Light-metal and high-capacity composite hydrogen storage material and preparation method thereof

Abstract

The invention belongs to the field of hydrogen storage and discloses a light-metal and high-capacity composite hydrogen storage material and a preparation method thereof. The light-metal and high-capacity composite hydrogen storage material consists of lithium borohydride and magnesium-based hydride in stoichiometric ratio of (4:1)-(5:1), wherein a chemical general formula of the magnesium-based hydride is Mg2MHx and M is Fe or Co. The preparation method of the light-metal and high-capacity composite hydrogen storage material comprises a high-energy ball milling method and a high-pressure hydrogenation method and is simple; no specific catalyst is needed to be doped in the obtained lithium borohydride and magnesium-based hydride composite hydrogen storage material; and the obtained lithium borohydride and magnesium-based hydride composite hydrogen storage material has a favorable hydrogen discharge performance. With favorable dispersibility and nano-grade size, the M generated in situ in the reaction process promotes a mutual chemical reaction of the lithium borohydride and the M. The invention can provide a method which can be used for better increasing the dispersibility and enhancing the mutual chemical action for in-situ modification of complex hydrides.

Description

technical field [0001] The invention belongs to the field of hydrogen storage materials, and in particular relates to a light metal high-capacity composite hydrogen storage material and a preparation method thereof. Background technique [0002] With the development of society, the contradiction between human's demand for energy and the depletion of traditional energy has become increasingly prominent. To achieve sustainable development, new energy must be developed. As a secondary energy source, hydrogen energy has the advantages of being clean, pollution-free, and high in energy conversion efficiency, but the storage of hydrogen is the bottleneck of hydrogen energy utilization, so the development of high-capacity hydrogen storage materials has become the core of the hydrogen economy. So far, liquid hydrogen, lightweight high-pressure containers and metal hydride systems in hydrogen storage technology have all been successfully operated on hydrogen-fired vehicles or electri...

AI Technical Summary

Problems solved by technology

This system MgB 2 The generation of is the key to ensure the reversible performance of the system, but the MgB 2 A long incubation period is required for the full generation of , which leads to the reduction of hydrogen desorption kinetics

So a lot of research has been devoted to shortening the MgB 2 incubation period, thereby improving the hydrogen desorption performance of the system, most of these studies use inorganic catalysts (such as TiCl 3 、TiF 3 , NbF 5 etc.) itself does not have the ability to store hydrogen and has a large molecular weight, and in the reaction process, the catalyst and LiBH 4 The reaction consumes part of the hydrogen storage material, making LiBH 4 with MgH 2 The actual hydrogen storage capacity of the composite material hydrogen storage system is reduced

On the other hand, TiCl 3 、TiF 3 , NbF 5 The preparation process of such inorganic compound catalysts is complicated, the technical requirements are strict, and the price is expensive, which cannot adapt to the large-scale application of industrial production.

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