Very low emission hybrid electric vehicle incorporating an integrated propulsion system including a fuel cell and a high power nickel metal hydride battery pack

• US 20030129459A1
• Filed: 12/09/2002
• Published: 07/10/2003
• Est. Priority Date: 10/13/2000
• Status: Active Grant

• Current Assignee: Chevron Technology Ventures LLC (Chevron Corp.)
• Original Assignee: Chevron Technology Ventures LLC (Chevron Corp.)
• Inventors: Ovshinsky, Stanford R., Stempel, Robert C.
• Granted Patent: US 7,226,675 B2
• Time in Patent Office: Days
• US Class Current: 429/9
• CPC Class Codes: B60L 50/72 Constructional details of fuel cells specially adapted for electric vehicles
• CPC Class Codes: C01B 13/02 Preparation of oxygen by liquefying F25J
• CPC Class Codes: C01B 3/0031 Intermetallic compounds; Metal alloys; Treatment thereof
• CPC Class Codes: H01M 2004/8684 Negative electrodes
• CPC Class Codes: H01M 2004/8689 Positive electrodes
• CPC Class Codes: H01M 4/86 Inert electrodes with catalytic activity, e.g. for fuel cells
• CPC Class Codes: H01M 4/8615 Bifunctional electrodes for rechargeable cells
• CPC Class Codes: H01M 4/90 Selection of catalytic material
• CPC Class Codes: H01M 4/9041 Metals or alloys H01M4/92 takes precedence
• CPC Class Codes: H01M 8/0267 having heating or cooling means, e.g. heaters or coolant flow channels
• CPC Class Codes: H01M 8/04225 during start-up
• CPC Class Codes: H01M 8/04291 Arrangements for managing water in solid electrolyte fuel cell systems H01M8/04119 takes precedence
• CPC Class Codes: H01M 8/065 by dissolution of metals or alloys; by dehydriding metallic substances
• CPC Class Codes: H01M 8/0668 Removal of carbon monoxide or carbon dioxide
• CPC Class Codes: H01M 8/08 Fuel cells with aqueous electrolytes
• CPC Class Codes: H01M 8/083 Alkaline fuel cells
• CPC Class Codes: H01M 8/184 Regeneration by electrochemical means
• CPC Class Codes: H01M 8/186 by electrolytic decomposition of the electrolytic solution or the formed water product
• CPC Class Codes: Y02E 60/32 Hydrogen storage
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 90/40 : Application of hydrogen technology to transportation, e.g. using fuel cells
• CPC Class Codes: Y10S 420/90 : Hydrogen storage

Abstract

A very low emission hybrid electric vehicle incorporating an integrated propulsion system which includes a fuel cell, a metal hydride hydrogen storage unit, an electric motor, high specific power, high energy density nickel-metal hydride (NiMH) batteries, and preferably a regenerative braking system. The nickel-metal hydride battery module preferably has a peak power density in relation to energy density as defined by:

P>1,375−15E,

where P is greater than 600 Watts/kilogram, where P is the peak power density as measured in Watts/kilogram and E is the energy density as measured in Watt-hours/kilogram.

Claims

1. A very low emission hybrid electric vehicle drive system comprising:

an electric motor;

at least one nickel-metal hydride battery module for powering said electric motor; and

a fuel cell for powering said electric motor and recharging said at least one nickel-metal hydride battery module.

2. The drive system according to claim 1, wherein said at least one battery module has an internal resistance effective to provide a peak power density in relation to an energy density as defined by:

P>

1,375−

15E, with P greater than 600 Watts/kilogram, where P is the peak power density as measured in Watts/kilogram and E is the energy density as measured in Watt-hours/kilogram.

3. The drive system according to claim 2, further including control means for operating said at least one battery module in a charge depleting mode.

4. The drive system according to claim 2, further including control means for operating said at least one battery module in a charge sustaining mode.

