Separation membrane for lithium secondary battery and lithium secondary battery including same

Patent metadata

Field	Value
Publication number	US-11967732-B2
Application number	US-201917044370-A
Country	US
Kind code	B2
Filing date	Apr 29, 2019
Priority date	Apr 27, 2018
Publication date	Apr 23, 2024
Grant date	Apr 23, 2024

Abstract

The present invention provides a separation membrane for a lithium secondary battery and a lithium secondary battery including the same, the separation membrane including: a substrate; a first coating layer containing a first organic binder which is able to be bonded to a gel polymer electrolyte through an epoxy ring-opening reaction; and a second coating layer containing a second organic binder, wherein the first organic binder has a functional group capable of ring-opening reaction with an epoxy group, or a combination thereof, and the gel polymer electrolyte is formed by polymerizing an oligomer having an epoxy group, a functional group capable of ring-opening reaction with an epoxy group, or a combination thereof.

First claim

The invention claimed is:

1. A separation membrane for a lithium secondary battery, the separation membrane comprising:
a substrate;
a first coating layer containing a first organic binder which is able to be bonded to a gel polymer electrolyte through an epoxy ring-opening reaction; and
a second coating layer containing a second organic binder,
wherein the first organic binder is substituted with epoxy group, a functional group capable of ring-opening reaction with an epoxy group, or a combination thereof, and
the gel polymer electrolyte is formed by polymerizing an oligomer having an epoxy group, a functional group capable of ring-opening reaction with an epoxy group, or a combination thereof.

2. The separation membrane of claim 1 ,
wherein the functional group capable of ring-opening reaction with an epoxy group is at least one functional group 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.

3. The separation membrane of claim 1 ,
wherein the first organic binder comprises a unit containing at least one selected from the group consisting of an alkylene group which is substituted with at least one halogen element and which has 1 to 5 carbon atoms, an alkylene oxide group having 1 to 5 carbon atoms, an alkylene oxide group which is substituted with at least one halogen and which has 1 to 5 carbon atoms, an imide group, and cellulose, and
an epoxy group, a functional group capable of ring-opening reaction with an epoxy group, or a combination thereof is substituted in a main chain which is formed of the unit.

4. The separation membrane of claim 1 ,
wherein the oligomer comprises at least one unit selected from the group consisting of a unit containing an alkylene oxide group and a unit containing an amine group, and
an epoxy group, a functional group capable of ring-opening reaction with an epoxy group, or a combination thereof is substituted in a main chain which is formed of the unit.

5. The separation membrane of claim 1 ,
wherein at least one coating layer, which is selected from the first coating layer and the second coating layer, comprises an inorganic oxide containing at least one element selected from the group consisting of Si, Al, Ti, Zr, Sn, Ce, Mg, Ca, Zn, Y, Pb, Ba, Hf, and Sr.

6. The separation membrane of claim 1 ,
wherein the first coating layer is formed on the substrate, and
the second coating layer is formed on the first coating layer.

7. The separation membrane of claim 1 ,
wherein the second coating layer is formed on the substrate, and
the first coating layer is formed on the second coating layer.

8. The separation membrane of claim 1 ,
wherein the total thickness of the first coating layer and the second coating layer is 0.2-20 μm.

9. A lithium secondary battery comprising:
an electrode assembly including at least one unit cell which contains at least one positive electrode, at least one negative electrode, and at least one first separation membrane disposed between the positive electrode and negative electrode; and
a gel polymer electrolyte formed by polymerizing an oligomer having an epoxy group, a functional group capable of ring-opening reaction with an epoxy group, or a combination thereof,
wherein the first separation membrane is a separation membrane for a lithium secondary battery of claim 1 .

10. The lithium secondary battery of claim 9 ,
wherein the electrode assembly comprises two or more unit cells, and further comprises a second separation membrane disposed between the unit cells.

Assignees

• Lg Chemical Ltd
• Lg Energy Solution Ltd

Inventors

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

Classifications

• H01M50/446 Primary

  Composite material consisting of a mixture of organic and inorganic materials · CPC title

• H01M4/622

  being polymers · CPC title

• H01M10/0525

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

• H01M10/0565 Primary

  Polymeric materials, e.g. gel-type or solid-type · CPC title

• H01M50/443 Primary

  Particulate material · CPC title