Negative electrode active material for nonaqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-10062903-B2
Application number	US-201515318884-A
Country	US
Kind code	B2
Filing date	Aug 21, 2015
Priority date	Sep 1, 2014
Publication date	Aug 28, 2018
Grant date	Aug 28, 2018

Abstract

There is provided a negative electrode active material for a nonaqueous electrolyte secondary battery, the negative electrode active material including a base particle containing Si and SiO2, a mixed phase coating that covers a surface of the base particle and contains SiO2 and carbon, and a carbon coating that covers a surface of the mixed phase coating. The base particle is preferably formed of SiOX (0.5≤X≤1.5). The mixed phase coating preferably contains carbon dispersed in a phase formed of SiO2. The cycle characteristics of a nonaqueous electrolyte secondary battery including negative electrode active material particles containing Si and SiO2 are improved.

First claim

The invention claimed is:

1. A negative electrode active material particle used for a nonaqueous electrolyte secondary battery, the negative electrode active material particle comprising:
a base particle containing Si chemically bonded with SiO 2 ;
a mixed phase coating that covers a surface of the base particle and contains SiO 2 and carbon; and
a carbon coating that covers a surface of the mixed phase coating.

2. The negative electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the base particle is formed of SiO X (0.5≤X≤1.5).

3. The negative electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the mixed phase coating comprises carbon dispersed in a phase formed of SiO 2 .

4. The negative electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the mixed phase coating consists-essentially SiO 2 and carbon.

5. The negative electrode active material for a nonaqueous electrolyte secondary battery according to claim 4 , wherein the mixed phase coating has an average thickness of 0.005 μm to 1 μm.

6. The negative electrode active material for a nonaqueous electrolyte secondary battery according to claim 5 , wherein the mixed phase coating covers 100% of the surface of the base particle.

7. The negative electrode active material for a nonaqueous electrolyte secondary battery according to claim 6 , wherein the carbon coating covers 50% or more and 100% or less of a surface of a particle comprising the base particle and the mixed phase coating.

8. The negative electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 ,
wherein the base particle is formed of SiO X (0.5≤X≤1.5),
wherein the mixed phase coating comprises carbon dispersed in a phase formed of SiO 2 ,
wherein the mixed phase coating consists-essentially SiO 2 and carbon,
wherein the mixed phase coating has an average thickness of 0.005 μm to 1 μm,
wherein the mixed phase coating covers 100% of the surface of the base particle, and,
wherein the carbon coating covers 50% or more and 100% or less of a surface of a particle comprising the base particle and the mixed phase coating.

Assignees

• Sanyo Electric Co

Inventors

• Akira Tatsuya
• Minami Hiroshi
• Sunano Taizou
• Kato Yoshio

Classifications

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title

• H01M4/386

  Silicon or alloys based on silicon · CPC title

• H01M4/483

  for non-aqueous cells (H01M4/485 takes precedence) · CPC title