NEGATIVE-ELECTRODE ACTIVE MATERIAL FOR NON-AQUEOUS ELECTROLYTE SECONDARY BATTERY, NEGATIVE ELECTRODE FOR NON-AQUEOUS ELECTROLYTE SECONDARY BATTERY, AND NON-AQUEOUS ELECTROLYTE SECONDARY BATTERY (as amended)

Patent metadata

Field	Value
Publication number	US-2017309950-A1
Application number	US-201615526011-A
Country	US
Kind code	A1
Filing date	Feb 15, 2016
Priority date	Feb 23, 2015
Publication date	Oct 26, 2017
Grant date	—

Abstract

A non-aqueous electrolyte secondary battery that contains a silicon material as a negative-electrode active material has improved cycle life. A negative-electrode active material particle ( 10 ) according to an embodiment includes a lithium silicate phase ( 11 ) represented by Li 2z SiO (2+z) ( 0 <z< 2 ), silicon particles ( 12 ) dispersed in the lithium silicate phase ( 11 ), and a metallic compound ( 15 ) (other than lithium compounds and silicon oxides) dispersed in the lithium silicate phase ( 11 ). The metallic compound ( 15 ) is preferably selected from zirconium oxide, aluminum oxide, zirconium carbide, tungsten carbide, and silicon carbide.

First claim

1 . A negative-electrode active material for a non-aqueous electrolyte secondary battery, comprising:
a lithium silicate phase represented by Li 2z SiO (2+z) {0<z<2};
silicon particles dispersed in the lithium silicate phase; and
a metallic compound dispersed in the lithium silicate phase (other than lithium compounds and silicon oxides).

2 . The negative-electrode active material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein the metallic compound is at least one selected from zirconium oxide, aluminum oxide, zirconium carbide, tungsten carbide, and silicon carbide.

3 . The negative-electrode active material for a non-aqueous electrolyte secondary battery according to claim 2 , wherein the metallic compound is composed mainly of zirconium oxide.

4 . The negative-electrode active material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein a ratio of the metal oxide to the lithium silicate phase and the silicon particles ranges from 0.01% to 10% by mass.

5 . The negative-electrode active material for a non-aqueous electrolyte secondary battery according to claim 1 wherein the metal oxide has an average particle size of 200 nm or less.

6 . The negative-electrode active material for a non-aqueous electrolyte, secondary battery according to claim 1 , wherein the silicon particles have an average particle size of 200 nm or less before initial charging.

7 . The negative-electrode active material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein the lithium silicate phase, the silicon particles, and the metal oxide constitute a base particle, and the base particle is covered with an electrically conductive layer.

8 . The negative-electrode active material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein the lithium silicate phase is composed mainly of Li 2 SiO 3 .

9 . The negative-electrode active material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein the lithium silicate phase is composed mainly of Li 2 Si 2 O 5 ;

10 . The negative-electrode active material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein no SiO 2 peak is observed at 2θ=25 degrees in an XRD pattern obtained by XRD measurement.

11 . The negative-electrode active material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein the negative-electrode active material for a non-aqueous electrolyte secondary battery after charging and discharging contains no Li 4 SiO 4 .

12 . A negative electrode for a non-aqueous electrolyte secondary battery, comprising:
a negative-electrode current collector; and a negative-electrode mixture layer on the negative-electrode current collector, the negative-electrode mixture layer containing the negative-electrode active material according to claim 1 and a binder.

13 . A non-aqueous electrolyte secondary battery comprising:
the negative electrode according to claim 12 ; a positive electrode; and a non-aqueous electrolyte.

Assignees

• Sanyo Electric Co

Inventors

• Minami Hiroshi
• Sunano Taizou

Classifications

• H01M10/052 Primary

  Li-accumulators · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M4/364

  as mixtures · CPC title

• H01M4/48

  of inorganic oxides or hydroxides · CPC title

• H01M4/405

  Alloys based on lithium · CPC title