title: Hydrogen release from mixtures of lithium borohydride and lithium amide: a phase diagram study.
abstract: We recently reported the synthesis of a new quaternary hydride in the lithium-boron-nitrogen-hydrogen quaternary phase diagram with the approximate composition LiB0.33N0.67H2.67 having a theoretical hydrogen content of 11.9 wt %. This new compound forms by the reaction of appropriate amounts of lithium amide (LiNH2) and lithium borohydride (LiBH4) and releases greater than 10 wt % hydrogen when heated. A small amount of ammonia, 2-3 mol % of the generated gas, is also released. We now report a study of hydrogen and ammonia release from the series of reactant mixtures (LiNH2)x(LiBH4)1-x, where x=0.667 corresponds to the composition LiB0.33N0.67H2.67. We measured hydrogen and ammonia release amounts as a function of composition and found that maximum hydrogen and minimum ammonia release do occur for x=0.667. We also present evidence for an additional new quaternary phase and for two possibly metastable phases in this system.
authors.affiliation: General Motors Research and Development Center, Warren, Michigan 48090-9055, USA. gregory.p.meisner@gm.com
authors.forename: Gregory P
authors.initials: GP
authors.lastname: Meisner
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Scullin
authors.forename: Michael P
authors.initials: MP
authors.lastname: Balogh
authors.forename: Frederick E
authors.initials: FE
authors.lastname: Pinkerton
authors.forename: Martin S
authors.initials: MS
authors.lastname: Meyer