Investigation of hydrogen storage properties for high entropy alloys (Ti30V30Cr30Fe10 and Ti40V30Cr10Fe10Al10)

Abstract

The broad compositional space of high entropy alloys (HEAs) presents an opportunity to research new hydrogen storage materials, with improved hydrogen storage properties under ambient temperature and pressure. The properties of these materials are influenced by several factors including composition, operating pressure, and temperature, as well as the fabrication techniques employed. As such this study investigated two HEAs, namely Ti30V30Cr30Fe10 and Ti40V30Cr10Fe10Al10 using empirical and thermodynamic modelling methods, where Ti30V30Cr30Fe10 was successfully synthesized using LENS. The phase prediction criterion showed formation of a single solid BCC structure with VEC ≤ 5.4 and XRD confirmed formation of BCC and Laves phase structure. The investigated HEAs demonstrated excellent performance for hydrogen storage with maximum hydrogen storage capacities of about 3.8 and 4 wt% respectively at 25 and 100 0C, exceeding the previously reported HEAs for hydrogen storage.