The dehydrogenation/hydrogenation properties of LiBH4-xMg(OH)(2) were systematically investigated. The results show that the LiBH4-0.3Mg(OH)(2) composite possesses optimal dehydrogenation properties: approximately 9.6 wt% of hydrogen is released via a stepwise reaction with an onset temperature of 100 degrees C. In the range of 100-250 degrees C, a chemical reaction between LiBH4 and Mg(OH)(2) first occurs to give rise to the generation of LiMgBO3, MgO and H-2. From 250 to 390 degrees C, the newly developed LiMgBO3 reacts with LiBH4 to form MgO, Li3BO3, LiH, B2O3 and Li2B12H12 with hydrogen release. From 390 to 450 degrees C, the decomposition of LiBH4 and Li2B12H12 proceeds to release additional hydrogen and to form LiH and B. A further hydrogenation experiment indicates that the dehydrogenated LiBH4-0.3Mg(OH)(2) sample can take up 4.7 wt% of hydrogen at 450 degrees C and 100 bar of hydrogen with good cycling stability, which is superior to the pristine LiBH4. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.