Non-pyrophoric hydrogen storage alloys and hydrogen storage systems using the alloys
A non-pyrophoric AB 2 -type Laves phase hydrogen storage alloy and hydrogen storage systems using the alloy. The alloy has an A-site to B-site elemental ratio of no more than about 0.5. The alloy has an alloy composition including about (in at %): Zr: 2.0-5.5, Ti: 27-31.3, V: 8.3-9.9, Cr: 20.6-30.5, Mn: 25.4-33.0, Fe: 1.0-5.9, Al: 0.1-0.4, and/or Ni: 0.0-4.0. The hydrogen storage system has one or more hydrogen storage alloy containment vessels with the alloy disposed therein.
1. A non-pyrophoric AB2 Laves phase hydrogen storage alloy comprising:
an alloy composition including about (in at %): Zr: 2.0-5.5, Ti: 27-31.3, V: 8.3-9.9, Cr: 20.6-30.5, Mn: 25.4-33.0, Fe: 1.0-5.9, and Al: 0.1-0.4.
2. The non-pyrophoric AB2 Laves phase hydrogen storage alloy of claim 1 , further comprising an A-site to B-site elemental ratio of not more than about 0.5.
3. The non-pyrophoric AB2 Laves phase hydrogen storage alloy of claim 1 , wherein said alloy composition includes (in at %): Zr: 2.9-5.5, Ti: 27-30.3, V: 8.3-9.3, Cr: 20.6-26.5, Mn: 29.4-32.1, Fe: 1.5-5.9, and Al: 0.1-0.4.
4. The non-pyrophoric AB2 Laves phase hydrogen storage alloy of claim 1 , wherein said alloy composition further includes up to about 4 at % nickel as an equal substitute for up to about 2 at % chromium or up to about 2 at % manganese or both.
5. The non-pyrophoric AB2 Laves phase hydrogen storage alloy of claim 1 , wherein said alloy composition has a total hydrogen storage capacity of at least about 1.7 wt % at about 500 psi and about 20° C.
6. The non-pyrophoric AB2 Laves phase hydrogen storage alloy of claim 1 , wherein said alloy composition has a total hydrogen storage capacity of at least about 1.8 wt % at about 500 psi and about 20° C.
7. The non-pyrophoric AB2 Laves phase hydrogen storage alloy of claim 1 , wherein said alloy composition has a trapped hydrogen capacity of no more than about 0.25 wt % at about 14.5 psi and about 20° C.
8. The non-pyrophoric AB2 Laves phase hydrogen storage alloy of claim 1 , wherein said alloy composition has a trapped hydrogen capacity of no more than about 0.20 wt % at about 14.5 psi and about 20° C.
9. The non-pyrophoric AB2 Laves phase hydrogen storage alloy of claim 1 , wherein said alloy composition has a trapped hydrogen capacity of no more than about 0.15 wt % at about 14.5 psi and about 20° C.
10. The non-pyrophoric AB2 Laves phase hydrogen storage alloy of claim 1 , wherein said alloy composition has a trapped hydrogen capacity of no more than about 0.10 wt % at about 14.5 psi and about 20° C.
11. The non-pyrophoric AB2 Laves phase hydrogen storage alloy of claim 1 , wherein said alloy composition has a pressure composition temperature (PCT) isotherm slope of no more than about 0.8.
12. The non-pyrophoric AB2 Laves phase hydrogen storage alloy of claim 1 , wherein said alloy composition has a PCT isotherm slope of no more than about 0.7.
13. The non-pyrophoric AB2 Laves phase hydrogen storage alloy of claim 1 , wherein said alloy composition has a PCT isotherm slope of no more than about 0.6.
14. The non-pyrophoric AB2 Laves phase hydrogen storage alloy of claim 1 , wherein said alloy composition has a hysteresis of not more than about 0.5.
15. The non-pyrophoric AB 2 Laves phase hydrogen storage alloy of claim 1 , wherein said alloy composition has a hysteresis of not more than about 0.4.
