Hydrogen Storage Properties and Reactive Mechanism of LiBH4/Mg10YNi-H Composite

Abstract

The Mg 10 YNi alloy was hydrogenated and then coupled with LiBH 4 to form LiBH 4 /Mg 10 YNi-H reactive hydride composite. The results indicate that thermal dehydrogenation stability of LiBH 4 can be remarkably reduced by combining with Mg 10 YNi hydride. The starting and ending temperatures for hydrogen desorption from the LiBH 4 /Mg 10 YNi-H composite are approximately 275 and 430 ºC, respectively. Dehydrogenation of the LiBH 4 /Mg 10 YNi-H composite proceeds mainly in two steps with a total reaction of 12LiBH 4 + 2.5Mg 10 YNiH 20 → 24Mg + MgNi 2.5 B 2 + 2.5YB 4 + 12LiH + 43H 2. After rehydrogenation at 450 ºC under 9 MPa hydrogen pressure, the LiBH 4 /Mg 10 YNi-H composite starts to release hydrogen around 260 ºC, and as much as approximately 5.2 wt.% of hydrogen can be desorbed during the second dehydrogenation process.

Destabilization of Boron-Based Compounds for Hydrogen Storage in the Solid-State: Recent Advances

“…% H2) and Mg10YNi-H (6.7 wt. % H2) alloys [97,98]. The destabilization of LiBH4 occurred due to the formation of intermediates such as Mg, Mg2Ni, CeH2 and YB4.…”