摘要
在 AB5型混合稀土 -镍系贮氢多元合金的研究中 ,为设计高性能的 AB5型贮氢电极合金 ,人们对其 B侧多元合金化和 A侧稀土组元分别进行了系统地研究。在 B侧金属多元合金化研究工作比较成熟的基础上 ,进行贮氢合金中稀土组元的综合优化研究 ,是挖掘提高 AB5型合金性能另一重要途径。 La、Ce、Nd和 Pr含量及比例对 RE( Ni Co Mn Ti) 5合金电化学性能有很大影响 ,但添加纯 La,Ce和 Nd来调整其稀土成分 ,价格昂贵。本工作通过对 RE( Ni Co Mn Ti) 5合金中稀土组元 ( RE=MlβMm1-β)进行组合优化研究 ,主要还是依赖于市售的混合稀土金属原材料 ,利用不同种类的混合稀土中 L a、Ce、Nd和 Pr组元相应变化 ,来调整其稀土成分。结果表明 ,Ml:Mm比例对其电化学有显著影响。Ml0 .85Mm0 .15( Ni Co Mn Ti) 5对应合金具有最高放电容量为 2 80 m A h/ g和较好的循环寿命 ,并采用Rietveld精细结构法分析 La、Ce、Nd和 Pr作用机理。
In the development of hydrogen storage alloys for Ni MH battery,multicomponent AB 5 type of mischmetal nickel based hydrogen storage alloys were mostly investigated not only on B side of nickel and nickel substitute element, i.e.,multicomponent alloy of B-side, but also on A(RE) side (RE=La 1-x-y-z Ce xNd yPr z) with different La, Ce, Nd and Pr compositions in order to optimize the hydride electrode alloy. The results showed that La,Ce,Nd,and Pr had great effects on the electrode performance.Due to the high price of pure La, Ce, Nd and Pr,the REB 5 type electrode material for mass production should not be pure rare earths.The use of unrefined rare earth mixture (mischmetal—a mixture of different composition of lanthanum, cerium, neodymium, preseodymium, etc) was very economical. Generally, they are categorized as lanthanum rich mischmetal (denoted as Ml), cerium rich mischmetal (denoted as Mm) and high lanthanum mischmetal (denoted as Lm) owing to different mineral resources and extractive metallurgical methods. Therefore, good electrochemical properties of RENi 5 alloys could be obtained by choosing a proper Mm:Ml ratio. In this paper, the electrochemical properties Ml βMm 1 β (NiCoMnTi) 5 hydrogen storage alloys with different composition of rare earth components were systematically examined. By the optimization of the Ml:Mm ratio, the alloy Ml 0.85 Mm 0.15 (NiCoMnTi) 5 showed a maximum capacity 280 mAhg -1 and good cycling stability. The basic structure of Ml βMm 1-β (NiCoMnTi) 5 was revealed by the Rietveld refinement analysis method.
出处
《功能材料》
EI
CAS
CSCD
北大核心
1998年第1期33-37,共5页
Journal of Functional Materials
基金
"863"资助项目
关键词
贮氢合金
稀土
金属氢化物电极
电化学性能
hydrogen storage alloy
rare earth
metal hydride electrode
electrochemical property
