An investigation on electrochemical hydrogen storage performances of Mg-Y-Ni alloys prepared by mechanical milling
来源期刊：Journal of Rare Earths2015年第8期
论文作者：张羊换 张朋军 袁泽明 杨泰 祁焱 赵栋梁
文章页码：874 - 883
摘 要：The nanocrystalline and amorphous Mg2Ni-type electrode alloys with a composition of Mg20-xYxNi10（x=0, 1, 2, 3 and 4） were fabricated by mechanical milling. Effects of Y content on the structures and electrochemical hydrogen storage performances of the alloys were investigated in detail. The inspections of X-ray diffraction（XRD）, transmission electron microscopy（TEM） and scanning electron microscopy（SEM） revealed that the substitution of Y for Mg brought on an obvious change in the phase composition of the alloys. The substitution of Y for Mg resulted in the formation of secondary YMgN i4 phases without altering the major phase Mg2 Ni when Y content x≤1. But with the further increase of Y content, the major phase of the alloys changed into YMgN i4 phase. In addition, such substitution facilitated the glass forming of the Mg2Ni-type alloy. The discharge capacities of the as-milled alloys had the maximum values with Y content varying, but Y content with which the alloy yielded the biggest discharge capacity was changeable with milling time varying. The substitution of Y for Mg had an insignificant effect on the activation ability of the alloys, but it dramatically improved the cycle stability of the as-milled alloys. The effect of Y content on the electrochemical kinetics of the alloys was related to milling time. When milling time was 10 h, the high rate discharge ability（HRD）, diffusion coefficient of hydrogen atom（D） and charge transfer rate all had the maximum value with Y content increasing, but they always decreased in the same condition when milling time increased to 70 h.
张羊换1,2，张朋军1，袁泽明2，杨泰2，祁焱2，赵栋梁2
1. Key Laboratory of Integrated Exploitation of Baiyun Obo Multi-Metal Resources, Inner Mongolia University of Science and Technology2. Department of Functional Material Research, Central Iron and Steel Research Institute
摘 要：The nanocrystalline and amorphous Mg2Ni-type electrode alloys with a composition of Mg20-xYxNi10（x=0, 1, 2, 3 and 4） were fabricated by mechanical milling. Effects of Y content on the structures and electrochemical hydrogen storage performances of the alloys were investigated in detail. The inspections of X-ray diffraction（XRD）, transmission electron microscopy（TEM） and scanning electron microscopy（SEM） revealed that the substitution of Y for Mg brought on an obvious change in the phase composition of the alloys. The substitution of Y for Mg resulted in the formation of secondary YMgN i4 phases without altering the major phase Mg2 Ni when Y content x≤1. But with the further increase of Y content, the major phase of the alloys changed into YMgN i4 phase. In addition, such substitution facilitated the glass forming of the Mg2Ni-type alloy. The discharge capacities of the as-milled alloys had the maximum values with Y content varying, but Y content with which the alloy yielded the biggest discharge capacity was changeable with milling time varying. The substitution of Y for Mg had an insignificant effect on the activation ability of the alloys, but it dramatically improved the cycle stability of the as-milled alloys. The effect of Y content on the electrochemical kinetics of the alloys was related to milling time. When milling time was 10 h, the high rate discharge ability（HRD）, diffusion coefficient of hydrogen atom（D） and charge transfer rate all had the maximum value with Y content increasing, but they always decreased in the same condition when milling time increased to 70 h.
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