Investigation on the hydrogen absorption and dissociation properties of ball milling CeMg12/Ni/NbF5 type alloy for emergency power supply of fuel cell for meteorological radar station

Abstract

In this article, in order to investigate the mechanism of action of catalysis on the hydrogenation and dehydrogenation properties of CeMg12-type alloy, the catalysis Ni and NbF5 was been added to prepare the CeMg12/Ni/NbF5 composite materials during ball milling treatment. The results in term of microstructure indicate that part of NbF5 is transformed into low valence NbF4 and helpful for forming MgF2 phase after ball milling treatment, which is advantageous for ameliorating the hydriding and dehydriding performances of experimental alloy. The results of the study from the perspective of hydrogen absorption and desorption performance test show that the increasing NbF5 decreases the enthalpy-value for hydrogen release and the platform pressure for the process of hydrogen releasing of ball-milled alloy, which is good for improving the hydrogen release performance of the alloy. The addition of a certain amount of NbF5 can effectively upgrade the kinetics of hydrogen dissociation of CeMg12-type alloy treated through mechanical ball milling. The alloy with 6 wt.% NbF5 has the best kinetic performance of hydrogen release, corresponding to activation energy can be reduced from 90.86 kJ/mol (0 wt.% NbF5) to 86.41 kJ/mol(6 wt.% NbF5).