Effect of Ce substitution on hydrogen absorption/ desorption of Laves phase-related BCC solid solution Ti33V37Mn30 alloy

Abstract

In order to understand the effects of rare element substitution on activation performance of Laves phase-related BCC solid solution alloys, cerium (Ce) is used to partial substitute for Mn in Ti33V37Mn30 alloy. Results show that Ce substitution leads to the formation of Ce/CeO2 while decreases C14 Laves phase. Ce substituting alloys can absorb hydrogen without being activated at a high temperature, which means the activation performance of Ti33V37Mn30 alloys is improved greatly by the Ce/CeO2 rather than C14 Laves phase. The maximum hydrogen absorption capacity also increases when Ce content increases. The hydrogen absorption capacity and effective hydrogen storage capacity reach the maximum when the composition is Ti33V37Mn29.4Ce0.6, with the values of 3.35 wt% at 293 K and 2.25 wt% at 423 K. The dehydriding enthalpy (ΔH) of 0.6 at.%-Ce-substituting alloy is higher than that of Ce-free alloy, which indicates that Ce substitution can increase the stability of hydrides.