Dehydrogenation properties of doped LiAlH4 compacts for hydrogen generator applications

Lithium aluminum hydride (LiAlH4) is an attractive hydrogen source for fuel cell systems due to its high hydrogen storage capacity and the moderate dehydrogenation conditions. In this contribution, TiCl3- and ZrCl4-doped LiAlH4 powders are prepared and pelletized under different compaction pressures in a uniaxial press. At constant 80 degrees C and a hydrogen partial pressure of 0.1 MPa, the maximal hydrogen release of suchlike LiAlH4 compacts amounts to 6.64 wt.%-H-2 (gravimetric capacity) and 53.88 g-H-2 l(-1) (volumetric capacity). The hydrogen release properties of the doped LiAlH4 compacts are studied systematically under variation of the compaction pressure, temperature and hydrogen partial pressure. Furthermore, the volume change of doped LiAlH4 compacts during dehydrogenation as well as their short-term storability are investigated (shelf life).