Silicon material and negative electrode of secondary battery

Patent metadata

Field	Value
Publication number	US-10217990-B2
Application number	US-201515314246-A
Country	US
Kind code	B2
Filing date	May 26, 2015
Priority date	May 29, 2014
Publication date	Feb 26, 2019
Grant date	Feb 26, 2019

Abstract

A silicon material useful as a negative electrode active material is provided.
The silicon material has an Si/O atom ratio within a range of greater than 1/0.5 and not greater than 1/0.1 and a band gap within a range of greater than 1.1 eV and not greater than 2.1 eV. A secondary battery in which this silicon material is used as a negative electrode active material has long life.

First claim

The invention claimed is:

1. A silicon material having an Si/O atom ratio within a range of greater than 1/0.5 and not greater than 1/0.1 and a band gap within a range of greater than 1.1 eV and not greater than 2.1 eV, wherein the silicon material has a BET specific surface area of 3 to 100 m2/g.

2. The silicon material according to claim 1 , wherein the silicon material contains nano-sized silicon crystallites.

3. The silicon material according to claim 2 , wherein the silicon crystallites have a crystallite size of 0.5 nm to 300 nm.

4. The silicon material according to claim 2 , wherein the silicon material is complex particles further containing at least one of amorphous silicon, a silicon oxide (SiOx, 0 21 x<2), or a silicon compound.

5. The silicon material according to claim 4 , wherein the silicon crystallites are present on a surface of and/or within the at least one of the amorphous silicon, the silicon oxide (SiOx, 0<x<2), or the silicon compound.

6. The silicon material according to claim 4 , wherein the silicon crystallites are dispersed in an island state within a matrix mainly formed from amorphous silicon, or adhere to surfaces of particles mainly formed from amorphous silicon, in an island state.

7. The silicon material according to claim 1 , wherein a contained oxygen (O) amount in the silicon material is not greater than 20 mass %.

8. A negative electrode active material composed of the silicon material according to claim 1 .

9. A negative electrode containing the negative electrode active material according to claim 8 .

10. A secondary battery comprising the negative electrode according to claim 9 .

Assignees

• Toyota Jidoshokki Kk

Inventors

• Mohri Takashi
• Harata Masanori
• Nakanishi Masataka
• Oshima Hiroki
• Goda Nobuhiro

Classifications

• H01M2004/021

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

• H01M4/134

  Electrodes based on metals, Si or alloys · CPC title

• H01M4/483

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

• H01M4/362

  Composites · CPC title

• C01B33/021 Primary

  Preparation (chemical coating from the vapour phase C23C16/00) · CPC title