Improved reversible dehydrogenation of 2LiBH4+MgH2 system by introducing Ni nanoparticles

We report that the hydrogen de/resorption of the 2LiBH4+MgH2 system was modified by introducing Ni nanoparticles. Dehydrogenation analysis revealed that the first-step dehydrogenation, i.e., the decomposition of MgH2, can be significantly promoted by adding a small amount of Ni because of the catalytic effect. However, the improvement of the second-step dehydrogenation, corresponding to the decomposition of LiBH4, needs the addition of a large amount of Ni, resulting in the formation of a Mg–Ni–B ternary alloy. Furthermore, the presence of the Mg–Ni–B ternary alloy allowed an increased reversible H-capacity, in which about 5.3 wt% of hydrogen can be rehydrogenated under 400 °C and 55 bar hydrogen pressure over 10 h, which is higher than that of the pristine 2LiBH4+MgH2 system (4.4 wt%).