Effect of Mischmetal Introduction on Hydrogen Storage Properties in Impure Hydrogen Gas of Ti-Fe-Mn-Co Alloys

Abstract

The research aims to study the effect of adding mischmetal (Mm) to the TiFe0.86Mn0.07Co0.07 alloy on its hydrogen storage performance and cyclic stability. The results show that TiFe0.86Mn0.07Co0.07 + x% Mm (x = 0,4,6,8) alloys can be easily activated. The hydrogen absorption capacity of TiFe0.86Mn0.07Co0.07 + 4% Mm reaches 1.76 wt% (mass fraction) at 298 K. With the increase of Mm addition, the hydrogen storage capacity decreases slightly. Furthermore, after 40 absorption and desorption cycles in hydrogen containing 250 ppm O2, the alloy still has 36% of its initial hydrogen storage capacity, and the alloy can recover 93% of its hydrogen storage capacity through heat treatment.