Lithium ion battery and negative electrode material thereof

Patent metadata

Field	Value
Publication number	US-11050052-B2
Application number	US-201916432958-A
Country	US
Kind code	B2
Filing date	Jun 6, 2019
Priority date	Dec 6, 2016
Publication date	Jun 29, 2021
Grant date	Jun 29, 2021

Abstract

The present invention provides a lithium ion battery and a negative electrode material thereof. The negative electrode material includes a mixture of a graphite and an amorphous carbon, wherein the graphite is subjected to a surface treatment, and the surface treatment manner is a combination of mechanical fusion modification and spray drying coating, and wherein the graphite has a graphitization degree of 90-96%, an average particle diameter D50 of 13-25 μm and a specific surface area BET of 0.8-2.5 m2/g, and the amorphous carbon has a graphitization degree of 65-80%, an average particle diameter D50 of 2-15 μm and a specific surface area BET of 1.0-3.0 m2/g.

First claim

What is claimed is:

1. A negative electrode material of a lithium ion battery, comprising a mixture of a graphite and an amorphous carbon, wherein the graphite is subjected to a surface treatment, and the surface treatment manner is a combination of mechanical fusion modification and spray drying coating, and wherein the graphite has a graphitization degree of 90-96%, an average particle diameter D50 of 13-25 μm and a specific surface area BET of 0.8-2.5 m 2 /g; the amorphous carbon has a graphitization degree of 65-80%, and an average particle diameter D50 of 2-15 μm and a specific surface area BET of 1.0-3.0 m 2 /g.

2. The negative electrode material according to claim 1 , wherein the graphite has an average diameter D50 of 13-15 μm.

3. The negative electrode material according to claim 1 , wherein the graphite has a specific surface area BET of 1.0-1.8 m 2 /g.

4. The negative electrode material according to claim 1 , wherein the amorphous carbon has an average particle diameter D50 of 5-15 μm.

5. The negative electrode material according to claim 1 , wherein a mass ratio of the graphite to the amorphous carbon is 1:1-9:1.

6. The negative electrode material according to claim 5 , wherein a mass content of the graphite in a total mass of the graphite and the amorphous carbon is 65-95%.

7. The negative electrode material according to claim 1 , wherein the surface treatment of the graphite comprising the steps of:
(1) changing the morphology of the graphite via grinding or extruding with equipment, to obtain uncoated graphite particles; and
(2) uniformly mixing the uncoated graphite particles in step (1) with a solution of a coating material to obtain a mixed solution, drying the mixed solution by a spray drying tower to obtain coated graphite particles having a particle diameter of 13-25 μm and a specific surface area of 0.8-2.5 m 2 /g.

8. The negative electrode material according to claim 7 , wherein the coating material comprises one or more of hard carbon, soft carbon, high molecular carbon material, asphalt, phenolic resin, amino phenolic resin, and coumarone resin.

9. The negative electrode material according to claim 1 , wherein the amorphous carbon is one or more of soft carbon and hard carbon.

10. The negative electrode material according to claim 9 , wherein the amorphous carbon is soft carbon.

11. A lithium ion battery, comprising a negative electrode, a positive electrode, a separator, and an electrolyte, the negative electrode comprises a negative electrode material, wherein the negative electrode material comprises a mixture of a graphite and an amorphous carbon, the graphite is subjected to a surface treatment, and the surface treatment manner is a combination of mechanical fusion modification and spray drying coating, the graphite has a graphitization degree of 90-96%, an average particle diameter D50 of 13-25 μm and a specific surface area BET of 0.8-2.5 m 2 /g; and the amorphous carbon has a graphitization degree of 65-80%, an average particle diameter D50 of 2-15 μm and a specific surface area BET of 1.0-3.0 m 2 /g.

12. The lithium ion battery according to claim 11 , wherein the positive electrode comprises a positive electrode material, the positive electrode material is one or more selected from a group consisting of a layered lithium cobaltate, a layered lithium nickel cobalt manganese oxide, a spinel type lithium manganese oxide, lithium titanium phosphate, lithium cadmium phosphate, lithium zirconium phosphate, and lithium iron phosphate.

13. The lithium ion battery according to claim 11 , wherein the graphite has an average diameter D50 of 13-15 μm.

14. The lithium ion battery according to claim 11 , wherein the graphite has a specific surface area BET of 1.0-1.8 m 2 /g.

15. The lithium ion battery according to claim 11 , wherein the amorphous carbon has an average particle diameter D50 of 5-15 μm and a specific surface area BET of 1.0-1.5 m 2 /g.

16. The lithium ion battery according to claim 11 , wherein a mass ratio of the graphite to the amorphous carbon is 1:1-9:1.

17. The lithium ion battery according to claim 16 , wherein a mass content of the graphite in a total mass of the graphite and the amorphous carbon is 65-95%.

Assignees

• Contemporary Amperex Technology Co Ltd

Inventors

• Xu Wenzhu
• Sun Jianqing
• Lu Guangbo
• Sun Fan
• Zou Qifan
• Wang Shengwei

Classifications

• H01M4/58

  of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates · CPC title

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M10/0525

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

• H01M4/131

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title