摘要
In order to investigate the effect of different B-site additions on phase structure and electrochemical properties of cobalt-free La-Mg-Ni based alloys, La0.80Mg0.20Ni2.85Al0.11M0.53 （M=Ni, Si, Cr, Cu, Fe） hydrogen storage alloys were prepared and studied systematically. X-ray powder diffraction showed that the alloys consisted mainly of LaNi3 phase and LaNi5 phase except that Cr addition caused a minor Cr phase. Electrochemical testing indicated that alloys with additional Ni, Cr, Cu or Fe were activated within only 1-2 cycles, while that with Si addition needed 4 cycles. Adding Si, Cu and Fe increased cycling stability of La-Mg-Ni based alloys. However, maximum discharge capacity decreased from 362 mAh/g to 215 mAh/g in the order of Ni〉Fe〉Cu〉Cr〉Si. In addition, electrochemical kinetics of alloy electrodes was also researched by measuring high rate discharge ability （HRD）, hydrogen diffusion coefficient （D） and limiting current density （IL）.
In order to investigate the effect of different B-site additions on phase structure and electrochemical properties of cobalt-free La-Mg-Ni based alloys, La0.80Mg0.20Ni2.85Al0.11M0.53 （M=Ni, Si, Cr, Cu, Fe） hydrogen storage alloys were prepared and studied systematically. X-ray powder diffraction showed that the alloys consisted mainly of LaNi3 phase and LaNi5 phase except that Cr addition caused a minor Cr phase. Electrochemical testing indicated that alloys with additional Ni, Cr, Cu or Fe were activated within only 1-2 cycles, while that with Si addition needed 4 cycles. Adding Si, Cu and Fe increased cycling stability of La-Mg-Ni based alloys. However, maximum discharge capacity decreased from 362 mAh/g to 215 mAh/g in the order of Ni〉Fe〉Cu〉Cr〉Si. In addition, electrochemical kinetics of alloy electrodes was also researched by measuring high rate discharge ability （HRD）, hydrogen diffusion coefficient （D） and limiting current density （IL）.
基金
supported by the National Natural Science Foundation of China (20673093)
the Natural Science Foundation of Hebei Province (B2007000303)
Support Program for Hundred Excellent Innovation Talents from the Universities and Colleges of Hebei Province
