Microstructure and hydrogen storage properties of Ti1-xCexV0.45Mn1.5 (x = 0, 0.05, 0.10, 0.15, and 0.20) alloys

Abstract

In this work, the microstructure and hydrogen storage properties of Ti1-xCexV0.45Mn1.5 (x = 0, 0.05, 0.10, 0.15, and 0.20) alloys have been studied. It shows that the x = 0 alloy consists of a C14 Laves single phase. Moreover, alloys containing Ce can exhibit the CeO2 phase, whose content rises as Ce content does. Furthermore, CeO2 phase aggregation causes the alloy to fracture and the hydrogen diffusion channel to enlarge. According to the PCT curves (25 °C), the plateau pressure increases with increasing Ce content, and the hydrogen storage capacity decreases with increasing Ce content due to increase in Ce content which does not absorb hydrogen. And it is also found that increase in Ce substitution for Ti results in better dynamic properties for the alloys. And the dehydrogenation kinetics curves show that hydrogen desorption rate substantially increases with x getting larger. This is because CeO2 phase acts as the "hydrogen pump" to increase the rate of hydrogen discharge in the alloy, The fastest hydrogenation kinetics are shown, the best hydrogen storage performance is achieved, and the maximum hydrogenation is reached in less than 100 s.