Hydrogen storage and electrochemical characteristics of Ti0.32Cr0.43 − xV0.25Fex (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 Ti0.32Cr0.43 − xV0.25Fex (x = 0–0.08) alloys and their ball-milled composites with AB5 type LmNi41Al0.25Mn0.3Co0.65 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 AB5 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.

► Examined hydrogen storage characteristics of Fe doped TiCrV and its composites.
► Examined electrochemical characteristics of Fe doped TiCrV and composites.
► Effect of temperature on their hydrogen storage and electrochemical characteristics.
► With increasing discharge rate, Fe doped composite showed better discharge capacity.
► At low temperatures, Fe doped composite showed better discharge capacity.