Alkali metal hydride doping of α-AlH3 for enhanced H2 desorption kinetics

AlH3 can meet the gravimetric and volumetric targets for onboard vehicular hydrogen storage, but must be regenerated offboard. Doping of AlH3 with small levels of the alkali metal hydrides LiH, NaH and KH results in accelerated H2 desorption rates at low temperature. The phenomenology of the doping process is discussed in terms of the formation of alanate windows for the transport of H2 from the alane phase. It is shown that the alanate windows can be further doped with Ti to allow significant desorption of H2 from AlH3 even at room temperature.