Binder and rechargeable battery including same

A technology for rechargeable batteries and binders, applied in battery electrodes, secondary batteries, circuits, etc., can solve the problems of active material shedding, pole piece breakage, etc., and achieve high adhesion, low crystallinity, and good ion transport performance. Effect

Active Publication Date: 2021-02-09
ZHEJIANG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] The first object of the present invention is to provide a binder to solve the problem that in the prior art, when PVDF or modified PVDF is used as a binder, it is easy to cause the pole piece to break or the active material to fall off.

Method used

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  • Binder and rechargeable battery including same
  • Binder and rechargeable battery including same
  • Binder and rechargeable battery including same

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1-4

[0066] Examples 1-4 are respectively a kind of binder, which are all formed by copolymerization of isobutyl vinyl ether, 2,2,2 trifluoroethyl methacrylate, acrylamide and hydroxyethyl acrylate. Specifically, the composition of the binder in Example 1 is listed in Table 1.

[0067] Table 1

[0068]

[0069]Wherein, the binders in Examples 1-4 are all prepared by emulsion polymerization. Specifically, the process steps of the preparation method are: add deionized water and emulsifier in a three-necked flask, and then feed nitrogen to remove oxygen. Add a certain amount of monomers in Table 1, then add an initiator, raise the temperature, control the temperature, and start the polymerization reaction. After a period of reaction, add the remaining monomers and initiators. After the polymerization is completed, the obtained solid content is 20%~ The 30% stable emulsion has a number average molecular weight of 300,000 to 1,000,000.

Embodiment 5-8

[0138] Embodiments 5-8 are respectively a kind of binder, and its difference from Example 1 is that the monomer composition of the binder in Examples 5-8 is different from that of Example 1, and the specific components are listed in Table 8 .

[0139] Table 8

[0140]

[0141] Wherein, the vinyl ether monomer, fluorine-containing acrylate monomer, acrylamide monomer and acrylate monomer used in Examples 5-8 are the same as those in Example 1.

Embodiment 9-13

[0143] Examples 9-13 are respectively a kind of binder, and its chemical formula can be represented by formula V, and the difference between them and Example 1 lies in the specific composition.

[0144]

[0145] Among them, R 1 ~R 9 The substituents are shown in Table 4, a, b, c, and d are mole percentages, and their values ​​are shown in Table 9 and Table 10.

[0146] Table 9

[0147] serial number R 1

R 2

R 3

R 4

R 5

R 6

R 7

R 8

R 9

Example 9 -H -H -H -H -H -H -CF 3

-H -H Example 10 -CH 3

-H -H -H -H -H -CF 3

-H -H Example 11 -CH 3

-CH 3

-CH 3

-H -H -H -H -H -CH 3

Example 12 -H -H -CH 3

-H -H -H -H -H -CH 3

Example 13 -H -H -CH 3

-H -H -H -CF 3

-H -CH 3

[0148] Table 10

[0149]

[0150]

[0151] After testing, the Raman shifts of the binders in Examples 5-13 are shown in Table 11.

[...

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Abstract

The invention provides a binder and a rechargeable battery containing the same, and relates to the field of batteries. The binder contains polymers of structural units shown as a formula I, a formulaII, a formula III and a formula IV; and the problem that in the prior art, when PVDF or modified PVDF is adopted as the binder, a pole piece is prone to breakage or active substances fall off can be solved through the binder, the purpose of improving the flexibility of the binder and the binding performance is achieved, and therefore, the cycling stability of the battery is improved.

Description

technical field [0001] The invention relates to the field of batteries, in particular to a binder and a rechargeable battery containing it. Background technique [0002] Lithium-ion batteries (LIBs) are widely used in electric vehicles and portable electronic devices due to their high specific capacity, long cycle life, and low self-discharge rate. Lithium cobalt oxide (LiCoO 2 ), lithium iron phosphate (LiFePO 4 ) etc. as the active material, conductive carbon as the conductive agent, and polyvinylidene F (PVDF) as the binder. [0003] However, PVDF as a binder has high hardness, high glass transition temperature and strong crystallinity. When used in battery pole pieces, it is prone to the problem that the pole piece becomes brittle after cold pressing, the active material may crack and fall off in the subsequent slitting and cutting, and the pole piece may break during the winding process. At the same time, serious Affects battery processing and performance. [0004]...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/62H01M10/0525
CPCH01M4/622H01M4/623H01M10/0525H01M2004/028Y02E60/10
Inventor 凌敏曾显清吴谷
Owner ZHEJIANG UNIV
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