Hybrid anode compositions for lithium ion batteries

• US 20090117466A1
• 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 8,119,288 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 2004/021 Physical characteristics, e.g. porosity, surface area
• CPC Class Codes: H01M 4/02 Electrodes composed of, or comprising, active material
• 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 4/364 as mixtures
• CPC Class Codes: H01M 4/366 as layered products
• 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 4/40 Alloys based on alkali metals
• CPC Class Codes: H01M 4/42 Alloys based on zinc
• CPC Class Codes: H01M 4/44 Alloys based on cadmium
• CPC Class Codes: H01M 4/463 Aluminium based
• CPC Class Codes: H01M 4/485 of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy H01M4/505, H01M4/525 take precedence
• CPC Class Codes: H01M 4/505 of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• CPC Class Codes: H01M 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: H01M 4/583 Carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries

Abstract

The present invention provides an exfoliated graphite-based hybrid 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 alkali or alkaline metal ions (particularly, lithium ions); and (b) exfoliated graphite flakes that are substantially interconnected to form a porous, conductive graphite network comprising pores, wherein at least one of the particles or coating resides in a pore of the network or attached to a flake of the network and the exfoliated graphite amount is in the range of 5% to 90% by weight and the amount of particles or coating is in the range of 95% to 10% by weight. Also provided is a lithium secondary battery comprising such a negative electrode (anode). The battery exhibits an exceptional specific capacity, excellent reversible capacity, and long cycle life.

Claims

1. An exfoliated graphite-based hybrid composition for use as an electrochemical cell electrode, said composition comprising:

a) micron- or nanometer-scaled particles or coating which are capable of absorbing and desorbing at least one of alkali or alkaline metal ions; and

b) exfoliated graphite flakes that are substantially interconnected to form a porous, conductive graphite network comprising pores, wherein at least one of said particles or coating resides in a pore of said network or attached to a flake of said network and the exfoliated graphite amount is in the range of 5% to 90% by weight and the amount of particles or coating is in the range of 95% to 10% by weight.

2. The hybrid composition of claim 1 wherein said exfoliated graphite flakes are obtained from intercalation and exfoliation 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 hybrid composition as defined in claim 1 wherein said graphite flakes have a specific surface area greater than about 100 m²/gm or said graphite flakes have an average thickness thinner than 10 nm.

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

5. The hybrid 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 hybrid composition as defined in claim 1 wherein said alkali or alkaline metal ions comprise lithium ions.

7. The hybrid 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 exfoliated graphite.

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

10. The hybrid composition as defined in claim 1 wherein the particles or coating comprises an active material 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 hybrid 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 hybrid 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 DVB, cellulosic polymers, and epoxy resins.

13. The hybrid 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 hybrid composition as defined in claim 1 which is capable of absorbing and desorbing lithium ions, and a non-aqueous 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 hybrid composition as defined in claim 10, which is capable of absorbing and desorbing lithium ions, and a non-aqueous electrolyte disposed between said negative electrode and said positive electrode.

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