A process for synthesizing the Li-Mg-N-H hydrogen storage system from Mg and LiNH.

作者：Okamoto Keisuke; Tokoyoda Kazuhiko; Ichikawa Takayuki^*; Fujii Hironobu

来源：Journal of Alloys and Compounds, 2007, 432(1-2): 289-292.

DOI：10.1016/j.jallcom.2006.05.119

• hydrogen storage materials
• mechanochemical synthesis
• X-ray diffraction
• thermal analysis

We successfully established a method to synthesize the Li-Mg-N-H hydrogen storage system composed of Mg(NH2)(2) and LiH from Mg and LiNH2 as starting materials. First of all, Mg and Li2NH were homogeneously mixed by ball-milling for 2 h under 1 MPa argon atmosphere. After that, the mixture was heat-treated at 250 degrees C for 16 h under vacuum condition to be transformed into Mg3N2 and Li2NH. Target materials, Mg(NH2)(2) and LiH2 were synthesized by a further heat-treatment for Mg3N2 and Li2NH at 200 degrees C under 10 MPa hydrogen atmosphere for 12 h. The phases in the sample at each processing stage were examined by X-ray diffraction (XRD) and Fourier transformation infrared absorption measurements and confirmed to be the expected ones. From experimental results of a thermal desorption mass spectroscopy, the final hydrogenated sample indicated that similar to 7 mass% hydrogen was desorbed starting from about 150 degrees C and peaked around 230 degrees C under helium flow condition at 5 degrees C/min heating rate without ammonia emission in our experimental accuracy.

• 出版日期2007-4-25