coating, a spray coating, and the like. The mixed coating was coated with one or both sur...

Embodiment 1

[0054] Preparation of composite diaphragm

[0055] Will D90 1 = 1.0 μm of the aluminum dioxide particles were added to deionized water, stirred for 30 minutes to obtain the first mixture; again D90 2 The polyvinylidene fluoride-hexafluoropropylene particles were added to deionized water, and the mixture was dispersed for 30 minutes to obtain a second mixture, and the first mixture was mixed with the second mixture, and the third mixture was uniformly obtained. The mass ratio of the oxide particles and polyvinylidene fluoride-hexafluoropropylene particles is 6: 4 (1.5: 1);

[0056]When the gravure coating is used, the third mixture is evenly applied to both surfaces of the polyethylene microporous membrane having a thickness of 7.1 μm. After drying, the thickness of the functional coating on both surfaces of the polyethylene microporous membrane is respectively. It was 2.0 μm, 2.0 μm, a composite diaphragm having a total thickness of 11.1 μm.

[0057] Preparation of lithium ion bat...

Embodiment 2

[0060] Put D90 1 = 0.4 μm Bumble particles were added to dendomethacolamide (DMAC), and the mixture was stirred for 30 minutes to obtain the first mixture. Put D90 2 The polyvinylidene fluoride-hexafluoropropylene particles of 4 μm were added to the DMAC, and the mixture was dispersed for 30 minutes to obtain a second mixture. The first mixture was added to the second mixture, and the distraction was mixed and dispersed evenly to obtain a third mixture, wherein the mass ratio of boehmite particles and polyvinylidene fluoride-hexafluoropropylene particles was 1.5: 1;

[0061] The third mixture is evenly applied to both sides of the polyethylene microporous membrane of 7.1 μm thick. After drying, the thickness of the polymer film is 2.0 μm, 1.8 μm, respectively. A composite diaphragm having a total thickness of 10.9 μm was obtained.

[0062] Preparation of lithium ion batteries

[0063] The complex diaphragm and the negative electrode sheet in Example 2 were laminated, and the bare ...

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Abstract

The invention provides a composite diaphragm and an electrochemical device, the composite diaphragm comprises a polymer film and a functional coating arranged on at least one surface of the polymer film, and the functional coating comprises inorganic particles and organic particles; the particle size D901 of the inorganic particles and the particle size D902 of the organic particles meet the following conditions: 0.01 * D902 < = D901 < = 0.5 * D902, and D901 is the particle size of the inorganic particles reaching 90% of the volume accumulation from the small particle size side in the volume-based particle size distribution, and D902 is the particle size of the organic particles reaching 90% of the volume accumulation from the small particle size side in the volume-based particle size distribution. D902 is that in volume-based particle size distribution, the particle size of the organic particles reaches 90% of volume accumulation from the small particle size side. The composite diaphragm has excellent heat-resistant shrinkage performance and interface bonding performance, and can give consideration to high energy density and high safety of an electrochemical device when being applied to the electrochemical device.

Description

Technical field [0001] The present invention relates to the field of electrochemical devices, and more particularly to a composite diaphragm and an electrochemical device. Background technique [0002] The lithium-ion battery has the advantages of high energy density, high operating voltage, wide temperature, long service life, high environmental and environment, has wide application in mobile phones, laptops, power tools, energy storage projects, and electric vehicles. At the same time, there is more and more incidents in the battery, and the safety problems are still important for consumers' important concerns about lithium-ion batteries. The diaphragm is an important part of the lithium ion battery, and the diaphragm is used to prevent contact between the positive electrode and the negative electrode while allowing lithium ions to be migrated in the electrolyte. The diaphragm affects the interface performance of the electrode and the electrolyte, so there is an important effec...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M50/449H01M50/446H01M50/443H01M50/403H01M10/0525
CPCH01M50/446H01M50/403H01M10/0525H01M50/443H01M50/449Y02E60/10
Inventor 贺飞李素丽
Owner ZHUHAI COSMX BATTERY CO LTD
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