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-11031597-B2
Application number	US-201816475857-A
Country	US
Kind code	B2
Filing date	Jan 4, 2018
Priority date	Jan 6, 2017
Publication date	Jun 8, 2021
Grant date	Jun 8, 2021

Abstract

A negative electrode material for a lithium-ion secondary battery contains graphitic particles of which a standard deviation of circularity at a cumulative frequency ranging from 10% by particle to 90% by particle from the lower circularity, determined by a flow-type particle analyzer, is from 0.05 to 0.1.

First claim

The invention claimed is:

1. A negative electrode material for a lithium-ion secondary battery, comprising graphitic particles of which a standard deviation of circularity at a cumulative frequency ranging from 10% by particle to 90% by particle from a lower circularity, determined by a flow-type particle analyzer, is from 0.05 to 0.1.

2. The negative electrode material for a lithium-ion secondary battery according to claim 1 , wherein the circularity at a cumulative frequency of 10% by particle of the graphitic particles is from 0.7 to 0.9.

3. The negative electrode material for a lithium-ion secondary battery according to claim 1 , wherein an average particle size of the graphitic particles is from 2 μm to 30 μm.

4. The negative electrode material for a lithium-ion secondary battery according to claim 1 , wherein a Raman R value (ID/IG), which is a ratio of a peak intensity ID within a range of from 1300 cm- 1 to 1400 cm- 1 to a peak intensity IG within a range of from 1580 cm −1 to 1620 cm −1 , upon irradiating the graphitic particles with laser light at 532 nm is from 0.10 to 0.60.

5. The negative electrode material for a lithium-ion secondary battery according to claim 1 , further comprising amorphous carbon particles, wherein a standard deviation of circularity at a cumulative frequency ranging from 10% by particle to 90% by particle from a lower circularity of mixed particles of the graphitic particles and the amorphous carbon particles, determined by a flow-type particle analyzer, is from 0.05 to 0.1.

6. The negative electrode material for a lithium-ion secondary battery according to claim 5 , wherein a content of the amorphous carbon particles in the negative electrode material is from 1% by mass to 30% by mass.

7. A negative electrode for a lithium-ion secondary battery, comprising:
a current collector; and
a negative electrode material layer that is provided on or above the current collector and that comprises the negative electrode material for a lithium-ion secondary battery according to claim 1 .

8. A lithium-ion secondary battery, comprising the negative electrode for a lithium-ion secondary battery according to claim 7 .

Assignees

• Hitachi Chemical Co Ltd
• Showa Denko Materials Co Ltd

Inventors

• Hoshi Kento
• Tsuchiya Hideyuki
• Satoh Tsutomu

Classifications

• H01M2004/027

  Negative electrodes · CPC title

• H01M2004/021

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

• H01M10/0525 Primary

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

• H01M4/587 Primary

  for inserting or intercalating light metals · CPC title

• H01M4/1393

  of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title