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-12176539-B2
Application number	US-201917420142-A
Country	US
Kind code	B2
Filing date	Jan 4, 2019
Priority date	Jan 4, 2019
Publication date	Dec 24, 2024
Grant date	Dec 24, 2024

Abstract

A negative electrode active material for a lithium ion secondary battery includes graphite particles for which an R value measured by Raman spectrometry is less than 0.27, and an intensity ratio (P1/P2) of a diffraction peak (P1) on a hexagonal structure (101) plane to a diffraction peak (P2) on a rhombohedral structure (101) plane in an X-ray diffraction pattern by CuKα ray is 5.0 or less.

First claim

The invention claimed is:

1. A negative electrode material for a lithium ion secondary battery, the negative electrode material comprising graphite particles for which an R value measured by Raman spectrometry is less than 0.27, and an intensity ratio (P1/P2) of a diffraction peak (P1) on a hexagonal structure (101) plane to a diffraction peak (P2) on a rhombohedral structure (101) plane in an X-ray diffraction pattern by CuKα ray is 3.6 or less, wherein a volume average particle size of the graphite particles is from 2 μm to 30 μm, the graphite particles are spherical natural graphite particles heat-treated in an atmosphere that includes CO 2 gas, water vapor, or O 2 gas, an average circularity of the graphite particles is 85% or more, and an average aspect ratio (major axis/minor axis) of the graphite particles is 1.6 or less.

2. The negative electrode material for a lithium ion secondary battery according to claim 1 , wherein a BET specific surface area, according to a nitrogen gas adsorption method, of the graphite particles is from 2 m 2 /g to 15 m 2 /g.

3. The negative electrode material for a lithium ion secondary battery according to claim 1 , wherein amorphous carbon is present on at least a part of a surface of the graphite particles.

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

5. A lithium ion secondary battery, comprising:
the negative electrode for a lithium ion secondary battery according to claim 4 ;
a positive electrode; and
an electrolyte solution.

6. A negative electrode material for a lithium ion secondary battery, the negative electrode material comprising graphite particles, for which an R value measured by Raman spectrometry is less than 0.27, and an intensity ratio (P3/P4) of a diffraction peak (P3) on a carbon (002) plane to a diffraction peak (P4) on a carbon (110) plane in an X-ray diffraction pattern by CuKα ray is 300 or less, wherein the graphite particles are spherical natural graphite particles heat-treated in an atmosphere that includes CO 2 gas, water vapor, or O 2 gas, an average circularity of the graphite particles is 85% or more, and an average aspect ratio (major axis/minor axis) of the graphite particles is 1.6 or less.

Assignees

• Showa Denko Materials Co Ltd
• Resonac Corp

Inventors

• Okamura Wakana
• Hoshi Kento

Classifications

• H01M2004/027

  Negative electrodes · CPC title

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title

• H01M10/0525

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

• C01P2006/12

  Surface area · CPC title

• C01P2004/61

  Micrometer sized, i.e. from 1-100 micrometer · CPC title