Hydrogen storage properties of new A3B2-type TiZrNbCrFe high-entropy alloy. (6th July 2021)

• Record Type: Journal Article
• Authors: Floriano, Ricardo; Zepon, Guilherme; Edalati, Kaveh; Fontana, Gabriel L.B.G.; Mohammadi, Abbas; Ma, Zhongliang; Li, Hai-Wen; Contieri, Rodrigo J.
• Is Part Of: International journal of hydrogen energy. Volume 46:Number 46(2021)
• Page Start: 23757
• Page End: 23766
• Publication Date: 2021-07-06
• Subjects: High-entropy alloys (HEAs) -- Hydrogen storage -- Metal hydrides -- C14 laves phase -- CALPHAD (Calculation of phase diagrams); Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2021.04.181
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Crystal structure and hydrogen storage properties of a novel equiatomic TiZrNbCrFe high-entropy alloy (HEA) were studied. The selected alloy, which had a A3 B2 -type configuration (A: elements forming hydride, B: elements with low chemical affinity with hydrogen) was designed to produce a hydride with a hydrogen-to-metal atomic ratio (H/M) higher than those for the AB2 - and AB-type alloys. The phase stability of alloy was investigated through thermodynamic calculations by the CALPHAD method. The alloy after arc melting showed the dominant presence of a solid solution C14 Laves phase (98.4%) with a minor proportion of a disordered BCC phase (1.6%). Hydrogen storage properties investigated at different temperatures revealed that the alloy was able to reversibly absorb and fully desorb 1.9 wt% of hydrogen at 473 K. During the hydrogenation, the initial C14 and BCC crystal structures were fully converted into the C14 and FCC hydrides, respectively. The H/M value was 1.32 which is higher than the value of 1 reported for the AB2 - and AB-type HEAs. The present results show that good hydrogen storage capacity and reversibility at moderate temperatures can be attained in HEAs with new configurations such as A3 B2 /A3 B2 H7 . Graphical abstract: Image 1 Highlights: Novel TiZrNbCrFe a A3 B2 -type alloy was designed for hydrogen storage. TiZrNbCrFe alloy showed a dominant presence of C14 Laves and minor BCC phases. TiZrNbCrFe alloy reversibly absorb and fully desorb 1.9 wt% (H/M = 1.32) of hydrogen at 473 K. After hydrogenation, the C14 and BCC phases were fully converted into the C14 and FCC hydrides.