The （La4MgNi17.5Mn1.5） alloys at different melt-spun speeds were prepared by using a vacuum melt-spun furnace, and the phase structure and electrochemical properties of alloys were studied. X-ray diffraction analysi...The （La4MgNi17.5Mn1.5） alloys at different melt-spun speeds were prepared by using a vacuum melt-spun furnace, and the phase structure and electrochemical properties of alloys were studied. X-ray diffraction analysis results show that melt-spun LaaMgNi17.5Mn1.5 alloys are composed of CeCus-type, PrsCo19-type and CeNi2-type phase. As the melt-spun speed increased, the phase abundance of CeCus-type increased, but that of PrsCo19-type decreased. Scanning electron microscopy-energy-dispersive spectroscopy analysis results show that melt-spun treatment can refine grain and make the alloys homogenization. Electrochemical tests show that all alloys have good activation performance within four cycles. With the increase in melt-spun speed, the cycle stability （S） of the alloys was improved obviously. After 100 cycles, the retention rate （S100） of the alloy increased from 54.82% （as-cast） to 82.29% （25 m/s）. Nevertheless, the maximum discharge capacity （Cmax） and high-rate dischargeability gradually decreased.展开更多
文摘The （La4MgNi17.5Mn1.5） alloys at different melt-spun speeds were prepared by using a vacuum melt-spun furnace, and the phase structure and electrochemical properties of alloys were studied. X-ray diffraction analysis results show that melt-spun LaaMgNi17.5Mn1.5 alloys are composed of CeCus-type, PrsCo19-type and CeNi2-type phase. As the melt-spun speed increased, the phase abundance of CeCus-type increased, but that of PrsCo19-type decreased. Scanning electron microscopy-energy-dispersive spectroscopy analysis results show that melt-spun treatment can refine grain and make the alloys homogenization. Electrochemical tests show that all alloys have good activation performance within four cycles. With the increase in melt-spun speed, the cycle stability （S） of the alloys was improved obviously. After 100 cycles, the retention rate （S100） of the alloy increased from 54.82% （as-cast） to 82.29% （25 m/s）. Nevertheless, the maximum discharge capacity （Cmax） and high-rate dischargeability gradually decreased.
