Lithium ion battery composite diaphragm, preparation method thereof and lithium ion battery

A technology of lithium-ion batteries and composite diaphragms, which is applied in secondary batteries, battery pack components, secondary battery repair/maintenance, etc., to achieve the effect of simple process, good heat resistance, strength and air permeability improvement

Active Publication Date: 2020-12-29
BYD CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present disclosure is to provide a lithium-ion battery composite separator and its preparation method, lithium-ion battery

Method used

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  • Lithium ion battery composite diaphragm, preparation method thereof and lithium ion battery
  • Lithium ion battery composite diaphragm, preparation method thereof and lithium ion battery
  • Lithium ion battery composite diaphragm, preparation method thereof and lithium ion battery

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0061] Add the first ceramic particles and the second ceramic particles with a weight ratio of 1:1 into deionized water at room temperature, and stir at a high speed of 1600 rpm for 15 minutes to obtain the first material; then add sodium polyacrylate, carboxymethyl fiber element, and stirred at a high speed of 1600 rpm for 1.5h to obtain the second material; reduce the rotational speed to 200 rpm, based on the total weight of the first ceramic particles and the second ceramic particles, and then add 13% by weight The polyacrylate emulsion continued to stir for 30min, the solid content of the polyacrylate emulsion was 40% by weight, and the coated slurry was prepared; the slurry was coated on both sides of a 16 μm polyolefin base film, and dried at 50°C. After baking and drying, a composite separator is obtained, and the thickness of the ceramic coating on each side is 2 μm.

[0062] Wherein, the first ceramic particle is Al with a particle size of 20nm sintered on the surface...

Embodiment 2

[0064]Add the first ceramic particles and the second ceramic particles with a weight ratio of 1:1 into deionized water at room temperature, and stir at a high speed of 1400 rpm for 20 minutes to obtain the first material; then add polyvinyl alcohol, methyl cellulose , and stirred at a high speed of 1400 rpm for 1.0h to obtain the second material; reduce the rotational speed to 300 rpm, based on the total weight of the first ceramic particles and the second ceramic particles, and then add 13% by weight of D The styrene-butadiene latex emulsion continued to stir for 30min, and the solid content of the styrene-butadiene latex emulsion was 25% by weight, and the coated slurry was prepared; the slurry was coated on both sides of a 16 μm polyolefin base film, baked at 50°C, After drying, a composite separator was obtained with a ceramic coating thickness of 4 μm on each side.

[0065] Among them, the first ceramic particle is SiO with a particle size of 40nm sintered on the surface....

Embodiment 3

[0067] Add the first ceramic particles and the second ceramic particles with a weight ratio of 3:7 into deionized water at room temperature, and stir at a high speed of 1600 rpm for 20 minutes to obtain the first material; then add polyvinyl alcohol, methyl cellulose , and stirred at a high speed of 1600 r / min for 1.0 h to obtain the second material; reduce the rotating speed to 300 r / min, based on the total weight of the first ceramic particles and the second ceramic particles, and then add 12% by weight of poly The acrylate emulsion was stirred for 30 minutes, and the solid content of the polyacrylate emulsion was 40% by weight, and the coated slurry was prepared; the slurry was coated on both sides of a 16 μm polyolefin base film, baked at 50°C, After drying, a composite separator was obtained with a ceramic coating thickness of 4 μm on each side.

[0068] Among them, the first ceramic particle is SiO with a particle size of 40nm sintered on the surface. 2 Nanoparticles of...

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Abstract

The invention relates to a lithium ion battery composite diaphragm, a preparation method thereof and a lithium ion battery. The composite diaphragm comprises a base membrane and a coating coated on the base membrane, wherein the coating contains first ceramic particles and second ceramic particles; the first ceramic particles comprise inner core particles and nanoscale ceramic particles sintered on the outer surfaces of the inner core particles, the average particle size of the first ceramic particles is 0.2-5 mu m, the average particle size of the second ceramic particles is 0.2-5 mu m, and the average particle size of the nanoscale ceramic particles is 10-90nm. The composite diaphragm disclosed by the invention has good heat resistance and strength, and coating is lighter and thinner.

Description

technical field [0001] The present disclosure relates to the field of lithium-ion batteries, in particular, to a lithium-ion battery composite diaphragm, a preparation method thereof, and a lithium-ion battery. Background technique [0002] Lithium-ion battery separator is a kind of film with a microporous structure, which is placed between the cathode and anode of the lithium-ion battery. It allows lithium ions to pass through while preventing the positive and negative electrodes from contacting. Its structure and characteristics greatly affect the performance of the battery. , including battery capacity, cycle life and safety performance. [0003] At present, commercial separators are all microporous membranes made of polyolefin materials, which can only provide limited heat resistance. Coating a layer of heat-resistant inorganic layer on the surface of the diaphragm is a common modification method, and the material of the heat-resistant inorganic layer can be titanium di...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M2/16H01M2/14H01M10/42
CPCH01M10/4235Y02E60/10
Inventor 陈丽杰陈俊越罗明俊刘会权
Owner BYD CO LTD
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