Effect of milling intensity on the formation of LiMgN from the dehydrogenation of LiNH2–MgH2 (1:1) mixture
Effect of milling intensity on the formation of LiMgN from the dehydrogenation of LiNH2–MgH2 (1:1) mixture
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DOI：
10.1016/j.jpowsour.2009.10.032
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发表时间：
2010-04
影响因子：
9.2
通讯作者：
Jun Lu;Y. Choi;Z. Fang;H. Sohn
中科院分区：
文献类型：
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作者：
Jun Lu;Y. Choi;Z. Fang;H. Sohn
金属-N-H系统作为传统金属氢化物的替代储氢材料最近引起了相当大的关注。在这项工作中，利用TGA、XRD和FT-IR研究了混合物LiNH2-MgH2(1:1)在不同机械研磨过程中的反应以及随后的脱氢反应，以确定形成纯LiMgN的最佳条件。这项工作使用了高能研磨（SPEX 研磨机）和低能研磨（滚罐）技术。结果表明，可以使用低能球磨技术生产整体式 LiMgN。通过 Sieverts 型仪器研究了所制备的 LiMgN 的加氢性能。相比之下，在使用SPEX磨机进行高能研磨过程中，发生了包括LiNH2和MgH2之间的复分解反应以及H2和/或NH3的释放在内的多种反应，这导致在随后的脱氢实验中发生复杂且意想不到的反应。因此，高能研磨样品的脱氢产物由多相混合物组成。
Metal–N–H systems have recently attracted considerable attention as alternative hydrogen storage materials to traditional metal hydrides. In this work, the reactions of the mixture LiNH2–MgH2(1:1) during different mechanical milling processes and the subsequent dehydrogenation reaction were investigated by using TGA, XRD and FT-IR in order to determine an optimal condition for the formation of pure LiMgN. High-energy milling (SPEX mill) and low-energy milling (rolling jar) techniques were used in this work. The results demonstrated that monolithic LiMgN can be produced using the low-energy ball milling technique. The hydrogenation properties of the as-prepared LiMgN were investigated by a Sieverts’ type instrument. In contrast, multiple reactions including the metathesis reaction between LiNH2and MgH2and release of H2and/or NH3took place during high-energy milling using the SPEX mill, which resulted in complicated and unexpected reactions during the subsequent dehydrogenation experiments. Consequently, the dehydrogenated products from the high-energy milled samples consisted of multi-phase mixtures.