Negative electrode active material for negative electrode material of non-aqueous electrolyte secondary battery, negative electrode for non-aqueous electrolyte secondary battery, and non-aqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-2016344019-A1
Application number	US-201515112622-A
Country	US
Kind code	A1
Filing date	Jan 26, 2015
Priority date	Feb 7, 2014
Publication date	Nov 24, 2016
Grant date	—

Abstract

A negative electrode active material for a negative electrode material of a non-aqueous electrolyte secondary battery, includes a silicon-based material expressed by SiO x where 0.5≦x≦1.6 and either or both of a crystalized fluorine compound and a compound containing —CF 2 —CF 2 — units in at least a part of a surface layer of the negative electrode active material, the silicon-based material containing at least one of Li 6 Si 2 O 7 , Li 2 Si 3 O 5 , and Li 4 SiO 4 . There can be provided a negative electrode active material that can increase the battery capacity and improve the cycle performance and initial charge and discharge performance when used for a lithium-ion secondary battery, as well as a lithium-ion secondary battery having a negative electrode using this negative electrode active material.

First claim

1 - 12 . (canceled)

13 . A negative electrode active material for a negative electrode material of a non-aqueous electrolyte secondary battery, comprising a silicon-based material expressed by SiO x where 0.5≦x≦1.6 and either or both of a crystalized fluorine compound and a compound containing —CF 2 —CF 2 — units in at least a part of a surface layer of the negative electrode active material, the silicon-based material containing at least one of Li 6 Si 2 O 7 , Li 2 Si 3 O 5 , Li 4 SiO 4 , and Li 2 SiO 3 .

14 . The negative electrode active material according to claim 13 , wherein the crystalized fluorine compound is bis(trifluoromethyl)dicarbonate.

15 . The negative electrode active material according to claim 13 , wherein the fluorine compound containing —CF 2 —CF 2 — units is one or more compounds selected from the group consisting of polytetrafluoroethylene, polyhexafluoropropylene, and polyperfluorokerosene.

16 . The negative electrode active material according to claim 13 , wherein the negative electrode active material at least partially contains SiO 2 having a tridymite structure.

17 . The negative electrode active material according to claim 13 , wherein a surface layer portion of the silicon-based material is coated with at least one of carbon, lithium carbonate, and fluorinated lithium.

18 . The negative electrode active material according to claim 13 , wherein a surface layer portion of the silicon-based material exhibits at least one of O 2 SiF − and OSiF − when subjected to Time-of-Flight Secondary Ion Mass Spectrometry.

19 . The negative electrode active material according to claim 13 , wherein a surface layer of the silicon-based material has a layered structure in which the silicon-based material is coated with a carbon-based material, at least one of the lithium carbonate and fluorinated lithium, and at least one of bis(trifluoromethyl)dicarbonate and the fluorine compound containing —CF 2 —CF 2 — units in this order.

20 . The negative electrode active material according to claim 13 , wherein the negative electrode active material satisfies A/B≧0.8 where A is a peak intensity of an Si region represented by a chemical shift value of −60 ppm to −100 ppm and B is a peak intensity of an SiO 2 region represented by a chemical shift value of −100 ppm to −150 ppm, the chemical shift value being obtained from a 29 Si-MAS-NMR spectrum.

21 . The negative electrode active material according to claim 13 , wherein the negative electrode active material exhibits a diffraction peak having a half width (2θ) of 1.2° or more, the diffraction peak being attributable to an Si(111) crystal face and obtained by X-ray diffraction, and a crystallite size attributable to the Si(111) crystal face is 7.5 nm or less.

22 . A negative electrode for a non-aqueous electrolyte secondary battery, comprising a negative electrode active material according to claim 13 .

23 . The negative electrode for a non-aqueous electrolyte secondary battery according to claim 22 , wherein the negative electrode comprises a carbon-based active material and a silicon-based active material with a silicon-based active material content of 6 wt % or more with respect to whole negative electrode active materials.

24 . A non-aqueous electrolyte secondary battery comprising a negative electrode for a non-aqueous electrolyte secondary battery according to claim 22 .

Assignees

• Shinetsu Chemical Co

Inventors

• Hirose Takakazu
• KAMO Hiromichi
• Yoshikawa Hiroki

Classifications

• H01M4/485

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title

• H01M4/622

  being polymers · CPC title

• H01M4/366 Primary

  as layered products · CPC title

• H01M4/0445

  Forming after manufacture of the electrode, e.g. first charge, cycling · CPC title

• H01M4/582

  Halogenides · CPC title