Separator for lithium secondary battery, lithium secondary battery using the separator, and method of manufacturing the lithium secondary battery

Patent metadata

Field	Value
Publication number	US-2016049628-A1
Application number	US-201514788509-A
Country	US
Kind code	A1
Filing date	Jun 30, 2015
Priority date	Aug 13, 2014
Publication date	Feb 18, 2016
Grant date	—

Abstract

A separator includes a porous base, and a first coating layer on a surface of the porous base, the first coating layer including a (meth)acrylic acid ester-based polymer having a glass transition temperature of about 10° C. to about 60° C. The first coating layer may be positioned opposite to a cathode of the lithium secondary battery. The separator may further include a second coating layer on a surface of the porous base opposite to the first coating layer and comprising a (meth)acrylic acid ester-based polymer.

First claim

What is claimed is:

1 . A separator for a lithium secondary battery, the separator comprising:
a porous base; and a first coating layer on a surface of the porous base, the first coating layer comprising a (meth)acrylic acid ester-based polymer having a glass transition temperature of about 10° C. to about 60° C.

2 . The separator of claim 1 , wherein the first coating layer is opposite to a cathode of the lithium secondary battery.

3 . The separator of claim 1 , wherein the (meth)acrylic acid ester-based polymer has a glass transition temperature of about 20° C. to about 60° C.

4 . The separator of claim 1 , wherein the first coating layer is a dot-patterned layer comprising a plurality of dots arranged at intervals.

5 . The separator of claim 4 , wherein the plurality of dots have an average diameter of about 0.1 mm to about 1 mm and an average thickness of about 0.3 μm to about 10 μm, and at least one of the intervals between the dots is about 0.1 mm to about 10 mm.

6 . The separator of claim 1 , further comprising a second coating layer on a surface of the porous base opposite to the first coating layer and comprising a (meth)acrylic acid ester-based polymer.

7 . The separator of claim 6 , wherein the second coating layer is a dot-patterned layer comprising a plurality of dots arranged at intervals.

8 . The separator of claim 7 , wherein the plurality of dots have an average diameter of about 0.1 mm to about 1 mm and an average thickness of about 0.3 μm to about 10 μm, and at least one of the intervals between the dots is about 0.1 mm to about 10 mm.

9 . The separator of claim 6 , further comprising an inorganic coating layer between the porous base and the second coating layer, the inorganic coating layer comprising inorganic particles of at least one selected from the group consisting of colloidal silica, α-alumina (α-Al 2 O 3 ), γ-alumina (γ-Al 2 O 3 ), boehmite (γ-AlO (OH)), gibbsite (γ-Al (OH) 3 ), zirconium oxide, magnesium fluoride, BaTiO 3 , SnO 2 , CeO 2 , MgO, NiO, CaO, ZnO, Y 2 O 3 , TiO 2 , SiC, and combinations thereof.

10 . The separator of claim 1 , further comprising an inorganic coating layer between the porous base and the first coating layer, the inorganic coating layer comprising inorganic particles of at least one selected from the group consisting of colloidal silica, α-alumina (α-Al 2 O 3 ), γ-alumina (γ-Al 2 O 3 ), boehmite (γ-AlO (OH)), gibbsite (γ-Al (OH) 3 ), zirconium oxide, magnesium fluoride, BaTiO 3 , SnO 2 , CeO 2 , MgO, NiO, CaO, ZnO, Y 2 O 3 , TiO 2 , SiC, and combinations thereof.

11 . The separator of claim 1 , wherein the (meth)acrylic acid ester-based polymer comprises a polymerization product between an ethylenically unsaturated carboxylic acid ester and a monomer that is copolymerizable with the ethylenically unsaturated carboxylic acid ester.

12 . The separator of claim 6 , wherein the first coating layer and the second coating layer comprise the same (meth)acrylic acid ester-based polymer.

13 . A lithium secondary battery comprising:
a cathode; an anode; and the separator of claim 1 between the cathode and the anode.

13 . A method of manufacturing a lithium secondary battery, the method comprising:
forming a battery assembly comprising a cathode, an anode, and the separator of claim 1 ; rolling up or stacking the battery assembly to obtain a rolled or stacked battery assembly, and heat-pressing the rolled or stacked battery assembly at a temperature of about 80° C. to about 120° C. to obtain a combined battery assembly; and impregnating the combined battery assembly with an electrolyte.

14 . The method of claim 13 , wherein the separator is obtained by coating an aqueous emulsion comprising a (meth)acrylic acid ester-based polymer on a surface of a porous base and drying the coated (meth)acrylic acid ester-based polymer.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Kim Ihn
• Kim Youngsu
• Jo Yunkyung
• Park Narae
• Moon Jungjin
• Min Seungjun
• Ko Sunggwi

Classifications

• H01M10/0525 Primary

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

• H01M50/443

  Particulate material · CPC title

• H01M50/457

  comprising three or more layers · CPC title

• H01M50/451

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

• H01M50/42 Primary

  Acrylic resins · CPC title