Electrochemical performance of La2–xSmxMg16Ni+200 wt.% Ni（x=0, 0.1, 0.2, 0.3, 0.4） alloys
来源期刊：Journal of Rare Earths2017年第7期
论文作者：冯佃臣 王西涛 张羊换
文章页码：683 - 689
摘 要：Nanocrystalline and amorphous La2–xSmxMg16Ni+200wt.% Ni（x=0, 0.1, 0.2, 0.3, 0.4） alloys were prepared by mechanical milling technology. The structures of as-cast and milled alloys were investigated by X-ray diffraction（XRD）, scanning electron microscopy（SEM） and transmission electron microscopy（TEM）. Electrochemical performance of the alloy was studied by using an automatic galvanostatic system. The electrochemical impedance spectra（EIS） and Tafel polarization curves were measured by electrochemical workstation. The results indicated that the structures of the as-cast and milled alloys presented a multiphase structure with nanocrystalline and amorphous phase, moreover, transforming from nanocrystalline to amorphous phase with Sm doping. With the increase of Sm content, the maximum discharge capacity of the alloy was decreased from 922.6 to 649.1 m Ah/g, the high-rate discharge ability（HRD） was decreased, the cycle stability was strengthened, and the alloy exhibited excellent electrochemical kinetics. In addition, the charge-transfer resistance(Rct) of alloy was lessened from 0.05874 to 0.02953 ? and the limiting current density（IL） was descended from 2.08366 to 1.04592 A/g with increasing Sm content.
冯佃臣1,2，王西涛1，张羊换2,3
1. State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing2. School of Materials and Metallurgy, Inner Mongolia University of Science and Technology3. Department of Functional Material Research, Central Iron and Steel Research Institute
摘 要：Nanocrystalline and amorphous La2–xSmxMg16Ni+200wt.% Ni（x=0, 0.1, 0.2, 0.3, 0.4） alloys were prepared by mechanical milling technology. The structures of as-cast and milled alloys were investigated by X-ray diffraction（XRD）, scanning electron microscopy（SEM） and transmission electron microscopy（TEM）. Electrochemical performance of the alloy was studied by using an automatic galvanostatic system. The electrochemical impedance spectra（EIS） and Tafel polarization curves were measured by electrochemical workstation. The results indicated that the structures of the as-cast and milled alloys presented a multiphase structure with nanocrystalline and amorphous phase, moreover, transforming from nanocrystalline to amorphous phase with Sm doping. With the increase of Sm content, the maximum discharge capacity of the alloy was decreased from 922.6 to 649.1 m Ah/g, the high-rate discharge ability（HRD） was decreased, the cycle stability was strengthened, and the alloy exhibited excellent electrochemical kinetics. In addition, the charge-transfer resistance(Rct) of alloy was lessened from 0.05874 to 0.02953 ? and the limiting current density（IL） was descended from 2.08366 to 1.04592 A/g with increasing Sm content.
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