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

Patent metadata

Field	Value
Publication number	US-2016181602-A1
Application number	US-201414909755-A
Country	US
Kind code	A1
Filing date	Aug 4, 2014
Priority date	Aug 5, 2013
Publication date	Jun 23, 2016
Grant date	—

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 ( 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 ), 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 ( 2 b ); and firing the pulverized product ( 2 b ), followed by pulverization.

First claim

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, to obtain a mixture 1 ; pulverizing the 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, to obtain a mixture 1 ; adding carbon particles (B) to the 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 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 or 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.

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 . A negative electrode material for a lithium ion battery, comprising a composite produced by the production method claimed in claim 1 .

12 . A lithium ion battery, comprising a negative electrode formed of the negative electrode material claimed in claim 11 .

13 . A negative electrode material for a lithium ion battery, comprising a composite produced by the production method claimed in claim 2 .

14 . A lithium ion battery, comprising a negative electrode formed of the negative electrode material claimed in claim 13 .

Assignees

• Showa Denko Kk
• Umicore Nv

Inventors

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

Classifications

• H01M4/583

  Carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• H01M4/386

  Silicon or alloys based on silicon · CPC title

• H01M4/364

  as mixtures · CPC title

• H01M4/48 Primary

  of inorganic oxides or hydroxides · CPC title

• H01M10/0525

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