Separator including coating layer and battery including the same

Patent metadata

Field	Value
Publication number	US-9685647-B2
Application number	US-201313778259-A
Country	US
Kind code	B2
Filing date	Feb 27, 2013
Priority date	Feb 29, 2012
Publication date	Jun 20, 2017
Grant date	Jun 20, 2017

Abstract

A separator includes a polyolefin base film and a coating layer, the coating layer containing inorganic particles having an average particle size of about 1 nm to about 700 nm and an organic binder of a polyvinylidene fluoride homopolymer, the coating layer having a density of about 1.2 g/cm 3 to about 2 g/cm 3 , the coating layer being disposed on one or both sides of the base film.

First claim

What is claimed is:

1. A separator, comprising:
a polyolefin base film; and
a coating layer, the coating layer containing inorganic particles having an average particle size of 1 nm to 700 nm and an organic binder of a polyvinylidene fluoride homopolymer that has a weight average molecular weight of 1,000,000 g/mol or more, and a polyvinylidene fluoride-hexafluoropropylene copolymer that has a weight average molecular weight of 800,000 g/mol or less, the coating layer having a density of 1.2 g/cm 3 to 2 g/cm 3 , the coating layer being disposed on one or both sides of the base film.

2. The separator as claimed in claim 1 , wherein the polyvinylidene fluoride homopolymer has a weight average molecular weight of 1,000,000 g/mol to 1,200,000 g/mol.

3. The separator as claimed in claim 1 , wherein the coating layer includes, based on 100 parts by weight of the coating layer in terms of solid content,
5 to 10 parts by weight of the polyvinylidene fluoride homopolymer;
5 to 20 parts by weight of the polyvinylidene fluoride-hexafluoropropylene copolymer; and
70 to 90 parts by weight of the inorganic particles.

4. The separator as claimed in claim 1 , wherein the coating layer has a thickness of 10 μm or less.

5. The separator as claimed in claim 1 , wherein the inorganic particles include one or more of Al 2 O 3 particles, SiO 2 particles, B 2 O 3 particles, Ga 2 O 3 particles, TiO 2 particles, or SnO 2 particles.

6. The separator as claimed in claim 1 , wherein the polyolefin base film is selected from the group of a polyethylene monolayer film, a polypropylene monolayer film, a polyethylene/polypropylene bilayer film, a polypropylene/polyethylene/polypropylene triple-layer film, and a polyethylene/polypropylene/polyethylene triple-layer film.

7. The separator as claimed in claim 1 , wherein the coating layer has a peel strength of 50 gf/cm 2 or more.

8. The separator as claimed in claim 1 , wherein an adhesive strength between the coating layer and electrodes of a battery is 20 gf/cm 2 or more.

9. The separator as claimed in claim 8 , wherein the battery is a lithium rechargeable battery.

10. The separator as claimed in claim 9 , wherein:
the electrodes include a positive electrode and a negative electrode,
the positive electrode is selected from the group of a lithium cobalt oxide electrode, a lithium nickel cobalt manganese oxide electrode, a lithium manganese oxide electrode, a lithium iron phosphate electrode, and a lithium nickel oxide electrode, and
the negative electrode is selected from the group of a crystalline carbon electrode and an amorphous carbon electrode.

11. An electrochemical battery, comprising:
a positive electrode;
a negative electrode;
the separator as claimed in claim 1 ; and
an electrolyte.

12. The electrochemical battery as claimed in claim 11 , wherein the electrochemical battery is a lithium rechargeable battery.

Assignees

• Hong Ki Chul
• Doh Jae Goo
• Lim Geon Ja
• Chung Jun Ho
• Cheil Ind Inc

Inventors

• Hong Ki Chul
• Doh Jae Goo
• Lim Geon Ja
• Chung Jun Ho

Classifications

• H01M50/446 Primary

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

• H01M50/417 Primary

  Polyolefins · 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

• H01M50/426

  Fluorocarbon polymers · CPC title