Effects of Ca additions on some Mg-alloy hydrides

Abstract The hydrogenation of the alloy of composition CaMg 1.8 Ni 0.5 containing CaMg 2 and MgNi 2 shows fast activation kinetics. The Mg 2 Ni phase is observed in the dehydrided samples. The three plateaus on the hydrogen desorption isotherms correspond to the most stable magnesium hydrides observed up to now in Mg-alloy ( Δ H = 20–24 kcal/mol H 2 ). The effects of Ca additions on the hydrogen storage capacity and desorption rates of some Mg-rich alloys have been studied.