Abstract
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MgH2 with 10 wt% Ti0.4Mn0.22Cr0.1V0.28 (termed BCC for its body-centered cubic structure)
nanocomposite was fabricated by ball milling using different ball-to-powder weight ratios.
The X-ray diffraction patterns make it clear that pure Mg powder is partly transformed to
MgH2, while by adding the BCC, its hydriding becomes complete. The scanning electron
microscope images showed that the BCC particles were uniformly dispersed on the surface of
the Mg particles. Differential scanning calorimetry traces of the samples showed that the
addition of the BCC obviously decreases the desorption temperature, and an additional
decrease is observed from increasing the ball-to-powder weight ratio. The hydriding/
dehydriding and the pressure-composition isotherm curves indicate significant
improvement in the absorption/desorption kinetics and the hydrogen storage capacity of
MgH2 from both adding the BCC and increasing the ball-to-powder weight ratio. The results
indicate that the BCC acts as a medium that facilitates hydrogen absorption during
hydrogenation on Mg, thus improving hydrogen storage capacity and absorption/
desorption kinetics.