Positive electrode for rechargeable lithium battery and rechargeable lithium battery including the same

Patent metadata

Field	Value
Publication number	US-2024421313-A1
Application number	US-202418614371-A
Country	US
Kind code	A1
Filing date	Mar 22, 2024
Priority date	Jun 19, 2023
Publication date	Dec 19, 2024
Grant date	—

Abstract

Disclosed are a positive electrode for a rechargeable lithium battery and a rechargeable lithium battery including the same. The positive electrode includes a positive electrode current collector and a positive electrode mixture layer on the positive electrode current collector, wherein the positive electrode mixture layer includes a positive electrode active material and a first binder, and the first binder is a hydrogenated nitrile butadiene rubber (HNBR) derivative.

First claim

What is claimed is:

1 . A positive electrode for a rechargeable lithium battery, comprising:
a positive electrode current collector and a positive electrode mixture layer on the positive electrode current collector, wherein the positive electrode mixture layer comprises a positive electrode active material and a first binder, and the first binder comprises a hydrogenated nitrile butadiene rubber (HNBR) derivative.

2 . The positive electrode as claimed in claim 1 , wherein:
the first binder comprises: a repeating unit having an acrylonitrile-derived structure represented by Chemical Formula 1; a repeating unit including at least one of the repeating units having a hydrogenated butadiene-derived structure represented by one of Chemical Formulas 2 and 3; and a repeating unit represented by Chemical Formula 4:

wherein, in Chemical Formula 4,
R 1 and R 2 are each independently a substituted or unsubstituted C1 to C20 alkyl group, an ester group (—COOR, wherein R is a substituted or unsubstituted C1 to C20 alkyl group), a cyano group (—CN), pyrrolidonyl group (—C— 3 H 5 NHCO), a carboxyl group (—COOH), a caprolactamyl group (—NCOC 5 H 10 ), a morpholinyl group (—NC 4 H 8 O), a hydroxy group (—OH), an amino group (—NH 2 ), a vinyl group (—CH═CH 2 ), an epoxy group (—COCH 2 ), or a thiol group (—SH).

3 . The positive electrode as claimed in claim 1 , wherein:
the first binder is included in an amount of greater than or equal to about 0.1 wt % and less than or equal to about 5 wt % based on a total amount of the positive electrode mixture layer.

4 . The positive electrode as claimed in claim 1 , wherein:
the positive electrode mixture layer further comprises a second binder, and the second binder comprises a hydrogenated nitrile butadiene rubber (HNBR).

5 . The positive electrode as claimed in claim 4 , wherein:
the second binder comprises: a repeating unit having an acrylonitrile-derived structure represented by Chemical Formula 5; a repeating unit comprising at least one of an alkylene repeating unit represented by Chemical Formula 6 and a repeating unit having a hydrogenated butadiene-derived structure represented by Chemical Formula 7; and a repeating unit represented by Chemical Formula 8:

wherein, in Chemical Formula 8,
R 3 is a substituted or unsubstituted C1 to C20 alkyl group, an ester group (—COOR, where R is a substituted or unsubstituted C1 to C20 alkyl group), a cyano group (—CN), a pyrrolidonyl group (—C— 3 H 5 NHCO), a carboxyl group (—COOH), a caprolactamyl group (—NCOC 5 H 10 ), a morpholinyl group (—NC 4 H 8 O), a hydroxy group (—OH), an amino group (—NH 2 ), a vinyl group (—CH═CH 2 ), an epoxy group (—COCH 2 ), or a thiol group (—SH).

6 . The positive electrode as claimed in claim 4 , wherein:
the second binder is included in an amount of greater than about 0 wt % and less than or equal to about 5 wt % based on a total amount of the positive electrode mixture layer.

7 . The positive electrode for a rechargeable lithium battery as claimed in claim 1 , wherein:
the positive electrode mixture layer further comprises a third binder, and the third binder comprises polyvinylidene fluoride, a derivative thereof, a copolymer comprising the same, or a combination thereof.

8 . The positive electrode for a rechargeable lithium battery as claimed in claim 7 , wherein:
the third binder comprises a repeating unit having a vinylidene fluoride-derived structure represented by Chemical Formula 9:

9 . The positive electrode for a rechargeable lithium battery as claimed in claim 8 , wherein:
the third binder further comprises a repeating unit comprising at least one of a repeating unit having a vinylidenefluoride derivative-derived structure represented by Chemical Formula 10 and a repeating unit having a hexafluoropropylene-derived structure represented by Chemical Formula 11:

10 . The positive electrode as claimed in claim 7 , wherein:
the third binder is included in an amount of greater than about 0 wt % and less than or equal to about 3 wt % based on a total amount of the positive electrode mixture layer.

11 . The positive electrode as claimed in claim 1 , wherein:
the positive electrode mixture layer further comprises a fourth binder, and the fourth binder comprises poly(meth)acrylic acid, poly(meth)acrylate, polymethyl(meth)acrylate, polyacrylonitrile, an acrylonitrile-styrene-butadiene copolymer, or a combination thereof.

12 . The positive electrode as claimed in claim 11 , wherein:
the fourth binder is included in an amount of greater than about 0 wt % and less than or equal to about 3 wt % based on a total amount of the positive electrode mixture layer.

13 . The positive electrode as claimed in claim 1 , wherein:
The positive electrode mixture layer further comprises a crosslinking agent.

14 . The positive electrode as claimed in claim 13 , wherein:
the crosslinking agent is a crosslinking agent of the carbodiimide compound series.

15 . The positive electrode as claimed in claim 14 , wherein:
the crosslinking agent is represented by Chemical Formula 12:

wherein, in Chemical Formula 12,
R 4 and R 5 are each independently a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C6 to C20 aryl group, or a substituted or unsubstituted C2 to C20 heteroaryl group including at least one selected from N, O, S and P;
L 1 and L 2 are each independently a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C6 to C20 arylene group, or a substituted or unsubstituted C2 to C20 heteroarylene group including at least one selected from N, O, S and P; and
z is an integer from 1 to 20.

16 . The positive electrode as claimed in claim 13 , wherein:
the crosslinking agent is included in an amount of greater than about 0 wt % and less than or equal to about 3 wt % based on a total amount of the positive electrode mixture layer.

17 . The positive electrode as claimed in claim 1 , wherein:
the positive electrode mixture layer further comprises a conductive material.

18 . The positive electrode as claimed in claim 17 , wherein:
the conductive material is included in an amount of greater than about 0 wt % and less than or equal to about 5 wt % based on a total amount of the positive electrode mixture layer.

19 . A rechargeable lithium battery comprising the positive electrode as claimed in claim 1 .

Assignees

• Samsung Sdi Co Ltd

Inventors

• Yang Mihwa
• Kim Minjae
• Seol Jongheon

Classifications

• H01M2004/028

  Positive electrodes · CPC title

• H01M10/0587

  of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M4/13

  Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof · CPC title