Binder composition for rechargeable lithium battery, method of preparing same, electrode for rechargeable lithium battery and rechargeable lithium battery including same

Patent metadata

Field	Value
Publication number	US-9768448-B2
Application number	US-201514807834-A
Country	US
Kind code	B2
Filing date	Jul 23, 2015
Priority date	Aug 1, 2014
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

A binder composition for a rechargeable lithium battery includes: an interpenetrating polymer network (IPN) structure including a cyclic polymer including a structural unit represented by Chemical Formula 1 or a structural unit represented by Chemical Formula 2, and polyacrylamide. A method of preparing the same, and an electrode for a rechargeable lithium battery and a rechargeable lithium battery including the same are also disclosed.

In Chemical Formulae 1 and 2, R 1 to R 3 , R 11 to R 16 , and n and m are the same as defined in the detailed description.

First claim

What is claimed is:

1. An electrode for a rechargeable lithium battery, the electrode comprising:
an active material; and
a binder composition for a rechargeable lithium battery, the binder composition comprising:
an interpenetrating polymer network (IPN) structure comprising a cyclic polymer comprising a structural unit represented by Chemical Formula 1 or a structural unit represented by Chemical Formula 2, and
polyacrylamide,

 wherein,
R 1 , R 2 , R 11 , R 12 , R 14 and R 15 are the same or different and are independently selected from hydrogen, a substituted or unsubstituted C1 to C5 alkyl group, or —(CH 2 ) p —COOX 1 , p being an integer of 1 to 5, and X 1 being an alkali metal,
R 3 , R 13 and R 16 are the same or different and are independently —OR 4 , —NHR 5 or —COOX 2 , X 2 being an alkali metal, R 4 is hydrogen, a substituted or unsubstituted C1 to C5 alkyl group, or —(CH 2 ) p —COOX 1 , p being an integer of 1 to 5 and X 1 being an alkali metal, and R 5 is hydrogen or —COCH 3 , and
n and m are integers of 5 to 20,000.

2. The electrode of claim 1 , wherein the cyclic polymer comprises one of structural units represented by Chemical Formulae 3-1 to 3-6:

wherein,
n 1 to n 5 and m 1 are integers of 5 to 20,000.

3. The electrode of claim 1 , wherein the cyclic polymer has a weight average molecular weight of about 2,000 to about 2,000,000 g/mol.

4. The electrode of claim 1 , wherein the polyacrylamide has a weight average molecular weight of about 5,000 g/mol to about 1,000,000 g/mol.

5. The electrode of claim 1 , wherein a mole ratio of the cyclic polymer to the polyacrylamide is about 1:9 to about 9:1.

6. The electrode of claim 1 , wherein the binder composition further comprises an alkali metal ion added to the formed IPN structure.

7. The electrode of claim 6 , wherein the alkali metal ion is included in the binder composition in an amount of 1 part by mole to 10 parts by mole based on 100 parts by mole of the interpenetrating polymer network (IPN) structure.

8. The electrode of claim 1 , wherein the binder composition further comprises an alkali metal ion and a phosphorus (P)-based compound added to the formed IPN structure.

9. The electrode of claim 8 , wherein the alkali metal ion and the phosphorus-based compound are adsorbed on the interpenetrating polymer network (IPN) structure.

10. The electrode of claim 8 , wherein the phosphorus-based compound is included in the binder composition in an amount of about 1 part by mole to about 10 parts by mole based on 100 parts by mole of the interpenetrating polymer network (IPN) structure.

11. The electrode of claim 1 , wherein the binder composition further comprises polyalkylene glycol comprising a structural unit represented by Chemical Formula 4,

wherein,
i is an integer of 1 to 5, and
q is an integer of 1 to 500.

12. The electrode of claim 11 , wherein the polyalkylene glycol is included in the binder composition in an amount of about 5 mol % to about 50 mol % based on the total moles of the binder composition.

13. The electrode of claim 11 , wherein the polyalkylene glycol has a weight average molecular weight of about 400 g/mol to about 100,000 g/mol.

14. The electrode of claim 1 , wherein the active material comprises Si, SiO x , a Si—C composite, a Si-Q alloy, graphite, or a combination thereof, wherein 0<x<2, and Q is an alkali metal, an alkaline-earth metal, Group 13 to 16 elements, a transition metal, a rare earth element, or a combination thereof with the proviso that Q is not Si.

15. A rechargeable lithium battery, comprising
a positive electrode;
a negative electrode; and
an electrolyte,
wherein at least one of the positive electrode and the negative electrode is the electrode of claim 1 .

16. A method of preparing a binder composition for a rechargeable lithium battery, the method comprising:
preparing a cyclic polymer comprising a structural unit represented by Chemical Formula 1 or a structural unit represented by Chemical Formula 2;
adding an acrylamide monomer to a solution comprising the cyclic polymer to form an interpenetrating polymer network (IPN) structure of the cyclic polymer and a polyacrylamide formed from the acrylamide monomer,

wherein,
R 1 , R 2 , R 11 , R 12 , R 14 and R 15 are the same or different and are independently selected from hydrogen, a substituted or unsubstituted C1 to C5 alkyl group, or —(CH 2 ) p —COOX 1 , p being an integer of 1 to 5, and X 1 , being an alkali metal,
R 3 , R 13 and R 16 are the same or different and are independently —OR 4 , —NHR 5 or —COOX 2 , X 2 being an alkali metal, R 4 is hydrogen, a substituted or unsubstituted C1 to C5 alkyl group, or —(CH 2 ) p —COOX 1 , p being an integer of 1 to 5, and X 1 being an alkali metal, and R 5 is hydrogen or —COCH 3 , and
n and m are integers of 5 to 20,000; and
adding polyalkylene glycol comprising a structural unit represented by Chemical Formula 4 to a solution comprising the cyclic polymer before forming the interpenetrating polymer network (IPN) structure,

wherein,
i is an integer of 1 to 5, and
q is an integer of 1 to 500.

17. The method of claim 16 , further comprising adding an alkali metal compound to the formed interpenetrating polymer network (IPN) structure.

Assignees

• Samsung Sdi Co Ltd
• Aekyung Chemical Co Ltd

Inventors

• Chung Byung-Joo
• Yoon Yeon-Hee
• Kim Nam-Seon
• Choi Kwang-Sik
• Kim Soo-Jung

Classifications

• H01M10/052

  Li-accumulators · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title

• H01M4/622 Primary

  being polymers · CPC title

• H01M4/386

  Silicon or alloys based on silicon · CPC title

• H01M4/133

  Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title