Substitutional effect of Ti-based AB2 hydrogen storage alloys: A density functional theory study
Substitutional effect of Ti-based AB2 hydrogen storage alloys: A density functional theory study
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DOI：
10.1016/j.ijhydene.2022.12.083
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发表时间：
2023-01
影响因子：
7.2
通讯作者：
Siow Mean Loh;D. Grant;G. Walker;Sanliang Ling
中科院分区：
文献类型：
--
作者：
Siow Mean Loh;D. Grant;G. Walker;Sanliang Ling
采用第一性原理密度泛函理论模拟研究了ab2alloy在Laves相C14和C15中的稳定性。考虑了Ti1−xcxb2合金中bandc元素的一系列不同组合。这些合金的形成能一般随合金的晶胞体积增大而增大。体积也会影响相应金属氢化物的稳定性。我们发现ab2合金的形成能和氢化焓可能由至少三个因素决定：电负性、原子半径和共价半径。氢化后，ab2氢化物的焓随组成平均电负性的增加和体积变化而增加。然而，ab2氢化物的焓随组成平均原子半径和共价半径的增大而减小。该研究为进一步开发ab2型储氢合金提供了有益的见解。
Stability ofAB2alloy in Laves phases C14 and C15 were studied by first-principle density functional theory simulations. A range of different combinations ofBandCelements in the Ti1−xCxB2alloys were considered. The formation energies of these alloys generally increase with the unit cell volumes of alloys. The volume also affects the stability of the corresponding metal hydride. We find that the formation energies and the hydrogenation enthalpies ofAB2alloys are likely to be determined by at least three factors: electronegativity, atomic radius and covalent radius. The enthalpies of AB2hydrides increase with increasing compositionally-averaged electronegativity and volume change upon hydrogenation. However, the enthalpies of AB2hydrides decrease with increasing compositionally-averaged atomic and covalent radii. This study provides useful insights for future exploration ofAB2-type alloys for hydrogen storage applications.