Hydrogen storage properties of Laves phase Ti_(1-x)Zr_x(Mn_(0.5)Cr_(0.5))_2 alloys

摘要

The activation behaviors and hydrogen storage properties of the Laves phase Ti1-xZrx(Mn0.5Cr0.5)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 H/M=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.