Low-Temperature Activation and High Capacity Hydrogen Storage in TiVCr-BCC Alloys Modified with AB5 Intermetallics

Abstract

Effective hydrogen storage remains a significant barrier in the deployment of metal hydrides for energy applications, primarily due to kinetic limitations and high pretreatment requirements in high-capacity body-centered cubic (BCC) alloys. This study systematically investigates the influence of incremental additions of AB5-type intermetallic La0.9Ce0.1Ni5, (0–15 wt %) on the hydrogen sorption properties of Ti0.48V0.26Cr0.26 BCC solid solution alloys. The results proved that modest additions of La0.9Ce0.1Ni5 significantly reduce the activation temperature from >350 to 80 °C, enabling fast hydrogen absorption kinetics (t90% reduced to as low as 70 s) while maintaining high hydrogen capacities up to 3.5 wt %. The synergistic interaction between the BCC matrix and AB5 secondary phases, enriched in catalytically active Ni sites, promotes efficient hydrogen dissociation and diffusion pathways. Thermodynamic analysis reveals increased plateau pressures and improved reversible desorption. These results demonstrate that AB5-type intermetallics provide a viable route for overcoming the activation barrier in BCC-based alloys, enabling high-capacity and low-temperature hydrogen storage systems.