Boric acid derivative modified binder and lithium ion battery containing same

A binder and copolymer technology, applied in the direction of ester copolymer binders, adhesives, battery electrodes, etc., can solve the problems of poor bonding performance of binders, achieve low-temperature performance improvement, improve cycle performance, and expansion rate low effect

Active Publication Date: 2021-06-29
ZHUHAI COSMX BATTERY CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] In order to solve the problems of poor bonding performance of existing binders, the present invention provides a binder modified by boric acid derivatives and a lithium ion battery containing the binder. The binder modified by boric acid derivatives Compared with the existing binders, the bonding performance of the adhesive is greatly improved, and the mechanical stability of the prepared film is also improved.

Method used

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  • Boric acid derivative modified binder and lithium ion battery containing same
  • Boric acid derivative modified binder and lithium ion battery containing same
  • Boric acid derivative modified binder and lithium ion battery containing same

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preparation example Construction

[0078] [Preparation method of copolymer]

[0079] The present invention also provides the preparation method of above-mentioned copolymer, promptly prepares by the method for emulsion polymerization, and described method comprises the following steps:

[0080] The comonomer represented by the formula (1) is mixed with a matrix monomer and optionally a functional monomer, passed through an inert gas, and reacted to prepare the copolymer.

[0081] Wherein, the definitions of comonomer, matrix monomer and functional monomer represented by formula (1) are as mentioned above.

[0082] In a preferred solution, the inert gas is one of high-purity nitrogen and high-purity argon.

[0083] In a preferred embodiment, the reaction temperature is 30-120° C., and the reaction time is 5-24 hours.

[0084] In a preferred solution, depending on the difference of the matrix monomer and optionally the functional monomer, an auxiliary agent may also be added during the reaction. Exemplarily, t...

Embodiment 1

[0128]Add 30 parts (parts by mass, same below) of styrene, 70 parts of butadiene, 0.4 parts of acrylic acid, 0.1 part of divinylbenzene, and 2 parts of p-vinylbenzeneboronic acid (shown in formula 1-1) to the reaction kettle in sequence , 200 parts of water, 4.5 parts of sodium stearate, 0.5 part of molecular weight modifier dodecanethiol, nitrogen protection, stirring at 300 rpm, and heating up to 65°C. After continuing to stir for 20 minutes, add 0.31 parts of potassium persulfate, keep warm at 60°C, condense, continue to stir at 300rpm, and react for 7h. After the reaction is over, adjust the pH value with ammonia water, filter the gel therein with 200 mesh gauze, and obtain the Styrene-butadiene rubber emulsion binder modified by vinylbenzeneboronic acid, the glass transition temperature of the emulsion binder is 16°C, the average particle size is 168nm, the PDI is 0.06, the viscosity is 10-50mPa·s, and the solid content It is 40-42wt%, pH=6.5-7.5.

[0129] Disperse the p...

Embodiment 2

[0133] Add 33 parts of styrene, 67 parts of butadiene, 0.15 parts of divinylbenzene, 3 parts of boric acid derivatives shown in formula 1-3, 155 parts of water, 2 parts of acrylamide, 6 parts of stearin in the reaction kettle Na2SO4, 0.6 parts of molecular weight regulator dodecanethiol, nitrogen protection, stirring at 300 rpm, and heating up to 60°C. After continuing to stir for 20 minutes, add 0.3 parts of ammonium persulfate, keep warm at 65°C, condense, continue to stir at 300 rpm, and react for 6 hours. After the reaction is completed, adjust the pH with ammonia water, and filter the gel in it with 200-mesh gauze to obtain carboboric acid Derivative modified styrene-butadiene rubber emulsion binder, the glass transition temperature of the emulsion binder is 20°C, the average particle size of the emulsion binder is 165nm, the PDI is 0.036, and the viscosity is 15-50mPa· s, solid content is 39-41wt%, pH=7-8.

[0134] The process flow of the method for making the lithium-i...

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Abstract

The invention provides a boric acid derivative modified binder and a lithium ion battery containing the same. The surfaces of emulsion colloidal particles of the binder are provided with abundant boric acid groups (-B(OH)2). When applied to a battery pole piece, the boric acid group and -OH in a dispersant, namely sodium carboxymethyl cellulose or -OH in a functional monomer can undergo a dehydration condensation reaction in the drying process of the pole piece to form a three-dimensional network, so binding power is increased, and the peeling strength of the pole piece is greatly improved. The binder can also obviously improve the cycle performance of the lithium ion battery, so the cycle life of the lithium ion battery is prolonged; compared with a conventional binder, the lithium ion battery using the binder provided by the invention has the advantages that a cycle capacity retention rate is higher, and the expansion rate of the lithium ion battery after circulation is lower, so the expansion rate of the lithium ion battery after long-term use can be remarkably inhibited; and the low-temperature performance of the lithium ion battery using the binder disclosed by the invention is also obviously improved at the same time.

Description

technical field [0001] The invention relates to a binder modified by boric acid derivatives and a lithium ion battery containing the binder, belonging to the technical field of lithium ion batteries, in particular to the technical field of lithium ion battery binders. Background technique [0002] As a kind of polymer, the binder in lithium-ion batteries not only plays the role of bonding between the active material layers, but also can be used for the bonding between the active material layer and the pole sheet substrate. Aspect plays an important role, one of the important components of the battery. [0003] At present, the most widely used emulsion adhesives in the industry include SBR emulsion formed by copolymer of styrene and butadiene, and styrene-acrylic emulsion formed by copolymerization of styrene and acrylate. The films formed by these emulsions are all elastomers with different degrees of crosslinking, which can play a bonding role. However, there is only van ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08F236/10C08F212/08C08F220/06C08F212/36C08F230/06C08F220/18C08F220/14C08F220/20C08F220/56C08F222/38C09J147/00C09J133/08H01M4/62H01M10/0525
CPCC08F236/10C08F220/1804C09J147/00C09J133/066C09J135/00H01M4/622H01M10/0525C08F212/08C08F220/06C08F212/36C08F230/065C08F220/56C08F220/14C08F220/20C08F222/385Y02E60/10
Inventor 储霖郭盼龙陈伟平李素丽李俊义
Owner ZHUHAI COSMX BATTERY CO LTD
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