LiF-EMBEDDED SiG POWDER FOR LITHIUM ION BATTERY

• US 20180241033A1
• Filed: 10/05/2015
• Published: 08/23/2018
• Est. Priority Date: 10/06/2014
• Status: Active Grant

• Current Assignee: XG Sciences, Inc.
• Original Assignee: XG Sciences, Inc.
• Inventors: DO, Inhwan, WANG, Hong
• Granted Patent: US 10,644,309 B2
• Time in Patent Office: Days
• CPC Class Codes: C01B 32/19 by exfoliation
• CPC Class Codes: C01B 33/02 Silicon forming single crystals or homogeneous polycrystalline material with defined structure C30B
• CPC Class Codes: C01P 2004/61 Micrometer sized, i.e. from 1-100 micrometer
• CPC Class Codes: C01P 2004/62 Submicrometer sized, i.e. from 0.1-1 micrometer
• CPC Class Codes: C01P 2004/80 Particles consisting of a mixture of two or more inorganic phases
• CPC Class Codes: C01P 2006/11 Powder tap density
• CPC Class Codes: C01P 2006/12 Surface area
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 2004/021 Physical characteristics, e.g. porosity, surface area
• CPC Class Codes: H01M 2004/027 Negative electrodes
• CPC Class Codes: H01M 4/134 Electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/1395 of electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/366 as layered products
• CPC Class Codes: H01M 4/386 Silicon or alloys based on silicon
• CPC Class Codes: H01M 4/5835 Comprising fluorine or fluoride salts
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: H01M 4/62 Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
• CPC Class Codes: H01M 4/621 Binders
• CPC Class Codes: H01M 4/625 : Carbon or graphite
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries

Abstract

A nanographitic composite for use as an anode in a lithium ion battery is described, including: particles of an electroactive material; and a coating over the electroactive particles comprising a plurality of graphene nanoplatelets and an SEI modifier additive wherein the SEI modifier additive is a dry powder that is disposed over at least part of the surface of the electroactive material particles.

Claims

1. A nanographitic composite for use as an anode in a lithium ion battery, comprising:

particles of an electroactive material; and

a coating over the electroactive particles comprising a plurality of graphene nanoplatelets and an SEI modifier additive wherein the SEI modifier additive is a dry powder that is disposed over at least part of the surface of the electroactive material particles.

2. The nanographitic composite of claim 1, wherein the coating comprises a mixture of the graphene nanoplatelets and SEI modifier additive.

3. The nanographitic composite of claim 1, wherein the coating comprises an inner layer of SEI modifier additive and an outer layer of graphene nanoplatelets, wherein the graphene nanoplatelets coat at least a portion of the additive modified electroactive particles to form a layer made up of overlapping graphene nanoplatelets.

4. The nanographitic composite of claim 1, wherein the graphene nanoplatelets forms a contact with at least a portion of the electroactive particle.

5. The nanographitic composite of claim 1, wherein in the SEI modifier additive is LiF.

6. The nanographitic composite of claim 1, wherein the graphene nanoplatelets have a thickness of 0.34 nm to 50 nm and a lateral dimension of less than 900 nm.

7. The nanographitic composite of claim 1, wherein the SEI modifier additive results in a discontinuous layer.

8. The nanographitic composite of claim 1, wherein the SEI modifier additive results in a continuous layer.

9. The nanographitic composite of claim 1, wherein the graphene nanoplatelets-coated nanoscale particles form agglomerates.

10. The nanographitic composite of claim 1, wherein the graphene nanoplatelets have a lateral dimension of less than 500 nm.

11. The nanographitic composite of claim 1, wherein the graphene nanoplatelets have a lateral dimension of 30 nm to 200 nm.

12. The nanographitic composite of claim 1, wherein the coating of graphene nanoplatelets comprises multiple layers of graphene nanoplatelets.

13. The nanographitic composite of claim 1, wherein the electroactive material is one or more material selected from the group consisting of silicon, tin, iron, magnesium, aluminum, lead, gold, silver, titanium, platinum, palladium, ruthenium, copper, nickel, rhodium and nickel and combinations thereof.

14. The nanographitic composite of claim 1, wherein electroactive material comprises silicon.

15. The nanographitic composite of claim 14, wherein the silicon is present in a range from 5 wt % to 90 wt % of the composite.

16. The nanographitic composite of claim 14, wherein the silicon is present in a range from 40 wt % to 70 wt % of the composite.

17. The nanographitic composite of claim 14, wherein the silicon is present in a range from 30 wt % to 70 wt % of the composite

18. The nanographitic composite of claim 5, wherein the LiF is present in a range from 2 wt % to 30 wt % of the composite.

19. The nanographitic composite of claim 1, wherein the graphene is present in a range from 10 wt % to 40 wt % of the composite.

20. The nanographitic composite of claim 1, wherein the composite further comprises a conductive carbon additive.

21. The nanographitic composite of claim 20, wherein the conductive carbon additive is selected from the group consisting of carbon black, acetylene black, carbon nanotube, carbon fiber, carbon nanohorn, carbon nanocoil and combinations thereof.

