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在 AB5型混合稀土 -镍系贮氢多元合金的研究中 ,为设计高性能价廉的 AB5型贮氢电极合金 ,人们对其 B侧多元合金化和 A( =RE)侧稀土组元分别进行了系统地研究。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 ( Ml和 Mm)原材料 ,利用不同种类的混合稀土中 La,Ce,Nd和 Pr组元相应变化 ,来调整其稀土成分。结果表明 ,Ml∶Mm比例对其电化学性能有显著影响。 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 ,而合金电化学性能与相应的结构有关。因此 ,采用 Rietveld法对其精细结构分析具有重要意义。分析表明 ,合金仍保持母体合金 La Ni5和 Ca Cu5型六方晶系结构 ,空间群为 P6/mmm;合金中 La,Ce,Nd,Pr( 1a) - Ni,Co,Mn,Ti( 2 c)键长对电化学容量起决定作用。
In AB5 hybrid rare earth - nickel hydrogen storage multi-element alloy research, in order to design a high performance and low cost AB5 hydrogen storage electrode alloy, its B-side multi-alloying and A (= RE) Study systematically. In this work, the combination optimization of rare earth elements (RE = MlβMm1-β) in RE (Ni Co Mn Ti) 5 alloy relies mainly on commercially available mixed rare earth metal (Ml and Mm) raw materials, using different kinds of La, Ce, Nd and Pr elements in the mixed rare earth corresponding changes, to adjust its rare earth composition. The results show that the Ml: Mm ratio has a significant effect on the electrochemical properties. The corresponding alloy Ml0.85Mm0.15 (NiCoMnTi) 5 has the highest discharge capacity of280 mA · h / g and a good cycle life, and the electrochemical performance of the alloy is related to the corresponding structure. Therefore, the use of Rietveld method for its fine structure analysis is of great significance. The analysis shows that the alloy still maintains the hexagonal structure of La Ni5 and Ca Cu5, the space group is P6 / mmm. The La, Ce, Nd, Pr (1a) - Ni, Co, Mn and Ti Bond length plays a decisive role in electrochemical capacity.