采用机械合金化制备(Mg58Al42)0.9Ni0.1储氢合金,研究其在不同球磨时间下的电化学性能以及添加Ni对其电化学性能的影响。结果表明:合金粉末经球磨后产生Mg17Al12新相,Ni未溶入其它相中;合金的放电容量随球磨时间延长先增加而后又降低,其中球磨20h的合金放电容量最大,为345.8mA·h/g;合金的腐蚀速度随球磨时间延长先减慢而后加快,其中球磨10h的合金腐蚀电流密度最低,为14.85μA/cm^2,且腐蚀速度最慢;合金的动电位极化曲线出现钝化现象,钝化区间较宽;交流阻抗谱由单容抗弧组成,没有出现扩散尾,腐蚀过程受电化学反应控制;添加Ni后,合金放电容量增大,腐蚀速度减慢。
(Mg58Al42)0.9Ni0.1 hydrogen storage alloy was prepared by mechanical alloying (MA) method. Its electrochemical properties and the effect of adding Ni on the electrochemical properties of Mg58Al42 alloy were also investigated. The results show that (Mg58Al42)0.9Ni0.1 alloy produces a new Mg17-Al12 phase and Ni cannot be dissolved in the other phases after ball milling. The discharge capacities of the present alloy increase at the beginning of ball milling and afterwards decrease. The maximum discharge capacity is 345.8 mA.h/g when the alloy is milled for 20 h. There are passive phenomena in potentiodynamic polarization curves. The corrosion currents of the present alloy decrease at the beginning of ball milling and afterwards increase. The minimum corrosion rate is 14.85 μA/cm^2 when the alloy is milled for 10 h. The electrochemical impedance spectroscopies (EIS) of the present alloy are composed of single capacitive loop without diffusion tail. The corrosion processes are controlled by electrochemical reactions. The discharge capacities of the present alloy increase and corrosion rates decrease after Ni is added to Mg58Al42 hydrogen storage alloy.