Lithium battery polyimide diaphragm and preparation method thereof

A polyimide and lithium battery technology, applied in secondary batteries, battery components, circuits, etc., can solve the problems of lithium battery leakage current, air pollution costs, etc., to improve mechanical strength and temperature resistance, reduce Production cost, effect of reducing tail gas treatment steps

Inactive Publication Date: 2020-05-22
王美岭
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The present invention cross-links diethylenetriamine to form a network structure, which can improve the mechanical strength of the polyimide lithium battery separator, especially the puncture strength, and can solve the lithium battery leakage current problem of the polyimide separator
The invention improves the porosity by adding nano-sodium bicarbonate pore-forming agent and removes unnecessary steps, and the decomposed gas is environmentally friendly, which solves the problem of air pollution and high cost of decomposed gas in the preparation of polyimide diaphragms in the prior art The problem

Method used

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  • Lithium battery polyimide diaphragm and preparation method thereof
  • Lithium battery polyimide diaphragm and preparation method thereof
  • Lithium battery polyimide diaphragm and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033] (1) Preparation of polyamic acid: take 6g nano-sodium bicarbonate and add it to 200g N,N-dimethylacetamide, then take 20g of 4,4'-diaminodiphenyl ether and add it to the solvent, After the diamine was dissolved, 21.8 g of pyromellitic anhydride was added to the above solvent, stirred at 25° C. for 6 hours, and vacuum degassed to obtain a polyamic acid solution with a concentration of 40%. Pour an appropriate amount of polyamic acid solution after degassing on a clean glass plate, scrape the film with a scraper, stay in the air for 30s, and then slowly and uniformly immerse it in 50% ethanol aqueous solution at 25°C to form a film. After forming micropores for 30 minutes, peel off the porous base film with polyamic acid, soak it in deionized water for 30 minutes and take it out;

[0034] (2) Preparation of polyimide diaphragm: Take the above-mentioned porous base film with polyamic acid out of deionized water, program the temperature to imidize, raise the temperature to ...

Embodiment 2

[0038] (1) Preparation of polyamic acid: Weigh 8g of nano-sodium bicarbonate and add it to 200g N,N-dimethylacetamide, then weigh 10.8g of p-phenylenediamine and add it to the above solvent, after the diamine dissolves , 21.8 g of pyromellitic anhydride was added to the above solvent, stirred at 25° C. for 7 hours, and vacuum degassed to obtain a polyamic acid solution with a concentration of 45%. Pour an appropriate amount of polyamic acid solution after degassing on a clean glass plate, scrape the film with a scraper, stay in the air for 30s, and then slowly and uniformly immerse it in 50% ethanol aqueous solution at 25°C to form a film. After forming micropores for 30 minutes, peel off the porous base film with polyamic acid, soak it in deionized water for 30 minutes, and then take it out;

[0039] (2) Preparation of polyimide diaphragm: Take the above-mentioned porous base film with polyamic acid out of deionized water, program the temperature to imidize, raise the tempera...

Embodiment 3

[0042] (1) Preparation of polyamic acid: Weigh 10g of nano-sodium bicarbonate and add it to 200g N,N-dimethylacetamide, then weigh 10.8g of p-phenylenediamine and add it to the above solvent, after the diamine dissolves , 29.4g of biphenyltetracarboxylic dianhydride was added to the above solvent, stirred at 25°C for 8 hours, and vacuum degassed to obtain a polyamic acid solution with a concentration of 50%. Pour an appropriate amount of polyamic acid solution after degassing on a clean glass plate, scrape the film with a scraper, stay in the air for 30s, and then slowly and uniformly immerse it in 50% ethanol aqueous solution at 25°C to form a film. After forming micropores for 30 minutes, peel off the porous base film with polyamic acid, soak it in deionized water for 30 minutes, and then take it out;

[0043] (2) Preparation of polyimide diaphragm: Take the above-mentioned porous base membrane with polyamic acid out of deionized water, program the temperature to imidize, ra...

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Abstract

The invention discloses a lithium battery polyimide diaphragm and a preparation method thereof. According to the invention, the porosity of the polyimide battery diaphragm is increased by utilizing the nano sodium bicarbonate pore-forming agent; and meanwhile, diethylenetriamine is used for crosslinking the polyimide battery diaphragm, the strength of the polyimide battery diaphragm is improved, and the thermal decomposition temperature of sodium bicarbonate coincides with the temperature interval of polyamic acid imidization, so that the polyamic acid imidization can be performed while thermal decomposition is performed, and the polyimide diaphragm with high porosity is prepared under the condition of high production efficiency. The polyimide diaphragm prepared by the method is high in porosity; the decomposition gas is environment-friendly, tail gas treatment measures are not needed, diaphragm strength is high, and production cost is low; and the lithium battery polyimide diaphragm has unique combined balance performance of electrical performance, thermal performance, chemical performance and mechanical performance, retains respective characteristics of the above performances, and is a high-end lithium battery diaphragm.

Description

technical field [0001] The invention belongs to the field of lithium battery materials, and relates to a polyimide lithium battery diaphragm and a preparation method thereof. Background technique [0002] Lithium batteries have the advantages of large specific capacity, high power density, long cycle life, no memory effect, low self-discharge rate, stable discharge voltage, fast charge and discharge, etc., and are widely used in portable communication equipment, electric vehicles, aerospace and other fields , has become the representative of the current high-performance battery. Separators are an important part of lithium-ion batteries. At present, the commonly used lithium-ion battery separator is polyolefin separator, but when the battery is used improperly and the inside or outside of the battery is overheated, the traditional polyolefin separator will fuse when the battery temperature exceeds 160 ° C, resulting in positive and negative contacts. A short circuit will ca...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M2/14H01M2/16H01M10/0525C08J5/18C08J9/08C08J9/36C08L79/08
CPCH01M10/0525C08J5/18C08J9/08C08J9/36C08J2379/08C08J2203/02H01M50/403H01M50/411Y02E60/10
Inventor 王美岭
Owner 王美岭
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