RE（NiCoMnAl）电极合金中RE成分对微结构和电化学性能的影响

研究了4种具有A侧不同稀土组分的RE（NiCoMnAl）电极合金的微结构和电化学性能。研究结果表明，不论A侧稀土组分如何，铸态合金的显微组织为树枝晶形貌，晶体结构为CaCu5型六方结构，但合金的显胞体积随着A侧La被其他稀土元素的替代而减小。A侧的稀土组分对合金电化学性能影响明显，A侧为纯La时，合金的化学容量最大，倍率放电性能和充放电循环寿命较差；A侧的La被少量的Ce，Pr，Nd等稀土元素替代后，合金的电化学容量减小，倍率放电性能和循环寿命则有一定程度的改善，这与合金微结构的变化有关。

Effect of the Composition of Rare Earth on the Microstructure and Electrochemical Properties of RE(NiCoMnAl) 5 Hydride Alloy

In this paper, the microstructure and the electrochemical properties of RE(NiCoMnAl) 5 hydride alloy with different composition of rare earth have been investigated. The results show that, for all the samples studied, the crystalline structure is CaCu 5 type hexagonal structure and the metallographic structure is dendrite, while, the unit-cell volume decreases after being substituted part La by other rare earth elements. The effect of the composition of rare earth on the electrochemical properties of RE(NiCoMnAl) 5 alloy is marked. As compared with La(NiCoMnAl) 5 alloy, the electrochemical capacity of RE(NiCoMnAl) 5 alloy decreases, the high-rate dischargeability improves and the cycling life enhances, where La is part substituted by others rare earth including Ce, Pr, Nd. The effect of the composition of rare earth on the electrochemical properties is related to the change of the microstructure of RE(NiCoMnAl) 5 alloy.