A kind of lanthanum-magnesium-nickel series ab3 type hydrogen storage alloy containing yttrium element and its preparation process

Abstract

The invention discloses a lanthanum-magnesium-nickel-system AB3 type hydrogen-storage alloy containing elemental yttrium and a preparation process thereof. The hydrogen-storage alloy has a chemical formula of LaYbMg<c>Ca<d>Ni<9>, wherein a, b, c and d represent the atomic ratio of the elements of the alloy; a is more than 0 and no more than 0.65; b is more than 0 and no more than 0.65; c is more than 0; d is more than 0; and the sum of a, b, c and d is no less than 2.5 and no more than 3.5. The preparation process for the hydrogen-storage alloy comprises the following steps: weighing raw materials according to the ratio expressed in the chemical formula; putting metals difficult to volatilize, except elemental Mg and Ca, into a copper crucible, successively carrying out vacuum-pumping, introduction of helium until a pressure is 0.1 MPa, vacuum-pumping and introduction of helium until the pressure is 0.1 MPa, and repeating the successive operations three times for gas washing; turning on a power supply, baking raw materials for 1 min, then allowing the pressure of helium to be fixed at 0.1 MPa, carrying out heating and melting, and after all the metals are completely fused, carrying out cooling to 20 DEG C; and putting metal Mg and Ca easy to volatilize into the crucible, carrying out gas washing three times, baking the raw materials for 1 min and then carrying out melting under the condition of a helium pressure of 0.1 MPa. The hydrogen-storage alloy provided by the invention is low in cost and has high hydrogen absorption and desorption capacity, good activation performance, good cyclic stability and adjustable hydrogen absorption and desorption plateau pressure.

Description

technical field [0001] The invention relates to a lanthanum-magnesium-nickel AB containing yttrium element 3 A type hydrogen storage alloy and a preparation process thereof belong to the technical field of hydrogen storage alloys. Background technique [0002] With the depletion of fossil energy and the increasing severity of environmental problems, it has become a top priority for society to find other efficient and environmentally friendly alternative energy sources. Due to the advantages of abundant storage capacity and environmental friendliness, hydrogen has good application prospects, and has received extensive attention from governments around the world. So far, the key factor hindering the development of "hydrogen economy" is the storage of hydrogen, so the selection of suitable hydrogen storage materials has become the focus of research. [0003] The widely used hydrogen storage material is LaNi 5 Type hydrogen storage alloy, the alloy is mainly used as the negat...

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Problems solved by technology

[0006] However, the preparation method of the La-Mg-Ca-Ni AB3 type alloy reported in the literature is powder sintering method, and the research method is relatively simple, only the hydrogen storage capacity is tested, and there is no systematic study on its gaseous hydrogen storage properties. There is no research on the effect of other element substitution on its hydrogen storage capacity and hydrogen absorption and desorption platform pressure

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