Magnesium-based hydrogen storage materials modified by mechanical alloying
Magnesium-based hydrogen storage materials modified by mechanical alloying
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DOI：
10.1016/s1359-6454(99)00249-9
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发表时间：
1999-10
期刊：
影响因子：
9.4
通讯作者：
N. Cui;P. He;Jingli Luo
中科院分区：
文献类型：
--
作者：
N. Cui;P. He;Jingli Luo
研究了机械合金化对Mg-Ni-Y-Al系储氢合金在6M KOH溶液中微观组织和电化学性能的影响。用X射线衍射仪、透射电子显微镜、选区电子衍射仪和能谱仪对球磨后的粉末进行了表征。透射电子显微镜和能谱分析表明，机械研磨72 h后，较小的镍团簇或颗粒在较大的镁合金颗粒表面均匀分散，随着球磨时间的增加到240 h，镍团簇或颗粒消失，形成新的非晶态单相合金。在72 h内，随着球磨时间的增加，改性材料的电化学容量显著增加，当球磨时间达到240 h时，电化学容量几乎为零，但随着球磨时间的增加，容量衰减一直在改善。并在此基础上进行了进一步的分析和讨论。极化和交流。阻抗谱测量结果。
The effects of mechanical alloying on microstructure and electrochemical performance of a Mg–Ni–Y–Al hydrogen storage alloy in 6 M KOH solution were studied. The ball-milled powders were examined by X-ray diffraction (XRD), transmission electron microscopy (TEM), selected-area electron diffraction (SED) and energy dispersion spectrometry (EDS). TEM and EDS results clearly reveal that the smaller nickel clusters or particles were well dispersed on the surface of larger magnesium alloy particles by mechanical grinding for 72 h. With an increase in milling time to 240 h, the nickel clusters or particles disappeared and a new monophase alloy with amorphous structure was formed. The electrochemical capacity of the modified material significantly increased with increasing milling time within 72 h and then dropped to nearly nil when the milling time reached 240 h. The capacity decay, however, was always improved with increasing grinding time. Further analysis and discussion were made based on d.c. polarization and a.c. impedance spectroscopy measurement results.