Computational Modeling of the Feti Hydrogenation: Scale-Bridging Atoms and Microstructure

The intermetallic alloy FeTi is regarded as a promising storage material for solid-state hydrogen storage: cost-effective, safe, and operable under near-ambient conditions. However, a consistent multiscale model capable of describung the various atomic, thermodynamic, and microstructural processes involved in FeTi hydrogenation has so far been elusive.

This dissertation presents, for the first time, an integrated computational model based on density functional theory (DFT), CALPHAD, and phase-field methodology that quantitatively describes the hydrogenation of FeTi. Starting from First-Principles calculations, thermodynamic properties, interfacial energies, and elastic effects are determined with high accuracy and incorporated into mesoscale simulations. The resulting model accuratelyreproduces experimental isotherms, explains the formation and stability of the occurring hydride phases, and enables realistic predictions of microstructural evolution during hydrogen uptake.

Thus, this work provides a foundation for the digital design and computational optimization of FeTi-based hydrogen storage materials.