Separator for rechargeable lithium battery and rechargeable lithium battery including the same

Patent metadata

Field	Value
Publication number	US-2025174827-A1
Application number	US-202418962982-A
Country	US
Kind code	A1
Filing date	Nov 27, 2024
Priority date	Nov 29, 2023
Publication date	May 29, 2025
Grant date	—

Abstract

Examples of the present disclosure include a separator for a rechargeable lithium battery, and a rechargeable lithium battery including the. An example separator for a rechargeable lithium battery includes a porous substrate and a coating layer located on at least one surface of the porous substrate. The coating layer includes a cross-linked product of a binder and a cross-linking agent, a filler, and an adhesive binder. The adhesive binder includes a (meth)acryl-based binder containing a first structural unit derived from (meth)acrylamide and a heterocyclic ketone group-containing second structural unit, the cross-linking agent includes an aziridine-based cross-linking agent, the filler has a particle diameter D100 of about 1.0 μm or less, and the adhesive binder includes a cross-linked (meth)acryl-based adhesive binder.

First claim

What is claimed is:

1 . A separator for a rechargeable lithium battery, the separator comprising:
a porous substrate; and a coating layer located on at least one surface of the porous substrate, wherein the coating layer includes a cross-linked product of a binder and a cross-linking agent, a filler, and an adhesive binder, the binder includes a (meth)acryl-based binder including a first structural unit derived from (meth)acrylamide and a heterocyclic ketone group-containing second structural unit, the cross-linking agent includes an aziridine-based cross-linking agent, the filler has a particle diameter D100 of about 1.0 μm or less, and the adhesive binder includes a cross-linked (meth)acryl-based adhesive binder.

2 . The separator of claim 1 , wherein the coating layer is formed from a composition including the (meth)acryl-based binder, the aziridine-based cross-linking agent, and the filler having a particle diameter D100 of about 1.0 μm or less, and the adhesive binder.

3 . The separator of claim 1 , wherein the coating layer comprises a heat-resistant layer formed from a composition containing the (meth)acryl-based binder, the aziridine-based cross-linking agent, and the filler having a particle diameter D100 of about 1.0 m or less, and an adhesive layer located on the heat-resistant layer and including the adhesive binder.

4 . The separator of claim 1 , wherein the aziridine-based cross-linking agent comprises one or more of N,N′-toluene-2,4-bis(1-aziridinecarboxamide), N,N′-(methylenedi-p-phenylene)bis(aziridine-1-carboxamide), triethylenemelamine, 1,1-isophthaloyl bis(2-methylaziridine), tris(1-aziridinyl)phosphine oxide, N,N-hexamethylene-bis(aziridine carboxamide), trimethylolpropane tris(2-methyl-1-aziridine propionate), trimethylolpropane tris(beta-N-aziridinyl)propionate, and pentaerythritol tris(3-(1-aziridinyl)propionate).

5 . The separator of claim 1 , wherein the aziridine-based cross-linking agent is included in an amount ranging from about 5 wt % to about 50 wt % with respect to a content of the (meth)acryl-based binder.

6 . The separator of claim 1 , wherein a mass ratio of the (meth)acryl-based binder and the filler ranges from about 1:10 to about 1:50.

7 . The separator of claim 1 , wherein the filler has a particle diameter D50 of about 0.4 μm or less.

8 . The separator of claim 1 , wherein the filler comprises a plate-shaped inorganic filler.

9 . The separator of claim 1 , wherein the first structural unit derived from the (meth)acrylamide is represented by Chemical Formula 1:

in Chemical Formula 1,
R 1 and R 11 each independently comprise hydrogen or a methyl group,
the heterocyclic ketone group-containing second structural unit is represented by Chemical Formula 2:

in Chemical Formula 2,
R 2 to R 6 each independently comprise hydrogen, deuterium, a halogen group, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C1 to C10 heteroalkyl group, a substituted or unsubstituted C6 to C20 aryl group, or a substituted or unsubstituted C1 to C20 heteroaryl group,
m is an integer ranging from 1 to 10, and
n is equal to 0 or 1.

10 . The separator of claim 1 , wherein the heterocyclic ketone group-containing second structural unit is represented by Chemical Formula 3:

in Chemical Formula 3,
R 2 , R 3 , and R 4 each independently comprise hydrogen or a methyl group, and
n is 0 or 1.

11 . The separator of claim 1 , wherein the first structural unit is included in an amount ranging from about 55 mol % to about 95 mol %, and the second structural unit is included in an amount ranging from about 5 mol % to about 45 mol % with respect to 100 mol % of the (meth)acryl-based binder.

12 . The separator of claim 1 , wherein a total of the first structural unit derived from the (meth)acrylamide and the heterocyclic ketone group-containing second structural unit of the binder is equal to about 95 mol % or more.

13 . The separator of claim 1 , wherein the cross-linked (meth)acryl-based adhesive binder comprises cross-linked polymethyl (meth)acrylate.

14 . The separator of claim 1 , wherein the coating layer has a thickness ranging from about 1 μm to about 3 μm.

15 . A rechargeable lithium battery comprising:
the separator for a rechargeable lithium battery of claim 1 ; a positive electrode; and a negative electrode.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Seo Jin Weon
• Ko Chang Hong
• Park Sam Jin
• Kim Soo Hee
• Lee Eon Mi
• Lee Min Jeong
• Han Yoo Bin
• Lee Jung Yoon

Classifications

• Y02E60/10

  Energy storage using batteries · CPC title

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• C08F212/08

  Styrene · CPC title

• C08F220/06

  Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof · CPC title

• C08F220/56

  Acrylamide; Methacrylamide · CPC title