Method for manufacturing negative electrode active material for non-aqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-9537142-B2
Application number	US-201514687612-A
Country	US
Kind code	B2
Filing date	Apr 15, 2015
Priority date	May 24, 2010
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

The present invention is a method for manufacturing a negative electrode active material for a non-aqueous electrolyte secondary battery. The method includes depositing silicon on a substrate by vapor deposition by using a metallic silicon as a raw material, the substrate having a temperature controlled to 300° C. to 800° C. under reduced pressure; and pulverizing and classifying the deposited silicon. The resulting negative electrode active material composed of silicon particles is an active material useful as a negative electrode of a non-aqueous electrolyte secondary battery in which high initial efficiency and high battery capacity of silicon are kept, cycle performance is superior, and an amount of a change in volume decreases at the time of charge and discharge.

First claim

What is claimed is:

1. A method for manufacturing a negative electrode active material for a non-aqueous electrolyte secondary battery, the method comprising:
depositing silicon on a substrate by vapor deposition by using a metallic silicon as a raw material, the substrate having a temperature controlled to 300° C. to 800° C. under reduced pressure; and
pulverizing and classifying the deposited silicon.

2. The method for manufacturing a negative electrode active material according to claim 1 , further comprising:
subjecting the deposited silicon to a heat treatment at 600° C. to 1100° C.

3. The method for manufacturing a negative electrode active material according to claim 2 , wherein the silicon to be deposited is doped with one or more dopants selected from the group consisting of boron, aluminum, phosphorus, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, arsenic, tin, tantalum, and tungsten, at the time of the depositing of the silicon on the substrate.

4. The method for manufacturing a negative electrode active material according to claim 3 , wherein the pulverizing and the classifying are performed so that a volume average particle size D 50 of the negative electrode active material is from 1 μm to 20 μm based on a particle size distribution obtained by laser diffraction scattering.

5. The method for manufacturing a negative electrode active material according to claim 4 , wherein the substrate is composed of a material incapable of alloying with silicon at the time of the depositing of the silicon.

6. The method for manufacturing a negative electrode active material according to claim 3 , wherein the substrate is composed of a material incapable of alloying with silicon at the time of the depositing of the silicon.

7. The method for manufacturing a negative electrode active material according to claim 2 , wherein the substrate is composed of a material incapable of alloying with silicon at the time of the depositing of the silicon.

8. The method for manufacturing a negative electrode active material according to claim 2 , wherein the pulverizing and the classifying are performed so that a volume average particle size D 50 of the negative electrode active material is from 1 μm to 20 μm based on a particle size distribution obtained by laser diffraction scattering.

9. The method for manufacturing a negative electrode active material according to claim 8 , wherein the substrate is composed of a material incapable of alloying with silicon at the time of the depositing of the silicon.

10. The method for manufacturing a negative electrode active material according to claim 1 , wherein the silicon to be deposited is doped with one or more dopants selected from the group consisting of boron, aluminum, phosphorus, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, arsenic, tin, tantalum, and tungsten, at the time of the depositing of the silicon on the substrate.

11. The method for manufacturing a negative electrode active material according to claim 10 , wherein the substrate is composed of a material incapable of alloying with silicon at the time of the depositing of the silicon.

12. The method for manufacturing a negative electrode active material according to claim 10 , wherein the pulverizing and the classifying are performed so that a volume average particle size D 50 of the negative electrode active material is from 1 μm to 20 μm based on a particle size distribution obtained by laser diffraction scattering.

13. The method for manufacturing a negative electrode active material according to claim 12 , wherein the substrate is composed of a material incapable of alloying with silicon at the time of the depositing of the silicon.

14. The method for manufacturing a negative electrode active material according to claim 1 , wherein the pulverizing and the classifying are performed so that a volume average particle size D 50 of the negative electrode active material is from 1 μm to 20 μm based on a particle size distribution obtained by laser diffraction scattering.

15. The method for manufacturing a negative electrode active material according to claim 14 , wherein the substrate is composed of a material incapable of alloying with silicon at the time of the depositing of the silicon.

16. The method for manufacturing a negative electrode active material according to claim 1 , wherein the substrate is composed of a material incapable of alloying with silicon at the time of the depositing of the silicon.

Assignees

• Shinetsu Chemical Co

Inventors

• Nakanishi Tetsuo

Classifications

• H01M2004/027

  Negative electrodes · CPC title

• H01M10/052

  Li-accumulators · CPC title

• B02C23/08

  Separating or sorting of material, associated with crushing or disintegrating (B02C23/18 takes precedence {; beater mills combined with sifting devices B02C13/13, B02C13/14; for tumbling mills B02C17/1835}) · CPC title

• H01M4/0471

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

• H01M4/386

  Silicon or alloys based on silicon · CPC title