To improve the hydrogen storage property of LiBH4, the LiBH4/Ca(AlH4)(2) reactive systems with various ratios were constructed, and their de-/hydrogenation properties as well as the reaction mechanisms were investigated experimentally. It was found that the sample with the LiBH4 to Ca(AlH4)(2) molar ratio of 6:1 exhibits the best comprehensive hydrogen storage properties, desorbing hydrogen completely (8.2 wt.%) within 35 min at 450 degrees C and reversibly absorbing 4.5 wt.% of hydrogen at 450 degrees C under a hydrogen pressure as low as 4.0 MPa. During the first dehydrogenation process of the LiBH4/Ca(AlH4)(2) systems, the CaH2 and Al particles were in situ precipitated via the self-decomposition of Ca(AlH4)(2), and then reacted with LiBH4 to form CaB6, AlB2 and LiH. Whereafter, the sample can cycle between LiBH4 + Ca(BH4)(2) + Al in the hydrogenated state and CaB6 + AlB2 + LiH in the dehydrogenated state. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.