Amorphous Ti2Ni Alloys Prepared by Mechanical Alloyingand Its Hydrogen Storage Properties

Amorphous Ti2Ni alloys were prepared by mechanical alloying using raw materials of Ti and Ni powders. Scanning electron microscopy, X-ray diffraction, Differential scanning calorimetry, charge/discharge testing and potential step testing were used to study the change of structure and hydrogen storage characteristics of Ti2Ni alloy electrodes. The results show that the particle size of alloy powders increased first and then decreased by the increase of milling time. Amorphous Ti2Ni alloy was formed after milling for 30 h, and the stability of amorphous alloy powders was enhanced by further mechanical milling. The Ti2Ni alloy milled for 80 h exhibited the best hydrogen storage properties, including a maximal discharge capacity of 147 mAh·g-1, a capacity-keeping rate of 92.5% after circulating for 30 times and a diffusion coefficient for hydrogen of 2.18×10-11 cm2·s-1.