Separator for rechargeable lithium battery and rechargeable lithium battery including the same

Patent metadata

Field	Value
Publication number	US-2016149189-A1
Application number	US-201514930533-A
Country	US
Kind code	A1
Filing date	Nov 2, 2015
Priority date	Nov 21, 2014
Publication date	May 26, 2016
Grant date	—

Abstract

A separator for a rechargeable lithium battery includes: a substrate; and a coating layer on at least one side of the substrate, the coating layer including an acrylic-based copolymer obtained from polymerization of a (meth)acrylate salt and (meth)acrylonitrile, and a polyvinyl alcohol-based compound. A rechargeable lithium battery including the separator is also provided.

First claim

What is claimed is:

1 . A separator for a rechargeable lithium battery comprising:
a substrate; and a coating layer on at least one side of the substrate, the coating layer comprising an acrylic-based copolymer obtained from polymerization of a (meth)acrylate salt and (meth)acrylonitrile, and a polyvinyl alcohol-based compound.

2 . The separator for a rechargeable lithium battery of claim 1 , wherein the (meth)acrylate salt comprises an alkali metal, an alkaline-earth metal, ammonium, an amine salt, or a mixture thereof.

3 . The separator for a rechargeable lithium battery of claim 1 , wherein the acrylic-based copolymer is formed by polymerization of about 30 to about 90 wt % of the (meth)acrylate salt and about 10 to about 70 wt % of the (meth)acrylonitrile, based on the total weight of the (meth)acrylate salt and the (meth)acrylonitrile.

4 . The separator for a rechargeable lithium battery of claim 1 , wherein the acrylic-based copolymer has a viscosity of about 500 cps to about 10,000 cps.

5 . The separator for a rechargeable lithium battery of claim 1 , wherein the polyvinyl alcohol-based compound comprises polyvinyl alcohol, modified polyvinyl alcohol, or a mixture thereof.

6 . The separator for a rechargeable lithium battery of claim 1 , wherein the coating layer comprises about 75 to about 99.5 wt % of the acrylic-based copolymer and about 0.5 to about 25 wt % of the polyvinyl alcohol-based compound, based on the total weight of the coating layer.

7 . The separator for a rechargeable lithium battery of claim 1 , wherein the coating layer further comprises an inorganic particle,
wherein the inorganic particle comprises SiO 2 , Al 2 O 3 , Al(OH) 3 , AlO(OH), TiO 2 , BaTiO 2 , ZnO 2 , Mg(OH) 2 , MgO, Ti(OH) 4 , aluminum nitride (AlN), silicon carbide (SiC), boron nitride (BoN), clay, a glass powder, or a mixture thereof.

8 . The separator for a rechargeable lithium battery of claim 7 , wherein the coating layer further comprises a dispersing agent,
wherein the dispersing agent comprises an acrylic-based compound that is different from the acrylic-based copolymer.

9 . The separator for a rechargeable lithium battery of claim 8 , wherein the dispersing agent is included in an amount of about 0.1 to about 5 parts by weight based on 100 parts by weight of the inorganic particle.

10 . The separator for a rechargeable lithium battery of claim 1 , wherein the coating layer has a thickness of about 1 μm to about 7 μm.

11 . The separator for a rechargeable lithium battery of claim 1 , wherein the separator has a shrinkage ratio of less than or equal to about 5% obtained according to the following Equation 1:
Shrinkage ratio (%)=[( L 0− L 1)/ L 0]×100  Equation 1
wherein, in Equation 1, L 0 is the initial length of the separator, and the L 1 is the length of the separator after being allowed to stand at 130° C. for 1 hour.

12 . A rechargeable lithium battery comprising the separator of claim 1 .

Assignees

• Samsung Sdi Co Ltd

Inventors

• Park Jong-Hwan
• Cho Byeong-Gyu
• Kim Hyung-Bae
• Lee Eun-Gyeong
• In Jin-Hyuk

Classifications

• H01M10/0525 Primary

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

• H01M50/451

  comprising layers of only organic material and layers containing inorganic material · CPC title

• H01M50/42 Primary

  Acrylic resins · CPC title

• H01M50/417

  Polyolefins · CPC title

• H01M50/426

  Fluorocarbon polymers · CPC title