Stoichiometry and annealing condition on hydrogen capacity of TiCr2-x AB2 alloys

McGrath, Alexander J.; Wadge, Matthew D.; Adams, Marcus; Manickam, Kandavel; Ling, Sanliang; Walker, Gavin S.; Grant, David M.

doi:10.1016/j.ijhydene.2023.12.062

Stoichiometry and annealing condition on hydrogen capacity of TiCr2-x AB2 alloys

McGrath, Alexander J.; Wadge, Matthew D.; Adams, Marcus; Manickam, Kandavel; Ling, Sanliang; Walker, Gavin S.; Grant, David M.

Authors

Alexander J. McGrath

Matthew D. Wadge

Mr MARCUS ADAMS Marcus.Adams1@nottingham.ac.uk
Senior Research Fellow in novel metal hydrides solid-state hydrogen stores and compressors

Kandavel Manickam

Dr SANLIANG LING SANLIANG.LING@NOTTINGHAM.AC.UK
ASSOCIATE PROFESSOR

Gavin S. Walker

Professor DAVID GRANT DAVID.GRANT@NOTTINGHAM.AC.UK
PROFESSOR OF MATERIALS SCIENCE

Abstract

This study presents the effect of stoichiometry and annealing condition on Ti–Cr AB2-type hydrogen storage alloys. Prior to annealing the majority phase of the as-cast alloys was the C14 Laves phase, with separate Ti and Cr phases. Annealing treatment (1273 K/14 d) led to a transition from C14 to C15 Laves phase structure. Both C14 (as-cast) and C15 (annealed) cell size increased with Ti content, up to a ratio (Cr/Ti) of 1.6, due to B-site Ti substitution in the lattice up to a limit. Pressure composition isotherm (PCI) measurements demonstrated alloys containing a greater Ti content had a better maximum hydrogen storage capacity (1.5 vs. 1.03 wt%) and lower plateau pressure (9.4 vs. 15.8 bar) at 253 K. Annealing resulted in a lower storage capacity (1.05 vs. 1.49 wt%), greater plateau pressure (ca. 30 bar) and flatter plateau slope (25 % reduction in plateau slope). Reduction in hydrogen storage capacity of annealed alloys could be due to diffusion of residual Cr in the alloy into the C15 Laves phase during the annealing process, thereby changing the local composition as confirmed through X-ray diffraction (XRD).

Citation

McGrath, A. J., Wadge, M. D., Adams, M., Manickam, K., Ling, S., Walker, G. S., & Grant, D. M. (2024). Stoichiometry and annealing condition on hydrogen capacity of TiCr2-x AB2 alloys. International Journal of Hydrogen Energy, 53, 582-591. https://doi.org/10.1016/j.ijhydene.2023.12.062

Journal Article Type	Article
Acceptance Date	Dec 7, 2023
Online Publication Date	Dec 18, 2023
Publication Date	Jan 31, 2024
Deposit Date	Dec 21, 2023
Publicly Available Date	Dec 21, 2023
Journal	International Journal of Hydrogen Energy
Print ISSN	0360-3199
Electronic ISSN	1879-3487
Publisher	Elsevier
Peer Reviewed	Peer Reviewed
Volume	53
Pages	582-591
DOI	https://doi.org/10.1016/j.ijhydene.2023.12.062
Keywords	Hydrogen storage; Metal hydrides; AB2 alloys; TiCr
Public URL	https://nottingham-repository.worktribe.com/output/28714136
Publisher URL	https://www.sciencedirect.com/science/article/pii/S0360319923063620