铸态及退火态La_(0.8-x)Pr_xMg_(0.2)Ni_(3.35)Al_(0.1)Si_(0.05)(x=0~0.4)电极合金的电化学贮氢性能(英文)  

Electrochemical Hydrogen Storage Characteristics of the as-Cast and Annealed La_(0.8-x)Pr_xMg_(0.2)Ni_(3.35)Al_(0.1)Si_(0.05)(x=0~0.4) Electrode Alloys

作　　者：张羊换[1,2] 蔡颖[1] 李保卫[1] 任慧平[1] 侯忠辉[1] 赵栋梁[2] 

机构地区：[1]内蒙古科技大学国家重点实验室培育基地,内蒙古包头014010 [2]钢铁研究总院,北京100081

出　　处：《稀有金属材料与工程》2013年第10期1981-1987,共7页Rare Metal Materials and Engineering

基　　金：National Natural Science Foundations of China(51161015,50961009);"863" Program(2011AA03A408);Natural Science Foundation of Inner Mongolia,China(2011ZD10,2010ZD05)

摘　　要：采用铸造及退火工艺制备了La0.8-x Prx Mg0.2Ni3.35Al0.1Si0.05(x=0,0.1,0.2,0.3,0.4)电极合金。系统研究了Pr的替代对合金的结构与电化学储氢性质的影响,结果表明除少量残余LaNi3相外,铸造及退火合金是由六方Ce2Ni7型(La,Mg)2Ni7相与六方CaCu5型LaNi5相构成的。Pr对La的置换对合金的电化学储氢性质产生明显影响,铸造及退火合金的放电容量和高倍率放电能力随Pr含量的增加先升后降。当Pr含量由0增加至0.4时,铸造及退火合金的100次充放电循环后容积保持率S100从64.96%和72.82%分别增加至77.94%和91.81%。The electrode alloys with the chemical compositions of La0.8-xPrxMg0.2Ni3.35Al0.1Si0.05 （x=0,0.1,0.2,0.3,0.4） were prepared by casting and annealing.The effects of Pr substitution on the structure and electrochemical hydrogen storage characteristics of the alloys were investigated.The results indicate that the as-cast and the annealed alloys consist of Ce2Ni7-type hexagonal （La,Mg）2Ni7 phase and CaCu5-type hexagonal LaNi5 phase as well as a little residual phase LaNi3.The substitution of Pr for La observably affects the electrochemical hydrogen storage characteristics of the alloys.The discharge capacity and the high rate discharge ability （HRD） of the as-cast and the annealed alloys first increase and then decline with the growing of Pr content.The as-cast and the annealed （x-=0.3） alloys yield the largest discharge capacities of 363.1 and 389.7 mAh/g,respectively.The electrochemical cycle stability of the as-cast and the annealed alloys markedly grows with the rising of Pr content.The capacity retaining rate （S100） at 100th charging and discharging cycle is enhanced from 64.96％ to 77.94％ for the as-cast alloy,and from 72.82％ to 91.81％ for the as-annealed alloy by raising Pr content from 0 to 0.4.

关 键 词：A2B7型电极合金 Pr置换La 结构 电化学性质 

分 类 号：TG139.7[一般工业技术—材料科学与工程]