Composite isolation membrane and preparation method thereof

An isolation film and metal technology, applied in the field of composite isolation film and its preparation, can solve the problems of reducing the water absorption of the coated isolation film, peeling off of the surface coating of the isolation film, limited drying and water removal effect, etc. Low-demand, low-cost effects

Active Publication Date: 2019-11-05
GUANGDONG UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, since the coating layer is a mixture of water-soluble polymer and ceramic powder, it will absorb moisture greatly in a humid environment, so that the moisture content of the separator exceeds 2000ppm, which is much higher than the upper limit of the lithium battery separator. Although the separator is in use It needs to be dried before removing water, but when the mutually sticky surface layers are separated, the surface coating of the isolation film will be peeled off, and this damage is irreversible.
In addition, the effect of drying and removing water is limited, and it will take a long time to meet the requirements of use. Therefore, improving the performance of the surface of the coated isolation film and reducing the water absorption of the coated isolation film itself are the main technical methods to improve this problem.

Method used

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  • Composite isolation membrane and preparation method thereof
  • Composite isolation membrane and preparation method thereof

Examples

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Effect test

Embodiment 1

[0039] This embodiment provides the first kind of composite isolation membrane, and its specific preparation process is as follows:

[0040] S11. Selecting alumina with an average particle size (D50) of 0.5 μm and calcining in a high-temperature muffle furnace at 1400° C. for 12 hours, and cooling in the furnace after calcining to obtain pretreated alumina powder.

[0041] S12. Put the pretreated alumina powder and stearic acid into the ball mill at a mass ratio of 100:3, the number ratio of large balls (5-8mm in diameter) and small balls (2-4mm in diameter) in the ball mill 3:5, ball milled at room temperature for 12 hours, and sieved to obtain surface-hydrophobized alumina.

[0042] S13. Mix the binder, water and surface-hydrophobized alumina uniformly at room temperature, and stir for 12 hours to obtain a coating slurry, wherein the binder is prepared by mixing β-cyclodextrin with hydrogen peroxide React at 70°C for 24 hours, and obtain the binder after drying. The mass r...

Embodiment 2

[0046] This embodiment provides the second composite isolation membrane, and its specific preparation process is as follows:

[0047] S21. Selecting alumina with an average particle size (D50) of 1.5 μm and calcining at a high temperature muffle of 1700° C. for 48 hours, and cooling in the furnace after calcining to obtain pretreated alumina powder.

[0048] S22. Put the pretreated alumina powder and oleic acid into the ball mill together in a mass ratio of 100:12. The number ratio of large balls (5-8 mm in diameter) and small balls (2-4 mm in diameter) in the ball mill is 3:5, ball milled at room temperature for 24 hours, and sieved to obtain surface-hydrophobized alumina.

[0049] S23. Mix the binder, water and surface-hydrophobized alumina uniformly at room temperature, and stir for 12 hours to obtain a coating slurry, wherein the binder is prepared by mixing β-cyclodextrin with hydrogen peroxide React at 100°C for 48 hours, and obtain the binder after drying. The mass ra...

Embodiment 3

[0053] This embodiment provides the third kind of composite isolation membrane, and its specific preparation process is as follows:

[0054] S31, selecting alumina with an average particle size (D50) of 1 μm and calcining at a high temperature muffle of 1500° C. for 24 hours, and cooling in the furnace after calcining to obtain pretreated alumina powder.

[0055] S32. Add the pretreated alumina powder and zinc stearate into the ball mill at a mass ratio of 100:8, the number of large balls (5-8 mm in diameter) and small balls (2-4 mm in diameter) in the ball mill The ratio is 3:5, ball milling at room temperature for 48 hours, and the surface hydrophobized alumina is obtained after sieving.

[0056] S33. Mix the binder, water and surface-hydrophobized alumina uniformly at room temperature, and stir for 12 hours to obtain a coating slurry, wherein the binder is prepared by mixing β-cyclodextrin with hydrogen peroxide React at 90°C for 48 hours, and obtain the binder after dryin...

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Abstract

The invention belongs to the technical field of high-performance lithium battery isolation membranes, and particularly relates to a composite isolation membrane and a preparation method thereof. The preparation method of the composite isolation membrane includes the following steps that 1, after pretreated metal oxide powder and an organic lubricant are mixed, ball-milling dispersion is performedto obtain a surface-hydrophobic metal oxide; 2, the surface-hydrophobic metal oxide, a binder and water are mixed to obtain coating slurry; 3, the coating slurry coats the surface of the isolation membrane and is dried to obtain the composite isolation membrane. The composite isolation membrane is used for solving the technical defect of large water absorbability of the traditional isolation membrane.

Description

technical field [0001] The invention belongs to the technical field of high-performance lithium battery separators, and in particular relates to a composite separator and a preparation method thereof. Background technique [0002] As an important part of lithium-ion batteries, separators have received widespread attention. The high performance of lithium-ion batteries is closely related to the properties of separators. Especially in lithium batteries with high rate and fast charge and discharge, the performance requirements of separators are more obvious. In view of the fact that the separator has a crucial impact on the performance of the actual battery, it must have good chemical and electrochemical stability and maintain a high degree of wettability to the electrolyte during repeated charge and discharge. The interface between the separator material and the electrode The compatibility and the retention of the electrolyte by the separator have a great influence on the char...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08J9/42D06M11/45D06M15/03H01M2/14H01M2/16H01M10/0525C08L23/06C08L23/12D06M101/20
CPCC08J9/42D06M11/45D06M15/03H01M10/0525C08J2323/12C08J2323/06C08J2405/16C08K9/04C08K2003/2227D06M2101/20H01M50/446H01M50/403Y02E60/10
Inventor 徐睿杰陈加强雷彩红
Owner GUANGDONG UNIV OF TECH
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