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The dehydriding process and hydrogen-deuterium exchange (H-D exchange) of xLiBH4 + (1 - x)Mg2FeD6 (x = 0.25, 0.75) composites has been studied in detail. For the composition with x = 0.25, only one overlapping mass peak of all hydrogen and deuterium related species was observed in mass spectrometry. This implied the simultaneous dehydriding of LiBH4 and Mg2FeD6, despite an almost 190 °C difference in the dehydriding temperatures of the respective discrete complex hydrides. In situ infrared spectroscopy measurements indicated that H-D exchange between [BH4]- and [FeD6]4- had occurred during ball-milling and was promoted upon heating. The extent of H-D exchange was estimated from the areas of the relevant mass signals: immediately prior to the dehydriding, more than two H atoms in [BH4]- was replaced by D atoms. For x = 0.75, H-D exchange also occurred and about one to two H atoms in [BH4]- was replaced by D atoms immediately before the dehydriding. In contrast to the situation for x = 0.25, firstly LiBH4 and Mg2FeD6 dehydrided simultaneously with a special molar ratio = 1:1 at x = 0.75, and then the remaining LiBH4 reacted with the Mg and Fe derived from the dehydriding of Mg2FeD6. [ABSTRACT FROM AUTHOR]

Lithium hexahydridoaluminate Li3AlH6and lithium amide LiNH2with 1:2 molar ratio were mechanically milled, yielding a Li−Al−N−H system. LiNH2destabilized Li3AlH6during the dehydrogenation process of Li3AlH6, because the dehydrogenation starting temperature of the Li−Al−N−H system was lower than that of Li3AlH6. Temperature-programmed desorption scans of the Li−Al−N−H system indicated that a large amount of hydrogen (6.9 wt %) can be released between 370 and 773 K. After initial H2desorption, the H2absorption and the desorption capacities of the Li−Al−N−H system with a nano-Ni catalyst exhibited 3−4 wt % at 10−0.004 MPa and 473−573 K, while the capacities of the system without the catalyst were 1−2 wt %. The remarkably increased capacity was due to the fact that the kinetics was improved by addition of the nano-Ni catalyst. [ABSTRACT FROM AUTHOR]

The article features the research on the significance of complex hydrides with (BH4)- and (NH2)- as new lithium fast-ion conductors. When researchers heated these hydrides, these metals exhibited lithium fast-ion conductivity of 2 x 10-4 Siemen per centimeter (S/cm) at ~370 Kelvin (K). Moreover, they concluded that the combination of complex hydrogen anions provide new occupation site for Li+ ions.