Lithium-ion battery separator and preparation method thereof and lithium-ion battery

A lithium ion battery and separator technology, applied in the field of lithium ion battery porous separator and its preparation, can solve the problems of uneven size and distribution, poor mechanical properties of the separator, poor ionic conductivity, etc. Good performance, evenly sized and distributed effects

Inactive Publication Date: 2016-12-14
SOUTH CHINA UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] One of the purposes of the present invention is to overcome the size and uneven distribution of polyimide lithium-ion battery diaphragm aperture in the prior art, liquid absorption rate, poor liquid retention rate and the ionic conductance of polyvinylidene fluoride lithium-ion battery diaphragm Poor efficiency; and the shortcomings of the poor mechanical properties of the separator obtained by the electrospinning method widely used in the preparation of polyimide and polyvinylidene fluoride separators, providing a uniform pore size and distribution, and excellent wettability with the electrolyte Lithium-ion battery separators, especially high-strength polyimide-polyvinylidene fluoride (PI-PVDF) lithium-ion battery separators

Method used

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  • Lithium-ion battery separator and preparation method thereof and lithium-ion battery
  • Lithium-ion battery separator and preparation method thereof and lithium-ion battery
  • Lithium-ion battery separator and preparation method thereof and lithium-ion battery

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0046] Step a, dissolving 6FAPB-ODPA in the organic solvent N,N'-dimethylacetamide to obtain a uniform casting solution, wherein the solid content of polyimide in the solvent N,N'-dimethylacetamide It is 17.00wt.%; the temperature of the control solution is 90°C during the preparation process.

[0047] Step b. Use a four-sided preparer to coat the casting solution prepared in step a on a clean and dry glass substrate with a coating thickness of 200 μm, and let it stand at room temperature for 3 minutes.

[0048] Step c, immerse the glass plate substrate coated with the casting solution obtained in step b into a watch glass filled with anhydrous ethanol to a sufficient depth, and let it stand for 1 min; the temperature is controlled at 18-23° C. during the preparation process.

[0049] Step d. Separate the diaphragm prepared in step c from the substrate and soak in 50 ml of absolute ethanol at room temperature for 15 min.

[0050] Step e, putting the separator obtained in step...

Embodiment 2

[0052] Step a. Dissolve 6FAPB-ODPA in the organic solvent N,N'-dimethylacetamide, add polyethylene glycol 200 as a pore forming agent, and obtain a uniform casting solution, wherein the polyimide is in the solvent N,N The solid content in '-dimethylacetamide is 17.00.wt%, and the mass fraction of polyethylene glycol 200 in solvent N,N'-dimethylacetamide is 1.45wt.%; The temperature is 60°C.

[0053] Step b. Use a four-sided preparer to coat the casting solution prepared in step a on a clean and dry glass substrate with a coating thickness of 200 μm, and let it stand at room temperature for 3 minutes.

[0054] Step c, immerse the glass plate substrate coated with the casting solution obtained in step b into a watch glass filled with anhydrous ethanol to a sufficient depth, and let it stand for 1 min; the temperature is controlled at 18-23° C. during the preparation process.

[0055] Step d. Separate the diaphragm prepared in step c from the substrate and soak in 50 ml of absol...

Embodiment 3

[0058] Step a. Use and Synthesize polyimide as a monomer; dissolve the synthesized polyimide and polyvinylidene fluoride in organic solvent N,N'-dimethylacetamide to obtain a uniform casting solution, in which polyimide The mass ratio to polyvinylidene fluoride is 9:1, and the solid content of the solid mixture of polyimide and polyvinylidene fluoride in the solvent N,N'-dimethylacetamide is 17.29wt.%. The temperature of the solution was controlled at 90°C during the process.

[0059] Step b. Use a four-sided preparer to coat the casting solution prepared in step a on a clean and dry glass substrate with a coating thickness of 200 μm, and let it stand at room temperature for 3 minutes.

[0060] Step c, immerse the glass plate substrate coated with the casting solution obtained in step b into a watch glass filled with anhydrous ethanol to a sufficient depth, and let it stand for 1 min; the temperature is controlled at 18-23° C. during the preparation process.

[0061] Step...

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Abstract

The invention discloses a lithium-ion battery separator and a preparation method thereof and a lithium-ion battery. The preparation method comprises the steps as follows (a) polyimide and polyvinylidene fluoride are dissolved into a solvent at the mass ratio of 10:0 to 10:10, and the total solid content of the polymer in the solvent is 5-30wt.% to obtain a uniform casting solution; and (b) a substrate is coated with the casting solution prepared in the step (a), wherein the coating thickness is 20-450 microns, and phase transformation, washing and drying are sequentially carried out after standing to obtain the lithium-ion battery separator. The separator prepared by the method is uniform in pore size and distribution and the safety and the stability of the lithium-ion battery are improved. The lithium-ion battery separator is relatively high in mechanical strength; processing and transportation of the separator are facilitated; the processing yield of the lithium-ion battery is improved; and meanwhile, the lithium-ion battery separator is excellent in porosity, liquid absorption rate and liquid retention rate and is suitable for a quick charge and discharge high-capacity power lithium-ion battery.

Description

technical field [0001] The invention belongs to the field of lithium ion batteries, and in particular relates to a lithium ion battery porous diaphragm, a preparation method thereof, and a lithium ion battery including the diaphragm. Background technique [0002] Membrane technology refers to the use of functional separation membranes as filter media to achieve high separation and purification of liquid-liquid, gas-liquid or other phase states. According to the pore size of the porous membrane, it can be divided into microfiltration membrane (MF), ultrafiltration membrane (UF), nanofiltration membrane (NF), reverse osmosis membrane (RO) and so on. For example, porous membranes with a certain pore size can be used in wastewater treatment, such as oil refineries and drinking water plants; they can also be used in air filtration, such as ultra-pure purification chambers in the semiconductor industry; they can also be used in biochemical industries, such as Filtration of blood ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M2/14H01M2/16H01M2/18H01M10/0525
CPCH01M10/0525H01M50/403H01M50/411H01M50/463Y02E60/10
Inventor 谭锦炎邱志明严玉蓉谭旭
Owner SOUTH CHINA UNIV OF TECH
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