Amorphous MgNi, Mg0.9Ti0.1Ni, and Mg0.9Ti0.1NiAl0.05 compounds have been prepared by mechanical alloying and evaluated as metal hydride electrodes. The Mg0.9Ti0.1NiAl0.05 electrode retains 67% of its initial discharge capacity (404 mAh/g) after 15 cycles, compared to 54% for Mg0.9Ti0.1Ni and 34% for MgNi. This confirms the synergetic effect between Ti and Al that improves the cycling stability of the MgNi-based metal hydride electrode. X-ray photoelectron spectroscopy shows the presence of TiO2 and Al2O3 onto the Mg0.9Ti0.1NiAl0.05 particles. These two oxides appear to be very efficient at preventing the accumulation of Mg(OH)(2) onto the particles upon cycling as suggested by X-ray diffraction analyses and cyclic voltammetry experiments. Moreover, on the basis of the evolution with cycling of the ratio of the hydrogen diffusion coefficient to the particle radius (D/a(2)), Mg0.9Ti0.1NiAl0.05 material appears less sensitive to pulverization. This is in accordance with an increase of the maximal amount of hydrogen absorbed into Mg0.9Ti0.1NiAl0.05 before a significant decay in capacity occurs. Finally, we have fabricated a Mg0.9Ti0.1NiAl0.05 electrode with large particles (diameter > 150 mu m) having, under controlled charging conditions, a capacity decay rate as low as that observed for a commercial LaNi5-type alloy (i.e., similar to 0.2% per cycle). (c) 2005 The Electrochemical Society. All rights reserved.