Claims
- 1. An AB.sub.5 hydrogen absorbing alloy composition for use in an electrochemical cell, essentially according to the formulation
- LM.sub.x Ni.sub.A-(B+C+D) Co.sub.B Al.sub.C Mn.sub.D
- wherein
- L comprises mischmetal including between about 45 and 70 percent lanthanum,
- M comprises an element selected from the group consisting of titanium and zirconium,
- X is between 0.001 and 0.01,
- B C, and D are each greater than zero, and
- A is about 5,
- wherein the AB.sub.5 hydrogen absorbing alloy composition comprises a homogeneous alloy.
- 2. The AB.sub.5 alloy of claim 1 wherein B is between about 0.4 and 1.0.
- 3. The AB.sub.5 alloy of claim 1 wherein C is between about 0.1 and 0.6.
- 4. The AB.sub.5 alloy of claim 1 wherein D is less than about 0.45.
- 5. The AB.sub.5 alloy of claim 1 wherein B is between about 0.4 and 1.0, C is between about 0.1 and 0.6, and D is less than about 0.45.
- 6. The AB.sub.5 alloy of claim 1 wherein X is between about 0.002 and 0.006.
- 7. The AB.sub.5 alloy of claim 1 wherein X is about 0.0035.
- 8. An AB.sub.5 hydrogen absorbing alloy composition for use in an electrochemical cell, essentially according to the formulation
- La.sub.0.63 Ce.sub.0.26 Nd.sub.0.08 Pr.sub.0.03 M.sub.x Ni.sub.3.7 Co.sub.0.78 Al.sub.0.28 Mn.sub.0.36
- wherein M comprises an alloying element selected from the group consisting of titanium and zirconium and combinations thereof, and X is between 0.001 and 0.01,
- wherein the AB.sub.5 hydrogen absorbing alloy composition comprises a homogeneous alloy.
- 9. The AB.sub.5 alloy of claim 8 wherein X is between about 0.002 and 0.006.
- 10. The AB.sub.5 alloy of claim 8 wherein X is about 0.0035.
- 11. A method of producing an AB.sub.5 hydrogen storage alloy for use in an electrochemical cell, the method comprising
- melting a melt charge in an inert environment under superatmospheric pressure, the melt charge comprising mischmetal, nickel, cobalt and aluminum;
- adding an alloying element to the molten melt charge, the alloying element selected from the group consisting of zirconium, titanium, and mixtures thereof, the amount of added alloying element selected to produce an alloy having between 0.01 and 0.001 mole percent of said alloying element; and
- allowing the melt charge to cool to room temperature.
- 12. A method of producing an AB.sub.5 hydrogen storage alloy for use in an electrochemical cell, the method comprising
- providing a melt charge comprising mischmetal, nickel, cobalt and aluminum;
- placing the melt charge in a furnace;
- establishing a pressurized furnace environment substantially of argon gas;
- melting the melt charge while maintaining the furnace environment pressure;
- adding an alloying element to the molten melt charge, the alloying element selected from the group consisting of zirconium, titanium, and mixtures thereof, the amount of added alloying element selected to produce an alloy with between 0.01 and 0.001 mole percent of said alloying element; and
- allowing the alloy to cool to less than 50 degrees Celsius.
- 13. The method of claim 12 further comprising heat treating the cooled alloy for at least about 6 hours at about 1050 degrees Celsius.
- 14. The method of claim 12 further comprising pulverizing the cooled alloy to produce an alloy powder, and sieving the powder to remove particles greater than about 75 microns in size.
- 15. An electrochemical cell comprising:
- a positive electrode containing nickel hydroxide; and
- a negative electrode containing an AB.sub.5 hydrogen absorbing alloy, essentially according to the formulation
- LM.sub.x Ni.sub.A-(B+C+D) Co.sub.B Al.sub.C Mn.sub.D
- wherein
- L comprises mischmetal including between about 45 and 70 percent lanthanum,
- M comprises an element selected from the group consisting of titanium, zirconium, and combinations thereof,
- X is between 0.001 and 0.01,
- B C, and D are each greater than zero, and
- A is about 5,
- wherein the AB.sub.5 hydrogen absorbing alloy comprises a homogeneous alloy.
- 16. A metallic particle for use in an electrode of an electrochemical cell, the particle consisting essentially of an AB.sub.5 hydrogen absorbing alloy comprising
- LM.sub.x Ni.sub.A-(B+C+D) Co.sub.B Al.sub.C Mn.sub.D
- wherein
- L comprises mischmetal including between about 45 and 70 percent lanthanum,
- M comprises an element selected from the group consisting of titanium and zirconium,
- X is between 0.001 and 0.01,
- B C, and D are each greater than zero, and
- A is about 5,
- wherein the AB.sub.5 hydrogen absorbing alloy composition comprises a homogeneous alloy.
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims an invention disclosed in U.S. provisional application Ser. No. 60/033,616, filed Dec. 19, 1996.
US Referenced Citations (8)
Foreign Referenced Citations (1)
Number |
Date |
Country |
H5-132322 |
Apr 1993 |
JPX |