在氩气保护下用悬浮熔炼制备La0.7-xTixMg0.3Ni3.5(x=0.00,0.05,0.10)储氢合金,研究Ti含量对合金电极电化学性能的影响。X射线衍射(XRD)分析表明,合金相主要由LaNi5、LaMg2Ni9和La2Ni3相组成。当x=0.10时,合金中有TiNi3相产生,随着Ti含量的增加,LaNi5、LaMg2Ni9和La2Ni3相的晶胞体积减小。电化学性能测试表明,合金电极最大放电容量分别为370 mAh/g(x=0.00)、331 mAh/g(x=0.05)和252 mAh/g(x=0.10);合金电极循环伏安特性曲线氧化峰电位随着Ti含量的增加而降低,表明Ti的加入使合金电极易于发生氧化反应。
The La0.7-xTixMg0.3Ni3.5(x=0.00,0.05,0.10) hydrogen storage alloys were prepared by magnetic levitation melting under Ar atmosphere,and the effects of Ti on electrochemical properties of the alloys were studied systematically.X-ray diffraction(XRD)analyses showed that the alloys are mainly composed of LaNi5,LaMg2Ni9 and La2Ni3 phases.When x=0.10,TiNi3 phase appears.The cell volumes of LaNi5,LaMg2Ni9 and La2Ni3 phase decrease with the Ti content increasing.Electrochemical investigations showed that the maximum discharge capacity of the alloy electrodes are 370 mAh/g(x=0.00),331 mAh/g(x=0.05) and 252 mAh/g(x=0.10),respectively.The anodic peak potential of the cyclic voltammograms curve shifts to negative with the Ti content increasing,which means that the adding of Ti make the oxidation reaction of electrodes occur more easily.