The RE0.9Mg0.1Ni3.9Al0.2 alloy was synthesized using the previously reported method [17]. The RE consists of La, Pr and Nd with the molar ratio of 0.5:0.15:0.35. The phase compositions of the samples were characterized by Xray
diffraction (XRD) using the synchrotron radiation facility, SPring-8, Japan. The structural analysis was carried out using the Rietveld program, RIETAN-2000 [20]. The negative electrodes were prepared by the paste method. The alloy powder, styrene butadiene rubber (SBR) as the binder and carboxyl–methyl-cellulose (CMC) as the thickening agent were thoroughly mixed with water. The paste was loaded on a nickel-foam substrate and pressed to form a plate with a thickness of 0.4 mm.