Claims
- 1. An electrochemical hydrogen storage alloy comprising on an atomic percent basis:
- 14 to 22 percent vanadium;
- 28 to 39 percent nickel;
- 7 to 15 percent titanium;
- 15 to 34 percent zirconium; and
- at least one member selected from the group consisting of
- 0.01 to 7 percent chromium,
- 0.01 to 7 percent cobalt, and
- 0.01 to 7 percent iron.
- 2. An electrochemical, hydrogen storage alloy as in claim 1, wherein the atomic ratio of the vanadium to zirconium is in the range of 1:2.26 to 1:0.68.
- 3. An electrochemical, hydrogen storage alloy as in claim 1, having the composition V.sub.21 Ti.sub.10 Zr.sub.20 Ni.sub.31 Cr.sub.6 Co.sub.6 Fe.sub.6.
- 4. An electrochemical, hydrogen storage alloy as in claim 1, having the composition V.sub.21 Ti.sub.13 Zr.sub.17 Ni.sub.31 Cr.sub.6 Co.sub.6 Fe.sub.6.
- 5. An electrochemical, hydrogen storage alloy as in claim 1, having the composition V.sub.15 Ti.sub.15 Zr.sub.21 Ni.sub.31 Cr.sub.6 Co.sub.6 Fe.sub.6.
- 6. An electrochemical, hydrogen storage alloy as in claim 1, having the composition V.sub.18 Ti.sub.15 Zr.sub.18 Ni.sub.31 Cr.sub.6 Co.sub.6 Fe.sub.6.
- 7. An electrochemical, hydrogen storage alloy as in claim 1, having the composition V.sub.22 Ti.sub.11 Zr.sub.21 Ni.sub.39 Fe.sub.7.
- 8. An electrochemical, hydrogen storage alloy as in claim 1, having the composition V.sub.22 Ti.sub.11 Zr.sub.21 Ni.sub.32 Co.sub.7 Fe.sub.7.
- 9. An electrochemical, hydrogen storage alloy as in claim 1, having the composition V.sub.22 Ti.sub.15 Zr.sub.15 Ni.sub.32 Cr.sub.6 Co.sub.6 Fe.sub.3.
- 10. An negative electrode comprising an electrochemical hydrogen storage alloy, which on an atomic percent basis, comprises:
- 14 to 22 percent vanadium;
- 28 to 39 percent nickel;
- 7 to 15 percent titanium;
- 15 to 34 percent zirconium; and
- at least one member selected from the group consisting of
- 0.01 to 7 percent chromium,
- 0.01 to 7 percent cobalt, and
- 0.01 to 7 percent iron,
- 11. The negative electrode comprising an electrochemical hydrogen storage alloy claimed in claim 10, wherein the atomic ratio of the vanadium to zirconium is in the range of 1:2.26 to 1:0.68.
- 12. An electrochemical cell which includes a negative electrode formed of a hydrogen storage alloy wherein said hydrogen storage alloy comprises:
- hydrogen storing elements consisting of 14 to 22 percent vanadium; 28 to 39 percent nickel; 7 to 15 percent titanium; 15 to 34 percent zirconium; present in a ratio that optimizes hydrogen overpressure during operation of said electrochemical cell; and
- at least one modifying element selected from the group consisting of 0.01 to 7 percent chromium, 0.01 to 7 percent cobalt, and 0.01 to 7 percent iron, selected to optimize desirable operational parameters of said electrochemical cell.
- 13. The electrochemical cell claimed in claim 12, wherein the atomic ratio of vanadium to zirconium is 1:2.26 to 1:0.68.
- 14. A method for optimizing the composition of an electrochemical, hydrogen storage material for use in a negative electrode of an electrochemical cell exhibiting reduced hydrogen overpressure and other desirable operational parameters comprising the steps of:
- selecting a hydrogen storage alloy comprising
- hydrogen storing elements consisting of 14 to 22 percent vanadium; 28 to 39 percent nickel; 7 to 15 percent titanium; 15 to 34 percent zirconium; and
- at least one modifying element selected from the group consisting of 0.01 to 7 percent chromium, 0.01 to 7 percent cobalt, and 0.01 to 7 percent iron; and
- adjusting the ratio of at least one pair of said hydrogen storing elements, to decrease the hydrogen overpressure during operation of said electrochemical cell, while keeping the ratio of said at least one modifying element unchanged to maintain a particular set of operational parameters for said electrochemical cell.
- 15. The method for optimizing the composition of an electrochemical, hydrogen storage material as claimed in claim 14, further comprising optimizing said hydrogen storage materials for use in a low pressure electrochemical cell by treating said hydrogen storage materials with an alkaline etch.
- 16. The method for optimizing the composition of an electrochemical, hydrogen storage material as claimed in claim 14, wherein said hydrogen storage material also exhibits a very low self-discharge, further comprising the step of
- selecting said hydrogen storage material having a heterogeneous, disordered microstructure resulting from changes in the mutual solubility of the said hydrogen storing elements and said at least one modifying element.
- 17. An electrochemical hydrogen storage alloy having a reduced self-discharge rate comprising:
- an alloy having a heterogeneous, disordered microstructure resulting from changes in the mutual solubility of the elements of said alloy, wherein hydrogen in a particular phase is not easily discharged either through low surface area, or an oxide of limited porosity or catalytic property.
Parent Case Info
This application is a continuation-in-part of application Ser. No. 07/515,020 filed on Apr. 26, 1990 now U.S. Pat. No. 5,104,617.
US Referenced Citations (3)
Continuation in Parts (1)
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Number |
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515020 |
Apr 1990 |
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