Electrochemically modified carbon material for lithium-ion battery

Patent metadata

Field	Value
Publication number	US-10535876-B2
Application number	US-201415506805-A
Country	US
Kind code	B2
Filing date	Aug 29, 2014
Priority date	Aug 29, 2014
Publication date	Jan 14, 2020
Grant date	Jan 14, 2020

Abstract

The present invention provides an anode material for a lithium-ion battery comprising a carbon particle having a particle size of 5 μm to 30 μm, and including defective portions on a surface of the carbon particle, the defective portions being grooves formed by cathodically exfoliating graphene layers from the carbon particle.

First claim

The invention claimed is:

1. An anode material for a lithium-ion battery comprising a carbon particle having a particle size of 5 μm to 30 μm, and including defective portions on a surface of the carbon particle, wherein the defective portions are grooves formed by removing graphene layers from a raw carbon particle by cathodic exfoliation and the width of the grooves is distributed between 100 nm and 500 nm, inclusive.

2. The anode material according to claim 1 , wherein the carbon particle is a soft carbon particle.

3. A lithium ion battery comprising the anode material according to claim 2 .

4. The anode material according to claim 1 , further comprising anode active particles which are capable of absorbing and desorbing lithium ions.

5. The anode material according to claim 4 , wherein the anode active particles are metal or semi-metal particles or compound particles of at least one element selected from a group consisting of Si, Sn, Al, Ge and Pb.

6. A lithium ion battery comprising the anode material according to claim 5 .

7. The anode material according to claim 4 , wherein the anode active particles adhere on the carbon particle.

8. The anode material according to claim 7 , wherein the carbon particle and the anode active particles are composited with amorphous carbon layer.

9. A lithium ion battery comprising the anode material according to claim 8 .

10. A lithium ion battery comprising the anode material according to claim 7 .

11. A lithium ion battery comprising the anode material according to claim 4 .

12. A lithium ion battery comprising the anode material according to claim 1 .

13. A method for preparing an anode material comprising:
soaking carbon particles having a particle size of 5 μm to 30 μm into an electrolytic solution, the electrolytic solution containing a cation that intercalates between graphene layers in the carbon particles;
removing graphene layers from raw carbon particles by cathodic exfoliation by intercalating the cation between graphene layers so as to form defective portions on surfaces of the carbon particles; and
collecting the carbon particles after the cathodic exfoliation.

14. The method according to claim 13 , further comprising heat treating the collected carbon particles under inert atmosphere.

15. The method according to claim 13 , wherein the cation is a solvate of alkaline metal cation with an organic solvent.

16. The method according to claim 15 , wherein the cation is a solvate of sodium ion with dimethyl sulfoxide.

17. An anode material for a lithium-ion battery comprising a soft carbon particle having a particle size of 5 μm to 30 μm, and including defective portions on a surface of the carbon particle, the defective portions being grooves formed by cathodically exfoliating graphene layers from the carbon particle.

18. A lithium ion battery comprising the anode material according to claim 17 .

Assignees

• Nec Corp

Inventors

• Cheng Qian
• Tamura Noriyuki

Classifications

• H01M4/364

  as mixtures · CPC title

• H01M10/0525

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

• H01M4/38

  of elements or alloys · CPC title

• H01M4/133

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

• C01P2004/61

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