Negative electrode material for lithium ion secondary battery, negative electrode for lithium ion secondary battery, and lithium ion secondary battery

Patent metadata

Field	Value
Publication number	US-2020280053-A1
Application number	US-202015930498-A
Country	US
Kind code	A1
Filing date	May 13, 2020
Priority date	Oct 26, 2012
Publication date	Sep 3, 2020
Grant date	—

Abstract

A negative electrode material for a lithium ion secondary battery including carbon over a part or a whole of a surface of an oxide of silicon, in which the content of the carbon is from 0.5 mass-% to less than 5 mass-%.

First claim

1 . A negative electrode material for a lithium ion secondary battery, comprising a negative electrode material (SiOx-C) that includes an oxide of silicon and silicon crystallites, and carbon over a part or a whole of a surface of the oxide of silicon, wherein:
a content of the carbon with respect to the whole negative electrode material (SiOx-C) is from 0.5 mass % to 4.5 mass %; and a crystallite size of the silicon crystallites is 2 nm or more.

2 . The negative electrode material for a lithium ion secondary battery according to claim 1 , wherein the crystallite size of the silicon crystallites is from 2 nm to 8 nm.

3 . The negative electrode material for a lithium ion secondary battery according to claim 1 , wherein the crystallite size of the silicon crystallites is from 3 nm to 6 nm.

4 . The negative electrode material for a lithium ion secondary battery according to claim 1 , wherein the carbon comprises low crystallinity carbon, and has an R value, defined as a ratio Id/Ig of a peak Id in a profile obtained by laser Raman spectrometry with an excitation wavelength of 532 nm observed between 1300 cm −1 and 1400 cm −1 to a peak Ig in a profile obtained by laser Raman spectrometry with an excitation wavelength of 532 nm observed between 1530 cm −1 and 1630 cm −1 , of 0.5 or more.

5 . The negative electrode material for a lithium ion secondary battery according to claim 4 , wherein the carbon has an R value of from 0.7 to 1.3.

6 . The negative electrode material for a lithium ion secondary battery according to claim 4 , wherein the carbon has an R value of from 0.8 to 1.2.

7 . The negative electrode material for a lithium ion secondary battery according to claim 1 , wherein a diffraction peak assignable to Si (111) is observed when the negative electrode material (SiOx-C) is subjected to a powder X-ray diffraction (XRD) analysis.

8 . The negative electrode material for a lithium ion secondary battery according to claim 1 , wherein the oxide of silicon is represented by a formula SiOx (x is 0<x≤2).

9 . The negative electrode material for a lithium ion secondary battery according to claim 1 , further comprising a carbonaceous negative electrode material (C) that includes at least one selected from the group consisting of natural graphite, artificial graphite, and amorphous carbon.

10 . The negative electrode material for a lithium ion secondary battery according to claim 9 , wherein a ratio of the negative electrode material (SiOx-C) with respect to the carbonaceous negative electrode material (C) is from 0.1:99.9 to 20:80 in terms of mass.

11 . The negative electrode material for a lithium ion secondary battery according to claim 9 , wherein the crystallite size of the silicon crystallites that is included in the negative electrode material (SiOx-C) is from 2 nm to 8 nm.

12 . The negative electrode material for a lithium ion secondary battery according to claim 9 , wherein the crystallite size of the silicon crystallites that is included in the negative electrode material (SiOx-C) is from 3 nm to 6 nm.

13 . The negative electrode material for a lithium ion secondary battery according to claim 9 , wherein the carbon that is included in the negative electrode material (SiOx-C) comprises low crystallinity carbon, and has an R value, defined as a ratio Id/Ig of a peak Id in a profile obtained by laser Raman spectrometry with an excitation wavelength of 532 nm observed between 1300 cm −1 and 1400 cm −1 to a peak Ig in a profile obtained by laser Raman spectrometry with an excitation wavelength of 532 nm observed between 1530 cm −1 and 1630 cm −1 , of 0.5 or more.

14 . The negative electrode material for a lithium ion secondary battery according to claim 13 , wherein the carbon that is included in the negative electrode material (SiOx-C) has an R value of from 0.7 to 1.3.

15 . The negative electrode material for a lithium ion secondary battery according to claim 9 , wherein the oxide of silicon that is included in the negative electrode material (SiOx-C) is represented by a formula SiOx (x is 0<x≤2).

16 . The negative electrode material for a lithium ion secondary battery according to claim 1 , further comprising a carbonaceous negative electrode material (C) that includes at least one selected from the group consisting of natural graphite, artificial graphite, and amorphous carbon, wherein:
the crystallite size of the silicon crystallites that is included in the negative electrode material (SiOx-C) is 3 nm or more and 6 nm or less; the carbon that is included in the negative electrode material (SiOx-C) comprises low crystallinity carbon, and has an R value, defined as a ratio Id/Ig of a peak Id in a profile obtained by laser Raman spectrometry with an excitation wavelength of 532 nm observed between 1300 cm −1 and 1400 cm −1 to a peak Ig in a profile obtained by laser Raman spectrometry with an excitation wavelength of 532 nm observed between 1530 cm −1 and 1630 cm −1 , of from 0.7 to 1.3; the oxide of silicon that is included in the negative electrode material (SiOx-C) is represented by a formula SiOx (x is 0<x≤2); and a ratio of the negative electrode material (SiOx-C) with respect to the carbonaceous negative electrode material (C) is from 0.1:99.9 to 20:80 in terms of mass.

17 . A negative electrode for a lithium ion secondary battery, comprising:
a current collector; and a negative electrode material layer provided on the current collector and comprising the negative electrode material according to claim 1 .

18 . A lithium ion secondary battery, comprising:
a positive electrode; the negative electrode for a lithium ion secondary battery according to claim 17 ; and an electrolyte.

Assignees

• Hitachi Chemical Co Ltd

Inventors

• Kouzu Masayuki
• Tsuchiya Hideyuki
• Ohzeki Katsutomo
• Oosaki Yoshie
• Nishida Tatsuya

Classifications

• H01M10/0525

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

• H01M4/587

  for inserting or intercalating light metals · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M4/134

  Electrodes based on metals, Si or alloys · CPC title

• H01M4/366 Primary

  as layered products · CPC title