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

The Mg10YNi alloy was hydrogenated and then coupled with LiBH4 to form LiBH4/Mg10YNi-H reactive hydride composite. The results indicate that thermal dehydrogenation stability of LiBH4 can be remarkably reduced by combining with Mg10YNi hydride. The starting and ending temperatures for hydrogen desorption from the LiBH4/Mg10YNi-H composite are approximately 275 and 430 degrees C, respectively. Dehydrogenation of the LiBH4/Mg10YNi-H composite proceeds mainly in two steps with a total reaction of 12LiBH(4) + 2.5Mg(10) YNiH20 -> 24Mg + MgNi2.5B2 + 2.5YB(4) + 12LiH + 43H(2). After rehydrogenation at 450 degrees C under 9 MPa hydrogen pressure, the LiBH4/Mg10YNi-H composite starts to release hydrogen around 260 degrees C, and as much as approximately 5.2 wt.% of hydrogen can be desorbed during the second dehydrogenation process.