Substitutional effect of Ti-based AB2 hydrogen storage alloys: A density functional theory study

Loh, Siow Mean; Grant, David M.; Walker, Gavin S.; Ling, Sanliang

Abstract

Stability of AB2 alloy in Laves phases C14 and C15 were studied by first-principle density functional theory simulations. A range of different combinations of B and C elements in the Ti1−xCxB2 alloys 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 of AB2 alloys are likely to be determined by at least three factors: electronegativity, atomic radius and covalent radius. The enthalpies of AB2 hydrides increase with increasing compositionally-averaged electronegativity and volume change upon hydrogenation. However, the enthalpies of AB2 hydrides decrease with increasing compositionally-averaged atomic and covalent radii. This study provides useful insights for future exploration of AB2-type alloys for hydrogen storage applications.

Citation

Loh, S. M., Grant, D. M., Walker, G. S., & Ling, S. (2023). Substitutional effect of Ti-based AB2 hydrogen storage alloys: A density functional theory study. International Journal of Hydrogen Energy, 48(35), 13227-13235. https://doi.org/10.1016/j.ijhydene.2022.12.083

• Journal Article Type: Article
• Acceptance Date: Dec 7, 2022
• Online Publication Date: Jan 6, 2023
• Publication Date: Apr 26, 2023
• Deposit Date: Jan 10, 2023
• Publicly Available Date: Jan 11, 2023
• Journal: International Journal of Hydrogen Energy
• Print ISSN: 0360-3199
• Electronic ISSN: 1879-3487
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 48
• Issue: 35
• Pages: 13227-13235
• DOI: https://doi.org/10.1016/j.ijhydene.2022.12.083
• Keywords: Energy Engineering and Power Technology; Condensed Matter Physics; Fuel Technology; Renewable Energy, Sustainability and the Environment
• Public URL: https://nottingham-repository.worktribe.com/output/15718530
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0360319922057998?via%3Dihub