(桂林电子科技大学 材料科学与工程学院，桂林541004)
摘 要: 在制备La-Ni-Co-Fe中间合金的基础上，采用机械合金化方法制备La0.7Mg0.3Ni2.8Co0.5−xFex (x=0, 0.1, 0.2, 0.3, 0.4, 0.5)系列储氢合金，研究在不同球磨时间下储氢合金的物相、微观形貌和电化学性能及元素置换对其储氢性能的影响。结果表明：La0.7Mg0.3Ni2.8Co0.5合金的主相为LaNi5相，La0.7Mg0.3Ni2.8Co0.5−xFex系列储氢合金球磨40 h和80 h后，主相为LaNi5相和少量LaMg2Ni9相；且随着球磨时间的增加，合金晶粒变细小，La0.7Mg0.3Ni2.8Co0.5合金的最大放电容量呈变大的趋势，从142.4 mA∙h/g 增加到157.5 mA∙h/g，La0.7Mg0.3Ni2.8Co0.2Fe0.3合金的最大放电容量从150.7mA∙h/g增加到162.1mA∙h/g，合金具有较好的循环稳定性能。
关键字: 储氢合金；元素置换；XRD相分析；电化学性能
（School of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China）
Abstract:The La0.7Mg0.3Ni2.8Co0.5−xFex (x=0, 0.1, 0.2, 0.3, 0.4, 0.5) series alloys were prepared by mechanical alloying (MA) based on the preparation of intermediate alloy. The phases, microstructures and electrochemical properties of the alloys were investigated. The results indicate that LaNi5 is the dominant phase in the alloy La0.7Mg0.3Ni2.8Co0.5, LaNi5 and small amount of LaMg2Ni9 phase exist in the alloys La0.7Mg0.3Ni2.8Co0.5−xFex after ball milling for 40 h and 80 h. The grains size decrease with increasing the ball milling time. The largest discharge capacity of the alloy La0.7Mg0.3Ni2.8Co0.5 increases to 157.5 mA∙h/g from 142.4 mA∙h/g with increasing the ball milling time. The largest discharge capacity of La0.7Mg0.3Ni2.8Co0.2Fe0.3 alloy increases to 162.1 mA∙h/g from 150.7 mA∙h/g, as well as the improved cycling stability.
Key words: hydrogen storage alloys; element substitution; XRD phase identification; electrochemical properties
