Influences of heat treatment on the structure and electrochemical properties of Mg0.9Ti0.1Ni hydrogen storage alloys

In the present study, the effects of heat treatment on the structures and electrochemical properties of Mg0.9Ti0.1Ni hydrogen storage alloys have been investigated in detail. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses showed that the samples exhibited a predominantly amorphous structure. Electrochemical investigations revealed that heat treatment can improve the maximum discharge capacity and cyclic stability of the alloy electrodes. For Mg0.9Ti0.1Ni alloy prepare by ball milling, the value of Cmax was only 229.9 mAh g-1, however, the value reached 331.9 mAh g-1 after heat treatment at 873K for 8 h and then milling. The cycle voltammetry, electrochemical impedance spectroscopy and potentiodynamic polarization indicated that heat treatment not only increased the discharge capacity but also improved the charge/discharge kinetics of Mg0.9Ti0.1Ni alloy.