7. Conclusions and outlook

In conclusion, research into high-entropy hydridable alloys for hydrogen storage is still in its infancy, but some compositions are already showing promising performance.

Various large-scale experiments suggest that hydrogen occupation is not limited to the sites usually occupied in conventional alloys. One possible explanation is the significant lattice distortion in these alloys, which implies different interstitial volumes depending on the local environment. Further research is needed to understand the effect of local environment variation at the atomic scale and its implication on macroscopic properties. To shed light on short- and long-range structures and their change under the effect of hydrogen absorption/desorption, one possibility will be to apply the known synchrotron technique of X-ray absorption spectroscopy, to provide information selectively on the...