Structures and hydrogen storage properties of RE-Mg-Ni-Mn-based AB2-type alloys prepared by casting and melt spinning  

作　　者：Yang-Huan Zhang Zhong-Hui Hou Ying Cai Feng Hu Yan Qi Dong-Liang Zhao 

机构地区：[1]Key Laboratory of Integrated Exploitation of Baiyun Obo Multi-Metal Resources,Inner Mongolia University of Science and Technology,Baotou 014010,China [2]Department of Functional Material Research,Central Iron and Steel Research Institute,Beijing 100081,China

出　　处：《Rare Metals》2019年第11期1086-1096,共11页稀有金属（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(Nos.51161015,51371094 and 51471054);the Natural Science Foundation of Inner Mongolia,China(No.2015MS0558)

摘　　要：To ameliorate the electrochemical hydrogen storage properties of RE-Mg-Ni-Mn-based AB2-type electrode alloys,La element was partially substituted by Ce,and La1-xCexMgNi3.5Mn0.5(x=0,0.1,0.2,0.3,0.4)alloys were fabricated by casting and melt spinning.The effects of Ce content on structures and electrochemical hydrogen storage properties of prepared alloys were studied in detail.Results show that the experimental alloys consist of LaMgNi4 and LaNi5 phases.The variation of Ce content,instead of changing phase composition,results in an obvious phase abundance change in the alloys,namely the amount of LaMgNi4 and LaNi5 phases,respectively,increases and decreases with Ce content growing.Moreover,the partial substitution of Ce for La leads to that the lattice keeps constant,cell volumes clearly decreases and the alloy grains are markedly refined.The electrochemical measurements reveal that the as-cast and as-spun alloys obtain the maximum discharge capacities at the first cycling without any activation needed.With Ce content increasing,the discharge capacity of as-cast alloys visibly decreases.By contrast,the as-spun alloys have the maximum discharge capacity value.The substitution of Ce for La dramatically promotes the cycle stability.Moreover,the electrochemical kinetic performances of as-cast and asspun alloys first increase and then decrease with Ce content increasing.To ameliorate the electrochemical hydrogen storage properties of RE-Mg-Ni-Mn-based AB2-type electrode alloys,La element was partially substituted by Ce,and La1-xCexMgNi3.5Mn0.5（x=0,0.1,0.2,0.3,0.4）alloys were fabricated by casting and melt spinning.The effects of Ce content on structures and electrochemical hydrogen storage properties of prepared alloys were studied in detail.Results show that the experimental alloys consist of LaMgNi4 and LaNi5 phases.The variation of Ce content,instead of changing phase composition,results in an obvious phase abundance change in the alloys,namely the amount of LaMgNi4 and LaNi5 phases,respectively,increases and decreases with Ce content growing.Moreover,the partial substitution of Ce for La leads to that the lattice keeps constant,cell volumes clearly decreases and the alloy grains are markedly refined.The electrochemical measurements reveal that the as-cast and as-spun alloys obtain the maximum discharge capacities at the first cycling without any activation needed.With Ce content increasing,the discharge capacity of as-cast alloys visibly decreases.By contrast,the as-spun alloys have the maximum discharge capacity value.The substitution of Ce for La dramatically promotes the cycle stability.Moreover,the electrochemical kinetic performances of as-cast and asspun alloys first increase and then decrease with Ce content increasing.

关 键 词：AB2-type alloy Ce SUBSTITUTION for La MELT SPINNING ELECTROCHEMICAL properties 

分 类 号：TG1[金属学及工艺—金属学]