Rare earth hydrogen storage alloy and preparation method and application thereof

Abstract

The invention provides rare earth hydrogen storage alloy and a preparation method and application thereof. The preparation method comprises the following steps that type-A metal, type-B metal and rare earth metal are mixed and then sequentially subjected to smelting and vacuum suction casting to obtain an alloy bar; and the obtained alloy bar is subjected to surface modification to obtain the rare earth hydrogen storage alloy. According to the preparation method, through optimal design, vacuum suction casting and surface modification of all the components, the activation performance, the hydrogen absorption and desorption rate, the effective hydrogen desorption amount and the cycle stability of the alloy are remarkably improved; and the preparation method is simple in technological process, low in cost and beneficial to large-scale production, and has a good industrial application prospect.

Description

technical field [0001] The invention belongs to the technical field of hydrogen storage materials, and in particular relates to a rare earth hydrogen storage alloy and its preparation method and application. Background technique [0002] Hydrogen storage alloys are a class of functional materials with high hydrogen storage density discovered in the late 1960s, mainly including titanium hydrogen storage alloys, zirconium hydrogen storage alloys, iron hydrogen storage alloys and rare earth hydrogen storage alloys. At present, rare earth hydrogen storage alloys have been developed mainly in LaNi 5 , La-Mg-Ni, TiCrVFeCe and other hydrogen storage alloys, among which the research on VFe alloys with BCC structure is particularly popular, mainly because the hydrogen storage alloys with BCC structure have excellent hydrogen storage capacity, and the use of VFe alloys can replace high-cost The metal vanadium thus greatly reduces the cost of hydrogen storage alloys. [0003] For exa...

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Problems solved by technology

[0005] CN101153362A discloses a solid solution type hydrogen storage alloy made of V80Fe master alloy as raw material and its preparation method. The chemical formula of the hydrogen storage alloy is Ti (100-a-b-c-d-e-f-g) V a Cr b Fe e al d RE e m f , this method reduces the alloy cost by adopting low-cost VFe, adding rare earth elements and heat treatment process, but the reversible hydrogen storage capacity can only reach 2.2wt% at 373K

At the same time, it also shows that there are obvious rare earth oxide phases in the main phase of the hydrogen storage alloy, which affects the hydrogen storage capacity.

[0006] From the above method, it can be seen that the addition of rare earth elements will lead to the presence of dispersed rare earth oxide second phases in the main phase of hydrogen storage alloys, which will reduce the hydrogen storage performance to a certain extent; in addition, the current research on hydrogen storage alloys is biased towards hydrogen storage capacity while ignoring the hydrogen absorption and desorption rate of the hydrogen storage alloy

If a material cannot absorb and desorb hydrogen within a suitable time period, its application in reversible storage devices will be limited

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