Preparation method of LiMgN-containing high-capacity hydrogen storage material

Abstract

The invention belongs to the field of hydrogen storage material preparation, and particularly relates to a preparation method of a LiMgN-containing high-capacity hydrogen storage material. The preparation method comprises the following steps: a. uniformly mixing Li3N powder and MgH2 powder in a molar ratio of 1:1 to 2:1, and putting in a ball-milling tank; and b. ball-milling on a ball mill by adopting a mechanical alloying method and a mechanical milling method, thus obtaining the LiMgN and LiH mixture, wherein the weight ratio of grinding balls to the mixed raw material is 15: 1 to 40: 1, argon is charged for protection, the ball milling lasts for 2-48 hours, and the rotating speed of the ball milling is 300-500rpm. The LiMgN obtained by the method is granular, the size of the LiMgN is 40-50 nanometers, the phase content of LiMgN reaches 73.8wt%, and the hydrogen storage capacity reaches 3.2wt%. The raw materials used in the method are easy to obtain, the preparation process is simple, and the operation is convenient. According to the preparation method, no surface active agents, catalysts and the like do not need to be added in the reaction process, and the high-purity product is easily obtained.

Description

technical field [0001] The invention belongs to the field of hydrogen storage material preparation, in particular to a preparation method of LiMgN-containing high-capacity hydrogen storage material. Background technique [0002] With the energy crisis and environmental deterioration, hydrogen energy is considered to be an ideal clean energy in the future. Hydrogen storage materials related to hydrogen energy technology have also attracted widespread attention at home and abroad. The goal of the development of hydrogen storage materials is to explore a new generation of hydrogen storage materials with high hydrogen storage capacity and good comprehensive performance. Metal-N-H hydrogen storage materials are new high-capacity hydrogen storage materials developed in recent years. They have better reversible hydrogen absorption and desorption properties and more suitable hydrogen absorption and desorption thermodynamic properties. They are also several hydrogen storage material...

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Problems solved by technology

People mainly through Li 3 N and Mg 3 N 2 LiMgN is prepared by high-temperature sintering of raw materials (such as the literature Ternary nitrides prepared in the Li 3 N–Mg 3 N 2 system at900–1000K: H.Yamane, T.H.Okabe, O.Ishiyama, Y.Waseda, M.Shimada, Journal of Alloys and Compounds, Volume319, April2001, 124–130); there are also people through LiNH 2 and MgH 2 The raw material is ball milled, and the product after ball milling is dehydrogenated to prepare LiMgN (such as literature: J.Lu, Z.Z.Fang, Y.J.Choi, H.Y.Sohn, J.Phys.Chem.C2007, 111, 12129–12134), but this method is prepared It is controversial that the same product cannot be obtained due to different ball milling processes, and the LiMgN phase content in the obtained product is relatively low

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