Studies on the hydrogen absorption/desorption properties of Zr1−xMmxFe1.4Cr0.6 and Zr1−2xMmxTixFe1.4Cr0.6 (x=0, 0.05, 0.1 and 0.2) Laves phase alloys

The Mm, Ti-substituted Zr1−2xMmxTixFe1.4Cr0.6 (x=0, 0.05,0.1 and 0.2) Laves phase alloys show high hydrogen storage capacity of ∼1.75 wt% and kinetics of ∼30 cm3 min−1 g−1 which is 3 times faster than the parent alloy ZrFe1.4Cr0.6. High hydrogen storage capacity is observed for small concentrations of Mm (x=0.03–0.07). The best storage materials correspond to the composition of x=0.05. Eventhough the Mm-substituted Laves phase alloys Zr1−xMmxFe1.4Cr0.6 (x=0, 0.05,0.1 and 0.2) have high capacity of 1.6 wt%, their kinetics is rather poor (<10 cm3 min−1 g−1). The high hydrogen storage capacity and fast kinetics of Mm, Ti-substituted alloys are attributed to disorder/defects introduced as evidenced through XRD, SEM and TEM studies.