Hydrogen desorption exceeding ten weight percent from the new quaternary hydride Li3BN2H8

Mobile applications of hydrogen power have long demanded new solid hydride materials with large hydrogen storage capacities. We report synthesis of a new quaternary hydride having the approximate composition Li3BN2H8 with 11.9 wt % theoretical hydrogen capacity. It forms by reacting LiNH2 and LiBH4 powders in a 2:1 molar ratio either by ball milling or by heating the mixed powders above 95 °C. This new quaternary hydride melts at ∼190 °C and releases ≥10 wt % hydrogen above ∼250 °C. A small amount of ammonia (2−3 mol % of the generated gas) is released simultaneously. Preliminary calorimetric measurements suggest that hydrogen release is exothermic and, hence, not easily reversible.