中文摘要：

为了提出La-Mg-Ni（PuNi3型）系贮氢合金的电化学循环稳定性,在La2Mg（Ni0.85Co0.15）9合金中添加微量的B,用铸造及快淬工艺制备La2Mg（Ni0.85Co0.15）9Bx（x=0,0.05,0.10,0.15,0.20）贮氢合金,分析测试铸态及快淬态合金的微观结构与电化学性能,研究硼对合金微观结构及电化学性能的影响。结果表明：铸态合金具有多相结构,包括主相（La,Mg）Ni3相（PuNi3型）和LaNi5相,一定量的LaNi2相和微量的Ni2B相经快淬处理后,Ni2B相消失,且其他相的相对量随淬速的变化而变化。硼的加入提高了铸态及快淬态合金的循环稳定性,但使铸态合金的容量下降;铸态合金的电化学容量随B含量的增加单调下降,而快淬态合金的容量随B含量的增加有一极大值,B对铸态及快淬态合金电化学性能的影响机理是完全不同的。

英文摘要：

In order to improve the electrochemical cycle stability of La-Mg-Ni system （PuNi3-type） hydrogen storage alloy, B was added to La2Mg（Nio.ssCoo.15）9 alloy. La2MgfNio.ssCoo.ls）9Bx （x = 0, 0.05, 0.10, 0.15, 0.20） hydrogen storage alloys were prepared by casting and rapid quenching. The microstructures and electrochemical performances of the as-cast and quenched alloys were analyzed and measured. The effects of B additive on the microstructures and electrochemical performances of as-cast and quenched alloys were investigated. The results show that the as-cast and quenched alloys are composed of the （La, Mg）Ni3 phase （PuNi3 structure）, LaNi5 phase and LaNi2 phase, Ni2B phase exists in the as-cast alloys containing B. The Ni2B phase in the alloys containing B nearly disappears after rapid quenching, and the relative amount of each phase in the alloys changes with the variety of the quenching rate. The addition of B markedly enhances the cycle stabilities of the as-cast and quenched alloys, but obviously decreases the capacity of the alloys. With the increase of the quenching rate, the capacity of the as-cast alloy decreases monotonously, whereas the capacity of the as-quenched alloy has a maximum value. The activation behaviour of B additive on the electrochemical performances of the as-cast and quenched alloys is completely different.