Effect of Ti–Al substitution on the electrochemical properties of amorphous MgNi-based secondary hydride electrodes
Effect of Ti–Al substitution on the electrochemical properties of amorphous MgNi-based secondary hydride electrodes
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DOI：
10.1016/j.jallcom.2004.08.060
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发表时间：
2005-04
影响因子：
6.2
通讯作者：
Jing-Wang Liu;H. Yuan;Jian-sheng Cao;Yijing Wang
中科院分区：
文献类型：
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作者：
Jing-Wang Liu;H. Yuan;Jian-sheng Cao;Yijing Wang
采用机械合金化方法制备了一种新型非晶Mg0.7Ti0.225Al0.075Ni合金，经50次循环后，其放电容量达到218.32mAhg− 1，仍保持初始容量343.44mAhg−1的63.57%。在5M KOH电解液中循环过程中，合金表面的X射线光电子能谱（XPS）表明，合金中的镁和铝大部分以金属态存在，钛以+3氧化态存在。电化学阻抗谱（EIS）表明，铝降低了电荷转移电阻。采用X射线衍射（XRD）和扫描电镜（SEM）对合金的结构进行了表征。电极循环寿命的提高与MgTi2O4的形成有关。研究了该合金电极在碱性溶液中的耐腐蚀性能，结果表明，Ti和Al取代Mg显著提高了电极的耐腐蚀性能。结果表明，Ti和Al取代Mg可以改善MgNi基电极的电化学性能。
A new amorphous Mg0.7Ti0.225Al0.075Ni alloy was prepared by means of mechanical alloying (MA), its discharge capacity reached 218.32mAhg−1after 50 cycles, which retains 63.57% of the initial capacity of 343.44mAhg−1. On the surface of the alloy during cycling in the electrolyte of 5M KOH, the X-ray photoelectron spectroscopy (XPS) shows that the majority of magnesium and aluminum in the alloy exist in metallic state; Ti exists in the +3 oxidation state. Electrochemical impedance spectroscopy (EIS) shows that the aluminum lowered the charge transfer resistance. The structure of the alloy was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). And the improvement of cycle life of the electrode can be related to the formation of MgTi2O4. A study on the anti-corrosion properties in alkaline solution of the alloy electrode has been done, and it is shown that Ti and Al substitution of Mg improves the anti-corrosion properties significantly. It is found that Ti and Al substitution of Mg could improve the electrochemical behavior of MgNi-based electrodes.