Negative electrode material for secondary battery having lithium-doped silicon-silicon oxide composite, method for manufacturing negative electrode, and lithium secondary battery

Patent metadata

Field	Value
Publication number	US-9825290-B2
Application number	US-201715438292-A
Country	US
Kind code	B2
Filing date	Feb 21, 2017
Priority date	Apr 5, 2010
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

The present invention is a negative electrode material for a secondary battery with a non-aqueous electrolyte comprising at least a silicon-silicon oxide composite and a carbon coating formed on a surface of the silicon-silicon oxide composite, wherein at least the silicon-silicon oxide composite is doped with lithium, and a ratio I(SiC)/I(Si) of a peak intensity I(SiC) attributable to SiC of 2θ=35.8±0.2° to a peak intensity I(Si) attributable to Si of 2θ=28.4±0.2° satisfies a relation of I(SiC)/I(Si)≦0.03, when x-ray diffraction using Cu-Kα ray. As a result, there is provided a negative electrode material for a secondary battery with a non-aqueous electrolyte that is superior in first efficiency and cycle durability to a conventional negative electrode material.

First claim

What is claimed is:

1. A negative electrode material for a secondary battery with a non-aqueous electrolyte, the negative electrode material comprising:
a silicon-silicon oxide composite doped with lithium; and
a carbon coating formed on a surface of the silicon-silicon oxide composite,
wherein:
a ratio I(SiC)/I(Si) of a peak intensity I(SiC) attributable to SiC of 2θ=35.8±0.2° to a peak intensity I(Si) attributable to Si of 2θ=28.4±0.2° satisfies a relation of I(SiC)/I(Si)≧0.03, when an x-ray diffraction is performed on the negative electrode material using a Cu-Kα ray, and
an additive amount of lithium is equal to or less than a difference between a charge capacity and a discharge capacity at the first charge/discharge to satisfy a relation: Li/O<1.

2. A lithium ion secondary battery comprising:
a positive electrode,
a negative electrode, and
a non-aqueous electrolyte having lithium ion conductivity,
wherein the negative electrode is formed from the negative electrode material for a secondary battery with a non-aqueous electrolyte according to claim 1 .

Assignees

• Shinetsu Chemical Co

Inventors

• Kawada Nobuo

Classifications

• H01M4/48

  of inorganic oxides or hydroxides · CPC title

• C23C16/4417

  Methods specially adapted for coating powder · CPC title

• C23C16/26 Primary

  Deposition of carbon only · CPC title

• H01M4/134

  Electrodes based on metals, Si or alloys · CPC title

• H01M10/052

  Li-accumulators · CPC title