First hydrogenation enhancement in TiFe alloys for hydrogen storage

In this paper, we report the first hydrogenation kinetics of TiFe + X wt.% Zr with X = 4, 8, 12, and 16. We found that these alloys are multiphase with a TiFe matrix having about 1 at.% of zirconium in it and two secondary phases, which are rich in zirconium but also contain Ti and Fe. When X increases, the chemical composition of one of the secondary phases stays constant but the other secondary phase presents a change of composition. The sample with X = 8 presented the fastest first hydrogenation kinetics. Hydrogen capacity increases with increasing X but for X greater than 8, there was the appearance of an incubation time. The secondary phases are probably acting as a gateway for hydrogen, thus facilitating the hydrogen absorption in the TiFe phase.