Modified silicon dioxide and high-property lithium ion battery diaphragm and application thereof

A lithium-ion battery, silicon dioxide technology, applied in silicon dioxide, silicon oxide, battery pack components and other directions, can solve the problems of complex process, decreased membrane mechanical strength, thick diaphragm thickness, etc., and achieves a simple and easy preparation process. The effect of industrialization and good film strength

Inactive Publication Date: 2012-03-07
中科广化(重庆)新材料研究院有限公司 +3
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The process of "thermally induced phase separation" method (also called wet method) is more complicated than that of "hard elastic" method, and diluent needs to be added and removed, so the production cost is relatively high and may cause secondary pollution. At present, this method is adopted in the world. Japan's Asahi Kasei, Tonen, etc.
[0010] However, the main problems of polyolefin separators for lithium-ion batteries prepa

Method used

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  • Modified silicon dioxide and high-property lithium ion battery diaphragm and application thereof
  • Modified silicon dioxide and high-property lithium ion battery diaphragm and application thereof
  • Modified silicon dioxide and high-property lithium ion battery diaphragm and application thereof

Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0060] Example 1

[0061] A modified silica prepared by the following method:

[0062] (1) Disperse 20g of silicon dioxide with a particle size of 90nm in 600ml of anhydrous toluene, add 100g of aminopropyltriethoxysilane, fill with nitrogen and heat to boiling, then reflux at a constant temperature (105°C) for 48h, and then sequentially Wash with anhydrous toluene, anhydrous acetone, and vacuum dry to obtain aminated silica;

[0063] (2) Disperse 15 g of aminated silica in 300 ml of anhydrous toluene, add 80 g of triethylamine, and drop 20 g of 2-bromoisobutyryl bromide in an ice-water bath. Then the ice-water bath was removed and the reaction system was naturally heated to 20°C for 4 hours, and then washed with acetone, water, and acetone in sequence. Vacuum drying to obtain silica with ATRP initiator on the surface;

[0064] (3) Add 30g (0.30mol) methyl methacrylate, 12.5g (2mmol) of silicon dioxide with ATRP initiator on the surface prepared in step (2), 1.6346g (4mmol) 4 in a 1...

Example Embodiment

[0069] Example 2

[0070] A modified silica prepared by the following method:

[0071] (1) Disperse 25g of silica with a particle size of 300nm in 600ml of anhydrous toluene, add 100g of aminopropyltriethoxysilane, fill with nitrogen and heat to boiling, then reflux at a constant temperature (105°C) for 48h, and then sequentially Wash with anhydrous toluene and anhydrous acetone, and dry in vacuum to obtain aminated silica;

[0072] (2) Disperse 20 g of aminated silica in 300 ml of anhydrous toluene, add 80 g of pyridine, and drop 20 g of 2-bromoisobutyryl bromide under ice-water bath conditions. Then the ice-water bath was removed and the reaction system was naturally heated to 30°C for 4 hours, and then washed with acetone, water, and acetone in sequence. Vacuum drying to obtain silica with ATRP initiator on the surface;

[0073] (3) Add 42.7g (0.30mol) butyl methacrylate, 10g (1.60mmol) of silicon dioxide with ATRP initiator on the surface prepared in step (2), 1.3077g (3.20mmol)...

Example Embodiment

[0078] Example 3

[0079] A polyolefin microporous diaphragm for lithium ion batteries is prepared by the following method:

[0080] (1) Mix 100g of the modified silica prepared in Example 1 with 125g of ultra-high molecular weight polyethylene (the intrinsic viscosity measured in decalin at 135°C is 22dL / g), and then add 1250g of ordinary polyethylene resin for total Mixed granulation to obtain modified masterbatch;

[0081] (2) Melt blending and extruding 5000g modified masterbatch and 45000g polyethylene resin through a twin-screw (or single-screw) extruder, with a melt temperature of 200℃, a melt stretching ratio of 400 times, and crystallize under a stress field , Forming a diaphragm with a hard and elastic structure;

[0082] (3) Continuously stretch the membrane with a uniaxial stretching machine at a stretching ratio of 2 times and a stretching temperature of 100°C. After stretching, heat-set at 125°C for 10 minutes to prepare polyolefin for lithium ion batteries. Microporou...

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Abstract

The invention belongs to the field of lithium ion battery diaphragm materials and discloses modified silicon dioxide and a lithium ion battery polyolefin microporous diaphragm. The diaphragm is prepared by the following method: blending modified silicon dioxide with polyolefin having high/ultrahigh molecular weight, adding common polyolefin, and pelleting so as to obtain modified masterbatch; mixing the modified masterbatch with polyolefin and then carrying out melt blending and extrusion so as to form a diaphragm with a hard elastic structure; and carrying out continuous tension on the diaphragm, and then carrying out heat shaping at the temperature of 100-150 DEG C so as to obtain the lithium ion battery polyolefin microporous diaphragm. According to the invention, the thickness of the lithium ion battery polyolefin microporous diaphragm is relatively low (less than 15mu m); the strength of the diaphragm is better (the longitudinal breaking strength is larger than 100MPa, the transversal breaking strength is about 8MPa, and breaking elongation is 50%); the porosity and pore structure of the diaphragm are adjustable (the porosity is more than 50%, and the pore diameter is 0.1-1mum); and the thermal shrinkage factor of the diaphragm is smaller (less than 5%). According to the invention, the defect and lack of the existing dry preparation technology of the lithium ion battery diaphragm are overcome.

Description

technical field [0001] The invention belongs to the field of diaphragm materials for lithium ion batteries, and in particular relates to a modified silicon dioxide, a polyolefin microporous diaphragm for lithium ion batteries prepared by the modified silicon dioxide and applications thereof. Background technique [0002] Lithium-ion batteries are widely used in portable electronic products such as mobile phones, notebook computers, camcorders, etc. The development of electric vehicles will also drive greater demand for lithium-ion batteries. Lithium-ion batteries are used in aerospace, navigation, satellites, small It has also been widely used in fields such as medical treatment and military communication equipment. [0003] Lithium-ion batteries are mainly composed of electrodes, electrolytes, and polymer separators. Between the positive and negative electrodes of lithium-ion batteries is a diaphragm material, usually called a polymer diaphragm. As one of the main componen...

Claims

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Application Information

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IPC IPC(8): C01B33/12H01M2/16
CPCY02E60/10
Inventor 胡继文肖定书张干伟李银辉涂园园刘国军胡美龙胡盛逾李妃
Owner 中科广化(重庆)新材料研究院有限公司
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