Nano graphene platelet-based composite anode compositions for lithium ion batteries

• US 20090117467A1
• Filed: 11/05/2007
• Published: 05/07/2009
• Est. Priority Date: 11/05/2007
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Nanotek Instruments, Inc.
• Inventors: Zhamu, Aruna, Jang, Bor Z.
• Granted Patent: US 7,745,047 B2
• Time in Patent Office: Days
• US Class Current: 429/231.800
• 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 4/133 Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/134 Electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/136 Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
• CPC Class Codes: H01M 4/139 Processes of manufacture
• CPC Class Codes: H01M 4/38 of elements or alloys
• CPC Class Codes: H01M 4/386 Silicon or alloys based on silicon
• CPC Class Codes: H01M 4/387 Tin or alloys based on tin
• 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

The present invention provides a nano-scaled graphene platelet-based composite material composition for use as an electrode, particularly as an anode of a lithium ion battery. The composition comprises: (a) micron- or nanometer-scaled particles or coating which are capable of absorbing and desorbing lithium ions; and (b) a plurality of nano-scaled graphene platelets (NGPs), wherein a platelet comprises a graphene sheet or a stack of graphene sheets having a platelet thickness less than 100 nm; wherein at least one of the particles or coating is physically attached or chemically bonded to at least one of the graphene platelets and the amount of platelets is in the range of 2% to 90% by weight and the amount of particles or coating in the range of 98% to 10% by weight. Also provided is a lithium secondary battery comprising such a negative electrode (anode). The battery exhibits an exceptional specific capacity, an excellent reversible capacity, and a long cycle life.

Claims

1. A nano-scaled graphene platelet-based composite composition for use as a lithium ion battery anode, said composition comprising:

a) micron- or nanometer-scaled particles or coating which are capable of absorbing and desorbing lithium ions; and

b) a plurality of nano-scaled graphene platelets (NGPs), wherein a platelet comprises a graphene sheet or a stack of graphene sheets having a platelet thickness less than 100 nm;

wherein at least one of said particles or coating is physically attached or chemically bonded to at least one of said platelets and the amount of platelets is in the range of 2% to 90% by weight and the amount of particles or coating is in the range of 98% to 10% by weight.

2. The composite composition of claim 1 wherein said NGPs are obtained from exfoliation and separation of graphene sheets of a laminar graphite material selected from natural graphite, synthetic graphite, highly oriented pyrolytic graphite, graphite fiber, carbon fiber, carbon nano-fiber, graphitic nano-fiber, spherical graphite or graphite globule, meso-phase micro-bead, meso-phase pitch, graphitic coke, graphitized polymeric carbon, or a combination thereof.

3. The composite composition as defined in claim 1 wherein said platelets have a specific surface area greater than about 100 m²/gm or have an average thickness thinner than 10 nm.

4. The hybrid composition as defined in claim 1 wherein said platelets have a specific surface area greater than about 500 m²/gm or have an average thickness thinner than 2 nm.

5. The composite composition as defined in claim 1 wherein said particles have a dimension less than 5 μ

m or said coating has a thickness less than 5 μ

m.

6. The composite composition as defined in claim 1, further comprising a conductive additive selected from carbon or graphitic nano-fiber, carbon nano-tube, carbon black, activated carbon powder, or a combination thereof.

7. The composite composition as defined in claim 1 wherein the particles or coating comprise Sn or Si as a primary element with Si or Sn content no less than 20% by weight based on the total weight of the particles or coating and nano-scaled graphene platelets.

8. The composite composition as defined in claim 1 wherein the particles comprise an element selected from Si, Ge, Sn, Cd, Sb, Pb, Bi, or Zn.

9. The composite composition as defined in claim 1 wherein the particles or coating are substantially amorphous or comprise nano crystallites.

10. The composite composition as defined in claim 1 wherein the particles or coating comprises an active material capable of absorbing or extracting lithium ions and said active material is selected from the group consisting of:

(a) silicon (Si), germanium (Ge), tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi), zinc (Zn), aluminum (Al), and cadmium (Cd);

(b) alloys or intermetallic compounds of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, or Cd with other elements, wherein said alloys or compounds are stoichiometric or non-stoichiometric;

(c) oxides, carbides, nitrides, sulfides, phosphides, selenides, and tellurides of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Fe, or Cd, and their mixtures or composites;

(d) salts and hydroxides of Sn; and

(e) combinations thereof.

11. The composite composition as defined in claim 1 further comprising an amorphous carbon, polymeric carbon, carbon black, coal tar pitch, petroleum pitch, or meso-phase pitch in physical contact with said particles or coating.

12. The composite composition as defined in claim 11 wherein said polymeric carbon is obtained from pyrolyzation of a polymer selected from the group consisting of phenol-formaldehyde, polyacrylonitrile, styrene-based polymers, cellulosic polymers, epoxy resins, and combinations thereof.

13. The composite composition of claim 11 wherein said amorphous carbon phase is obtained from chemical vapor deposition, chemical vapor infiltration, or pyrolyzation of an organic precursor.

14. A lithium secondary battery comprising a positive electrode, a negative electrode comprising a composite composition as defined in claim 1 which is capable of absorbing and desorbing lithium ions, and an electrolyte disposed between said negative electrode and said positive electrode.

15. The lithium secondary battery according to claim 14, wherein said positive electrode comprises lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium iron phosphate, lithium vanadium phosphate, or a combination thereof.

16. A lithium secondary battery comprising a positive electrode, a negative electrode comprising a composite composition as defined in claim 10, which is capable of absorbing and desorbing lithium ions, and an electrolyte disposed between said negative electrode and said positive electrode.

17. The lithium secondary battery as defined in claim 14, wherein said composite composition further comprises a binder material selected from a polymer, coal tar pitch, petroleum pitch, meso-phase pitch, coke, or a derivative thereof.

18. The lithium secondary battery as defined in claim 16, wherein said composite composition further comprises a binder material selected from a polymer, coal tar pitch, petroleum pitch, meso-phase pitch, coke, or a derivative thereof.

19. The lithium secondary battery as defined in claim 14, wherein said composite composition provides a specific capacity of no less than 600 mAh per gram of the anode composition.

20. The lithium secondary battery as defined in claim 14, wherein said composite composition provides a specific capacity of no less than 1,000 mAh per gram of the anode composition.