An aqueous ceramic/PVDF mixed coating slurry, a preparation method and an application thereof

A ceramic material and water-based technology, which is applied in the field of water-based ceramic/PVDF mixed coating slurry and its preparation, can solve the problem of uneven dispersion of coating particles of mixed-coated separators, shortened cycle life of lithium ion batteries, and uneven local current density. and other problems, to achieve the effect of strong binding force, dense surface and good uniformity

Active Publication Date: 2018-12-21
湖南烁普新材料有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, PVDF is a hydrophobic polymer material, and ceramics are a hydrophilic material, and it is difficult to disperse the two in the same system
Even if the conventional technology can disperse the coating material, it is difficult to disperse it evenly, resulting in uneven dispersion of the coating particles of the mixed coating separator, and the uneven coating will cause uneven local current density during the charging and discharging process of the battery , so that the structure of the electrode material is more easily damaged during cycling, which greatly shortens the cycle life of lithium-ion batteries

Method used

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  • An aqueous ceramic/PVDF mixed coating slurry, a preparation method and an application thereof

Examples

Experimental program
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Effect test

Embodiment 1

[0051] Add 170g of high-purity water, 0.5g of perfluoroalkyl acrylate, 0.5g of perfluoroalkyl carboxylic acid amine, 0.5g of tert-butyl hydroperoxide and 1g of acetone into an autoclave filled with nitrogen. Under the conditions, 60g of vinylidene fluoride monomer and 40g of hexafluoropropylene monomer gas are continuously introduced into the mixed solution, and the reaction pressure is controlled to 4.0Mpa by adjusting the gas flow rate. After reacting for 8 hours, filter and wash 5 times with pure water to obtain Concentrated PVDF polymer emulsion, adding deionized water to the concentrated PVDF polymer emulsion to adjust the solid content, and preparing a water-based PVDF polymer emulsion with a mass fraction of 20%.

[0052] Add 20g magnesium hydroxide, 0.1g styrene-maleic anhydride and 0.4g sodium polyacrylate in 45g deionized water, after stirring for 3 hours, add 0.2g hydroxyethyl cellulose and 15g polyurethane, continue stirring for 6 hours, and finally 20g of water-ba...

Embodiment 2

[0056] Add 150g of high-purity water, 0.5g of sodium perfluoroalkane sulfonate, 0.9g of tert-butyl hydroperoxide and 0.8g of acetone into an autoclave filled with nitrogen, mix well, and continue to pass through the mixed solution at 80°C Add 60g vinylidene fluoride monomer and 40g hexafluoropropylene monomer gas, control the reaction pressure to 2.0Mpa by adjusting the gas flow rate, after reacting for 10h, filter the prepared PVDF emulsion, wash 3 times with pure water to obtain concentrated PVDF For the polymer emulsion, deionized water is added to the concentrated PVDF polymer emulsion to adjust the solid content, and the water-based PVDF polymer emulsion with a mass fraction of 20% is prepared.

[0057] Add 10g of aluminum oxide and 0.01g of sodium polyacrylate to 45g of deionized water, and after stirring for 8 hours, add 0.25g of sodium carboxymethyl cellulose, 0.25g of sodium alginate and 7.5g of styrene-butadiene latex, continue stirring for 10 hours, and finally mix 4...

Embodiment 3

[0061] Add 200g of high-purity water, 0.8g of perfluoroalkyl acrylate, 0.3g of tert-butyl hydroperoxide and 1.7g of acetone into an autoclave filled with nitrogen. 60g vinylidene fluoride monomer and 40g hexafluoropropylene monomer gas, control the reaction pressure to 1.5Mpa by adjusting the gas flow rate, after 15 hours of reaction, filter the prepared PVDF emulsion, wash 4 times with pure water to obtain concentrated PVDF polymerization Add deionized water to the concentrated PVDF polymer emulsion to adjust the solid content, and prepare a water-based PVDF polymer emulsion with a mass fraction of 20%.

[0062] Add 10g titanium dioxide, 20g boehmite and 2.0g polyethylene glycol in 45g deionized water, after stirring for 3 hours, add 0.5g methyl hydroxyethyl cellulose, 5.0g styrene-acrylic latex and 6.0g polyacrylate emulsion, continue Stir for 6 hours, and finally add 10 g of water-based PVDF polymer emulsion and 0.05 g of fluoroalkyl ethoxy ether alcohol simultaneously and ...

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Abstract

A method for prepare an aqueous ceramic / PVDF mixed coat slurry comprises uniformly mixing high-purity water, perfluoroalkyl dispersant, tert-butyl hydrogen peroxide and acetone, continuously introducevinylidene fluoride and hexafluoropropylene gas to obtain aqueous PVDF emulsion; The ceramic material and the first dispersant are dispersed in deionized water, then thickener and adhesive, water-based PVDF emulsion and wetting agent are added, and the slurry is obtained after being uniformly mixed. The water-based ceramic / PVDF mixed coating slurry prepared by the invention is coated on a polyethylene diaphragm to obtain a wet film; A water-based ceramic / PVDF mix coating membrane is obtain by drying. The invention aims at remarkably improving the dispersion uniformity of ceramic / PVDF blend slurry, improving the uniformity of ceramic / PVDF blend coating separator coating, combining the characteristics of ceramic material and PVDF material, and remarkably improving the comprehensive performance of lithium ion battery separator.

Description

technical field [0001] The invention relates to the technical field of battery separator materials, in particular to a water-based ceramic / PVDF mixed coating slurry and a preparation method and application thereof. Background technique [0002] Lithium-ion battery separators are mainly divided into single-layer microporous membranes, composite membranes, blended membranes and non-woven membranes. Coated diaphragm is one of the composite membranes. At present, ternary batteries are used in conjunction with wet-coated separators in the market. As the market share of ternary batteries continues to increase, the demand for wet-coated separators will continue to grow. Coated separators are mainly divided into inorganic ceramic coatings and polymer coatings. The structure and properties of the coating layer will vary greatly depending on the raw materials and processes, which will affect the performance of the battery. Battery performance includes chemical properties, such as ox...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M2/14H01M2/16H01M10/0525H01M10/058H01M50/403H01M50/446H01M50/489
CPCH01M10/0525H01M10/058H01M50/431H01M50/403H01M50/449H01M50/411Y02E60/10Y02P70/50
Inventor 吴秀锋钟海燕张杨肖欢张鹏孙先维雷建清蔡滔罗建
Owner 湖南烁普新材料有限公司
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