La_(0.75-x)Pr_xMg_(0.25)Ni_(2.9)Co_(0.4)Al_(0.2)(x=0-0.4)电极合金的微观结构及电化学性能  

Microstructures and electrochemical performance of as-cast and quenched La_(0.75-x)Pr_xMg_(0.25)Ni_(2.9)Co_(0.4)Al_(0.2)(x=0-0.4)electrode alloys

作　　者：高金良[1,2] 张羊换[2] 任江远 王新林[2] 赵栋梁[2] 葛启录[2] 

机构地区：[1]包头三德电池材料有限公司,内蒙古包头014010 [2]北京钢铁研究总院功能材料研究所,北京100081

出　　处：《电源技术》2010年第4期382-386,共5页Chinese Journal of Power Sources

摘　　要：为了提高La-Mg-Ni系(PuNi3)型贮氢合金的电化学循环稳定性,用Pr部分替代La,用铸造和快淬工艺制备了La0.75-xPrxMg0.25Ni2.9Co0.4Al0.2(x=0～0.4)贮氢合金。分析测试了铸态及快淬态合金的电化学性能和微观结构、铸态合金的交流阻抗谱,研究了Pr替代对铸态及快淬态合金微观结构及电化学性能的影响。结果表明,铸态及快淬态合金具有多相结构,包括(La,Mg)Ni3相(PuNi3结构),LaNi5相和一定量的LaNi2相。随Pr含量的增加,铸态及快淬态合金中LaNi5相略有增加。Pr的替代提高了铸态及快淬态合金的循环稳定性,但使合金的容量有所下降。铸态及快淬态合金均有优良的活化性能。合金的循环寿命随淬速的增加而增加。In order to improve the electrochemical cycle stability of La-Mg-Ni system （PuNi3-type） hydrogen storage alloy, the La in the alloy was partially substituted by Pr. La0.75-xPrxMg0.25Ni2.9Co0.4Al0.2 （x=0-0.4） hydrogen storage alloys were prepared by casting and rapid quenching. The electrochemical performance and microstructure of the as-cast and quenched alloys were determined and measured. In the meantime the EIS of the as-cast were measured. The effects of Pr substitution on the microstructure and electrochemical properties of the as-cast and quenched alloys were investigated in detail. The obtained results show that the as-cast and quenched alloys are multi-phase structure and are composed of the （La, Mg）Ni3 phase （PuNi3-type structure） and the LaNi5 phase as well as a certain amount of LaNi2 phase. The amount of the LaNi5 phase slightly increases with the increase of Pr content. The addition of Pr enhances the cycle stability of the as-cast and quenched alloys, but decreases the discharge capacities of the alloys. The as-cast and quenched alloys have an excellent activation performance. The cycle lives of the alloys increase with the increase of the quenching rate.

关 键 词：LA-MG-NI系贮氢合金 快淬 微观结构 电化学性能 

分 类 号：TM912[电气工程—电力电子与电力传动]