(沈陽師范大學 化學與生命科學學院,沈陽 110034)
摘 要: 采用機械合金化制備(Mg58Al42)0.9Ni0.1儲氫合金,研究其在不同球磨時間下的電化學性能以及添加Ni對其電化學性能的影響。 結果表明:合金粉末經球磨后產生Mg17Al12新相,Ni未溶入其它相中;合金的放電容量隨球磨時間延長先增加而后又降低,其中球磨20 h的合金放電容量最大,為345.8 mA∙h/g;合金的腐蝕速度隨球磨時間延長先減慢而后加快, 其中球磨10 h的合金腐蝕電流密度最低,為14.85 μA/cm2,且腐蝕速度最慢;合金的動電位極化曲線出現鈍化現象,鈍化區(qū)間較寬;交流阻抗譜由單容抗弧組成,沒有出現擴散尾,腐蝕過程受電化學反應控制;添加Ni后,合金放電容量增大,腐蝕速度減慢。
關鍵字: 鎂基儲氫合金;Ni;電化學性能;交流阻抗譜(EIS)
(Mg58Al42)0.9Ni0.1 hydrogen storage alloy
(College of Chemistry and Life Science, Shenyang Normal University, Shenyang 110034, China)
Abstract:(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 Mg17Al12 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/cm2 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.
Key words: Mg-based hydrogen storage alloy; Ni; electrochemical properties; electrochemical impedance spectroscopy (EIS)


