Amorphous Mg-Ni-La hydrogen-storage alloys were prepared by melt-spinning. The phase structures of the ribbons before and after charge/discharge cycling were characterized by X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM) analysis, respectively. The effects of different contents of La are discussed on the basis of discharge-capacity, the morphology, limiting current density and electrochemical impedance spectra of the Mg-Ni-La electrodes. The Mg65Ni27La8 alloy exhibits the best reaction kinetics performance, the lowest contact resistance and a maximum discharge capacity of 582 mAh g(-1) at room temperature. The non-isothermal dehydrogenation process of Mg(65)sNi(27)La(8) alloy was analyzed in detail by differential scanning calorimetry (DSC) and thermogravimetry (TG). The experimental results showed a maximum 4.0 wt.% of released hydrogen at a heating rate of 5 degrees C min(-1). The non-isothermal dehydrogenation process of the alloy can be divided in two steps, corresponding to the dehydrogenation of amorphous phase (1.45 wt.% H) and Mg2NiH4 (2.55 wt.% H), respectively. It indicated that the amorphous structure was a key factor to achieve high discharge capacity and good cycling stability. (C) 2013 Elsevier B.V. All rights reserved.