根据正交试验方案,采用共沉淀还原扩散法制备LaMg2Ni9-x-y-zCoxMnyCuz(x=1.8,2.1,2.4,2.7,3.0;y=2.1,2.4,2.7,3.0,3.3;z=0.3,0.6,0.9,1.2,1.5)系列AB3型稀土基储氢合金,研究该系列合金的放电容量和循环稳定性,并用X射线衍射对产物的结构进行微观分析。结果表明:3元素同时替代时合金的放电容量均高于单元素替代时合金的放电容量,但循环稳定性有所下降。合金结构分析表明,合金主相为La4Co3相。该系列合金中LaMg2Ni2.7Co2.1Mn2.7Cu1.5合金电极表现出的综合电化学性能较优。
AB3 type LaMg2Ni9-x-y-zCoxMnyCuz (x=1.8, 2.1, 2.4, 2.7, 3.0; y=2.1, 2.4, 2.7, 3.0, 3.3; z=0.3, 0.6, 0.9, 1.2, 1.5) hydrogen storage alloys were synthesized by a coprecipitation-reduction-diffusion method according to the orthogonal experimental design. Their discharge capacity and cycle stability were studied and the structure was analyzed by XRD. The results indicate that the maximum discharge capacity of the series of alloys under multielement substitution is higher than the alloys under single element substitution, but the cycle stability decline slightly. Structure analyses show that the main phase of alloys is La4Co3. LaMg2Ni2.7Co2.1Mn2.7Cu1.5 alloy shows the best electrochemical properties in the series of hydrogen storage alloys.