摘要
研究了 4种具有A侧不同稀土组分的RE(NiCoMnAl) 5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 ,但合金的晶胞体积随着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 ,合金的电化学容量最大 ,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。
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.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2002年第3期217-220,共4页
Rare Metal Materials and Engineering
关键词
贮氢合金
AB5型电极合金
微结构
电化学性能
稀土
hydrogen storage alloy
AB 5 type hydride alloy
microstructure
electrochemical properties
