Microstructure and hydrogen storage property of Mg/MWNTs composites

作者：Chen D^*; Chen L; Liu S; Ma C X; Chen D M; Wang L B

来源：Journal of Alloys and Compounds, 2004, 372(1-2): 231-237.

DOI：10.1016/j.jallcom.2003.08.104

• Catalytic reacting ball-milling
• Hydrogen absorption/desorption kinetics
• Mg/MWNTs composites

The Mg-x wt.% multi-walled nanotubes (MWNTs) (x = 5, 20) composites were made by catalytic reacting ball-milling under the hydrogen atmosphere. Their microstructures were characterized by using XRD and TEM-SAED techniques. The absorption/desorption kinetics for Mg/MWNTs were examined by taking the hydriding/dehydriding apparatus. It was found that under 2.0MPa hydrogen pressure, the maximum hydrogen storage capacities of the composites were both very low and similar at 298K; at 373, 473 and 553K, the maximum hydrogen storage capacities of Mg-5wt.% MWNTs were 5.34, 5.89 and 6.08wt.%, respectively; but only 2.11, 2.68 and 2.75wt.% for Mg-20wt.% MWNTs. Compared with other hydrogen storage composite materials, the Mg-5wt.% MWNTs not only keeps the maximum hydrogen storage capacities better but also has good hydrogen absorption/desorption rates. It absorbed 4.27, 4.86wt.% (80% maximum hydrogen storage capacity) within 15 and 1min at 373 and 553K under 2.0MPa, while it desorbed 3.62wt.% within 30min at 473K in vacuum. The carbon component (the broken MWNTs) in the composite may play an important role in the hydrogen uptake and release. A favorable discussion was given in this paper.

• 出版日期2004