Secondary battery

Patent metadata

Field	Value
Publication number	US-10367205-B2
Application number	US-201213471098-A
Country	US
Kind code	B2
Filing date	May 14, 2012
Priority date	Jul 6, 2011
Publication date	Jul 30, 2019
Grant date	Jul 30, 2019

Abstract

A secondary battery includes a base material, an intermediate layer including a carbon material on the base material, and an active material layer on the intermediate layer. A secondary battery including an intermediate layer may improve adhesion between the base material and the active material layer, thereby reducing the risk of separation of the active material from the base material and improving the reliability and lifetime of the secondary battery.

First claim

What is claimed is:

1. A secondary battery comprising:
a base material;
an intermediate layer on the base material, the intermediate layer consisting of a carbon material and a binder; and
an active material layer on the intermediate layer,
wherein
the binder is mixed with the carbon material,
the binder comprises at least one material selected from the group consisting of polyimide (PI), polyamideimide (PAI), chitosan, and styrene-butadiene rubber (SBR),
the carbon material is graphene nano-sheets having a thickness of 5 to 50 nm,
an adhesive force between the base material and the active material layer is 0.5 to 5.0 gf/mm, and
each of the graphene nano-sheets contains: an amorphous region and a crystalline region, the amorphous region being mixed with the crystalline region in a crystallographic basal plane,
wherein the base material comprises a positive current collector, and
the active material layer comprises a lithium complex metal compound selected from LiCoO 2 , LiMn 2 O 4 , LiNiO 2 , LiNi 1-x Co x O 2 (0<x>1), and LiMnO 2 .

2. The secondary battery of claim 1 , wherein a thickness of the intermediate layer is 0.2 to 5 μm.

3. The secondary battery of claim 1 , wherein the amorphous region of the carbon material is 2 to 50% of the total carbon.

4. A method of manufacturing a secondary battery, the method comprising:
preparing a base material;
coating a carbon material and a binder on the base material to form an intermediate layer, the intermediate layer consisting of the carbon material and the binder; and
and
forming an active material layer on the intermediate layer,
wherein the binder comprises at least one material selected from the group consisting of polyimide (PI), polyamideimide (PAI), chitosan, and styrene-butadiene rubber (SBR),
wherein the carbon material and the binder are mixed together prior to coating,
the carbon material is graphene nano-sheets having a thickness of 5 to 50 nm,
wherein an adhesive force between the base material and the active material layer is 0.5 to 5.0 gf/mm, and
each of the graphene nano-sheets contains: an amorphous region and a crystalline region, the amorphous region being mixed with the crystalline region in a crystallographic basal plane,
wherein the base material comprises a positive current collector, and
the active material layer comprises a lithium complex metal compound selected from LiCoO 2 , LiMn 2 O 4 , LiNiO 2 , LiNi 1-x Co x O 2 (0<x>1), and LiMnO 2 .

5. The method of claim 4 , wherein the coating comprises coating the mixture using screen printing.

6. The method of claim 4 , wherein the coating comprises coating the mixture using spray coating.

7. The secondary battery of claim 1 , wherein a bonding force between the amorphous region of the carbon material and a functional group of the binder is stronger than a bonding force between the crystalline region of the carbon material and the functional group of the binder.

8. The method of claim 4 , wherein a bonding force between the amorphous region of the carbon material and a functional group of the binder is stronger than a bonding force between the crystalline region of the carbon material and the functional group of the binder.

Assignees

• Kim Jun Sik
• Lee So Ra
• Kim Sung Soo
• Song Soo An
• Shin Jeong Soon
• Samsung Sdi Co Ltd

Inventors

• Kim Jun-Sik
• Lee So-Ra
• Kim Sung-Soo
• Song Soo-An
• Shin Jeong-Soon

Classifications

• H01M4/666

  in the form of mixed materials (H01M4/668 takes precedence) · CPC title

• H01M4/667

  in the form of layers, e.g. coatings · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• H01M4/0419

  involving spraying · CPC title

• H01M4/0414

  by screen printing · CPC title