High throughput screening of the ternary LiNH2-MgH2-LiBH4 phase diagram

Here we apply combinatorial synthesis and screening (CSS) techniques with synthesis and testing of up to 48 samples in parallel to increase the rate of discovery of improved complex hydrides and dopants. In this paper we will demonstrate the application of CSS to a detailed investigation of the ternary LiNH2-MgH2-LiBH4 phase diagram. Most points on this phase diagram yield materials with high theoretical hydrogen storage and offer the potential for improved storage properties as inspired by previous studies of binary systems (edges of the phase diagram) that have yielded interesting results in the literature. By using CSS we have found ternary mixtures that exhibit reversible chemistry similar to the 2LiNH(2)-MgH2 system that have superior properties with respect to reversibility and desorption temperature, an optimum occurring at 0.6LiNH(2)-0.3MgH(2)-0.1LiBH(4). Hydrogen storage capacities and the structural characterization of the as-synthesized and dehydrided materials will be reported as a function of composition. Detailed characterization of the most promising materials will also be presented. (C) 2007 Elsevier B.V. All rights reserved.