16. The non-pyrophoric AB 2 Laves phase hydrogen storage alloy of claim 1 , wherein said alloy composition has a hysteresis of not more than about 0.3.
17. The non-pyrophoric AB 2 Laves phase hydrogen storage alloy of claim 1 , wherein said alloy composition has a hysteresis of not more than about 0.2.
18. The non-pyrophoric AB 2 Laves phase hydrogen storage alloy of claim 1 , wherein said alloy composition has a hysteresis of not more than about 0.1.
19. The non-pyrophoric AB 2 Laves phase hydrogen storage alloy of claim 1 , wherein in said alloy composition further comprises about 1.0-10.0 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 (where Mm is mischmetal).
20. A hydrogen storage system comprising:
one or more hydrogen storage alloy containment vessels; and
a non-pyrophoric AB 2 Laves phase hydrogen storage alloy disposed within the hydrogen storage alloy containment vessel, wherein said non-pyrophoric AB 2 Laves phase hydrogen storage alloy comprises:
an alloy composition including about (in at %): Zr: 2.0-5.5, Ti: 27-31.3, V: 8.3-9.9, Cr: 20.6-30.5, Mn: 25.4-33.0, Fe: 1.0-5.9, and Al: 0.1-0.4.
21. The hydrogen storage system of claim 20 , wherein said allow composition further comprises an A-site to B-site elemental ratio of not more than about 0.5.
22. The hydrogen storage system of claim 20 , wherein said alloy composition includes (in at %): Zr: 2.9-5.5, Ti: 27-30.3, V: 8.3-9.3, Cr: 20.6-26.5, Mn: 29.4-32.1, Fe: 1.5-5.9, and Al: 0.1-0.4.
23. The hydrogen storage system of claim 20 , wherein said alloy composition further includes up to about 4 at % nickel as an equal substitute for up to about 2 at % chromium or up to about 2 at % manganese or both.
24. The hydrogen storage system of claim 20 , wherein said alloy composition has a total hydrogen storage capacity of at least about 1.7 wt % at about 500 psi and about 20° C.
25. The hydrogen storage system of claim 20 , wherein said alloy composition has a total hydrogen storage capacity of at least about 1.8 wt % at about 500 psi and about 20° C.
26. The hydrogen storage system of claim 20 , wherein said alloy composition has a trapped hydrogen capacity of no more than about 0.25 wt % at about 14.5 psi and about 20° C.
27. The hydrogen storage system of claim 20 , wherein said alloy composition has a trapped hydrogen capacity of no more than about 0.20 wt % at about 14.5 psi and about 20° C.
28. The hydrogen storage system of claim 20 , wherein said alloy composition has a trapped hydrogen capacity of no more than about 0.15 wt % at about 14.5 psi and about 20° C.
29. The hydrogen storage system of claim 20 , wherein said alloy composition has a trapped hydrogen capacity of no more than about 0.10 wt % at about 14.5 psi and about 20° C.
30. The hydrogen storage system of claim 20 , wherein said alloy composition has a PCT isotherm slope of no more than about 0.8.
31. The hydrogen storage system of claim 20 , wherein said alloy composition has a PCT isotherm slope of no more than about 0.7.
32. The hydrogen storage system of claim 20 , wherein said alloy composition has a PCT isotherm slope of no more than about 0.6.
33. The hydrogen storage system of claim 20 , wherein said alloy composition has a hysteresis of not more than about 0.5.
34. The hydrogen storage system of claim 20 , wherein said alloy composition has a hysteresis of not more than about 0.4.
35. The hydrogen storage system of claim 20 , wherein said alloy composition has a hysteresis of not more than about 0.3.
36. The hydrogen storage system of claim 20 , wherein said alloy composition has a hysteresis of not more than about 0.2.
37. The hydrogen storage system of claim 20 , wherein said alloy composition has a hysteresis of not more than about 0.1.
38. The hydrogen storage system of claim 20 , wherein said alloy composition further comprises about 1.0-10.0 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 (where Mm is mischmetal).