Magnesium-base hydrogen storage material based on high-entropy effect and preparing method thereof

Abstract

The invention discloses a magnesium-base hydrogen storage material based on a high-entropy effect and a preparing method thereof. The magnesium-base hydrogen storage material comprises A<a->Mg<90-a>+bwt.% B hydrogen storage alloy, wherein in the formula, a is larger than or equal to 0 and smaller than or equal to 20, b is larger than or equal to 0 and smaller than or equal to 20, and a and b areequal to 0 preferably for the nitrogen storage alloy; A represents lanthanide rare earth elements and comprises Y elements (lanthanum, cerium, praseodymium, neodymium, samarium and the like) of whichat least five types of elements coexist, for instance, A is La<c1>Ce<c2>Pr<c3>Nd<c4>Sm<c5>, and c is larger than 0 and smaller than or equal to 50; B represents transition metal elements from Sc (withthe atomic number of 21) to Cd (with the atomic number of 48) and comprises the Al elements of which at least five types of elements coexist, for instance, B is Hf<d1>Zr<d2>V<d3>Nb<d4>Ti<d5>, and d is larger than 0 and smaller than or equal to 50; and the example alloy is preferential alloy, and c and d are equal to 20. After the alloy is hydrogenated, phases AH<2+x> and B of an unstable cubic structure are generated; in the nitrogen absorption process, the cubic structure in the AH<2+x> and B can be twisted into a square structure when the nitrogen content is increased, and the accordingly-generated internal stress changes reduce the thermal stability of magnesium-base hydrides, weaken the bond energy between Mg and H and effectively improve the hydrogen storage performance of the magnesium-base hydrogen storage material.

Description

technical field [0001] The invention relates to the field of rare earth magnesium hydrogen storage alloy material and its preparation process, in particular to a magnesium-based hydrogen storage material based on high entropy effect and its preparation method. Background technique [0002] With the improvement of industrial level and the development of human society, traditional energy sources such as oil and coal are becoming exhausted day by day, and have caused serious pollution to the environment. The living environment and health of human beings are facing a huge threat. Especially in the past two years, smog and haze have occurred frequently, and environmental issues have once again become the focus of attention. In the face of energy and environmental crises, human beings are experiencing unprecedented severe challenges. Therefore, the development and utilization of clean energy is imminent, and hydrogen energy, as a clean, efficient, safe, abundant and sustainable i...

AI Technical Summary

Problems solved by technology

However, the shortcomings of magnesium-based hydrogen storage materials are also significant. Due to the stable Mg-H bond, magnesium-based hydrides not only have poor hydrogen desorption kinetics and high dehydrogenation temperature, but also tend to crystallize during the hydrogen absorption and desorption cycle. Problems such as particle growth and particle agglomeration will eventually lead to performance attenuation and poor cycle stability

The existence of these problems makes the application of Mg-based hydrogen storage materials still difficult to realize.

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