Hydrogen storage and electrochemical characteristics of Ti0.32Cr0.43−V0.25Fe (x= 0–0.08) alloys and its composites with LmNi4.1Al0.25Mn0.3Co0.65 alloy

This study examined the hydrogen storage and electrochemical characteristics of bcc type Ti 0.32 Cr 0.43 − x V 0.25 Fe x ( x = 0–0.08) alloys and their ball-milled composites with AB 5 type LmNi 41 Al 0.25 Mn 0.3 Co 0.65 alloy. With increasing Fe content in the bcc alloy, the hydrogen storage capacity decreased and the plateau pressure increased due to the decreased lattice volume. In addition, the plateau pressure of the bcc alloys decreased with decrease in its temperature. The discharge capacity of the composite alloys of bcc and AB 5 alloy decreased with increasing Fe content in the bcc alloy at 25 °C, attributed to the increased plateau pressure. On the other hand, at low temperatures, the discharge capacity of the Fe-doped composite alloys was higher than that of the un-doped alloy due to the catalytic effect of Fe. In addition, with increasing discharge rate, the Fe-doped composite alloys with improved surface catalytic activity showed better discharge capacity.