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La(2-x)Ti(x)MgNi(9) (x = 0.2, 0.3) alloys have been prepared by magnetic levitation melting under an Argon atmosphere, and the as-cast alloys were annealed at 800 degrees C, 900 degrees C for 10 h under vacuum. The effects of annealing on the hydrogen storage properties of the alloys were investigated systematically by XRD, PCT and electrochemical measurements. For the La(2-x)Ti(x)MgNi(9) (x = 0.2, 0.3) alloys, LaNi(5), LaMg(2)Ni(9) and LaNi(3) are the main phases and a Ti(2)Ni phase appears at 900 degrees C. The effective hydrogen storage capacity increases from 1.10, 1.10 wt.% (as-cast) to 1.22, 1.16 wt.% (annealed 800 degrees C) and 1.31, 1.27 wt.% (annealed 900 degrees C), respectively. The annealing not only improves the hydrogen absorption/desorption kinetics but also increases the maximum discharge capacity and enhances the cycling stability. The La(1.8)Ti(0.2)MgNi(9) alloy annealed at 900 degrees C exhibits good electrochemical properties, and the discharge capacities decrease from 366.1 mA h/g to 219.6 mA h/g after 177 charge-discharge cycles. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.