摘要
用铸造及快淬工艺制备了Mg2Ni型Mg20-xLaxNi10(x=0、2、4、6)贮氢合金。用XRD、SEM、HR-TEM分析了铸态及快淬态合金的微观结构,结果发现,在快淬无La合金中没有出现非晶相,但快淬含La合金显示了以非晶相为主的结构。用DSC研究了快淬合金的热稳定性,表明La含量及快淬对非晶相的晶化温度影响很小。应用Sieverts装置研究了铸态及快淬态合金的吸放氢动力学,发现铸态合金的吸放氢量及动力学随La含量的增加显著改善,且快淬显著地改善了(x=2)合金的吸放氢动力学。电化学测试的结果表明,铸态合金的放电容量随La含量的增加而增加,(x=2)合金的放电容量随淬速的增加而增加。La替代Mg显著地提高了铸态及快淬态合金的循环稳定性。
Mg2Ni-type Mg20-xLaxNi10 （x=0,2,4,6） hydrogen storage alloys were prepared by casting and rapid quenching. The structures of the as-cast and quenched alloys were studied by XRD,SEM and HRTEM,founding that no amorphous phase forms in the as-quenched La-free alloy,but the as-quenched alloys containing La hold a major amorphous phase. Thermal stability of the as-quenched alloys is studied by DSC,showing that La content and the quenching rate induce a negligible influence on the crystallization temperature of the amorphous phase. The hydrogen absorption and desorption kinetics of the as-cast and quenched alloys are measured using an automatically controlled Sieverts apparatus,confirming that the hydrogen absorption and desorption capacities and the kinetics of the as-cast alloys are markedly ameliorated with increasing La content,and rapid quenching significantly improves the hydrogen absorption and desorption kinetics of the alloy （x=2）. The electrochemical measurement shows that the discharge capacity of the as-cast alloys grow with the increase of La content,and for the as-quenched alloy （x=2）,the discharge capacity increases with rising quenching rate. The substitution of La for Mg markedly enhances the cycle stability of the as-cast and quenched alloys.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2010年第5期771-774,共4页
Journal of Functional Materials
基金
国家高技术研究发展计划(863计划)资助项目(2007AA03Z227)
国家自然科学基金资助项目(50871050
50701011)
内蒙古自然科学基金重点资助项目(200711020703)
内蒙古高等教育科学研究资助项目(NJzy08071)
关键词
MG2NI型合金
快淬
La替代Mg
贮氢性能
Mg2Ni-type alloy
rapid quenching
substituting Mg with La
hydrogen storage characteristic
