铸态及快淬态La_(0.55)M_(0.2)Mg_(0.25)Ni_(3.2)Co_(0.2)Al_(0.1)(M=Zr,Pr)合金的电化学贮氢动力学  

Electrochemical Hydrogen Storage Kinetics of As-Cast and Melt-spun La_(0.55)M_(0.2)Mg_(0.25)Ni_(3.2)Co_(0.2)Al_(0.1)(M=Zr,Pr) Alloys

作　　者：高金良[1,2] 尚宏伟 徐超 雍辉 许胜[2,3] 王海涛[2,3] 张羊换[2,3] 

机构地区：[1]微山钢研稀土材料有限公司,山东济宁277600 [2]钢铁研究总院功能材料研究所,北京100081 [3]内蒙古科技大学材料与冶金学院,内蒙古包头014010

出　　处：《金属功能材料》2014年第2期1-7,共7页Metallic Functional Materials

基　　金：国家自然科学基金项目(51161015和50961009);国家"863计划"项目(2011AA03A408)

摘　　要：为了改善La-Mg-Ni系A2B7型电极合金的动力学性能,用M(M=Zr,Pr)部分替代合金中的A侧元素La。用真空快淬技术制备了La0.5 5M0.2Mg0.25Ni3.2Co0.2Al0.1(M=Zr,Pr)电极合金,探索了快淬工艺参数对合金电化学贮氢动力学性能的影响。用XRD、SEM及TEM表征了铸态及快淬态合金的结构,结果发现,铸态及快淬态合金均由多相组成,包括两个主相(La,Mg)2Ni7和LaNi5以及残余相LaNi2。快淬Pr替代合金具有微晶、纳米晶结构,而在快淬Zr替代合金中发现明显的非晶相。电化学测试结果表明,合金的高倍率放电能力随淬速的增加先增加后减小。电化学交流阻抗(EIS)、Tafel极化曲线及电位阶跃测试的结果都表明,合金的电化学贮氢动力学性能随淬速的增加先上升后下降。In order to enhance the La-Mg-Ni-based Az BT-type electrode hydrogen storage alloy＇s dynamic perform- ance, the element La in A side has been partically substitued by M （M=Zr, Pr）. In this paper, La0. 55 M0. 2 Mg0. 25 Ni3.2C00.2 Al0.1（M=Zr,Pr） electrode alloy has been prepared by melt spinning in vacuum. At the same time, the structures of the as-cast and spun alloys are characterized by XRD,SEM and TEM, which reveal that the as-cast and spun alloys are of multiphase structures, including （La, Mg）2 Ni7 and LaNis major phases and LaNiz residual phase. Except for this, the as-spun Pr substituted all.oy ho].d a mixed structure of nanocrystalline and amorphous structure, but for the as-spun Zr substituted alloy, displaying amorphous structure obviously. With the increasing of spinning rate, the high rate discharge capacity of the alloys first mount up and then decline. The tests of EIS, Tafel and Po- tentiostatic discharge imply that the kinetics of electrochemical hydrogen storage first mount up and then decline.

关 键 词：A2B 型电极合金 熔体快淬 微观结构 循环稳定性 

分 类 号：TG139.7[一般工业技术—材料科学与工程]