5. The drive system according to claim 2, wherein said peak energy density is at least 70 Wh/Kg.

6. The drive system according to claim 2, wherein said peak power density is greater than 700 Watts/kilogram.

7. The drive system according to claim 2, wherein said peak power density is at least 1000 Watts/kilogram.

8. The drive system according to claim 2, wherein each of said nickel-metal hydride batteries have at least one negative electrode, said negative electrode including a porous metal substrate comprising a material selected from the group consisting of copper, copper alloy, nickel coated with copper, and nickel coated with copper alloy.

9. The drive system according to claim 8, wherein said negative electrode includes an electrode tab, said electrode tab welded to said porous metal substrate.

10. The drive system according to claim 9, where said negative electrode comprises Ovonic alloys.

11. The drive system according to claim 10, where said Ovonic alloys comprise the composition:

(Base Alloy)_aCo_bMn_cAl_dFe_eLa_fMo_g

where

Base Alloy represents a disordered multicomponent alloy having at least one structure selected from the group consisting of amorphous, microcrystalline, polycrystalline, and any combination of these structures;

b is 0 to 7.5 atomic percent;

c is 0 to 8.5 atomic percent;

d is 0 to 2.5 atomic percent;

e is 0 to 6 atomic percent;

f is 0 to 4.5 atomic percent;

g is 0 to 6.5 atomic percent;

b+c+d+e+f+g>

0; and

a+b+c+d+e+f+g=100 atomic percent.

12. The drive system according to claim 2, wherein each of said nickel-metal hydride batteries includes at least one positive electrode, said positive electrode comprising an active material comprising a disordered γ

-phase positive electrode material.

13. The drive system according to claim 12, wherein said active material further comprises an additive chosen from the group consisting of nickel particles, nickel fibers, graphite particles, nickel plated graphite particles, nickel plated copper particles, nickel plated copper fibers, nickel flakes, and nickel plated copper flakes.

14. The drive system according to claim 2, wherein said nickel metal hydride batteries are low pressure nickel metal hydride electrochemical cells comprising:

a negative electrode comprising a metal hydride active material;

a positive electrode comprising a nickel hydroxide active material; and

a reduced thickness separator positioned around said negative electrode and around said positive electrode, said separator comprising a material selected from the group consisting of nylon, and grafted polyethylene.

15. The drive system according to claim 14, wherein said negative electrode or the surface of said reduced thickness separator facing said negative electrode has a uniform distribution of hydrophobic material.

16. The drive system according to claim 15, where said hydrophobic material comprises a 1% aqueous solution of polytetrafluoroethylene.

17. The drive system according to claim 1, further comprising a fluid cooled battery-pack system, said system comprising:

a battery-pack case including at least one coolant inlet means and at least one coolant outlet means, said at least one battery module disposed within said case such that said module is spacedly disposed from said case and from any other module disposed within said case to form coolant flow channels along at least one surface of said module; and

at least one coolant transport means, said coolant transport means causing said coolant to enter said coolant inlet means of said case, to flow through said coolant flow channels and to exit said coolant outlet means of said case.

18. The drive system according to claim 1, further comprising a cooling system for cooling said at least one nickel metal hydride battery module.

19. The drive system according to claim 1, wherein said at least one battery module includes negative electrodes having porous metal substates formed substantially of copper.

20. The drive system according to claim 1, further comprising:

a regenerative braking system providing charging current for said nickel-metal hydride batteries.

21. The drive system according to claim 1, wherein said fuel cell is selected from the group consisting of an alkaline fuel cell, a PEM fuel cell, a molten carbonate fuel cell, a direct methanol fuel cell, a phosphoric acid fuel cell, and a solid oxide fuel cell.

22. The drive system according to claim 21, wherein said alkaline fuel cell comprises:

a hydrogen electrode;

an oxygen electrode;

means for contacting said hydrogen electrode with a gaseous hydrogen stream;

means for contacting said oxygen electrode with a gaseous oxygen containing stream; and

means for contacting said hydrogen electrode and said oxygen electrode with an electrolyte stream.

