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

A lithium-ion battery and diaphragm technology, applied in the field of lithium-ion battery diaphragm and its preparation, can solve the problems of small rising space for coating pores, narrow lithium analysis window, insufficient electrolyte infiltration, etc.

Inactive Publication Date: 2021-09-14
HUIZHOU LIWINON ELECTRONIC TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Conventional isolation membrane coatings are single-layer or multi-layer ceramics, polymers or ceramic-polymer hybrid materials, which form lithium ion channels through the accumulated pores between the particles after drying, because the material itself has a small particle size and a relatively high packing density. Large, the space for the pores of the coating to rise is very small, and the ability of the coating to absorb the electrolyte has to continue to rise to become a bottleneck. There are still some disadvantages in projects with high dynamic performance: for example: as the number of cycles increases, the magnification increases , the more prone to insufficient electrolyte infiltration, black spots on the interface, narrow lithium analysis window, low cycle capacity retention rate, etc.

Method used

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

Examples

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preparation example Construction

[0049] 2, a kind of preparation method of lithium-ion battery diaphragm, comprises the following steps:

[0050] Step (A): Prepare ceramic composite slurry: ceramic particles, thickeners, dispersants, binders, and foaming agents are prepared in a ratio of 50-99 parts by weight: 0.1-1: 0.01-1: 2-6 : 0.1-5 mixing and stirring to form a ceramic composite slurry with a solid content of 20-40%;

[0051] Step (B): Prepare the adhesive slurry: mix and stir the adhesive particles, thickener, dispersant and binder in a weight ratio of 80-95:0.1-1.5:0.01-1:0.1-5 Adhesive slurry with a solid content of 2-6%;

[0052] Step (C): coating a ceramic composite slurry on one surface of the base film layer 1, drying to form a ceramic composite layer 2, coating an adhesive slurry on the surface of the ceramic composite layer 2, and drying to form a first adhesive layer 3, The adhesive slurry is coated on the other surface of the base film layer 1 and dried to form a second adhesive layer 4 to o...

Embodiment 1

[0069] (1) Preparation of positive electrode sheet

[0070] Mix NCM811 positive electrode active material, conductive agent superconducting carbon and carbon tubes, and binder polyvinylidene fluoride at a mass ratio of 96:2.0:0.5:1.5 to make positive electrode slurry, and coat the positive electrode slurry on the current collector aluminum foil On one surface of the aluminum foil, after drying and winding at 85°C, the positive electrode slurry is coated and dried on the other side of the aluminum foil according to the above method, and then the prepared aluminum foil is double-sided coated with the positive electrode active material layer. Cold pressing treatment; edge trimming, cutting into pieces, slitting, and slitting to make lithium-ion battery cathode sheets.

[0071] (2) Preparation of negative electrode sheet

[0072] The silicon carbon negative electrode active material, the conductive agent superconducting carbon, the thickener sodium carboxymethyl cellulose, and th...

Embodiment 2

[0094] The difference from Example 1 is:

[0095] (3) Preparation of diaphragm

[0096] A preparation method of a lithium-ion battery diaphragm, comprising the following steps:

[0097] Step (A): Prepare ceramic composite slurry: mix and stir ceramic particles, thickener, dispersant, binder, and foaming agent in a ratio of parts by weight of 90:0.5:0.5:5:0.8 to form a solid content of 30% ceramic composite slurry;

[0098] Step (B): Prepare the adhesive slurry: mix the adhesive particles, thickener, dispersant and binder at a weight ratio of 90:0.5:0.5:4 to form an adhesive with a solid content of 5%. slurry;

[0099] Step (C): coating a ceramic composite slurry on one surface of the base film layer 1, drying to form a ceramic composite layer 2, coating an adhesive slurry on the surface of the ceramic composite layer 2, and drying to form a first adhesive layer 3, The adhesive slurry is coated on the other surface of the base film layer 1 and dried to form a second adhesiv...

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Abstract

The invention belongs to the technical field of lithium ion batteries, and particularly relates to a lithium ion battery diaphragm and a preparation method thereof. The lithium ion battery diaphragm comprises a base membrane layer and a ceramic composite layer, the ceramic composite layer is arranged on the surface of the base membrane layer, the porosity of the ceramic composite layer is 50-80%, and the pore size is 0.1-0.5 [mu]m. According to the lithium ion battery diaphragm disclosed by the invention, the base membrane layer is coated with the ceramic composite layer, and the ceramic composite layer has relatively large porosity and relatively large pore diameter, so that the overall mechanical strength of the diaphragm is improved, the liquid absorption rate is also improved, and the lithium ion transmission rate is increased therefore, the conditions of insufficient electrolyte infiltration, interface black spots, lithium precipitation and low cycle retention rate after high-power and high-rate output or multiple charge-discharge cycles are improved.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a lithium ion battery diaphragm, a preparation method thereof and a lithium ion battery. Background technique [0002] Lithium-ion batteries not only have the characteristics of high working voltage, high energy density, long cycle life, no memory effect and no pollution, but also have the advantages of safety, reliability and fast charging and discharging. They are the main power source of various electronic products and are green Environmentally friendly and pollution-free secondary batteries meet the development needs of energy and environmental protection in various countries today, and their usage in all walks of life is increasing rapidly. [0003] The four key materials of lithium-ion batteries are positive electrode material, negative electrode material, electrolyte and diaphragm. The main function of the separator is to isolate the positive and...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M50/434H01M50/451H01M50/414H01M50/403H01M10/058H01M10/0525H01M10/42
CPCH01M50/434H01M50/451H01M50/414H01M50/403H01M10/058H01M10/0525H01M10/4235Y02P70/50Y02E60/10
Inventor 孙先维赖旭伦陈杰杨山郑明清
Owner HUIZHOU LIWINON ELECTRONIC TECH CO LTD
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