HIGH PERFORMANCE BATTERIES WITH CARBON NANOMATERIALS AND IONIC LIQUIDS

• US 20090246625A1
• Filed: 03/26/2009
• Published: 10/01/2009
• Est. Priority Date: 03/26/2008
• Status: Active Grant

• Current Assignee: ADA Technologies, Inc.
• Original Assignee: ADA Technologies, Inc.
• Inventors: Lu, Wen
• Granted Patent: US 8,236,446 B2
• Time in Patent Office: Days
• US Class Current: 429/207
• CPC Class Codes: H01G 11/56 Solid electrolytes, e.g. gels; Additives therein
• CPC Class Codes: H01M 10/0568 characterised by the solutes
• CPC Class Codes: H01M 10/0569 characterised by the solvents
• CPC Class Codes: H01M 4/133 Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/1393 of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/583 Carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/625 Carbon or graphite
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors
• CPC Class Codes: Y10S 977/742 Carbon nanotubes, CNTs
• CPC Class Codes: Y10S 977/743 having specified tube end structure, e.g. close-ended shell or open-ended tube
• CPC Class Codes: Y10T 29/49108 Electric battery cell making

Abstract

The present invention is directed to lithium-ion batteries in general and more particularly to lithium-ion batteries based on aligned graphene ribbon anodes, V₂O₅ graphene ribbon composite cathodes, and ionic liquid electrolytes. The lithium-ion batteries have excellent performance metrics of cell voltages, energy densities, and power densities.

Claims

1. A battery, comprising:

(a) an anodic electrode;

(b) a cathodic electrode; and

(c) an electrolyte material positioned between and in contact with the anodic and cathodic electrodes, wherein;

at least one of the anodic and cathodic electrodes comprises a plurality of graphene nano-ribbons,

the graphene nano-ribbons comprise a plurality of carbon atoms,

at least most of the carbon atoms in the graphene nano-ribbons comprise sp2 hybridized carbon,

the graphene nano-ribbons are positioned adjacent to and/or in contact with the at least one of the anodic and cathodic electrodes, and

at least most of the graphene nano-ribbons are substantially aligned with one another.

2. The battery of claim 1, wherein longitudinal axes of at least most of the graphene nano-ribbons are substantially parallel to one another along substantially the entire length of the graphene ribbon and wherein at least most of the graphene nano-ribbons are carbon nanotubes.

3. The battery of claim 1, wherein at least most of the graphene nano-ribbons are substantially flat, wherein at least most of the graphene nano-ribbons are substantially parallel with one another, and wherein the spacing between substantially parallel oriented nearest neighbor graphene nano-ribbons ranges from about 10 to about 250 nm.

4. The battery of claim 1, wherein at least most of the graphene nano-ribbons are carbon nanotubes and wherein at least most of the first ends of the carbon nanotubes are open to permit ions in the electrolyte to access interior surfaces of the carbon nanotubes.

5. The battery of claim 1, wherein the anodic electrode comprises the graphene nano-ribbons, wherein at least most of the graphene are carbon nanotubes, wherein at least most of the carbon nanotubes have lengths ranging from about 20 to about 1,000 microns, diameters ranging from about 3 to about 50 nm, and inter-carbon nanotube spacings ranging from about 10 to about 250 nm.

6. The battery of claim 1, wherein the cathodic electrode comprises the graphene nano-ribbons and wherein at least one of a continuous and discontinuous thin film of a metal oxide is deposited on the graphene nano-ribbons.

7. The battery of claim 1, wherein at least most of the graphene nano-ribbons have an electron mobility of at least about 15,000 cm²V⁻

1s<sup>−

1</sup>.

8. The battery of claim 1, wherein at least most of the graphene nano-ribbons are plasma etched graphene nano-ribbons and wherein the graphene ribbon mass loading on the at least one of the anodic and cathodic electrodes ranges from about 0.1 to about 4.5 mg/cm² of the first electrode.

