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

10 Cites 14 Cited by

AI-Extracted 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...

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.

Application Domain

SilicaCell component details

Technology Topic

ChemistryThermal shrinkage +11

Image

Examples

Experimental program(7)
Effect test(1)

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 100ml round bottom flask, 4'-Dinonyl-2,2'-bipyridine and 30ml of toluene, stir and dissolve the reaction system, bubbling with argon for 30min, and then deoxygenate, then transfer the reaction system to 0.286g (2mmol) bromination In a 100ml round-bottomed cuprous flask, polymerization was carried out at 90℃ for 8h, the reaction product was passed through a neutral alumina column, vacuum dried, and then vacuum dried at 40℃ for 24h to constant weight, to obtain the polymethyl Silica of methyl acrylate homopolymer.

[0065] A polyolefin microporous diaphragm for lithium ion batteries is prepared by the following method:

[0066] (1) Mix 50g of the above-mentioned modified silica with 300g of ultra-high molecular weight polypropylene (the intrinsic viscosity measured in decalin at 135°C is 15dL/g), and then add 2150g of ordinary polypropylene resin for blending and granulation , Prepare modified masterbatch;

[0067] (2) Melt blending and extruding 5000g modified masterbatch and 45000g polypropylene resin through a twin-screw (or single-screw) extruder at a melt temperature of 200°C and a melt stretching ratio of 200 times, crystallizing under a stress field , Forming a membrane with a hard and elastic structure;

[0068] (3) Continuously stretch the membrane with a uniaxial stretching machine with a stretching ratio of 3 times and a stretching temperature of 100°C. After stretching, heat setting at 145°C for 10 minutes to prepare polyolefin for lithium ion batteries. Microporous diaphragm.

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) in a 100ml round bottom flask 4,4'-Dinonyl-2,2'-bipyridine and 30ml of toluene, the reaction system was stirred to dissolve, argon was bubbled for 30min, and oxygen was removed, and then the reaction system was transferred to 0.2288g (1.59mmol ) In a 100ml round-bottomed flask of cuprous bromide, carry out the polymerization reaction at 50℃ for 48h, pass the reaction product through a neutral alumina column, vacuum dry, and then vacuum dry at 40℃ for 24h to constant weight to obtain the package with Polymethyl methacrylate homopolymer of silica.

[0074] A polyolefin microporous diaphragm for lithium ion batteries is prepared by the following method:

[0075] (1) Mix 50g of the above-mentioned modified silica with 100g of ultra-high molecular weight polypropylene (intrinsic viscosity measured in decalin at 135°C is 15dL/g), then add 850g of ordinary polypropylene resin for blending and granulation , Prepare modified masterbatch;

[0076] (2) Melt blending and extruding 5000g modified masterbatch and 20000g polypropylene resin through a twin-screw (or single-screw) extruder at a melt temperature of 230℃ and a melt stretching ratio of 300 times, crystallizing under stress field , Forming a membrane with a hard and elastic structure;

[0077] (3) Continuously stretch the membrane with a uniaxial stretching machine at a stretching ratio of 5 times and a stretching temperature of 140°C. After stretching, heat setting at 145°C for 5 minutes to prepare polyolefin for lithium ion batteries. Microporous diaphragm.

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. Microporous diaphragm.

PUM

Property	Measurement	Unit
Intrinsic viscosity	15.0	dl/g
Intrinsic viscosity	22.0	dl/g
Intrinsic viscosity	9.0	dl/g

Description & Claims & Application Information

We can also present the details of the Description, Claims and Application information to help users get a comprehensive understanding of the technical details of the patent, such as background art, summary of invention, brief description of drawings, description of embodiments, and other original content. On the other hand, users can also determine the specific scope of protection of the technology through the list of claims; as well as understand the changes in the life cycle of the technology with the presentation of the patent timeline. Login to view more.

Classification and recommendation of technical efficacy words

high strength
Easy to prepare

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

AI-Extracted Technical Summary

Problems solved by technology

Abstract

Image

Examples

Example Embodiment

Example Embodiment

Example Embodiment

PUM

Description & Claims & Application Information

Similar technology patents

Annuloplasty Device and Methods

Ultra-high-performance concrete reinforced concrete column with fiber reinforced polymers wound around steel pipe

Road traffic guardrail capable of buffering and absorbing impact

Rotor for rotating electric machine

Humic acid long-acting compound fertilizer and its preparing method

Classification and recommendation of technical efficacy words

High-nitrogen austenitic stainless steel

Method of preparing a poorly crystalline calcium phosphate and methods of its use

Hexagonal ferrite magnetic powder, method for producing the same and magnetic recording medium

Composition of and method for making high performance resins for infusion and transfer molding processes

600-MPa grade vanadium-containing high-strength hot-rolled steel bar and production method thereof

Method for removing pollutants in sewage

Carbon nanofiber aerogel as well as preparation method and application thereof

Health care medicinal tea and preparation process thereof

Non-mercury catalyst for acetylene hydrochlorination and method of preparing the same

High-strength ultra-high-toughness concrete and preparation method thereof