Negative electrode for rechargeable lithium battery, method of preparing the same and rechargeable lithium battery including the same

Patent metadata

Field	Value
Publication number	US-9437872-B2
Application number	US-201314083318-A
Country	US
Kind code	B2
Filing date	Nov 18, 2013
Priority date	Dec 4, 2012
Publication date	Sep 6, 2016
Grant date	Sep 6, 2016

Abstract

A negative electrode for a rechargeable lithium battery is disclosed. The negative electrode includes a current collector and a negative active material layer positioned on the current collector and including a negative active material and a binder, wherein the negative active material includes a silicon-based material, a tin-based material, or a combination thereof, and the binder includes an organic acid including a carboxyl group-containing polymer and an organic base having a cyclic structure. A method of preparing the same, and a rechargeable lithium battery including the same are also disclosed.

First claim

What is claimed is:

1. A negative electrode for a rechargeable lithium battery, comprising
a current collector; and
a negative active material layer positioned on the current collector and including a negative active material and a binder,
wherein the negative active material comprises a silicon-based material, a tin-based material, or a combination thereof,
the binder comprises an organic acid comprising a carboxyl group-containing polymer and an organic base having a cyclic structure, and
wherein the organic base is selected from aromatic amine, alicyclic amine, and combination thereof.

2. The negative electrode for a rechargeable lithium battery of claim 1 , wherein the organic acid comprises at least one selected from polyasparaginic acid, polyaspartic acid, alginic acid of a natural polymer, a homopolymer of acrylic acid, a copolymer of acrylic acid and another monomer, and any combinations thereof.

3. The negative electrode for a rechargeable lithium battery of claim 1 , wherein the weight average molecular weight of the organic acid is in the range of about 5,000 g/mol to about 1,000,000 g/mol.

4. The negative electrode for a rechargeable lithium battery of claim 1 , wherein the aromatic amine comprises at least one selected from paraphenylene diamine, metaphenylene diamine, aniline, 3,5-diaminobenzoic acid, melamine, and a derivative thereof.

5. The negative electrode for a rechargeable lithium battery of claim 1 , wherein the alicyclic amine comprises at least one selected from cyclohexyl amine, cyclopentyl amine, norbornene amine, adamantane amine, and a derivative thereof.

6. The negative electrode for a rechargeable lithium battery of claim 1 , wherein the cyclic amine comprises at least one selected from a pyridine, piperidine, azole-based compound, and a derivative thereof.

7. The negative electrode for a rechargeable lithium battery of claim 6 , wherein the azole-based compound comprises at least one selected from pyrrole, imidazole, pyrazole, and a triazole.

8. The negative electrode for a rechargeable lithium battery of claim 1 , wherein the binder comprises the organic acid and the organic base in a weight ratio of about 1:0.3 to about 1:1.

9. The negative electrode for a rechargeable lithium battery of claim 1 , wherein the binder has a thermosetting temperature of less than or equal to about 200° C.

10. The negative electrode for a rechargeable lithium battery of claim 1 , wherein the silicon-based material comprises a silicon-containing alloy.

11. A method of preparing a negative electrode for a rechargeable lithium battery, comprising
dissolving a carboxyl group-containing organic acid in water to obtain an acid solution;
adding an organic base having a cyclic structure to the acid solution to obtain a binder solution;
adding a negative active material including a silicon-based material, a tin-based material, or a combination thereof to the binder solution to provide a slurry; and
coating the slurry on a current collector to form a negative active material layer.

12. The method of claim 11 , wherein the viscosity of the acid solution is about 4,000 cps to about 5,000 cps.

13. The method of claim 11 , wherein the binder solution has pH of about 6 to about 9.

14. A rechargeable lithium battery, comprising
a positive electrode;
the negative electrode according to claim 1 ; and
an electrolyte.

15. The method of claim 11 , wherein the organic acid comprises at least one selected from polyasparaginic acid, polyaspartic acid, alginic acid of a natural polymer, a homopolymer of acrylic acid, a copolymer of acrylic acid and another monomer, and any combinations thereof.

16. The method of claim 11 , wherein the organic base is an amine-based compound having a cyclic structure.

17. The method of claim 11 , wherein the binder comprises the organic acid and the organic base in a weight ratio of about 1:0.3 to about 1:1.

18. The method of claim 11 , wherein the silicon-based material comprises a silicon-containing alloy.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Fukuchi Iwao

Classifications

• H01M4/386 Primary

  Silicon or alloys based on silicon · CPC title

• H01M4/387

  Tin or alloys based on tin · CPC title

• H01M4/134 Primary

  Electrodes based on metals, Si or alloys · CPC title

• H01M4/622

  being polymers · CPC title

• H01M10/052

  Li-accumulators · CPC title