Diaphragm for lithium ion battery and preparation method thereof

A technology of lithium-ion batteries and diaphragms, which is applied to battery components, separators/films/diaphragms/spacers, circuits, etc., can solve problems such as complex methods and high costs, achieve good thermal stability, and improve high temperature resistance performance, easy absorption effect

Active Publication Date: 2019-09-27
GUANGZHOU YUEWANG AGRI CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

It improves high temperature resistance by coating organic polymers, the method is more complicated and the cost is higher

Method used

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  • Diaphragm for lithium ion battery and preparation method thereof
  • Diaphragm for lithium ion battery and preparation method thereof
  • Diaphragm for lithium ion battery and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] Such as figure 1 Shown, the preparation method of separator for lithium ion battery of the present invention comprises the following steps,

[0028] 1. Coating the first ceramic layer 1 on one side of the polyethylene base film, the first ceramic layer includes 65% ceramic oxide and 35% adhesive by weight, and the ceramic oxide is aluminum oxide and vanadium oxide The mixture (weight ratio is 1:1), the average particle size is 15nm, the binder is polyvinyl alcohol, and the coating thickness is 0.5-1μm. After completion, it is dried at 70°C for 30-50min.

[0029] 2. After drying, coat the gel polymer layer 2 on the other side of the polyethylene base film and the surface of the first ceramic layer. The gel polymer layer is a mixture of polytetrafluoroethylene and polyacrylonitrile (weight ratio It is an aqueous solution of 2:1), the particle size of polytetrafluoroethylene and polyacrylonitrile is 30-50nm, and the thickness of the coating is 1-2μm. After the coating is ...

Embodiment 2

[0032] The preparation method of separator for lithium ion battery of the present invention comprises the following steps,

[0033] 1. Coating the first ceramic layer on one side of the polyethylene base film, the first ceramic layer includes 75% ceramic oxide and 25% adhesive by weight, and the ceramic oxide is a mixture of alumina and zirconia (The weight ratio is 1:1), the average particle size is 30nm, the binder is sodium carboxymethyl cellulose, and the coating thickness is 0.5-1μm. After completion, dry at 70°C for 30-50min.

[0034]2. After drying, coat the gel polymer layer on the other side of the polyethylene base film and the surface of the first ceramic layer. The gel polymer layer is a mixture of polytetrafluoroethylene and polyacrylonitrile (the weight ratio is 2:1) aqueous solution, the particle size of polytetrafluoroethylene and polyacrylonitrile is 30-50nm, and the thickness of the coating is 1-2μm. After the coating is completed, dry it at about 85°C for 50...

Embodiment 3

[0037] The preparation method of separator for lithium ion battery of the present invention comprises the following steps,

[0038] 1. Coating the first ceramic layer on one side of the polyethylene base film, the first ceramic layer includes 70% ceramic oxide and 30% adhesive by weight, and the ceramic oxide is a mixture of aluminum oxide and vanadium oxide (The weight ratio is 1:1), the average particle size is 20nm, the binder is polyvinyl alcohol, and the coating thickness is 0.5-1μm. After completion, dry at 70°C for 30-50min.

[0039] 2. After drying, coat the gel polymer layer on the other side of the polyethylene base film and the surface of the first ceramic layer. The gel polymer layer is a mixture of polyimide and aramid resin (the weight ratio is 1:1) aqueous solution, the particle size of polyimide and aramid resin is 30-50nm, and the coating thickness is 1-2μm. After coating, dry at about 90°C for 50-80min.

[0040] 3. After drying, coat the third ceramic layer ...

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Abstract

The invention relates to a diaphragm for a lithium ion battery and a preparation method thereof. The diaphragm has a thickness of 5-10[mu]m and a thermal shrinkage rate of less than 1.2% at 150 degrees centigrade, and comprises a first ceramic layer, gel polymer layers on both sides of the first ceramic layer, and third ceramic layers on the outer surfaces of the gel polymer layers, wherein the first ceramic layer comprises 60-80% by weight of ceramic oxide and 20-40% by weight of a binder, wherein the ceramic oxide has a particle diameter of 10-30 nm; each gel polymer layers is an aqueous solution of polymer particles having a particle diameter of 30 to 50 nm; and each third ceramic layer comprises 80-90% by weight of ceramic oxide and 10-20% by weight of the binder, wherein the ceramic oxide has a particle diameter of 30-80 nm. The diaphragm has a low thickness, good high temperature resistance, a low thermal shrinkage rate and good stability.

Description

technical field [0001] The invention belongs to the field of lithium-ion battery materials, and in particular relates to a separator for lithium-ion batteries and a preparation method. Background technique [0002] Diaphragm is the core material that blocks the positive and negative electrodes of lithium-ion batteries. Its high energy and power density requires the thickness of the lithium-ion battery diaphragm to be as thin as possible. The thinner the diaphragm, the lower the impedance and the higher the heat generated when lithium ions migrate between the positive and negative electrodes. The lower the energy density, the higher the energy density; but the separator is too thin, and its ability to retain the electrolyte is low, which will adversely affect the performance of the battery. The thickness of the diaphragm of lithium-ion batteries for general use is less than 25 microns, and the thickness of the battery diaphragm of electric vehicles is generally around 40 micr...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M2/14H01M2/16
CPCH01M50/40H01M50/403H01M50/431H01M50/44Y02E60/10
Inventor 丁祥靳俊玲吴雅欣黄小兵申有名张向阳张春香
Owner GUANGZHOU YUEWANG AGRI CO LTD
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