Cooperative effects of Sm and Mg on electrochemical performance of La–Mg–Ni-based alloys with A2B7- and A5B19-type super-stacking structure
Cooperative effects of Sm and Mg on electrochemical performance of La–Mg–Ni-based alloys with A2B7- and A5B19-type super-stacking structure
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DOI：
10.1016/j.ijhydene.2014.11.024
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发表时间：
2015-01
影响因子：
7.2
通讯作者：
Jingjing Liu;Shumin Han;Yuan Li;Xin Zhao;Shu-qin Yang;Yumeng Zhao
中科院分区：
文献类型：
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作者：
Jingjing Liu;Shumin Han;Yuan Li;Xin Zhao;Shu-qin Yang;Yumeng Zhao
研究了Sm和Mg对La0.85−x(Sm0.75Mg0.25)xMg0.15Ni3.65(x= 0, 0.1, 0.15, 0.2, 0.25)合金电化学性能的协同影响。结果发现合金主要含有(La,Mg)2Ni7、(La,Mg)5Ni19和LaNi5相。用Sm和Mg部分替代La，增加了(La,Mg)2Ni7和(La,Mg)5Ni19超堆垛相的总丰度，细化了晶粒，减小了晶胞体积。事实证明，Mg有助于增加超级堆积相的总丰度，从而提高放电容量和高倍率放电能力（HRD）。 Sm有利于晶粒的细化，有助于提高HRD和循环稳定性。 Sm和Mg共同改善合金电极的整体电化学性能效果显着。 x=0.20的合金的电化学循环寿命达到280次循环，是原始合金的两倍多。同时HRD1500提升了12.3%，最大放电容量也有所提升。
The cooperative effects of Sm and Mg on the electrochemical properties of La0.85−x(Sm0.75Mg0.25)xMg0.15Ni3.65(x= 0, 0.1, 0.15, 0.2, 0.25) alloys were investigated. It was found that the alloys mainly contained (La,Mg)2Ni7, (La,Mg)5Ni19and LaNi5phases. Partial replacement of Sm and Mg for La increased the total abundance of (La,Mg)2Ni7and (La,Mg)5Ni19super-stacking phases, refined crystal grains and decreased cell volumes. It was proved that Mg contributed to increasing the total abundance of super-stacking phases so that the discharge capacity and high rate dischargeability (HRD) were enhanced. Sm was favorable to the refinement of crystal grains, which contributed to betterHRDand cycling stability. The joint effects of Sm and Mg in improving the overall electrochemical properties of the alloy electrodes were remarkable. The electrochemical cycle life for the alloy withx= 0.20 reached 280 cycles, more than two times that of the pristine alloy. Meanwhile theHRD1500was increased by 12.3% and the maximum discharge capacity was also improved.