Influences of Ti substitution on the structure and electrochemical properties of Mg1-xTixNi (x = 0,

• 作 者: HUANG Hongxia HUANG Kelong LIU Suqin CHEN Dongyang
• 机 构: College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China;Depa
• 出 处: 稀有金属（英文版）
• 发表日期: 2009年5期
• 关键词: hydrogen storage alloys Ti substitution structural characteristic electrochemica

MgNi-based hydrogen storage alloys Mg1-xTixNi (x = 0, 0.1, 0.2, and 0.3) were prepared by means of mechanical alloying. Mg in the alloy was partially substituted by Ti to improve the cycle stability of the alloys. The effects of the substitution of Ti for Mg on the microstructure and electrochemical performances of the alloys were investigated in detail. The results indicate that the substitution of Ti for Mg obviously decreases the discharge capacity, but it significantly improves their cycle stabilities. The microstructure of the alloys analyzed by X-ray dif-fraction (XRD) and scanning electron microscopy (SEM) shows that the alloys have a dominatingly amorphous structure. The substitution of Ti for Mg helps to improve the anti-oxidation/corrosion ability of the MgNi alloy but demolishes the electrochemical kinetics of hydrogena-tion/dehydrogenation. The Mg0.9Ti0.1Ni alloy electrode milled for 80 h exhibits the best integrative capability, which has the maximal dis-charge capacity of 331.66 mAh/g and the C30/Cmax of 63.65%.