22. The nanographitic composite of claim 1, wherein the electroactive particle is present in a range from 5 wt % to 90 wt % of the composite.

23. The nanographitic composite of claim 1, wherein the particles have a surface area is in the range of 50 to 200 m²/g.

24. An electrode for use as an anode in a lithium ion battery, said electrode comprising:

(a) the nanographitic composite according to claim 1; and

(b) a binder.

25. The electrode of claim 24, further comprising a conductive additive.

26. The electrode of claim 25, wherein the conductive additive comprises a graphene.

27. The electrode of claim 25, wherein the conductive additive is 2 to 20 wt % of the total electrode weight.

28. The electrode of claim 25, wherein the binder is 3 to 20 wt % of the total electrode weight.

29. A lithium ion battery comprising:

an anode according to claim 24;

a cathode; and

an electrolyte disposed between and in ionic contact with the anode and the cathode.

30. A method of making a nanocomposite suitable for use in a lithium ion battery, comprising:

introducing an electroactive particle powder into a high energy dry mill, wherein the particles are of a micron-scale dimension;

introducing an SEI modifier additive in the high energy dry mill as a dry powder, wherein the additive particles are of a micron-scale dimension and at least some of the SEI modifier additive gets disposed on the surface electroactive particle;

introducing a graphite particle powder into the high energy dry mill, wherein the graphite particles are greater than 0.5 μ

m; and

milling the electroactive particle powder with the SEI modifier additive and the graphite particle powder, to exfoliate the graphite and reduce the particle size of the electroactive particle;

wherein the exfoliated size-reduced graphite coats the surface of the size-reduced electroactive particle,

wherein the resultant nanocomposite has a bulk density of greater than 0.50 g/cm³.

31. The method of claim 30, wherein the milling results in the reduction of the particle size of the electroactive material to less than 3 um and reduce the particle size of the graphite particle to less than 900 nm.

32. A nanographitic composite for use as an anode in a lithium ion battery, comprising:

a plurality of composite particles comprising;

an electroactive particle;

a coating layer comprising an inner layer of graphene nanoplatelets that are tightly bound to the electroactive particle and an outer layer of graphene nanoplatelets that interact loosely with the inner layer of graphene nanoplatelets, wherein the nanographitic platelets covers at least a portion of the nanoscale particle to form a nanographitic layer; and

an SEI modifier additive wherein the SEI modifier additive is a dry powder.

33. The nanographitic composite of claim 32, wherein the SEI modifier additive is preferentially disposed at the interface of the electroactive particle and the inner layer of graphene nanoplatelets.

34. The nanographitic composite of claim 32, wherein the SEI modifier additive is disposed in the outer layer of the graphene nanoplatelets surrounding the electroactive particle.

35. The nanographitic composite of claim 32, wherein the inner layer comprises a mixture of carbon, silicon and LiF.

36. The nanographitic composite of claim 32, wherein the inner layer is covalently bonded to the electroactive particle.

37. The nanographitic composite of claim 32, wherein the covalent bond is a pi-bond or a partial pi-bond.

38. The nanographitic composite of claim 32, wherein the inner layer is bonded to the electroactive particle by van der Waals bond.

39. The nanographitic composite of claim 32, wherein the graphene nanoplatelets-coated nanoscale particles form agglomerates.

40. The nanographitic composite of claim 32, wherein the coating layer comprises multiple layers of graphene nanoplatelets.

41. The nanographitic composite of claim 32, wherein the electroactive particle is one or more selected from the group consisting of silicon, tin, iron, magnesium, aluminum, lead, gold, silver, titanium, platinum, palladium, ruthenium, copper, nickel, rhodium and nickel and combinations thereof.

42. The nanographitic composite of claim 32, wherein electroactive particle comprises silicon.

43. The nanographitic composite of claim 42, wherein the silicon is present in a range from 10 wt % to 90 wt % of the composite.

44. The nanographitic composite of claim 42, wherein the composite further comprises a conductive carbon additive.

45. The nanographitic composite of claim 44, wherein the conductive carbon additive is selected from the group consisting of carbon black, acetylene black, carbon nanotube, carbon fiber, carbon nanohorn, carbon nanocoil and combinations thereof.

46. An electrode for use as an anode in a lithium ion battery, said electrode comprising:

(a) the nanographitic composite according to claim 32; and

(b) a binder.

47. The electrode of claim 46, further comprising a conductive additive.

48. The electrode of claim 46, wherein the conductive additive comprises a graphene.

49. The electrode of claim 46, wherein the conductive additive is 2 to 20 wt % of the total electrode weight.

50. The electrode of claim 46, wherein the binder is 3 to 20 wt % of the total electrode weight.

51. A lithium ion battery comprising:

an anode according to claim 46;

a cathode;

a separator spacing apart the anode and the cathode; and

an electrolyte in contact with the anode and the cathode.