Granted Patent B2

US 12,531,310 · App. 17/273,238 · Granted Jan 20, 2026

Inventors: Yeonjoo Choi (Yongin-si, KR); Gain Kim (Yongin-si, KR); Yangseob Kim (Yongin-si, KR); Yongkyoung Kim (Yongin-si, KR); Dongwan Seo (Yongin-si, KR); Jungyoon Lee (Yongin-si, KR); Hyeonsun Choi (Yongin-si, KR)

Assignee: Samsung SDI Co., Ltd.

H01M50/42H01M10/0525H01M50/434H01M50/443H01M50/446H01M50/451

Abstract

Claims (38)

1 . A separator for a lithium secondary battery, comprising

a porous substrate, and

a coating layer on at least one surface of the porous substrate,

wherein the coating layer comprises an acrylic copolymer,

wherein the acrylic copolymer is represented by Chemical Formula 7,

wherein in Chemical Formula 7,

R 8 to R 10 are independently hydrogen or a methyl group,

R 11 is hydrogen or a C1 to C6 alkyl group,

L 2 is a substituted or unsubstituted C1 to C10 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 C3 to C20 heterocyclic group,

b is one of integers of 0 to 2,

M is an alkali metal selected from lithium, sodium, potassium, rubidium, and cesium,

0.55≤m≤0.95, 0.05≤(l+n)≤0.45, l+m+n=1, and 0<n, and

wherein a thickness ratio of a thickness of the coating layer to a thickness of the porous substrate is 0.1 to 0.2.

2 . The separator of claim 1 , wherein in Chemical Formula 7, 0.90≤m≤0.95, and 0≤l≤0.05, and 0<n≤0.05.

3 . The separator of claim 1 , wherein a weight average molecular weight of the acrylic copolymer is 350,000 to 970,000.

4 . The separator of claim 1 , wherein the coating layer comprises inorganic particles.

5 . The separator of claim 4 , wherein a weight ratio of the acrylic copolymer to the inorganic particles is from 1:20 to 1:40.

6 . The separator of claim 4 , wherein the inorganic particles comprise Al 2 O 3 , SiO 2 , TiO 2 , SnO 2 , CeO 2 , MgO, NiO, CaO, GaO, ZnO, ZrO 2 , Y 2 O 3 , SrTiO 3 , BaTiO 3 , Mg(OH) 2 , boehmite, or a combination thereof.

7 . The separator of claim 1 , wherein a thickness of the coating layer is 1 μm to 5 μm.

8 . A lithium secondary battery comprising

a positive electrode, a negative electrode, and the separator of claim 1 between the positive electrode and the negative electrode.

9 . A separator for a lithium secondary battery, comprising

a porous substrate, and

a coating layer on at least one surface of the porous substrate, wherein the coating layer comprises an acrylic copolymer and inorganic particles,

wherein the acrylic copolymer is represented by Chemical Formula 7,

in Chemical Formula 7,

R 8 to R 10 are independently hydrogen or a methyl group,

R 11 is hydrogen or a C1 to C6 alkyl group,

L 2 is a substituted or unsubstituted C1 to C10 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 C3 to C20 heterocyclic group,

b is one of integers of 0 to 2,

M is an alkali metal selected from lithium, sodium, potassium, rubidium, and cesium,

0.9≤m≤0.95, 0≤l≤0.05, 0<n≤0.05, and l+m+n=1, and

wherein a weight ratio of the acrylic copolymer to the inorganic particles is from 1:20 to 1:40.

10 . The separator of claim 9 , wherein a weight average molecular weight of the acrylic copolymer is 350,000 to 970,000.

11 . The separator of claim 9 , wherein the inorganic particles comprise Al 2 O 3 , SiO 2 , TiO 2 , SnO 2 , CeO 2 , MgO, NiO, CaO, GaO, ZnO, ZrO 2 , Y 2 O 3 , SrTiO 3 , BaTiO 3 , Mg(OH) 2 , boehmite, or a combination thereof.

12 . The separator of claim 9 , wherein a thickness of the coating layer is 1 μm to 5 μm.

13 . A lithium secondary battery comprising

a positive electrode, a negative electrode, and the separator of claim 9 between the positive electrode and the negative electrode.

Assignments (1)

Priority Claims (1)

Continuity (1)

References Cited (187)