Silicon material and negative electrode of secondary battery

Patent metadata

Field	Value
Publication number	US-2017194623-A1
Application number	US-201515314246-A
Country	US
Kind code	A1
Filing date	May 26, 2015
Priority date	May 29, 2014
Publication date	Jul 6, 2017
Grant date	—

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

1 - 5 . (canceled)

6 . 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.

7 . The silicon material according to claim 6 , wherein the silicon material contains nano-sized silicon crystallites.

8 . The silicon material according to claim 7 , wherein the silicon crystallites have a crystallite size of 0.5 nm to 300 nm.

9 . The silicon material according to claim 7 , wherein the silicon material is complex particles further containing at least one of amorphous silicon, a silicon oxide (SiOx, 0<x<2), or a silicon compound.

10 . The silicon material according to claim 9 , 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.

11 . The silicon material according to claim 9 , 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.

12 . The silicon material according to claim 6 , wherein the silicon material has a BET specific surface area of 3 to 100 m 2 /g.

13 . The silicon material according to claim 6 , wherein a contained oxygen (O) amount in the silicon material is not greater than 20 mass %.

14 . A negative electrode active material composed of the silicon material according to claim 6 .

15 . A negative electrode containing the negative electrode active material according to claim 14 .

16 . A secondary battery comprising the negative electrode according to claim 15 .

Assignees

• Toyota Jidoshokki Kk

Inventors

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

Classifications

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/134

  Electrodes based on metals, Si or alloys · CPC title

• C01B33/02 Primary

  Silicon (forming single crystals or homogeneous polycrystalline material with defined structure C30B) · CPC title

• H01M4/386 Primary

  Silicon or alloys based on silicon · CPC title

• H01M2004/021

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