Effect of rare earth (RE) elements on V-based hydrogen storage alloys

In this work, the effect of RE additives on the properties of V55Ti22.5Cr16.1Fe6.4V55Ti22.5Cr16.1Fe6.4 alloy (RE=LaRE=La, Pr, Ce and Nd, separately) was discussed. It was demonstrated that RE additives improve the activation property rather than kinetics during cycling, absorption capacity and the plateau pressure. Two phases, including BCC main phase and Ce second one, were found in Ce-containing alloy. It is inferred that RE element offers a route for hydrogen to enter the alloys more easily, which leads to the improvement of activation property of the alloys.