Hydrogen storage properties of Laves phase Ti 1− xZr x(Mn 0.5Cr 0.5) 2 alloys

Abstract

The activation behaviors and hydrogen storage properties of the Laves phase Ti 1− x Zr x (Mn 0.5 Cr 0.5) 2( x =0, 0.1, 0.2, 0.32, 0.5) alloys were investigated by the pressure-composition-temperature (P-C-T) measurements. All the studied alloys show the single C14-type Laves phase structure based on the XRD data. Except for the alloys with very low Zr content of x = 0 and x = 0.1, all these alloys can be fully activated. The P-C isotherms of the activated alloys show that, the introduction of Zr induces the decrease of the equilibrium pressures and the steeper plateaus. As the x increases, the maximum hydrogen absorption also increases, whereas the desorption of hydrogen decreases. These two effects result in a maximum reversible hydrogen storage capacity of HIM = 3.03 for the alloy at x = 0.32. Furthermore, the well-defined plateau associated with the smallest hysteresis also appears at x = 0.32.