Method for producing composite, and negative electrode material for lithium ion battery

Patent metadata

Field	Value
Publication number	US-10693135-B2
Application number	US-201414909755-A
Country	US
Kind code	B2
Filing date	Aug 4, 2014
Priority date	Aug 5, 2013
Publication date	Jun 23, 2020
Grant date	Jun 23, 2020

Abstract

A production method for a composite of fine particles (A) and carbon particles (B), including the steps of: mixing fine particles (A) formed of a substance comprising at least one kind of Si, Sn, Al, Ge and In; and molten pitch, to obtain a mixture (1); pulverizing the mixture (1) to obtain a pulverized product (2a); dry-mixing the pulverized product (2a) and carbon particles (B) to obtain a mixture (3a); and firing the mixture (3a), followed by pulverization; or including the steps of: adding carbon particles (B) to the mixture (1), followed by dry mixing and pulverizing, to obtain a pulverized product (2b); and firing the pulverized product (2b), followed by pulverization.

First claim

The invention claimed is:

1. A production method for a composite of fine particles (A) and carbon particles (B), comprising the steps of:
mixing fine particles (A) formed of a substance comprising at least one kind of Si, Sn, Al, Ge and In; and molten pitch at a temperature of 275° C. or higher, to obtain a mixture 1 ;
solidifying the mixture 1 to obtain a solidified mixture 1 ;
pulverizing the solidified mixture 1 to obtain a pulverized product 2 a;
dry-mixing the pulverized product 2 a and carbon particles (B) to obtain a mixture 3 a ; and
firing the mixture 3 a at a firing temperature of 800° C. or more and 1,200° C. or less, followed by pulverization.

2. A production method for a composite of fine particles (A) and carbon particles (B), comprising the steps of:
mixing fine particles (A) formed of a substance comprising at least one kind of Si, Sn, Al, Ge and In; and molten pitch at a temperature of 275° C. or higher, to obtain a mixture 1 ;
solidifying the mixture 1 to obtain a solidified mixture 1 ;
adding carbon particles (B) to the solidified mixture 1 , followed by dry mixing and pulverizing, to obtain a pulverized product 2 b ; and
firing the pulverized product 2 b at a firing temperature of 800° C. or more and 1,200° C. or less, followed by pulverization.

3. The production method for a composite according to claim 1 , in which a first heat treatment for removing a tar component is not performed before the firing step.

4. The production method according to claim 1 , in which the fine particles (A) are silicon particles each having a SiOx layer (0<x≤2) on a surface of the particle, have an oxygen content ratio of 1 mass % or more and 18 mass % or less, and contain, as a main component, particles each having a primary particle diameter of 200 nm or less.

5. The production method according to claim 1 , in which the step of obtaining the pulverized product 2 a comprises a step of performing the pulverizing with at least one of a ball mill, a jet mill, a rod mill, a pin mill, a rotary cutter mill, a hammer mill, an atomizer, or a mortar.

6. The production method according to claim 1 , in which the carbon particles (B) are graphite particles.

7. The production method according to claim 1 , in which the pitch has a softening point of 80° C. or more and 300° C. or less.

8. The production method according to claim 1 , in which the carbon particles (B) have a 50% particle diameter (D50) in a volume-based cumulative particle size distribution measured with a laser diffraction particle size distribution measuring apparatus of 2 μm or more and 50 μm or less.

9. The production method according to claim 1 , in which a total mass of a component derived from the pitch after the firing and the carbon particles (B) is twice or more and ten times or less as large as a mass of the fine particles (A).

10. The production method according to claim 1 , in which a mass ratio of a component derived from the pitch after the firing with respect to the fine particles (A) is 0.1 or more and 10 or less.

11. The production method for a composite according to claim 2 , in which a first heat treatment for removing a tar component is not performed before the firing step.

12. The production method according to claim 2 , in which the fine particles (A) are silicon particles each having a SiOx layer (0<x≤2) on a surface of the particle, have an oxygen content ratio of 1 mass % or more and 18 mass % or less, and contain, as a main component, particles each having a primary particle diameter of 200 nm or less.

13. The production method according to claim 2 , in which the step of obtaining the pulverized product 2 b comprises a step of performing the pulverizing with at least one of a ball mill, a jet mill, a rod mill, a pin mill, a rotary cutter mill, a hammer mill, an atomizer, or a mortar.

14. The production method according to claim 2 , in which the carbon particles (B) are graphite particles.

15. The production method according to claim 2 , in which the pitch has a softening point of 80° C. or more and 300° C. or less.

16. The production method according to claim 2 , in which the carbon particles (B) have a 50% particle diameter (D50) in a volume-based cumulative particle size distribution measured with a laser diffraction particle size distribution measuring apparatus of 2 μm or more and 50 μm or less.

17. The production method according to claim 2 , in which a total mass of a component derived from the pitch after the firing and the carbon particles (B) is twice or more and ten times or less as large as a mass of the fine particles (A).

18. The production method according to claim 2 , in which a mass ratio of a component derived from the pitch after the firing with respect to the fine particles (A) is 0.1 or more and 10 or less.

Assignees

• Showa Denko Kk
• Umicore Nv

Inventors

• Mutoh Arihiro
• Murata Hirokazu
• Takeuchi Masataka
• Gilleir Jan
• Driesen Kris
• Put Stijn

Classifications

• Y02E60/10

  Energy storage using batteries · CPC title

• C01B32/05 Primary

  Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30 · CPC title

• H01M4/364

  as mixtures · CPC title

• H01M4/387

  Tin or alloys based on tin · CPC title

• H01M4/386

  Silicon or alloys based on silicon · CPC title