Separator, method of manufacturing separator, and electrochemical device including separator

Patent metadata

Field	Value
Publication number	US-12394865-B2
Application number	US-202318473286-A
Country	US
Kind code	B2
Filing date	Sep 25, 2023
Priority date	Jun 9, 2022
Publication date	Aug 19, 2025
Grant date	Aug 19, 2025

Abstract

The present invention relates to a separator, a method of manufacturing the separator, and an electrochemical device including the separator. An embodiment of the present invention may provide a separator including: a porous substrate; an inorganic particle layer provided on at least one surface of the porous substrate; and a heat fusion layer provided on at least one surface of the inorganic particle layer, wherein a surface gloss value at 60° of a surface of the heat fusion layer is 10 GU or more.

First claim

What is claimed is:

1. A separator comprising:
a porous substrate;
an inorganic particle layer provided on at least one surface of the porous substrate; and
a heat fusion layer provided on at least one surface of the inorganic particle layer,
wherein the inorganic particle layer includes inorganic particles and a hydrolytic condensate of a silane compound,
wherein the heat fusion layer includes an acrylic particulate binder,
wherein a surface gloss value at 600 of a surface of the heat fusion layer is 20 GU or more.

2. The separator of claim 1 ,
wherein the porous substrate is a porous polyethylene, or porous polypropylene film having a thickness of 1 to 100 μm.

3. The separator of claim 1 , wherein when specimens each having a thickness of 5 to 50 μm, a width of 5 mm, and a length of 10 mm in each of a machine direction (MD) and a transverse direction (TD) serving as length directions are prepared from the separator, and each specimen is mounted on a chamber of a thermomechanical analyzer (TMA) by hooking both ends of each specimen to a metal jig and pulled downward with a force of 0.008 N while heating at 5° C. per minute, the specimens have a heat resistance in which the specimens are broken at a temperature of 180° C. or higher.

4. The separator of claim 1 , wherein a heat shrinkage rate in each of MD and TD is 3% or less when measured after the separator is allowed to stand at 150° C. for 60 minutes.

5. The separator of claim 1 , wherein the separator has an adhesive strength of more than 5 gf when measured by stacking the separator on a carbon sheet having a thickness of 200 μm so that the heat fusion layer of the separator faces the carbon sheet, compressing and fusing the carbon sheet and the separator at 80° C. and 1 MPa for 30 seconds with a heat press machine, and then peeling the separator at 180°.

6. The separator of claim 1 , wherein the separator has an amount of change in air permeability ΔG represented by the following Formula (1) of 60 sec/100 cc or less:
Δ G=G 1− G 2  (1)

wherein
G1 is a Gurley permeability of the separator,
G2 is a Gurley permeability of the porous substrate, and
the Gurley permeability is measured according to ASTM D 726.

7. The separator of claim 1 , wherein the acrylic particulate binder having a glass transition temperature (Tg) of 30° C. to 70° C.

8. The separator of claim 1 , wherein the hydrolytic condensate of the silane compound is a hydrolytic condensate obtained in a weakly acidic atmosphere.

9. The separator of claim 1 , wherein the silane compound is a compound represented by the following Chemical Formula 1:
AaSi(OR)b  [Chemical Formula 1]

wherein A is hydrogen, a polar functional group, or a C1-C10 alkyl group having a polar functional group, R is independently hydrogen or a C1-C5 alkyl group, a is 0 to 2, b is 2 to 4, and a+b is 4.

10. The separator of claim 9 , wherein the polar functional group includes one or two or more of an amino group, an epoxy group, a carboxyl group, a hydroxyl group, an amide group, a thiol group, a ketone group, an ester group, and an aldehyde group.

11. The separator of claim 1 , wherein the porous substrate has a surface including a polar functional group.

12. The separator of claim 1 , wherein the acrylic particulate binder has an average particle diameter greater than an average particle diameter of the inorganic particles.

13. An electrochemical device comprising the separator of claim 1 .

Assignees

• Sk Innovation Co Ltd
• Sk Ie Tech Co Ltd

Inventors

• Kwack Won Sub
• Kwon Tae Wook
• Bae Heung Taek
• Lee Chang Hee

Classifications

• H01M10/0525

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

• H01M50/449

  having a layered structure · CPC title

• H01M50/403 Primary

  Manufacturing processes of separators, membranes or diaphragms · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M50/431

  Inorganic material · CPC title