Abstract:The hydrogen storage properties of La1.8Ca0.2Mg14Ni3 were modified by mechanical ball-milling with addition of x wt%Ti (x=0,5,10). X-ray diffraction (XRD), scanning electron microscopy (SEM) and hydrogen absorption/desorption tests were carried out to study the effect of Ti. The results show that the hydrogen storage properties of La1.8Ca0.2Mg14Ni3 are remarkably improved after ball-milling with addition of small amount of Ti. For the as-cast alloy, 6 cycles of hydriding/dehydriding are needed to activate it at 613 K, and the maximum hydrogen storage capacity is around 4.12 %. After modification by ball-milling with addition of Ti, the activation behavior and the hydrogen storage capacity and the absorption/desorption kinetics are all improved. The effective desorption capacities of the alloys with x=0, 5 and 10 at 613 K are 4.69 %,4.80% and 4.83%, respectively. As x=10, the alloys can absorb more than 3% hydrogen at 373 K, and 4.81 % hydrogen (97% of the maximum hydrogen storage capacity) at 600 K within 2 min. The microstructure analysis indicated that the titanium powder on the alloy surface played the role of surface-catalysis, accelerated the hydrogen decomposition and formation, and provided more channels for hydrogen diffusion from surface, were partly transformed into amorphous structure. As a result, the hydrogen storage properties of La1.8Ca0.2Mg14Ni3 were improved