稀土学报(英文版)
稀土學報(英文版)
희토학보(영문판)
JOURNAL OF RARE EARTHS
2013年
12期
1175-1182
,共8页
张羊换%王海涛%杨泰%翟亭亭%张国芳%赵栋梁
張羊換%王海濤%楊泰%翟亭亭%張國芳%趙棟樑
장양환%왕해도%양태%적정정%장국방%조동량
Mg2Ni-type alloys%Nd addition%melt spinning%nanocrystalline and amorphous%electrochemical hydrogen storage per-formances%rare earths
Melt spinning technology was used to prepare the Mg2Ni-type (Mg24Ni10Cu2)100-xNdx (x=0, 5, 10, 15, 20) alloys in order to obtain a nanocrystalline and amorphous structure. The effects of Nd content and spinning rate on the structures and electrochemical hydrogen storage performances of the alloys were investigated. The structure characterizations of X-ray diffraction (XRD), transmis-sion electron microscopy (TEM) and scanning electron microscopy (SEM) linked with energy dispersive spectroscopy (EDS) re-vealed that the as-spun Nd-free alloy displayed an entire nanocrystalline structure, whereas the as-spun Nd-added alloys held a nanocrystalline and amorphous structure and the degree of amorphization visibly increased with the rising of Nd content and spinning rate, suggesting that the addition of Nd facilitated the glass forming of the Mg2Ni-type alloy. The electrochemical measurements in-dicated that the addition of Nd and melt spinning improved the electrochemical hydrogen storage performances of the alloys signifi-cantly. The discharge capacities of the as-cast and spun alloys exhibited maximum values when Nd content was x=10, which were 86.4, 200.5, 266.3, 402.5 and 452.8 mAh/g corresponding to the spinning rate of 0 (As-cast was defined as the spinning rate of 0 m/s), 10, 20, 30 and 40 m/s, respectively. The cycle stability (S20, the capacity maintain rate at 20th cycle) of the as-cast alloy always rose with the increasing of Nd content, and those of the as-spun alloys exhibited the maximum values for Nd content x=10, which were 77.9%, 83.4%89.2%and 89.7%, corresponding to the spinning rate of 10, 20, 30 and 40 m/s, respectively.