Separator having high heat resistance, manufacturing method thereof and secondary battery including the separator

Patent metadata

Field	Value
Publication number	US-2016149186-A1
Application number	US-201514918366-A
Country	US
Kind code	A1
Filing date	Oct 20, 2015
Priority date	Nov 21, 2014
Publication date	May 26, 2016
Grant date	—

Abstract

Provided are a separator having high heat resistance, a manufacturing method thereof and a secondary battery including the separator, which provides excellent dispersibility and reduced thermal shrinkage. The separator includes separator includes a porous base layer, and a coating layer formed on at least one surface of the base layer, wherein the coating layer includes inorganic particles and a binder, and the binder includes one selected from the group consisting of polyacrylic acid (PAA), polyacrylate or a mixture of polyacrylic acid (PAA) and polyacrylate, having a molecular weight of 100,000 to 1,000,000, as a first binder.

First claim

What is claimed is:

1 . A separator comprising:
a porous base layer; and a coating layer formed on at least one surface of the base layer, wherein the coating layer includes inorganic particles and a binder, and the binder includes one selected from the group consisting of polyacrylic acid (PAA), polyacrylate or a mixture of polyacrylic acid (PAA) and polyacrylate, having a molecular weight of 100,000 to 1,000,000, as a first binder.

2 . The separator of claim 1 , wherein the polyacrylate is sodium polyacrylate.

3 . The separator of claim 1 , wherein the binder is a mixture of the first binder and a second binder, and the second binder is one water-based binder selected from the group consisting of a styrene-butadiene rubber (SBR), carboxylmethylcellulose (CMC) and acrylate.

4 . The separator of claim 1 , wherein the first binder is contained in an amount of 50 wt % or greater based on the total weight of the binder.

5 . The separator of claim 4 , wherein the first binder and the second binder are contained in the binder in a mixing ratio of 50:50 to 100:0.

6 . The separator of claim 1 , wherein the first binder and the second binder are contained in the binder in a mixing ratio of 60:40 to 70:30.

7 . The separator of claim 1 , wherein the first binder is polyacrylic acid having a molecular weight of about 1,000,000.

8 . The separator of claim 1 , wherein the first binder is polyacrylic acid having a molecular weight of about 250,000.

9 . The separator of claim 1 , wherein the first binder is polyacrylic acid having a molecular weight of about 100,000.

10 . A secondary battery including the separator of claim 1 .

11 . A manufacturing method of a separator, comprising:
preparing a porous base layer; preparing a slurry by mixing inorganic particles, a binder and a solvent; and forming a coating layer by coating the slurry on at least one surface of the base layer and drying the coated slurry, wherein the binder includes one selected from the group consisting of poly acrylic acid (PAA), polyacrylate or a mixture of poly acrylic acid (PAA) and polyacrylate, having a molecular weight of 100,000 to 1,000,000, as a first binder.

12 . The manufacturing method of claim 11 , wherein the polyacrylate is sodium polyacrylate.

13 . The manufacturing method of claim 11 , wherein the binder is a mixture of the first binder and a second binder, and the second binder is one water-based binder selected from the group consisting of a styrene-butadiene rubber (SBR), carboxyl methyl cellulose (CMC) and acrylate.

14 . The manufacturing method of claim 13 , wherein the first binder is contained in an amount of 50 wt % or greater based on the total weight of the binder.

15 . The manufacturing method of claim 11 , wherein the first binder is polyacrylic acid having a molecular weight of about 1,000,000.

16 . The manufacturing method of claim 11 , wherein the first binder is polyacrylic acid having a molecular weight of about 250,000.

17 . The manufacturing method of claim 11 , wherein the first binder is polyacrylic acid having a molecular weight of about 100,000.

18 . The manufacturing method of claim 13 , wherein the first binder and the second binder are contained in the binder in a mixing ratio of 50:50 to 100:0.

19 . The manufacturing method of claim 13 , wherein the first binder and the second binder are contained in the binder in a mixing ratio of 60:40 to 70:30.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Kim Hyungbae
• Park Jonghwan
• Cho Byeonggyu
• Lee Eungyeong
• In Jinhyuk

Classifications

• H01M50/403 Primary

  Manufacturing processes of separators, membranes or diaphragms · CPC title

• H01M50/42

  Acrylic resins · CPC title

• H01M50/491

  Porosity · CPC title

• H01M50/429

  Natural polymers · CPC title

• H01M50/449 Primary

  having a layered structure · CPC title