23. The drive system according to claim 22, wherein said hydrogen electrode comprises:

an anode active material having hydrogen storage capacity;

said anode active material having a gaseous hydrogen contacting surface, an electrolyte contacting surface, and the bulk of said anode active material disposed between said gaseous hydrogen contacting surface and said electrolyte contacting surface;

said gaseous hydrogen contacting surface is adapted to dissociate and adsorb said gaseous hydrogen;

said bulk of said anode active material is adapted to store said adsorbed hydrogen;

said electrolyte contacting surface is adapted to react said stored hydrogen with an electrolyte solution.

24. The fuel cell of claim 23, wherein said anode additionally includes a substrate component which provides for both electrical conductivity and mechanical support and comprises an electrically conductive mesh, grid, foam, matte, foil, plate, or expanded metal.

25. The fuel cell of claim 23, wherein said anode active material is a hydrogen storage alloy which does not include noble metal catalysts.

26. The fuel cell of claim 25, wherein said hydrogen storage alloy is selected from the group consisting of rare-earth/Misch metal alloys, zirconium alloys, titanium alloys, and mixtures of alloys thereof.

27. The fuel cell of claim 26, wherein said hydrogen storage alloy has the following composition:

(Base Alloy)_aCo_bMn_cFe_dSn_e

where the Base Alloy comprises 0.1 to 60 atomic percent Ti, 0.1 to 40 atomic percent Zr, 0 to 60 atomic percent V, 0.1 to 57 atomic percent Ni, and 0 to 56 atomic percent Cr;

b is 0 to 7.5 atomic percent;

c is 13 to 17 atomic percent;

d is 0 to 3.5 atomic percent;

e is 0 to 1.5 atomic percent; and

a+b+c+d+e=100 atomic percent.

28. The fuel cell of claim 23, wherein said fuel cell further includes an anode which includes a hydrophobic component.

29. The fuel cell of claim 28, wherein said hydrophobic component is polytetrafluoroethylene (PTFE).

30. The fuel cell of claim 23, wherein said anode additionally includes a component which provides for electrical conductivity and comprises an electrically conductive powder intimately mixed with said hydrogen storage material.

31. The fuel cell of claim 30, wherein said electrically conductive powder comprises at least one material selected from the group consisting of copper, a copper alloy, nickel, a nickel alloy, and carbon.

32. The fuel cell of claim 24, wherein said mesh, grid, foam, or expanded metal is formed from nickel, nickel alloy, copper, copper plated nickel or a copper-nickel alloy.

33. The fuel cell of claim 23, wherein said anode active material comprises a composite hydrogen storage material including:

1) an active material having hydrogen storage capacity; and

2) a catalytic material having greater catalytic activity toward the dissociation of molecular hydrogen and/or oxidation of hydrogen than that of said active material having hydrogen storage capacity.

34. The fuel cell of claim 33, wherein said active material and said catalytic material are alternately layered throughout at least a portion of said composite hydrogen storage material.

35. The fuel cell of claim 33, wherein said catalytic material comprises a multicomponent compositionally disordered non-equilibrium catalytic material including a host matrix having at least one transition element and having incorporated therein one or more modifier elements, said modifier element modifying the local structural chemical environments of said material to provide said disorder, said material including means for creating an increased density of catalytically active sites for the dissociation of molecular hydrogen.

36. The fuel cell of claim 35, wherein said means include:

a) a plurality of chemical elements for providing a large number of catalytically active sites;

b) means designed to provide local chemical environments which include sites for selectively inactivating poisonous species; and

c) non-equilibrium metastable phases and configurations.

37. The fuel cell of claim 35, wherein said disordered material is selected from a group consisting of:

a) a substantially polycrystalline multicomponent material lacking long range compositional order;

b) a substantially microcrystalline material;

c) a mixture of polycrystalline or microcrystalline phase regions and amorphous phase regions;

d) an amorphous material containing at least one amorphous phase; and

e) a mixture of microcrystalline and polycrystalline phases.

