A magnesium-based hydrogen storage material based on high entropy effect and its preparation method

Abstract

The invention discloses a magnesium-based hydrogen storage material based on high entropy effect and its preparation method, comprising A a -Mg 90‑a +b wt.%B hydrogen storage alloy; in the formula, 0≤a≤20 and 0≤b≤20, the hydrogen storage alloy is preferably a=b=10, and A is a lanthanide rare earth element and contains Y element (lanthanum, cerium, praseodymium, neodymium, samarium, etc.) at least five kinds exist at the same time, such as A=La c1 Ce c2 PR c3 Nd c4 SM c5 , and 0<c≤50; B are transition metal elements from Sc (atomic number 21) to Cd (atomic number 48) and contain Al elements, and there are at least five kinds at the same time, such as B=Hf d1 Zr d2 V d3 Nb d4 Ti d5 , and 0<d≤50; the example alloy is a preferred alloy, and c=d=20. After hydrogenation of this alloy, AH with unstable cubic structure is formed 2+x and phase B, and during hydrogen absorption, AH 2+x The cubic structure in and B will distort into a tetragonal structure with the increase of hydrogen content, and the resulting internal stress change will reduce the thermal stability of magnesium-based hydrides, weaken the bond energy between Mg-H, and effectively improve the magnesium-based storage. Hydrogen storage properties of hydrogen materials.

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.

Images