无钴LaNi4.1Al0.3Mn0.4Si0.2Fex (x=0~0.4)储氢合金性能

Properties of Co-Free LaNi4.1Al0.3Mn0.4Si0.2Fex (x=0~0.4) Hydrogen Storage Alloys

摘要:

采用电弧熔炼制备LaNi4.1Al0.3Mn0.4Si0.2Fex（x=0~0.4）储氢合金，借助XRD、SEM等分析LaNi4.1Al0.3Mn0.4Si0.2Fex合金的晶体结构和相组成，并研究合金的电化学性能。结果表明：合金主要由LaNi5单相组成，当x≥0.1时，在LaNi5主相上分布着些许灰色的第二相。随着LaNi4.1Al0.3Mn0.4Si0.2Fex(x=0~0.4)合金中Fe的加入量增加，合金最大放电容量由295.4 mAh/g（x=0）降低到278.2 mAh/g（x=0.4），活化次数也由10次增加到18次。同时合金200次循环后的容量保持率却由66.85%（x=0）提高到93.33%（x=0.4）。

关键词:储氢合金;放电容量;循环稳定性

Abstract:

LaNi4.1Al0.3Mn0.4Si0.2Fex (x=0~0.4) hydrogen storage alloys were prepared by inductive melting. The crystal structure and phase composition of alloys were determined by XRD and SEM, and the electrochemical properties were also investigated. The results show that the alloys are composed of LaNi5 as main phase. When x≥0.1, some grey secondary phases are distributed on the main LaNi5 phase. With the increase of Fe content, the maximum discharge capacity decreases from 295.4 mAh/g (x=0) to 278.2 mAh/g (x=0.4), and the activity times increase from 10 to 18. Meanwhile the capacity retention rate increases from 66.85% (x=0) to 93.33% (x=0.4) after the charge/discharge cycle of 200 times.

Key words:hydrogen storage alloys; discharge capacity; cycling stability