9. The battery of claim 8, wherein the graphene ribbon surface area is from about 250 to about 10,000 cm² per cm² of the at least one of the anodic and cathodic electrode.

10. The battery of claim 1, wherein the electrolyte comprises an ionic liquid comprising:

(A) a lithium-containing salt;

(B) a solid electrolyte interphase film-forming additive;

(C) at least one cation selected from the group consisting essentially of the following compounds and mixtures thereof;

11. The battery of claim 1, wherein the electrolyte comprises an ionic liquid having a melting point of no more than about 100 degrees Celsius, a decomposition temperature of at least about 200 degrees Celsius, a viscosity of no more than about 200 Cp, an ionic conductivity of at least about 0.01 mS/cm, and an electrochemical window of at least about 4 Volts.

12. The battery of claim 1, wherein a solid electrolyte interphase is formed on the nano-ribbons in the anodic electrode and further comprising a microporous membrane separator positioned between the anodic and cathodic electrodes

13. An electrochemical battery, comprising:

(a) an ionic liquid electrolyte;

(b) first and second sets of aligned carbon nanotubes;

(c) an anode comprising the first set of carbon nanotubes;

(d) a cathode comprising the second set of carbon nanotubes, and

(e) a microporous membrane separator, wherein the ionic liquid and microporous membrane separator are positioned between the anode and cathode.

14. The battery of claim 13, wherein the first and second set of carbon nanotubes are plasma etched to open free ends of at least most of the carbon nanotubes, and wherein longitudinal axes of at least most of the graphene nano-ribbons are substantially parallel to one another along substantially the entire length of the graphene ribbon.

15. The battery of claim 13, wherein at least most of the first set of aligned carbon nanotubes have lengths ranging from about 20 to about 1,000 microns, diameters ranging from about 3 to about 50 nm, and inter-carbon nanotube spacings ranging from about 10 to about 250 nm.

16. The battery of claim 13, wherein a solid electrolyte interphase is located on the nanotubes in the anode and wherein at least one of a continuous and discontinuous thin film of a metal oxide is deposited on the second set of carbon nanotubes.

17. The battery of claim 13, wherein each of the first and second sets of carbon nanotubes have opposing first and second ends;

wherein the first ends of the first and second sets of carbon nanotubes are, respectively, positioned on the anode and cathode, and wherein the first and second sets of carbon nanotubes are substantially perpendicular to at least one of a conductive and semiconductive substantially planar electrode component of the anode and cathode, respectively.

18. The battery of claim 13, wherein the carbon nanotubes are hollow, wherein the carbon nanotubes have a diameter of about 3 nm to about 50 nm, wherein the first set of carbon nanotubes have average, mean, and or modal lengths ranging from about 200 to about 1,000 μ

m, wherein the second set of carbon nanotubes have an average, mean, and/or modal length of about 200 μ

m to about 1,000 μ

m, and wherein the carbon nanotubes have an electron mobility of at least about 15,000 cm²V<sup>−

1</sup>s<sup>−

1</sup>.

19. The battery of claim 14, wherein the first and second sets of carbon-nanotubes have surface areas of at least about 200 m²/g.

20. The battery of claim 14, wherein the first and second sets of carbon nanotubes have surface areas ranging from about 250 to about 10,000 cm² per cm² of one of the anode and cathode.

21. The battery of claim 14, wherein the carbon nano-tube loading on at least one of the anode and cathode is from about 0.1 to about 4.5 mg/cm².

22. The battery of claim 13, wherein the anode has a lithium-ion intercalation and/or de-intercalation value of at least 200 mAh/g.

23. The battery of claim 13, wherein members of the second set of carbon nanotubes further comprise a thin film metal oxide coating.

24. The battery of claim 23, wherein the metal oxide comprises vanadium oxide.

25. The battery of claim 24, wherein the carbon nanotubes are coated with vanadium oxide, wherein the cathode has a capacity of at least about 400 mAh per gram of vanadium oxide, wherein, for the cathode, the carbon nanotube length ranges from about 300 to about 700 μ

m, and wherein the vanadium oxide coating thickness is from about 1 to about 100 nm.

