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

¹ Photonics Center, Laser Enabled Manufacturing, CSIR, Pretoria, South Africa
² *Department of Material Science and Metallurgical Engineering, University of Pretoria, South Africa

^* Jacuquline Tau: Jtau@csir.co.za

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.