Negative electrode active material, material of mixed negative electrode active material, negative electrode for non-aqueous electrolyte secondary battery, lithium ion secondary battery, method for producing negative electrode active material and method for producing lithium ion secondary battery

Patent metadata

Field	Value
Publication number	US-10868303-B2
Application number	US-201716077345-A
Country	US
Kind code	B2
Filing date	Feb 14, 2017
Priority date	Feb 23, 2016
Publication date	Dec 15, 2020
Grant date	Dec 15, 2020

Abstract

A negative electrode active material contains particle of the negative electrode active material, wherein the particle of the negative electrode active material contains particle of a silicon compound which contains a silicon compound (SiOx: 0.5≤x≤1.6), the particle of the silicon compound contains lithium, and the particle of the negative electrode active material has a total content rate of a polyphenylene compound component and a polycyclic aromatic component measured by TPD-MS of 1 ppm by mass or more and 4,000 ppm by mass or less. As a result, a negative electrode active material is capable of improving cycle characteristics and initial charge/discharge characteristics when it is used as a negative electrode active material of a lithium ion secondary battery.

First claim

The invention claimed is:

1. A negative electrode active material containing particle of the negative electrode active material, wherein
the particle of the negative electrode active material contains particle of a silicon compound containing a silicon compound (SiO x : 0.5≤x≤1.6),
the particle of the silicon compound contains lithium, and
the particle of the negative electrode active material has a total content rate of a polyphenylene compound component and a polycyclic aromatic component measured by TPD-MS of 1 ppm by mass or more and 4,000 ppm by mass or less.

2. The negative electrode active material according to claim 1 , wherein the total content rate of the polyphenylene compound component and the polycyclic aromatic component is 1 ppm by mass or more and 1,000 ppm by mass or less.

3. The negative electrode active material according to claim 1 , wherein the polyphenylene compound is at least one among a biphenyl, a terphenyl and a derivative thereof, the polycyclic aromatic is at least one among naphthalene, anthracene, phenanthrene, naphthacene, pentacene, pyrene, picene, coronene, chrysene and a derivative thereof.

4. The negative electrode active material according to claim 2 , wherein the polyphenylene compound is at least one among a biphenyl, a terphenyl and a derivative thereof, the polycyclic aromatic is at least one among naphthalene, anthracene, phenanthrene, naphthacene, pentacene, pyrene, picene, coronene, chrysene and a derivative thereof.

5. The negative electrode active material according to claim 3 , wherein the particle of the negative electrode active material contains a component having a structure in which an even number of hydrogen atoms is added to at least one kind of the polyphenylene compound and the polycyclic aromatic.

6. The negative electrode active material according to claim 1 , wherein the particle of the silicon compound contains at least one kind of Li 2 SiO 3 and Li 4 SiO 4 .

7. The negative electrode active material according to claim 1 , wherein the particle of the silicon compound has a half value width (2θ) of a diffraction peak attributable to an Si (111) crystal plane obtained by X-ray diffraction of 1.2° or more and has a crystallite size corresponding to the crystal plane of 7.5 nm or less.

8. The negative electrode active material according to claim 1 , wherein, in the particle of the silicon compound, a maximum peak intensity value A of Si and Li silicate region given by −60 to −95 ppm as a chemical shift value, and a peak intensity value B of an SiO 2 region given by −96 to −150 ppm as a chemical shift value each obtained from 29 Si-MAS-NMR spectrum satisfy a relation A>B.

9. The negative electrode active material according to claim 1 , wherein a test cell comprising a negative electrode which contains a mixture of the negative electrode active material and a carbon-based active material and a counter electrode lithium is produced, and in the test cell, charging and discharging comprising charging which is to flow an electric current such that lithium is inserted into the negative electrode active material and discharging which is to flow an electric current such that lithium is released from the negative electrode active material are repeated 30 times, when a graph showing a relationship between a differentiated value dQ/dV in which a discharge capacity Q at each charge and discharge is differentiated by a potential V of the negative electrode on the basis of counter electrode lithium, and the potential V, is drawn, the negative electrode active material exhibits a peak in a range of the potential V of the negative electrode of 0.40 V to 0.55 V at the time of discharging on and after the Xth time (1≤X≤30).

10. The negative electrode active material according to claim 1 , wherein the particle of the negative electrode active material has a median diameter of 1.0 μm or more and 15 μm or less.

11. The negative electrode active material according to claim 1 , wherein the particle of the negative electrode active material contains a carbon material at a surface layer portion.

12. The negative electrode active material according to claim 11 , wherein an average thickness of the carbon material is 10 nm or more and 5,000 nm or less.

13. A material of a mixed negative electrode active material which comprises the negative electrode active material according to claim 1 and a carbon-based active material.

14. A negative electrode for a non-aqueous electrolyte secondary battery, wherein the negative electrode comprises the material of the mixed negative electrode active material according to claim 13 , and a ratio of mass of the negative electrode active material relative to a total mass of the negative electrode active material and the carbon-based active material is 6% by mass or more.

15. A negative electrode for a non-aqueous electrolyte secondary battery which comprises:
a layer of a negative electrode active material formed with the material of the mixed negative electrode active material according to claim 13 , and
a negative electrode current collector,
wherein the layer of the negative electrode active material is formed on the negative electrode current collector, and
the negative electrode current collector contains carbon and sulfur, and contents thereof are each 100 ppm by mass or less.

16. A lithium ion secondary battery, wherein the lithium ion secondary battery comprises a negative electrode which contains the negative electrode active material according to claim 1 , as a negative electrode.

17. A method for producing a negative electrode active material containing particle of the negative electrode active material which contain particle of a silicon compound, the method comprising:
producing the particle of the negative electrode active material by producing particle of a silicon compound which contains a silicon compound (SiO x : 0.5≤x≤1.6), and inserting lithium into the particle of the silicon compound;
measuring the polyphenylene compound component and the polycyclic aromatic component contained in the particle of the negative electrode active material by TPD-MS;
selecting particle of the negative electrode active material having a total content rate of the polyphenylene compound component and the polycyclic aromatic component measured by the TPD-MS of 1 ppm by mass or more and 4,000 ppm by mass or less; and
producing a negative electrode active material by using the selected particle of the negative electrode active material.

18. A method for producing a negative electrode active material containing particle of the negative electrode active material which contain particle of a silicon compound, the method comprising:
producing the particle of the negative electrode active material by producing particle of a silicon compound which contains a silicon compound (SiO x : 0.5≤x≤1.6), and inserting lithium into the particle of the silicon compound;
incorporating at least one kind of a polyphenylene compound component and a polycyclic aromatic component into the particle of the negative electrode active material; and
producing a negative electrode active material according to claim 1 by using the particle of the negative electrode active material to which at least one kind of the polyphenylene compound component and the polycyclic aromatic component is added.

19. The method for producing a negative electrode active material according to claim 18 , wherein a step of incorporating at least one kind of the polyphenylene compound component and the polycyclic aromatic componen

Assignees

• Shinetsu Chemical Co

Inventors

• KAMO Hiromichi
• Furuya Masahiro
• Awano Hidekazu
• Hirose Takakazu
• Matsuno Takumi
• Nishiura Katsunori
• Fang Nan

Classifications

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• H01M4/66

  Selection of materials · CPC title

• H01M4/364

  as mixtures · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title

• H01M4/62

  Selection of inactive substances as ingredients for active masses, e.g. binders, fillers · CPC title