机械合金化制备非晶态Ti_2Ni合金及其储氢性能

Amorphous Ti_2Ni Alloys Prepared by Mechanical Alloying and Its Hydrogen Storage Properties

以单质钛粉和镍粉为原料,通过机械合金化的方法制备了非晶态Ti2Ni合金,采用扫描电镜分析、X射线衍射、差热分析、充放电测试及电位阶跃测试等方法系统研究了Ti2Ni合金粉体的结构变化以及合金电极的储氢性能。结果表明:随球磨时间的延长,粉体颗粒尺寸先增大后减小;球磨至30h时,获得了非晶态的Ti2Ni,随后的球磨使非晶合金粉体的稳定性不断增大;球磨80h所得到合金的储氢性能最好,最大放电容量达到147mAh.g-1,循环30次后的容量保持率为92.5%,氢的扩散系数为2.18×10-11 cm2.s-1。

Amorphous Ti2 Ni 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 Ti2 Ni 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 Ti2 Ni 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 of2.18×10^cm^-2·s^-1.