Aqueous PVDF coated lithium ion battery diaphragm and preparation method thereof

A lithium-ion battery, water-based technology, applied in the preparation of lithium-ion battery separators, and in the field of water-based PVDF-coated lithium-ion battery separators, can solve the problem of poor adhesion, easy blockage of ion channels, uneven size of islands, etc. problem, achieve the effect of improving the process capability, improving the positive and negative interface of the battery cell, and increasing the air permeability

Active Publication Date: 2018-11-20
JIANGSU QINGTAO ENERGY TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the coating of the microgravure preparation process is relatively dense, which is easy to block the ion channel
The coating prepared by the spraying process is distributed in a discrete island shape, with uneven thickness, uneven island size, and poor final adhesion effect
Acrylic glue and polyacrylonitrile polymer, due to the large swelling, should strictly control the shape distribution, which will easily lead to blockage of ion channels, so it is rarely used

Method used

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  • Aqueous PVDF coated lithium ion battery diaphragm and preparation method thereof
  • Aqueous PVDF coated lithium ion battery diaphragm and preparation method thereof
  • Aqueous PVDF coated lithium ion battery diaphragm and preparation method thereof

Examples

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Effect test

Embodiment 1

[0024] A lithium-ion battery diaphragm coated with water-based PVDF of the present invention is composed of a lithium-ion battery base film and a coating on one or both sides of the base film, the coating is composed of PVDF slurry, and the PVDF slurry The composition and mass parts are: PVDF is 9 parts of polyvinylidene fluoride copolymer; water-based UV curable resin is preferably 15 parts of UP resin; water-based binder is preferably 4 parts of acrylic polymer; thickener is carboxymethyl Base cellulose is preferably 0.6 parts; water is 63 parts; photoinitiator is preferably benzophenone, preferably 7 parts; auxiliary agent is 0.09 parts of dispersant, and 1 part of polymerization inhibitor.

[0025] Among them, the polyvinylidene fluoride copolymer of PVDF has a molecular weight of 500,000-800,000 and a particle size of 150nm-300nm.

[0026] The lithium-ion battery base film is a polyethylene film with a thickness of 5um and a porosity of 36%.

[0027] A preparation method...

Embodiment 2

[0032] A lithium-ion battery diaphragm coated with water-based PVDF of the present invention is composed of a lithium-ion battery base film and a coating on one or both sides of the base film, the coating is composed of PVDF slurry, and the PVDF slurry The composition and mass parts are: PVDF is 8 parts of polyvinylidene fluoride copolymer; the water-based UV curable resin is preferably 17 parts of PUA resin; the water-based binder is preferably 5 parts of acrylic polymer; the thickener is methylol The base cellulose is preferably 0.8 parts; the water is 60 parts; the photoinitiator is preferably a carbonyl compound, preferably 8 parts; the auxiliary agent is 0.09 parts of a dispersant, and the polymerization inhibitor is 2 parts.

[0033] The PVDF is a polyvinylidene fluoride copolymer with a molecular weight of 500,000-800,000 and a particle size of 150nm-300nm.

[0034] The lithium ion battery base film is a polypropylene film with a thickness of 15um and a porosity of 40%....

Embodiment 3

[0040] A lithium-ion battery diaphragm coated with water-based PVDF of the present invention is composed of a lithium-ion battery base film and a coating on one or both sides of the base film, the coating is composed of PVDF slurry, and the PVDF slurry The composition and mass parts are: PVDF is polyvinylidene fluoride copolymer, 6 parts; water-based UV curing resin is EA resin, preferably 15 parts; water-based binder is acrylic polymer, preferably 2 parts; thickener is attapulgite Clay is preferably 1 part; water is 65 parts; photoinitiator is preferably azo compound, preferably 6 parts; auxiliary agent is 0.09 parts of dispersant, and polymerization inhibitor is 2.5 parts.

[0041] The lithium-ion battery base film is a polyimide film with a thickness of 25um and a porosity of 45%.

[0042] A preparation method of a water-based PVDF-coated lithium-ion battery diaphragm, the preparation steps of which are: a. Add the dispersant and attapulgite clay in the auxiliary agent to 3...

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Abstract

The invention discloses a preparation method of an aqueous PVDF coated lithium ion battery diaphragm. The preparation method comprises the following steps of adding a dispersing agent and a thickeningagent into water, uniformly stirring, and adding PVDF, and enabling PVDF to be blended into water to prepare a turbid liquid; enabling water-based UV resin, a water-based adhesive, a photoinitiator and a polymerization inhibitor to be added in to the residual water, performing dispersing uniformly, introducing the PVDF turbid liquid, and uniformly dispersing to prepare PVDF slurry; and enabling the PVDF slurry to be coated on one side or two sides of a lithium ion battery base membrane which is subjected to corona treatment, forming a point matrix type distribution coating layer, and performing curing to obtain a finished product. The method has the advantages that the water-based UV photo-curing technology is adopted, and the coating layer can be immediately dried, the energy consumptionis lower, and the problem that the diaphragm is deformed due to heat and tension is avoided. The drying time of the diaphragm coating layer can be shortened to 8-15 seconds, so that the continuous and stable large-scale production can be facilitated.

Description

technical field [0001] The invention relates to the technical field of lithium-ion batteries, in particular to an aqueous PVDF-coated lithium-ion battery diaphragm, and to a preparation method of the aqueous PVDF-coated lithium-ion battery diaphragm. Background technique [0002] Compared with steel-shell and aluminum-shell batteries, lithium-ion soft-pack batteries have the advantages of light weight, large capacity, small internal resistance, flexible design, and safety. They are widely used in 3C consumer electronics and power battery products. However, there is no hard shell on the interface between the positive and negative electrodes of the battery. During the charge and discharge process, due to the expansion of graphite, deformation is easy to occur. When deformation occurs, the interface between the positive and negative electrodes is likely to be unstable, resulting in poor battery performance. [0003] At present, in order to improve the interface between the posi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M2/14H01M2/16H01M10/0525
CPCH01M10/0525H01M50/403H01M50/409Y02E60/10
Inventor 李峥冯玉川席健陈雷杨帆南策文
Owner JIANGSU QINGTAO ENERGY TECH
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