Hydrogen Desorption and Absorption Properties of MgH_2, IiBH_4, and MgH_2 + LiBH_4 Composite

摘要

To increase the hydrogen storage capacity of Mg-based materials, a sample with a composition of 69.7 wt% MgH_2 + 30.3 wt% LiBH_4 was prepared by planetary ball milling under hydrogen. The absorption and desorption properties of unmilled MgH_2, unmilled LiBH_4, and 69.7 wt% MgH_2 + 30.3 wt% LiBH_4 were examined. At 648 K the unmilled MgH_2 desorbed 5.70 wt% for 60 min. The unmilled LiBH_4 desorbed 6.40 wt% H for 780 min at 673 K. The 69.7 wt% MgH_2 + 30.3 wt% LiBH_4 sample desorbed 3.10 wt% H for 50 min, and 3.32 wt% H for 300 min at 623 K at the second cycle.