Composite negative electrode material and method for preparing composite negative electrode material, negative electrode plate of lithium ion secondary battery, and lithium ion secondary battery

Patent metadata

Field	Value
Publication number	US-10770720-B2
Application number	US-201615339081-A
Country	US
Kind code	B2
Filing date	Oct 31, 2016
Priority date	Apr 29, 2014
Publication date	Sep 8, 2020
Grant date	Sep 8, 2020

Abstract

A composite negative electrode material, a method for preparing the composite negative electrode material, a negative electrode plate of a lithium ion secondary battery containing the composite negative electrode material, and a lithium ion secondary battery containing a negative electrode active material of the lithium ion secondary battery, where the composite negative electrode material includes a carbon core and a carbon coating layer, where the carbon coating layer is a carbon layer that coats a surface of the carbon core, and both the carbon core and the carbon coating layer include a doping element, where the doping element is at least one of element N, P, B, S, O, F, Cl, or H.

First claim

What is claimed is:

1. A composite negative electrode, comprising:
a doped carbon core containing a first doping element, wherein the first doping element comprises nitrogen, wherein a nitrogen atom of the first doping element and a carbon atom in the doped carbon core are bonded in at least one form of pyridinic nitrogen, graphite nitrogen or pyrrolic nitrogen; and
a doped carbon coating layer that coats a surface of the doped carbon core, wherein the doped carbon coating layer comprises a second doping element that is P, B, S, O, F, Cl, or H, and wherein the first doping element is different from the second doping element.

2. The composite negative electrode of claim 1 , wherein a mass of the doped carbon coating layer is 5% to 30% of a total mass of the doped carbon coating layer and the doped carbon core.

3. The composite negative electrode of claim 1 , wherein a mass content of the first doping element and the second doping element in the composite negative electrode is 0.1% to 50%.

4. The composite negative electrode of claim 1 , wherein the doped carbon core comprises natural graphite.

5. The composite negative electrode of claim 1 , wherein the second doping element is not S.

6. The composite negative electrode of claim 5 , wherein a specific capacity of the doped carbon core is greater than 372 milliamperehours/gram (mAh/g).

7. The composite negative electrode of claim 6 , wherein the specific capacity of the doped carbon core is 420-620 mAh/g.

8. A negative electrode plate of a lithium ion secondary battery, comprising:
a current collector; and
a composite negative electrode that covers the current collector, wherein the composite negative electrode comprises:
a doped carbon core containing a first doping element, wherein the first doping element comprises nitrogen, wherein a nitrogen atom of the first doping element and a carbon atom in the doped carbon core are bonded in at least one form of pyridinic nitrogen, graphite nitrogen or pyrrolic nitrogen; and
a doped carbon coating layer that coats a surface of the doped carbon core, wherein the doped carbon coating layer comprises a second doping element that is N, P, B, S, F, Cl, or H, and wherein the first doping element of the carbon core is different from the second doping element.

9. The negative electrode plate of claim 8 , wherein a mass of the doped carbon coating layer is 5% to 30% of a total mass of the doped carbon coating layer and the doped carbon core.

10. The negative electrode plate of claim 8 , wherein a mass content of the first doping element and the second doping element in the composite negative electrode is 0.1% to 50%.

11. The negative electrode plate of claim 8 , wherein the doped carbon core comprises natural graphite.

12. The negative electrode plate of the lithium ion secondary battery of claim 8 , wherein the second doping element is not S.

13. The negative electrode plate of the lithium ion secondary battery of claim 12 , wherein a specific capacity of the doped carbon core is greater than 372 milliamperehours/gram (mAh/g).

14. The negative electrode plate of the lithium ion secondary battery of claim 13 , wherein the specific capacity of the doped carbon core is 420-620 mAh/g.

15. A lithium ion secondary battery, comprising:
a negative electrode plate of the lithium ion secondary battery that comprises:
a current collector; and
a composite negative electrode that covers the current collector, wherein the composite negative electrode comprises:
a doped carbon core containing a first doping element, wherein the first doping element comprises nitrogen, wherein a nitrogen atom of the first doping element and a carbon atom in the doped carbon core are bonded in at least one form of pyridinic nitrogen, graphite nitrogen or pyrrolic nitrogen; and
a doped carbon coating layer that coats a surface of the doped carbon core, wherein the doped carbon coating layer comprises a second doping element that is N, P, B, S, O, F, Cl, or H, and wherein the first doping element is different from the second doping element;

a positive electrode;
a separator separating the negative electrode plate and positive electrode from each other;
a non-aqueous electrolyte; and
a shell that houses the negative electrode plate, the positive electrode, the separator, and the non-aqueous electrolyte to form the lithium ion secondary battery.

16. The lithium ion secondary battery of claim 15 , wherein a mass of the doped carbon coating layer is 5% to 30% of a total mass of the doped carbon coating layer and the doped carbon core.

17. The lithium ion secondary battery of claim 15 , wherein a mass content of the first doping element and the second doping element in the composite negative electrode is 0.1% to 50%.

18. The lithium ion secondary battery of claim 15 , wherein the doped carbon core comprises natural graphite.

19. The lithium ion secondary battery of claim 15 , wherein the second doping element is not S.

20. The lithium ion secondary battery of claim 19 , wherein a specific capacity of the doped carbon core is 420-620 milliamperehours/gram (mAh/g).

Assignees

• Huawei Tech Co Ltd

Inventors

• Xia Shengan
• Li Hui
• Xie Fengchao

Classifications

• H01M4/366 Primary

  as layered products · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title

• H01M4/133

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

• H01M4/62

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

• H01M10/0525

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