Binder for rechargeable lithium battery, electrode including the same, and rechargeable lithium battery including the same

Patent metadata

Field	Value
Publication number	US-2026058152-A1
Application number	US-202519305173-A
Country	US
Kind code	A1
Filing date	Aug 20, 2025
Priority date	Aug 22, 2024
Publication date	Feb 26, 2026
Grant date	—

Abstract

In some examples, a binder for a rechargeable lithium battery includes a first structural unit derived from a (meth)acrylic acid-based monomer; a second structural unit derived from a (C1-C10) alkylene glycol-based monomer; and a third structural unit derived from a zwitterionic vinyl-based monomer or a zwitterionic (meth)acryl-based monomer. The binder for a rechargeable lithium battery of some examples has high adhesive strength and low resistance, and thus can contribute to improving the performance of a rechargeable lithium battery.

First claim

What is claimed is:

1 . A binder for a rechargeable lithium battery, the binder comprising:
a first structural unit derived from a (meth)acrylic acid-based monomer; a second structural unit derived from a (C1-C10) alkylene glycol-based monomer; and a third structural unit derived from a zwitterionic vinyl-based monomer or a zwitterionic (meth)acryl-based monomer.

2 . The binder as claimed in claim 1 , wherein the first structural unit is represented by Chemical Formula 1-1 or 1-2, and
the second structural unit is represented by Chemical Formula 2-1 or 2-2:

wherein, in Chemical Formulas 1-1 and 1-2,
each R 1 independently comprises a hydrogen atom or a C1 to C20 alkyl group; and
M1 comprises an alkali metal,

wherein, in Chemical Formulas 2-1 and 2-2,
M2 comprises an alkali metal, and
n is an integer in a range between 1 and 100.

3 . The binder as claimed in claim 1 , wherein:
the zwitterionic vinyl-based monomer or zwitterionic (meth)acryl-based monomer has at least one cationic functional group comprising at least one of a substituted or unsubstituted ammonium cation, an imidazolium cation, a pyrazolium cation, a pyridinium cation, a piperidinium cation, a piperazinium cation, a sulfide cation, a naphthalenium cation, and a guanidium cation.

4 . The binder as claimed in claim 1 , wherein:
the zwitterionic vinyl-based monomer or zwitterionic (meth)acryl-based monomer has at least one anionic functional group comprising at least one of —SO 3 − , —CO 2 − , —O − —, and —NR − , and R comprises a substituted or unsubstituted C1 to C10 alkyl group or C1 to C10 haloalkyl group.

5 . The binder as claimed in claim 1 , wherein the zwitterionic vinyl-based monomer or zwitterionic (meth)acryl-based monomer comprises at least one of a sulfobetaine-based monomer, a phosphobetaine-based monomer, a carboxybetaine-based monomer, and an imidazolium-based monomer.

6 . The binder as claimed in claim 1 , wherein the third structural unit is represented by Chemical Formula 3-1 or 3-2:

wherein, in Chemical Formulas 3-1 and 3-2,
each R 2 independently comprises a hydrogen atom or a C1 to C20 alkyl group;
each R 3 independently comprises a hydrogen atom or a C1 to C20 alkyl group;
L 1 comprises *—(C═O)—NR 3 —CH 2 —* or *—(C═O)—O—*; and
L 2 to L 4 each independently comprises a single bond or a C1 to C20 alkylene group.

7 . The binder as claimed in claim 1 , wherein based on 100 wt % of the first structural unit, the second structural unit, and the third structural unit:
the first structural unit is included in an amount in a range of about 50 wt % to about 98 wt %, the second structural unit is included in an amount in a range of about 1 wt % to about 25 wt %, and the third structural unit is included in an amount in a range of about 1 wt % to about 25 wt %.

8 . The binder as claimed in claim 1 , further comprising a fourth structural unit derived from a (meth)acryl-based monomer.

9 . The binder as claimed in claim 8 , wherein the (meth)acryl-based monomer comprises one of an amide group and a nitrile group.

10 . The binder as claimed in claim 8 , wherein the fourth structural unit is represented by Chemical Formula 4:

wherein, in Chemical Formula 4,
R 4 comprises a hydrogen atom or a C1 to C20 alkyl group.

11 . The binder as claimed in claim 8 , wherein based on 100 wt % of the first structural unit, the second structural unit, the third structural unit, and the fourth structural unit:
the fourth structural unit is included in an amount in a range of about 20 wt % to about 50 wt %.

12 . The binder as claimed in claim 11 , wherein based on 100 wt % of the first structural unit, the second structural unit, the third structural unit, and the fourth structural unit:
the first structural unit is included in an amount in a range of about 30 wt % to about 70 wt %, the second structural unit is included in an amount in a range of about 1 wt % to about 15 wt %, and the third structural unit is included in an amount in a range of about 1 wt % to about 15 wt %.

13 . The binder as claimed in claim 1 , further comprising a lithium salt.

14 . The binder as claimed in claim 1 , wherein the binder has a viscosity in a range of about 450 cps to about 6500 cps in an aqueous solution at about 25° C., and has a solid content in a range of about 8.5 wt % to about 10 wt %.

15 . An electrode for a rechargeable lithium battery, the electrode comprising:
the binder as claimed in claim 1 ; and an electrode active material.

16 . The electrode as claimed in claim 15 , wherein the electrode comprises a negative electrode.

17 . The electrode as claimed in claim 16 , wherein the negative electrode comprises a negative electrode active material comprising at least one of a carbon-based negative electrode active material, and a silicon-based negative electrode active material.

18 . A separator for a rechargeable lithium battery, the separator comprising:
a porous substrate, and a coating layer on one surface or on both surfaces of the porous substrate, wherein the coating layer comprises the binder as claimed in claim 1 .

19 . A rechargeable lithium battery, comprising:
a negative electrode; a positive electrode; a separator between the negative electrode and positive electrode; and an electrolyte; wherein at least one of the negative electrode, the positive electrode, and the separator comprises the binder as claimed in claim 1 .

Assignees

• Samsung Sdi Co Ltd

Inventors

• Lee Kukjoo
• Park Sujin
• Cho Yunshik
• Lee Hyunseop
• Cho Minho
• Choi Jewon
• Kim Eunji
• Jung Kyunghwa

Classifications

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M10/0525

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

• H01M4/583

  Carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• H01M4/386

  Silicon or alloys based on silicon · CPC title