Synthesis and hydrogen storage properties of lithium borohydride amidoborane complex

A series of mixtures of LiAB/LiBH4 with different molar ratios were prepared and their hydrogen storage properties were investigated in this study. Among them, a new structure was found in the LiAB/LiBH4 sample with a molar ratio of 1/1. It is of orthorhombic structure and composed of alternative layers of LiAB and LiBH4. It shows similar hydrogen desorption behaviors of LiAB-LiBH4 and LiAB-0.5LiBH(4). For use in hydrogen storage, high hydrogen capacity and low operation temperature are demanded, thus, the dehydrogenation properties of LiAB-0.5LiBH(4) were subsequently measured. Three steps of desorption were observed during the heating process, with a total release of 11.5 wt% H-2 at 500 degrees C. The reaction path was identified using a combined investigation of XRD and B-11 solid state NMR. Dehydrogenation idnetic analyses show that the complex has lower activation energy (61 +/- 4 kJ mol(-1) H-2) than that of LiAB (71 +/- 5 kJ mol(-1) H-2). It is likely that dehydrogenation process was promoted due to the presence of LiBH4. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.