Negative electrode active material particles, lithium ion battery, and method of producing negative electrode active material particles

Patent metadata

Field	Value
Publication number	US-2024030421-A1
Application number	US-202318223211-A
Country	US
Kind code	A1
Filing date	Jul 18, 2023
Priority date	Jul 20, 2022
Publication date	Jan 25, 2024
Grant date	—

Abstract

Negative electrode active material particles of the present disclosure are Si particles with pores inside primary particles and having a clathrate type crystalline phase, and satisfying the following relationship: 0.061≤V/W. Here, V is a volume of pores having a pore diameter of 10 nm or less and W is a half width of a peak at 2θ=31.72°±0.50° in an X-ray diffraction test using CuKα.

First claim

What is claimed is:

1 . Negative electrode active material particles that are Si particles with pores inside primary particles and having a clathrate type crystalline phase, and satisfying the following relationship:
0.061≤ V/W
V: a volume of pores having a pore diameter of 10 nm or less (cc/g) W: a half width (°) of a peak at 2θ=31.72°±0.50° in an X-ray diffraction test using CuKα.

2 . The negative electrode active material particles according to claim 1 ,
wherein the clathrate type crystalline phase is wholly or partially a clathrate type II crystalline phase.

3 . The negative electrode active material particles according to claim 1 , satisfying the following relationship:
0.061 ≤V/W≤ 0.160

4 . The negative electrode active material particles according to claim 1 , satisfying the following relationship:
0.0195≤ V

5 . The negative electrode active material particles according to claim 1 , satisfying the following relationship:
V≤ 0.0447

6 . The negative electrode active material particles according to claim 1 , satisfying the following relationship:
W≤ 0.35

7 . A lithium ion battery including a negative electrode current collector layer, a negative electrode active material layer containing the negative electrode active material particles according to claim 1 , a solid electrolyte layer, a positive electrode active material layer, and a positive electrode current collector layer in this order.

8 . A method of producing negative electrode active material particles, comprising:
mechanically milling Si particles with pores inside and NaH particles, and performing heating at a heating temperature of 250° C. to 500° C. for a heating time of 1 hour to 60 hours to obtain NaSi alloy particles; and mixing the NaSi alloy particles and a Na trapping agent and performing heating at a heating temperature of 250° C. to 500° C. for a heating time of 30 hours to 250 hours.

Assignees

• Toyota Motor Co Ltd

Inventors

• Mashimo Naohiro
• Otaki Mitsutoshi
• Yoshida Jun
• Harata Masanori
• Yamaguchi Yasuhiro
• Urabe Kota
• Eguchi Tatsuya

Classifications

• H01M4/386 Primary

  Silicon or alloys based on silicon · CPC title

• H01M10/0525

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

• H01M4/0404

  by coating on electrode collectors · CPC title

• H01M4/0471

  involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis · CPC title

• H01M2004/027

  Negative electrodes · CPC title