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

Patent metadata

Field	Value
Publication number	US-12021257-B2
Application number	US-202318331692-A
Country	US
Kind code	B2
Filing date	Jun 8, 2023
Priority date	Jun 9, 2022
Publication date	Jun 25, 2024
Grant date	Jun 25, 2024

Abstract

Provided are a separator, a method of manufacturing the separator, and an electrochemical device including the separator. According to an embodiment of the present disclosure, a separator including: a porous substrate and an inorganic particle layer provided on at least one surface of the porous substrate may be provided, wherein a value of the following Formula (1) is 0.135 or more: (1) BDV/t, wherein BDV is a voltage (kV) when a leakage current value is 5 mA, and t is an overall average thickness (μm) of the separator.

First claim

What is claimed is:

1. A method of manufacturing a separator, the method comprising:
(a) adding inorganic particles and an acid component to an aqueous solution of a silane compound represented by the following Chemical Formula 1 and performing stirring or bubbling to prepare a slurry; and
(b) applying the prepared slurry on at least one surface of a hydrophilic surface-treated porous substrate to form an inorganic particle layer,
A a Si(OR) b   [Chemical Formula 1]

wherein ‘A’ is independently 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,

wherein a value of the following Formula (1) is 0.135 or more
BDV/t   (1)

wherein
‘BDV’ is a voltage (kV) measured in accordance with ASTM D 149 when a leakage current value is 5 mA measured under conditions of raising an applied voltage at 5 kV/10 sec after placing the separator between electrodes of a withstand voltage tester, and
‘t’ is an overall average thickness (μm) of the separator.

2. The method of manufacturing a separator of claim 1 , wherein a (D80-D20)/D50 value is 0.01 to 2.0 in the inorganic particles.

3. The method of manufacturing a separator of claim 1 , wherein the polar functional group includes any 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.

4. The method of manufacturing a separator of claim 1 , wherein the preparing of the slurry in the process (a) is performed under a weakly acidic atmosphere of more than pH 4 and pH 7 or less.

5. A method of manufacturing a separator, the method comprising:
(a) adding inorganic particles and an acid component to an aqueous solution of a silane compound represented by the following Chemical Formula 1 and performing stirring or bubbling to prepare a slurry; and
(b) applying the prepared slurry on at least one surface of a hydrophilic surface-treated porous substrate to form an inorganic particle layer,
A a Si(OR) b   [Chemical Formula 1]

wherein ‘A’ is independently 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,

wherein a value of the following Formula (1) is 0.135 or more
BDV/t   (1)

wherein
‘BDV’ is a voltage (kV) measured in accordance with ASTM D 149 when a leakage current value is 5 mA measured under conditions of raising an applied voltage at 5 kV/10 sec after placing the separator between electrodes of a withstand voltage tester, and

‘t’ is an overall average thickness (μm) of the separator,
wherein the acid component is carbon dioxide; or an organic acid including any one or two selected from acetic acid and lactic acid.

6. The method of manufacturing a separator of claim 1 , further comprising: (c) aging the hydrophilic surface-treated porous substrate having the inorganic particle layer provided thereon, after the process (b).

7. The method of manufacturing a separator of claim 1 , wherein the hydrophilic surface-treated porous substrate is formed by performing one or more of a corona discharge treatment and a plasma discharge treatment.

Assignees

• Sk Innovation Co Ltd
• Sk Ie Tech Co Ltd

Inventors

• Kwon Tae Wook
• Bae Heung Taek

Classifications

• H01M10/052

  Li-accumulators · CPC title

• H01M50/449

  having a layered structure · CPC title

• H01M50/403 Primary

  Manufacturing processes of separators, membranes or diaphragms · CPC title

• H01M50/446

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

• H01M50/494

  Tensile strength · CPC title