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

Patent metadata

Field	Value
Publication number	US-9368792-B2
Application number	US-201414191706-A
Country	US
Kind code	B2
Filing date	Feb 27, 2014
Priority date	Aug 28, 2012
Publication date	Jun 14, 2016
Grant date	Jun 14, 2016

Abstract

Disclosed are a negative active material for a rechargeable lithium battery including a spherically-shaped natural graphite-modified composite particle including: a spherically-shaped natural graphite particle where flake-shaped natural graphite fragments build up and assemble into a cabbage or random shape; and amorphous or semi-crystalline carbon, wherein an open gap between the flake-shaped natural graphite fragments is positioned on a surface part or inside the spherically-shaped natural graphite particle, the amorphous or semi-crystalline carbon is coated on the surface of the spherically-shaped natural graphite particle, and the amorphous or semi-crystalline carbon is present in the open gap, and thereby the open gap positioned on the surface part and inside the spherically-shaped natural graphite particle is maintained, a method of preparing the same, and a rechargeable lithium battery including the same.

First claim

What is claimed is:

1. A negative active material for a rechargeable lithium battery comprising a spherically-shaped natural graphite-modified composite particle, comprising:
a spherically-shaped natural graphite particle, in which flake-shaped natural graphite fragments build up and assemble into a cabbage shape at a surface part and a random shape at a core part, and
amorphous or semi-crystalline carbon,
wherein an open gap between the flake-shaped natural graphite fragments is positioned on the surface part and inside the spherically-shaped natural graphite particle,
the amorphous or semi-crystalline carbon is coated on the surface of the spherically-shaped natural graphite particle, and the amorphous or semi-crystalline carbon is present in the open gap, and thereby the open gap positioned on the surface part and inside the spherically-shaped natural graphite particle is maintained, and
the amorphous or semi-crystalline carbon is included in an amount of 1 to 20 parts by weight based on 100 parts by weight of the spherically-shaped natural graphite particle.

2. The negative active material for a rechargeable lithium battery of claim 1 , wherein the spherically-shaped natural graphite particle has an average particle diameter (D50) of about 5 to about 40 μm.

3. The negative active material for a rechargeable lithium battery of claim 1 , wherein the spherically-shaped natural graphite-modified composite particle further comprises a lithium compound,
wherein the lithium compound comprises Li 2 O, Li 2 CO 3 , or a combination thereof, and
the lithium compound is coated on the surface of the spherically-shaped natural graphite particle, and the lithium compound is present in the open gap positioned on the surface part and inside the spherically-shaped natural graphite particle.

4. The negative active material for a rechargeable lithium battery of claim 3 , wherein the lithium compound is included in an amount of about 0.01 to about 10 parts by weight based on 100 parts by weight of the spherically-shaped natural graphite particle.

5. A rechargeable lithium battery, comprising:
a negative electrode including the negative active material of claim 1 ;
a positive electrode; and
an electrolyte solution.

Assignees

• Knu Industry Cooperation Found
• Kangwon Nat University University Industry Cooperation Foundation

Inventors

• Lee Sung-Man
• Park Yoon-Soo

Classifications

• H01M4/366 Primary

  as layered products · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M4/0471

  involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis · CPC title

• H01M4/133

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