26. The battery of claim 25, wherein the cathode has a capacity of about 500 mAh per gram of vanadium oxide.

27. The battery of claim 13, wherein the electrolyte comprises an ionic liquid comprising:

(A) a lithium-containing salt;

(B) a solid electrolyte interphase film-forming additive;

(C) at least one cation selected from the group consisting essentially of the following compounds and mixtures thereof;

28. The battery of claim 13, wherein the electrolyte comprises an ionic liquid having a melting point of no more than about 100 degrees Celsius, a decomposition temperature of at least about 200 degrees Celsius, a viscosity of no more than about 200 Cp, an ionic conductivity of at least about 0.01 mS/cm, and an electrochemical window of at least about 4 Volts.

29. The battery of claim 13, further comprising a polymer host is selected from the group consisting essentially of homopolymers and copolymers of polyolefins, polystyrenes, polyvinyls, polyacrylics, polyhalo-olefins, polydienes, polyoxides/esthers/acetals, polysulfides, polyesters/thioesters, polyamides/thioamides, polyurethanes/thiourethanes, polyureas/thioureas, polyimides/thioimides, polyanhydrides/thianhydrides, polycarbonates/thiocarbonates, polyimines, polysiloxanes/silanes, polyphosphazenes, polyketones/thioketones, polysulfones/sulfoxides/sulfonates/sulfoamides, polyphylenes, and mixtures thereof.

30. The battery of claim 29, wherein a molar ratio of ionic liquid to polymer host ranges from about 0.1:

1 to about 10;

1.

31. The battery of claim 13, wherein the micro-porous membrane separator has a thickness from about 2 μ

m to about 200 μ

m and wherein the membrane separator is fully wettable by at least one of a hydrophobic and a hydrophilic ionic liquid.

32. A method, comprising:

de-intercalating ions from aligned carbon nano-ribbons in an anode;

passing the ions through an electrolyte and microporous membrane separator; and

intercalating the ions in aligned carbon nano-ribbons in a cathode.

33. The method of claim 32, wherein the steps of claim 32 occur during discharging and further comprising during charging:

de-intercalating ions from aligned carbon nano-ribbons in the cathode;

passing the ions through the electrolyte and microporous membrane separator;

forming a solid electrolyte interphase on at least one the anode or cathode; and

intercalating the ions in aligned carbon nano-ribbons in the anode.

34. The method of claim 32, wherein the carbon nano-ribbons in the cathode are coated with a metal oxide thin film and wherein a solid electrolyte film is formed on at least most of the nano-ribbons in the anode.

35. The method of claim 32, wherein the carbon nano-ribbons are carbon nanotubes and wherein at least most of the free ends of the carbon nanotubes are open.

36. A process for making an electrochemical battery, comprising the steps of:

(a) providing first and second conductive and/or semi-conductive substrates;

(b) forming graphene nano-ribbons on one or both of the conductive and/or semi-conductive substrates, wherein at least most of the carbon atoms in the graphene nano-ribbons comprise sp hybridized carbon, wherein the graphene nano-ribbons are positioned adjacent to and/or in contact with one of the first and second conductive and/or semi-conductive substrates and wherein at least most of the graphene ribbons are aligned with one another;

(c) positioning a membrane separator and an electrolyte between the first and second conductive and/or semi-conductive substrates.

37. The process of claim 36, wherein electrolyte further comprises:

(a) a lithium salt;

(b) an ionic liquid; and

(c) solid electrolyte interphase film-forming additive.

38. The process of claim 36, wherein the graphene nano-ribbons are carbon nanotubes and wherein the carbon nano-tubes are etched.

39. The process of claim 36, wherein after step (b) but before step (c), further comprising step (d)

(d) coating at least most of the graphene nano-ribbons on second conductive and/or semi-conductive substrate with a metal-containing film, wherein the film thickness ranges from about 0.5 to about 100 nm.