Polyolefin microporous diaphragm and preparation method thereof

A microporous diaphragm and polyolefin technology, which is applied to electrical components, circuits, battery pack components, etc., can solve the problems of polyolefin microporous membranes such as low strength, poor pore consistency, and low porosity, and achieve easy pore formation, High porosity and uniform pore formation

Active Publication Date: 2011-08-10
河南天工膜材新能源科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] In order to solve the problems of low strength, low air permeability, low porosity, and poor pore consistency of polyolefin microporous membranes, the technical solution of the present invention is to adopt a polyolefin microporous membrane, which is characterized in that β Crystal nucleating agent and antioxidant, wherein the content of β crystal nucleating agent accounts for 0.001-5.0% by mass of polyolefin resin, and the content of antioxidant accounts for 0.001-1% by mass of polyolefin resin

Method used

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  • Polyolefin microporous diaphragm and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] Example 1 In this example, a polyolefin microporous membrane, 0.001% by mass of benzoic acid and 0.001% of dibutylhydroxytoluene are added to the polyolefin resin; in the polyolefin resin, the mass percentage of ultra-high molecular weight polyolefin The percentage is 5%, and the balance is high-density polyolefin.

[0023] The specific preparation method is:

[0024] (1) Add ultra-high molecular weight polyethylene resin into the mixer, melt it at 200°C and stir it evenly;

[0025] (2) Cool the above molten liquid for 10 minutes, cool to 150°C, add high-density polyethylene resin, benzoic acid, dibutyl hydroxytoluene, melt at 150°C and stir evenly;

[0026] (3) Extrude the molten liquid from the extruder at 100°C, and then cool it through the cooling roll at 40°C to obtain the original flat film, and the cooling time is 1 minute;

[0027] (4) Stretch the original flat film simultaneously in both directions at a temperature of 40°C, with a stretching ratio of 1:5;

...

Embodiment 2

[0029] Example 2 In this example, a polyolefin microporous membrane, a mixture of clay, gypsum, and mica with a mass percentage of 0.06% is added to the polyolefin resin, wherein the mass ratio of clay, gypsum, and mica is 1:1:1; 0.01% dibutyl hydroxytoluene; in the polyolefin resin, the mass percentage of ultra-high molecular weight polyolefin is 20%, and the balance is high-density polyolefin.

[0030] The specific preparation method is:

[0031] (1) Add ultra-high molecular weight polypropylene resin into the mixer, melt it at 220°C and stir it evenly;

[0032] (2) Cool the above molten liquid for 20 minutes, cool to 155°C, add high-density polypropylene resin, a mixture of clay, gypsum, mica, dibutyl hydroxytoluene, melt at 170°C and stir evenly;

[0033] (3) Extrude the molten liquid from the extruder at 150°C, and then cool it through the cooling roll at 70°C to obtain the original flat film, and the cooling time is 3 minutes;

[0034] (4) Stretch the original flat fil...

Embodiment 3

[0036] Example 3 In this example, a polyolefin microporous membrane, a mixture of chalk and calcium stearate with a mass percentage of 2% is added to the polyolefin resin, wherein the mass ratio of chalk and calcium stearate is 1:1; 0.05% butyl hydroxyanisole; in the polyolefin resin, the mass percentage of ultra-high molecular weight polyolefin is 35%, and the balance is high-density polyolefin.

[0037] The specific preparation method is:

[0038] (1) Add ultra-high molecular weight polyethylene resin into the mixer, melt it at 250°C and stir it evenly;

[0039] (2) Cool the above molten liquid for 25 minutes to 160°C, add high-density polypropylene resin, a mixture of chalk and calcium stearate, butylated hydroxyanisole, melt at 200°C and stir evenly;

[0040] (3) Extrude the molten liquid from the extruder at 200°C, and then cool it through the cooling roll at 100°C to obtain the original flat film, and the cooling time is 5 minutes;

[0041] (4) Stretch the original fla...

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Abstract

The invention belongs to the technical field of preparation of lithium batteries and in particular relates to a polyolefin microporous diaphragm for a lithium ion power battery and a preparation method thereof. The polyolefin microporous diaphragm is formed by adding a beta crystal type nucleating agent and an antioxidant into polyolefin resin, wherein the weight percent of the content of the beta crystal type nucleating agent to the polyolefin resin is 0.001-5.0%, and the weight percent of the antioxidant to the polyolefin resin is 0.001-1%. By adopting the polyolefin resin after modification for preparing the porous diaphragm, the diaphragm is easy to form holes; furthermore, the formed holes are uniform, the aperture is small (the average aperture is 0.01-0.1 mu m), the porosity is high (35%-80%), the air permeability is good, and the strength of the diaphragm is high.

Description

technical field [0001] The invention belongs to the technical field of lithium battery preparation, and in particular relates to a polyolefin microporous diaphragm for a lithium ion power battery and a preparation method thereof. Background technique [0002] In the structure of lithium batteries, the separator is one of the key inner components. The performance of the separator determines the interface structure and internal resistance of the battery, which directly affects the capacity, cycle and safety performance of the battery. A separator with excellent performance plays an important role in improving the overall performance of the battery. [0003] The existing diaphragm materials usually use polypropylene (PP) film and polyethylene (PE) film, but the preparation of polypropylene and polyethylene film is relatively difficult at present. Commonly used polypropylene and polyethylene film preparation methods mainly include wet and dry methods. At present, most of the s...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M2/16H01M2/18C08L23/00C08L23/06C08L23/12C08J9/00
CPCY02E60/12Y02E60/10
Inventor 朱晓靳磊李顺阳吴志庭蒋占伟黄元强陈娜万新水
Owner 河南天工膜材新能源科技有限公司
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