Electrochemical characteristics of Mg2−xAlxNi (0≤x≤0.5) alloys

The Mg-based hydrogen storage alloy Mg 2− x Al x Ni (0≤ x ≤0.5) have been successfully synthesized by a diffusion method (DM). The structures of these alloys have been examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Electrochemical characteristics have also been investigated, such as corrosion resistance and electrochemical capacity. It is found that a new phase appears when Al is added to the Mg–Ni system. It can be observed that there are a large number of defects on the alloy surface, which strongly affect its characteristics. The electrochemical capacity and cycle lives of Al-containing alloys increase strongly compared to the Al-free alloy. With increasing Al concentration in the alloys, the capacity also increases due to the increase of the amount of the new phase.