Lithium battery, lithium battery diaphragm and preparation method of lithium battery diaphragm

A technology of lithium battery diaphragm and vinylidene fluoride, which is applied in the direction of lithium batteries, battery pack components, non-aqueous electrolyte batteries, etc., can solve the problems of low tensile strength, impossibility of real application, poor degradability and other problems, and achieve improvement Electrochemical performance and safety performance, good biodegradation performance, accelerated fracture and degradation effect

Active Publication Date: 2019-07-26
DONGGUAN DONGYANG SOLAR SCI RES & DEV CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

But this method has following deficiency: (1) this method adopts polylactic acid to prepare porous membrane completely, because the carbon-oxygen bond in polylactic acid is not resistant to electrolyte corrosion, this product can't really be applied to lithium battery diaphragm industry; (2) in addition , Polylactic acid has a low degree of polymerization and low crystallinity. The product prepared by the casting film-forming method in this patent has low tensile strength and poor mechanical properties, and cannot be applied to mechanical winding of lithium batteries.
But this method has the following disadvantages: (1) the porous membrane prepared by this method is an ion exchange membrane, the process is complicated, and the cost is high, and the product is only applicable to the fuel cell in the lithium battery field, and is not suitable as a lithium battery separator; (2) the method Methods The ion exchange membrane is prepared by blending polylactic acid with other materials. The amount of polylactic acid needs to be controlled at a very low ratio, otherwise due to the difference in molecular weight, crystallinity and compatibility of different polymers, it will obviously affect the various properties of the main material. basic performance
But this method has the following disadvantages: (1) the patent adopts the method of multi-layer co-extrusion and then stretching to prepare a multi-layer film, which has high equipment requirements, complicated process, and high production cost of the product; (2) the product prepared by the patent It is a multi-layer structure, and there is no cross-linking between the layers. Even if degradable biomaterials are used, the layers can only be separated during degradation, but the entire product cannot be broken and decomposed, and the degradability is poor.

Method used

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  • Lithium battery, lithium battery diaphragm and preparation method of lithium battery diaphragm
  • Lithium battery, lithium battery diaphragm and preparation method of lithium battery diaphragm
  • Lithium battery, lithium battery diaphragm and preparation method of lithium battery diaphragm

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] In parts by mass, add 10 parts of poly(vinylidene fluoride-chlorotrifluoroethylene) and 2 parts of lactic acid to 50 parts of organic solvent, stir to dissolve, add 0.5 parts of sodium persulfate and 2 parts of potassium acid, and then stir Reaction; the specific reaction formula is:

[0031]

[0032] After the reaction is finished, the reaction mixture is added to an alkaline aqueous solution, stirred and precipitated, filtered, washed, and dried to obtain the target product poly(vinylidene fluoride-chlorotrifluoroethylene-lactic acid) copolymer resin;

[0033] Add 15 parts by mass of poly(vinylidene fluoride-chlorotrifluoroethylene-lactic acid) copolymer resin, 8 parts by mass of polyvinylpyrrolidone and 2 parts by mass of polymethyl methacrylate to 75 parts of organic solvent, at 50 Stir and dissolve at ℃; then filter through a sieve and stand for defoaming, then scrape coat it on a coating machine to form a uniform film; finally put the coated film into an oven, ...

Embodiment 2

[0036] In parts by mass, add 11 parts of poly(vinylidene fluoride-chlorotrifluoroethylene) and 3 parts of lactic acid to 60 parts of N,N-dimethylacetamide, stir to dissolve, add 1 part of potassium persulfate and 4 parts of Potassium acid, then stirring reaction; Concrete reaction formula is:

[0037]

[0038] After the reaction is finished, the reaction mixture is added to an alkaline aqueous solution, stirred and precipitated, filtered, washed, and dried to obtain the target product poly(vinylidene fluoride-chlorotrifluoroethylene-lactic acid) copolymer resin;

[0039] Add 12 parts by mass of poly(vinylidene fluoride-chlorotrifluoroethylene-lactic acid) copolymer resin, 6 parts by mass of polyethylene glycol and 4 parts by mass of polyvinyl alcohol into 78 parts of N,N-dimethylacetamide, in Stir and dissolve at 60°C; then filter through a sieve and stand for defoaming, then scrape coat it on a coating machine to form a uniform film; finally put the coated film into an ove...

Embodiment 3

[0041]In parts by mass, 12 parts of poly(vinylidene fluoride-chlorotrifluoroethylene) and 4 parts of lactic acid are added to 70 parts of tetrahydrofuran, stirred to dissolve, 2 parts of sodium persulfate and 6 parts of ammonium formate are added, and the reaction is stirred The specific reaction formula is as in Example 1. After the reaction finishes, the reaction mixture is added to the alkaline aqueous solution to stir and precipitate, filter, wash, and dry to obtain the target product poly(vinylidene fluoride-chlorotrifluoroethylene-lactic acid) copolymer resin ;

[0042] Add 10 parts by mass of poly(vinylidene fluoride-chlorotrifluoroethylene-lactic acid) copolymer resin, 8 parts by mass of polypropylene glycol and 3 parts by mass of chitosan to 60 parts of tetrahydrofuran, stir and dissolve at 70°C; then pass through a sieve After screen filtration and static defoaming, it is scraped on a coating machine to form a uniform film; finally, the coated film is placed in an ov...

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PUM

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Abstract

An embodiment of the invention discloses a preparation method of a lithium battery diaphragm. The method comprises the steps of adding 10-15 parts by mass of poly(vinylidene fluoride-chlorotrifluoroethylene) and 2-7 parts by mass of lactic acid into 50-80 parts by mass of an organic solvent, and carrying out stirring and dissolving; adding 0.5-5 parts by mass of an initiator and 2-10 parts of a hydrogenation reducing agent, and then carrying out stirring and reacting; adding a reaction mixture into an alkaline aqueous solution, carrying out stirring and precipitating, and carrying out filtering, washing and drying precipitates to obtain poly(vinylidene fluoride-chlorotrifluoroethylene-lactic acid) copolymer resin; and preparing the lithium battery diaphragm from the poly(vinylidene fluoride-chlorotrifluoroethylene-lactic acid) copolymer resin. The lithium battery diaphragm is prepared from the poly(vinylidene fluoride-chlorotrifluoroethylene-lactic acid) copolymer resin, so that the lithium battery diaphragm has the characteristics of being degradable, resistant to electrolyte corrosion and high in tensile strength.

Description

technical field [0001] The embodiments of the present invention relate to the field of lithium battery separators, and in particular to a lithium battery, a lithium battery separator and a preparation method thereof. Background technique [0002] With the rapid development of the lithium battery industry, the shipment of lithium battery separators reached 2 billion square meters in 2018. Moreover, in the next 5-10 years, the lithium battery separator will maintain a high growth rate of 30%. At this stage, the materials used to prepare lithium battery separators are basically polyethylene and polypropylene. Such materials have very poor biodegradability and cannot be recycled and reused. If they are discarded or buried at will, they will cause serious environmental pollution. Therefore, in order to solve this problem, it is necessary to modify the preparation materials of lithium battery separators to prepare new lithium battery separators with degradable properties. [00...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M2/14H01M2/16H01M10/052H01M50/403H01M50/417
CPCH01M10/052H01M50/409H01M50/403H01M50/411H01M50/44Y02E60/10
Inventor 李义涛程宗盛肖文武黄连红满金芝吴慧娟杨华军张魁
Owner DONGGUAN DONGYANG SOLAR SCI RES & DEV CO LTD
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