38. The fuel cell of claim 33, wherein said catalytic material is continually compositionally graded with said anode active material throughout at least a portion of said anode.

39. The fuel cell of claim 33, wherein said anode active material is in the form of particulate material onto which a layer of said catalytic material is deposited.

40. The fuel cell of claim 39, wherein said catalytic layer is continually compositionally graded within said anode active material, and has the greatest concentration of catalytic material at the exterior surface of said layer.

41. The fuel cell of claim 35, wherein said host matrix includes Ni.

42. The fuel cell of claim 35, wherein said modifier element is a transition element.

43. The fuel cell of claim 35, wherein said modifier element is selected from the group consisting of Ti, Zr, Mo, V, Mg, Si and Al.

44. The fuel cell of claim 43, wherein said catalytic material is a Ni—

Ti—

Mo alloy.

45. The drive system according to claim 21, wherein said fuel cell is selected from the group consisting of an alkaline fuel cell, a PEM fuel cell, a molten carbonate fuel cell, a phosphoric acid fuel cell, and a solid oxide fuel cell.

46. The drive system according to claim 45 further comprising a hydrogen storage unit adapted to 1) receive hydrogen, 2) store hydrogen, and 3) supply hydrogen to said fuel cell.

47. The drive system according to claim 46, wherein said hydrogen storage unit is a metal hydride hydrogen storage unit including a hydrogen storage material.

48. The drive system according to claim 47, wherein said hydrogen storage material includes AB₂ or AB₅ type hydrogen storage alloys.

49. The drive system according to claim 48, wherein said AB₂ or AB₅ type hydrogen storage alloy is selected from the group consisting of rare earth-nickel alloys, titanium-manganese alloys, titanium-zirconium alloys, titanium-iron alloys, or magnesium alloys.

50. The drive system according to claim 49, wherein said hydrogen storage alloy is a powder characterized in that said alloy powder has:

a) a hydrogen storage capacity of at least 6 weight %;

b) absorption kinetics such that the alloy powder absorbs 80% of it'"'"'s total capacity within 5 minutes at 300 °

C.; and

c) a particle size range of between 30 and 70 microns.

51. The drive system according to claim 50, wherein said alloy includes at least 90 weight % magnesium.

52. The drive system according to claim 51, wherein said alloy further includes 0.5-2.5 weight % nickel.

53. The drive system according to claim 52, wherein said alloy further includes 1.0-4.0 weight % Misch metal.

54. The drive system according to claim 53, wherein said Misch metal comprises predominantly Ce, La and Pr.

55. The drive system according to claim 54, wherein said alloy further includes one or more from the group consisting of 3-7 weight % Al, 0.1-1.5 weight % Y and 0.3-1.5 weight % silicon.

56. The drive system according to claim 49, wherein said alloy is a non-pyrophoric alloy which comprises 0.5-10 at. % Zr, 29-35 at. % Ti, 10-15 at. % V, 13-20 at. % Cr, 32-38 at. % Mn, 1.5-3.0 at. % Fe, and 0.05-0.5 at. % Al.

57. The drive system according to claim 56, wherein said alloy comprises Zr₁ Ti₃₃ V_12.54 Cr₁₅ Mn₃₆ Fe_2.25 Al_0.21.

58. The drive system according to claim 56, wherein said alloy comprises Zr_1.5 Ti_32.5 V_12.54 Cr₁₅ Mn₃₆ Fe_2.25 Al_0.21.

59. The drive system according to claim 56, wherein said alloy further comprises 1-10 at. % total of at least one element selected from the group consisting of Ba, Co, Cu, Cs, K, Li, Mm, Mo, Na, Nb, Ni, Rb, Ta, Tl, and W.

60. The drive system according to claim 1, wherein said drive system is a series hybrid electric vehicle system.

61. The drive system according to claim 1, wherein said drive system is a parallel hybrid electric vehicle system.

62. The drive system according to claim 1, wherein said drive system is a series-parallel hybrid electric vehicle system.