Composite binder composition for secondary battery, cathode and lithium battery containing the binder composition

Patent metadata

Field	Value
Publication number	US-10109863-B2
Application number	US-201414167810-A
Country	US
Kind code	B2
Filing date	Jan 29, 2014
Priority date	Sep 24, 2013
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

In an aspect, a binder composition, a cathode including the same, and a lithium battery including the cathode, wherein the binder composition includes a first fluorine containing binder including a polar functional group; a second fluorine containing binder not including a polar functional group; and a non-fluorine containing binder including a repeating unit resulting from polymerization of an acryl monomer and a repeating unit resulting from polymerization of an olefin monomer, wherein the first fluorine containing binder is a vinylidene fluoride containing binder is provided.

First claim

What is claimed is:

1. A binder composition for a secondary battery, the binder composition comprises:
a first fluorine containing binder including a repeating unit comprising a polar functional group, wherein a weight average molecular weight of the first fluorine containing binder is in a range of 300,000 g/mol to 1,500,000 g/mol;
a second fluorine containing binder not including a polar functional group, wherein a weight average molecular weight of the second fluorine containing binder is in a range of 200,000 g/mol to 1,200,000 g/mol; and
a non-fluorine containing binder comprising a repeating unit resulting from polymerization of an acryl monomer and a repeating unit resulting from polymerization of an olefin monomer, wherein a weight average molecular weight of the non-fluorine containing binder is in a range of 100,000 g/mol to 500,000 g/mol,
wherein the first fluorine containing binder is a vinylidene fluoride containing binder,
wherein a content of the first fluorine containing binder including a repeating unit comprising a polar functional group is in a range of 5 wt % to 25 wt % based on the total weight of the binder composition,
wherein a content of the a second fluorine containing binder is in a range of 60 wt % to 80 wt % based on the total weight of the binder composition, and
wherein a content of the non-fluorine containing binder is in a range of 10 wt % to less than 25 wt % based on the total weight of the binder composition,
wherein the first fluorine containing binder is modified poly(vinylidene fluoride) (PVDF) containing a carboxylic group,
wherein the second fluorine containing binder is PVDF, and
wherein the non-fluorine containing binder is a hydrogenated acrylonitrile-butadiene binder.

2. The binder composition of claim 1 , wherein a content of the repeating unit comprising the polar functional group of the first fluorine containing binder is greater than 0 to 10 mol % or less.

3. The binder composition of claim 1 , wherein a weight average molecular weight of the first fluorine containing binder is in a range of 500,000 g/mol to 1,500,000 g/mol.

4. The binder composition of claim 1 , wherein a weight average molecular weight of the second fluorine containing binder is in a range of 300,000 g/mol to 1,000,000 g/mol.

5. The binder composition of claim 1 , wherein a content of the repeating unit resulting from polymerization of an acryl monomer is in a range of 1 wt % to 70 wt % in the non-fluorine containing binder.

6. The binder composition of claim 1 , wherein an iodine value of the non-fluorine containing binder is 100 or less.

7. The binder composition of claim 1 , wherein a glass transition temperature of the non-fluorine containing binder is in a range of −40° C. to 30° C.

8. A cathode comprising:
a cathode active material;
a conducting agent; and
the binder composition of claim 1 .

9. The cathode of claim 8 , wherein a content of the binder composition is in a range of 0.5 part to 5 parts by weight based on 100 parts by weight of the cathode active material.

10. A lithium battery comprising the cathode of claim 8 .

11. The lithium battery of claim 10 , wherein a voltage of the lithium battery is 4.0 V or greater.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Yeou Jung-Ock
• Lee Beom-Wook
• Park Sam-Jin

Classifications

• H01M4/623 Primary

  fluorinated polymers · CPC title

• H01M4/13

  Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof · CPC title

• H01M4/131

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• C08L1/00

  Compositions of cellulose, modified cellulose or cellulose derivatives · CPC title

• H01M10/052

  Li-accumulators · CPC title