摘要
为了了解新型稀土-镁-镍系储氢合金的结构和电化学性能与热处理温度的关系,通过中频感应熔炼法制备了La0.65Pr0.05Nd0.05Mg0.25Ni3.3Al0.1储氢合金,在氩气保护下进行退火热处理,温度为1123K、1173K和1223K,保温时间8h。应用X射线衍射、扫描电镜、能谱分析等方法研究了合金的结构,测试了合金的主要电化学性能。结果表明该合金由三相组成:(La,Mg)Ni3.5相、LaNi5相和(La,Mg)Ni2相,退火后三相的相对含量发生了变化,随着热处理温度的逐步提高,合金中LaNi5相和(La,Mg)Ni2相的比例减小,(La,Mg)Ni3.5相的比例增加。合金的放电容量、充放电循环稳定性与合金组成相所占比例密切相关,尤其是(La,Mg)Ni相的存在不容忽视。
In order to know the relation between the electrochemical properties of a new RE-Mg-Ni system hy-drogen storage alloy and heat treatment temperature, La0.65 Pr0.05 Nd0.05 Mg0.25Ni3.3 Al0.1 hydrogen storage alloy was prepared by casting and the effects of annealing at 1123, 1173 and 1223K for 8h on the crystal structures and the electrochemical properties of the alloy were investigated. XRD, SEM and EDS analyses have revealed that the major phases of the alloy are （La, Mg）Ni3.5,LaNi5 and （La, Mg）Ni2 phase. The phase abundance of these three phases varies differently with increasing annealing temperature. It is found that the discharge capacity and the cycle life of the alloys are improved after annealing treatment at an appropriate temperature owing to the variable phase abundance and composition homogenization, respectively. Compared with other related literature, the results obtained in this paper indicate that the effects of the （La, Mg）Ni2 phase in the tested alloy on the electrochemical properties of the alloy are remarkable.
出处
《稀土》
EI
CAS
CSCD
北大核心
2007年第5期1-5,共5页
Chinese Rare Earths
基金
国际科技合作项目(2006DFB52550)
国家自然科学基金项目(20363001)
