Hydrogen storage materials having excellent kinetics, capacity, and cycle stability

Abstract

A BCC phase hydrogen storage alloy capable of storing approximately 4.0 wt. % hydrogen and delivering reversibly up to 3.0 wt. % hydrogen at temperatures up to 110° C. The hydrogen storage alloys also possess excellent kinetics whereby up to 80% of the hydrogen storage capacity of the hydrogen storage alloy may be reached in 30 seconds and 80% of the total hydrogen storage capacity may be desorbed from the hydrogen storage alloy in 90 seconds. The hydrogen storage alloys also have excellent stability which provides for long cycle life.

1 . A process for producing a hydrogen storage alloy, said process comprising: 
 1) forming a hydrogen storage alloy having two or more elements;    2) annealing said hydrogen storage alloy to form a substantially single phase BCC structure;    3) quenching said annealed hydrogen storage alloy at a cooling rate in the range of 10 2  to 10 3 ° C./second; and    4) inhibiting the formation of said oxides on the surface of said hydrogen storage alloy during quenching and/or removing said oxides from the surface of said hydrogen storage alloy after quenching.    
     
     
         2 . The process according to  claim 1 , wherein said hydrogen storage alloy is formed via arc melting, cold wall induction melting, or levitation melting techniques.  
     
     
         3 . The process according to  claim 1 , wherein said hydrogen storage alloy is annealed at a temperature in the range of 1350° C. to 1450° C.  
     
     
         4 . The process according to  claim 1 , wherein said hydrogen storage alloy is quenched in liquid argon, liquid nitrogen, or water.  
     
     
         5 . The process according to  claim 1 , wherein said oxides on the surface of said hydrogen storage alloy are removed via etching or mechanical grinding.