Manufacturing method of porous silicon material, porous silicon material, and power storage device

Patent metadata

Field	Value
Publication number	US-12049685-B2
Application number	US-202318308736-A
Country	US
Kind code	B2
Filing date	Apr 28, 2023
Priority date	Jun 22, 2021
Publication date	Jul 30, 2024
Grant date	Jul 30, 2024

Abstract

The manufacturing method of a porous silicon material of the present disclosure includes a particle forming step of melting a raw material containing Al as a first element in an amount of 50% by mass or more and Si in an amount of 50% by mass or less to obtain a silicon alloy, a pore forming step of removing the first element from the silicon alloy to obtain a porous material, and a heat treatment step of heating the porous material to diffuse elements other than Si to a surface of the porous material.

First claim

What is claimed is:

1. A porous silicon material comprising skeletal silicon with a three-dimensional network structure having voids that is formed of silicon having a lattice constant of 5.435 Å or less, wherein:
an average porosity of the porous silicon material is in a range of 50% by volume or more and 95% by volume or less;
a proportion of Si contained in the porous silicon material as an element, excluding oxygen, is 85% by mass or more;
a proportion of Al contained in the porous silicon material as a first element is in a range of 15% by mass or less; and
Al is present on a surface of the porous silicon material, wherein the Al present on the surface of the porous silicon material is an oxide.

2. The porous silicon material according to claim 1 , wherein the proportion of the first element contained in the porous silicon material is in a range of 0.1% by mass or more and 5% by mass or less.

3. The porous silicon material according to claim 1 , wherein the average porosity is 60% by volume or more.

4. The porous silicon material according to claim 1 , wherein the oxide comprises Al oxide.

5. The porous silicon material according to claim 4 , wherein the oxide further comprises one or more of AlSi oxide, AlFe oxide, SiFe oxide, AlSiFe oxide.

6. The porous silicon material according to claim 5 , wherein the oxide comprises AlSi oxide.

7. The porous silicon material according to claim 5 , wherein the oxide comprises AlFe oxide.

8. The porous silicon material according to claim 5 , wherein the oxide comprises SiFe oxide.

9. The porous silicon material according to claim 5 , wherein the oxide comprises AlSiFe oxide.

10. The porous silicon material according to claim 1 , wherein the skeletal silicon has no solid solution of Al.

Assignees

• Toyota Motor Co Ltd

Inventors

• Kawaura Hiroyuki
• Kondo Yasuhito
• Suzuki Ryo
• Nozaki Hiroshi
• Yoshida Jun
• Waseda Tetsuya
• Otaki Mitsutoshi

Classifications

• H01M4/386

  Silicon or alloys based on silicon · CPC title

• C01B33/021 Primary

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

• C22C21/02 Primary

  with silicon as the next major constituent · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title