Lithium secondary battery and method of preparing the same

Patent metadata

Field	Value
Publication number	US-2021167392-A1
Application number	US-201916770931-A
Country	US
Kind code	A1
Filing date	Apr 1, 2019
Priority date	Apr 10, 2018
Publication date	Jun 3, 2021
Grant date	—

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

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 and the gel polymer electrolyte are bonded by an epoxy ring-opening reaction.

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

4 . 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.

5 . The lithium secondary battery of claim 1 , wherein the organic binder comprises a unit containing at least one selected from the group consisting of an alkylene group having 1 to 5 carbon atoms which is substituted with at least one halogen element, an alkylene oxide group having 1 to 5 carbon atoms, an alkylene oxide group having 1 to 5 carbon atoms which is substituted with at least one halogen element, an imide group, and celluloid,
wherein an epoxy group, a functional group capable of undergoing a ring-opening reaction with the an epoxy group, or a combination thereof is substituted into a chain composed of the unit.

6 . 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.

7 . A method of preparing a lithium secondary battery, 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 the an epoxy group of the oligomer, or a combination thereof, and thermally polymerizing the composition for a gel polymer electrolyte.

8 . The method of claim 7 , 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.

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

10 . The method of claim 7 , wherein the composition for a gel polymer electrolyte comprises a lithium salt, a non-aqueous organic solvent, and the oligomer.

11 . The lithium secondary battery of claim 3 , 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.

Assignees

• Lg Chemical Ltd

Inventors

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

Classifications

• H01M50/449

  having a layered structure · CPC title

• H01M50/443

  Particulate material · CPC title

• 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

• H01M2300/0082

  Organic polymers · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title