Lithium secondary battery and method of preparing the same

Patent metadata

Field	Value
Publication number	US-11658301-B2
Application number	US-201916770931-A
Country	US
Kind code	B2
Filing date	Apr 1, 2019
Priority date	Apr 10, 2018
Publication date	May 23, 2023
Grant date	May 23, 2023

Abstract

The present invention relates to a lithium secondary battery including a positive electrode, a negative electrode, a separator, which includes a coating layer including an organic binder and inorganic particles, and a gel polymer electrolyte formed by polymerization of an oligomer, wherein the organic binder and the gel polymer electrolyte are bonded by an epoxy ring-opening reaction, and a method of preparing the same.

First claim

The invention claimed is:

1. A lithium secondary battery comprising:
a positive electrode;
a negative electrode;
a separator comprising a coating layer that includes an organic binder and inorganic particles; and
a gel polymer electrolyte formed by polymerization of an oligomer,
wherein the organic binder comprises a main chain composed of unit represented by Formula X-1 or Formula X-2 and wherein an epoxy group, a functional group capable of undergoing a ring-opening reaction with an epoxy group, or a combination thereof is substituted into the main chain, and
the organic binder and the gel polymer electrolyte are bonded by an epoxy ring-opening reaction:

wherein in Formula X-1, ml is an integer of 1 to 10,000,

in Formula X-2, m2 and m3 are each independently an integer of 1 to 10,000 and
the oligomer comprises at least one compound selected from the group consisting of compounds represented by Formula 2 and Formula 3:

wherein, in Formula 2, n1 is an integer of 2 to 10,000,

wherein, in Formula 3,
R 6 to R 11 are each independently a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms,
R 12 to R 16 are each independently at least one selected from the group consisting of hydrogen (H), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, —NR 17 R 18 , and —R 19 NR 20 R 21 , wherein R 19 is a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, and R 17 , R 18 , R 20 , and R 21 are each independently hydrogen (H), a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, and —R 22 NH 2 , wherein R 22 is a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, and
n2 is an integer of 1 to 10,000.

2. The lithium secondary battery of claim 1 , wherein the oligomer comprises an epoxy group, a functional group capable of undergoing a ring-opening reaction with an epoxy group, or a combination thereof.

3. The lithium secondary battery of claim 1 , wherein the functional group capable of undergoing a ring-opening reaction with an epoxy group comprises at least one selected from the group consisting of a hydroxyl group (OH), a carboxylic acid group (COOH), an amine group, an isocyanate group, a mercaptan group, and an imide group.

4. The lithium secondary battery of claim 1 , wherein the oligomer comprises at least one unit containing an alkylene oxide group or an amine group,
wherein an epoxy group, a functional group capable of undergoing a ring-opening reaction with an epoxy group, or a combination thereof is substituted into a chain composed of the unit.

5. A method of preparing the lithium secondary battery according to claim 1 , the method comprising:
inserting into a battery case an electrode assembly comprising a positive electrode, a negative electrode, and a separator,
wherein the separator comprises a coating layer that includes inorganic particles and an organic binder that comprises an epoxy group, a functional group capable of undergoing a ring- opening reaction with an epoxy group, or a combination thereof;
injecting into the battery case a composition for a gel polymer electrolyte comprising an oligomer that comprises an epoxy group, a functional group capable of undergoing a ring- opening reaction with an epoxy group of the oligomer, or a combination thereof, and
thermally polymerizing the composition for a gel polymer electrolyte,
wherein the organic comprises a main chain composed of unit represented by Formula X-1 or Formula X-2 and wherein an epoxy group, a functional group capable of undergoing a ring-opening reaction with an epoxy group, or a combination thereof is substituted into the main chain:

wherein in Formula X-1, m1 is an integer of 1 to 10,000,

wherein in Formula X-2, m2 and m3 are each independently an integer of 1 to 10,000 and
the oligomer comprises at least one compound selected from the group consisting of compounds represented by Formula 2 and Formula 3:

wherein, in Formula 2, n1 is an integer of 2 to 10,000,

wherein, in Formula 3,
R 6 to R 11 are each independently a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms,
R 12 to R 16 are each independently at least one selected from the group consisting of hydrogen (H), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, —NR 17 R 18 , and —R 19 NR 20 R 21 , wherein R 19 is a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, and R 17 , R 18 , R 20 , and R 21 are each independently hydrogen (H), a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, and —R 22 NH 2 , wherein R 22 is a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, and
n2 is an integer of 1 to 10,000.

6. The method of claim 5 , wherein the functional group of the organic binder and the functional group of the oligomer undergo an epoxy ring-opening reaction when the oligomer is thermally polymerized.

7. The method of claim 5 , wherein the composition for a gel polymer electrolyte does not comprise an initiator.

8. The method of claim 5 , wherein the composition for a gel polymer electrolyte comprises a lithium salt, a non-aqueous organic solvent, and the oligomer.

9. The lithium secondary battery of claim 2 , wherein the functional group capable of undergoing a ring-opening reaction with an epoxy group comprises at least one selected from the group consisting of a hydroxyl group (OH), a carboxylic acid group (COOH), an amine group, an isocyanate group, a mercaptan group, and an imide group.

10. The lithium secondary battery of claim 1 , wherein the functional group capable of undergoing a ring-opening reaction with an epoxy group comprises a hydroxyl group (OH).

11. The lithium secondary battery of claim 1 , wherein the functional group capable of undergoing a ring-opening reaction with an epoxy group comprises a carboxylic acid group (COOH).

12. The lithium secondary battery of claim 1 , wherein the functional group capable of undergoing a ring-opening reaction with an epoxy group comprises an amine group.

13. The lithium secondary battery of claim 1 , wherein the functional group capable of undergoing a ring-opening reaction with an epoxy group comprises an isocyanate group.

14. The lithium secondary battery of claim 1 , wherein the functional group capable of undergoing a ring-opening reaction with an epoxy group comprises a mercaptan group.

15. The lithium secondary battery of claim 1 , wherein the functional group capable of undergoing a ring-opening reaction with an epoxy group comprises an imide group.

16. The lithium secondary battery of claim 1 , wherein the compound represented b

Assignees

• Lg Chemical Ltd
• Lg Energy Solution Ltd

Inventors

• Shin Won Kyung
• Ahn Kyoung Ho
• Lee Chul Haeng
• Lee Jae Won

Classifications

• H01M10/0583

  of accumulators with folded construction elements except wound ones, i.e. folded positive or negative electrodes or separators, e.g. with "Z"-shaped electrodes or separators · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M50/443

  Particulate material · CPC title

• H01M2004/027

  Negative electrodes · CPC title