Negative electrode material for lithium ion batteries and use thereof

Patent metadata

Field	Value
Publication number	US-10109848-B2
Application number	US-201414909762-A
Country	US
Kind code	B2
Filing date	Aug 4, 2014
Priority date	Aug 5, 2013
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

The present invention relates to a negative electrode material for a lithium ion battery, made of a composite material comprising silicon-containing particles, artificial graphite particles and a carbon coating layer, wherein the silicon-containing particles are silicon particles having a SiOx layer (0<x≤2) on a particle surface, have an oxygen content ratio of 1 mass % or more and 18 mass % or less, and mainly comprise particles having a primary particle diameter of 200 nm or less; and the artificial graphite particles have a scale-like shape. By using the negative electrode material, a lithium ion battery having a high capacitance and excellent charge-discharge cycle characteristics can be produced.

First claim

The invention claimed is:

1. A negative electrode material for a lithium ion battery, made of a composite material comprising silicon-containing particles, artificial graphite particles and a carbon coating layer, wherein the silicon-containing particles are silicon particles having a SiOx layer (0<x≤2) on a surface of the particle, have an oxygen content ratio of 1 mass % or more and 18 mass % or less, and mainly comprise particles having a primary particle diameter of 200 nm or less; and the artificial graphite particles have a scale-like shape,
wherein the ratio I G /I D (G value) of the negative electrode material between the peak area (I G ) of a peak in a range of 1580 to 1620 cm −1 and the peak area (I D ) of a peak in a range of 1300 to 1400 cm −1 measured by Raman spectroscopy spectra is 1.65 or more and 10 or less, and
wherein the ratio I G /I D (G value) between the peak area (I G ) of a peak in a range of 1580 to 1620 cm −1 and the peak area (I D ) of a peak in a range of 1300 to 1400 cm −1 measured by Raman spectroscopy spectra when an edge surface of the artificial graphite particle is measured with Raman microspectrometer is 5.2 or more and 100 or less; the average interplanar spacing d002 of plane (002) of the artificial graphite particles by the X-ray diffraction method is 0.337 nm or less; and by observing the optical structures in the cross-section of the formed body made of the artificial graphite particles in a rectangular field of 480 μm×640 μm under a polarizing microscope, when areas of the optical structures are accumulated from a smallest structure in an ascending order, SOP represents an area of an optical structure whose accumulated area corresponds to 60% of the total area of all the optical structures; when the structures are counted from a structure of a smallest aspect ratio in an ascending order, AROP represents the aspect ratio of the structure which ranks at the position of 60% in the total number of all the structures; and when D50 represents a volume-based average particle diameter by laser diffraction method; SOP, AROP and D50 satisfy the following relationship:
1.5≤ AROP≤ 6 and

0.2× D 50≤( SOP×AROP ) 1/2 <2× D 50.

2. The negative electrode material for a lithium ion battery as claimed in claim 1 , wherein the content of the silicon-containing particles is 5 parts by mass or more and 30 parts by mass or less to 100 parts by mass of the artificial graphite particles.

3. The negative electrode material for a lithium ion battery as claimed in claim 1 , wherein a volume-based average particle diameter by laser diffraction method (D50) of the negative electrode material is 5 μm or more and 30 μm or less.

4. The negative electrode material for a lithium ion battery as claimed in claim 1 , wherein the BET specific surface area of the negative electrode material is 7 m 2 /g or more and 20 m 2 /g or less.

5. The negative electrode material for a lithium ion battery as claimed in claim 1 , wherein the average interplanar spacing d002 of plane (002) by the X-ray diffraction method of the negative electrode material is 0.339 nm or less.

6. The negative electrode material for a lithium ion battery as claimed in claim 1 , wherein the carbon coating layer is obtained by subjecting petroleum pitch or coal pitch to heat treatment.

7. The negative electrode material for a lithium ion battery as claimed in claim 1 , wherein the mass of the carbon coating layer is 5 mass % or more and 30 mass % or less in the composite material.

8. A paste comprising the negative electrode material for a lithium ion battery claimed in claim 1 and a binder.

9. An electrode using a formed body of the paste for an electrode claimed in claim 8 .

10. A lithium ion battery comprising the electrode claimed in claim 9 as a constituting element.

Assignees

• Showa Denko Kk
• Umicore Nv

Inventors

• Murata Hirokazu
• Takeuchi Masataka
• Ishii Nobuaki
• Siau Sam
• Marx Nicolas
• Put Stijn

Classifications

• C01B32/21

  After-treatment · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title

• H01M10/0525

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

• H01M4/625

  Carbon or graphite · CPC title

• C01B32/05

  Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30 · CPC title