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-10826107-B2
Application number	US-201715699997-A
Country	US
Kind code	B2
Filing date	Sep 8, 2017
Priority date	Sep 21, 2011
Publication date	Nov 3, 2020
Grant date	Nov 3, 2020

Abstract

A negative active material for a rechargeable lithium battery includes a core including a SiO2 matrix and a Si grain, and a coating layer continuously or discontinuously coated on the core. The coating layer includes SiC and C, and the peak area ratio of the SiC (111) plane to the Si (111) plane as measured by X-ray diffraction analysis (XRD) using a CuKα ray ranges from about 0.01 to about 0.5.

First claim

What is claimed is:

1. A negative active material for a rechargeable lithium battery, comprising:
a core comprising a Si grain in a SiO 2 matrix; and
a coating layer on at least a portion of the core, the coating layer comprising SiC and a carbonized carbonaceous material, wherein a peak area ratio of SiC at a 111 plane to Si at a 111 plane, as measured by X-ray diffraction using a CuKα ray, is about 0.11 to about 0.5.

2. The negative active material of claim 1 , wherein amounts of the SiO 2 matrix and the Si grain are sufficient to yield an oxygen and silicon content represented by SiO x in which 0.3≤x≤1.2.

3. The negative active material of claim 1 , wherein the negative active material has an average particle size of about 0.5 μm to about 50 μm.

4. The negative active material of claim 1 , wherein the coating layer has a thickness of about 0.01 μm to about 1 μm.

5. The negative active material of claim 1 , wherein a weight ratio of the core to the coating layer is about 99.9:0.1 to about 90:10.

6. A rechargeable lithium battery comprising;
a negative electrode comprising a negative active material comprising:
a core comprising a Si grain in a SiO 2 matrix; and
a coating layer on at least a portion of the core, the coating layer comprising SiC and a carbonized carbonaceous material, wherein a peak area ratio of SiC at a 111 plane to Si at a 111 plane, as measured by X-ray diffraction using a CuKα ray, is about 0.11 to about 0.5;

a positive electrode comprising a positive active material; and
an electrolyte.

7. The rechargeable lithium battery of claim 6 , wherein amounts of the SiO 2 matrix and the Si grain are sufficient to yield an oxygen and silicon content represented by SiO x in which 0.3≤x≤1.2.

8. The rechargeable lithium battery of claim 6 , wherein the negative active material has an average particle size of about 0.5 μm to about 50 μm.

9. The rechargeable lithium battery of claim 6 , wherein the coating layer has a thickness of about 0.01 μm to about 1 μm.

10. The rechargeable lithium battery of claim 6 , wherein a weight ratio of the core to the coating layer is about 99.9:0.1 to about 90:10.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Park Sang-Eun
• Kim Young-Ugk

Classifications

• H01M4/366

  as layered products · CPC title

• H01M4/583 Primary

  Carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M4/1395

  of electrodes based on metals, Si or alloys · CPC title