Composite particles, method for manufacturing same, electrode, and non-aqueous electrolyte secondary cell

Patent metadata

Field	Value
Publication number	US-2016181601-A1
Application number	US-201414906587-A
Country	US
Kind code	A1
Filing date	Jul 4, 2014
Priority date	Jul 23, 2013
Publication date	Jun 23, 2016
Grant date	—

Abstract

An object of the present invention is to provide a negative electrode active material that can bring about improved charge/discharge cycle characteristics of nonaqueous electrolyte secondary cells that use silicon-containing particles as the negative electrode active material, and to provide a method for manufacturing the negative electrode active material. The method for manufacturing composite particles according to the present invention includes a mixing step and an annealing step. In the mixing step, a mixed powder is produced by mixing silicon phase-containing particles with a thermoplastic organic material powder. The mixed powder is annealed in the annealing step. The composite particles according to the present invention are obtained by this method for manufacturing composite particles.

First claim

1 . A method for manufacturing composite particles, comprising:
a mixing step for producing a mixed powder by mixing particles that contain a silicon phase (referred to herebelow as “silicon phase-containing particles”) with a thermoplastic organic material powder; and an annealing step for subjecting the mixed powder to an annealing.

2 . The method for manufacturing composite particles according to claim 1 , wherein the mixed powder is produced in the mixing step by mixing the silicon phase-containing particles and the thermoplastic organic material powder such that the percentage of the mass of the silicon phase-containing particles with respect to the sum of the mass of the silicon phase-containing particles and the mass of the thermoplastic organic material powder is in a range from 85% to 99%.

3 . The method for manufacturing composite particles according to claim 1 , wherein the mixed powder is annealed in the annealing step at a temperature within a range from 300° C. to 900° C.

4 . A composite particle manufactured by the method for manufacturing composite particles according to claim 1 .

5 . A composite particle comprising:
a particle portion that contains a silicon phase (referred to herebelow as a “silicon phase-containing particle portion); and a binder portion that binds the silicon phase-containing particle portion and that has at least one of a nongraphitic carbon and a carbon precursor as its main component.

6 . The composite particle according to claim 5 , wherein the percentage of the mass of the silicon phase-containing particle portion with respect to the sum of the mass of the silicon phase-containing particle portion and the mass of the binder portion is in a range from 92% to 99.5%.

7 . The composite particle according to claim 5 , wherein at least a portion of the silicon phase-containing particle portion is exposed to the outside.

8 . The composite particle according to claim 5 , wherein a maximum grain size of the silicon phase is in a range of equal to or less than 1000 nm.

9 . The composite particle according to claim 5 , having a specific surface area value in a range from 0.5 m 2 /g to 16 m 2 /g.

10 . An electrode comprising the composite particle according to claim 4 as an active material.

11 . A nonaqueous electrolyte secondary cell comprising the electrode according to claim 10 .

Assignees

• Nippon Steel & Sumitomo Metal Corp

Inventors

• Usui Masafumi
• Negi Noriyuki
• Fujiwara Tooru

Classifications

• H01M4/621

  Binders · CPC title

• H01M10/0525

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

• H01M4/386 Primary

  Silicon or alloys based on silicon · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M4/134

  Electrodes based on metals, Si or alloys · CPC title