TY - JOUR
T1 - Hydrogen storage in TiZrNbFeNi high entropy alloys, designed by thermodynamic calculations
AU - Floriano, Ricardo
AU - Zepon, Guilherme
AU - Edalati, Kaveh
AU - Fontana, Gabriel L.B.G.
AU - Mohammadi, Abbas
AU - Ma, Zhongliang
AU - Li, Hai Wen
AU - Contieri, Rodrigo J.
N1 - Funding Information:
This work is supported in part by a grant from the Brazilian Research Funding Agency FAPESP (Regular Project No. 2018/15968–4), in part by grant from the Serrapilheira Institute , Brazil (No. Serra-1709-17362 ), in part by grants-in-aid for scientific research from the MEXT , Japan (No. 16H04539 and 19H05176 ) and in part by the Coordination for the Improvement of Higher Education Personnel (CAPES), Brazil (Finance Code 001). Gabriel L. B. G. Fontana thanks for PIBIC/CNPq scholarship.
Publisher Copyright:
© 2020 Hydrogen Energy Publications LLC
PY - 2020
Y1 - 2020
N2 - The hydrogen storage properties of the novel equiatomic TiZrNbFeNi and non-equiatomic Ti20Zr20Nb5Fe40Ni15 high entropy alloys (HEAs) were studied. These alloys were designed with the aid of thermodynamic calculations using the CALPHAD method due to their tendency to form single C14 Laves phase, a phase desirable for room-temperature hydrogen storage. The alloys, which were synthesized by arc melting, showed a dominant presence of C14 Laves phases with the (Zr, Ti)1(Fe, Ni, Nb, Ti)2 constitution and small amounts of cubic phases (<1.4 wt%), in good agreement with the thermodynamic predictions. Hydrogen storage properties, examined at room temperature without any activation procedure, revealed that a maximum hydrogen storage capacity was reached for the equiatomic alloy in comparison to the non-equiatomic alloy (1.64 wt% vs 1.38 wt%) in the first cycle; however, the non-equiatomic alloy presented superior reversibility of 1.14 wt% of hydrogen. Such differences on reversibility and capacity among the two alloys were discussed based on the chemical fluctuations of hydride-forming and non-hydride-forming elements, the volume per unit cell of the C14 Laves phases and the distribution of valence electrons.
AB - The hydrogen storage properties of the novel equiatomic TiZrNbFeNi and non-equiatomic Ti20Zr20Nb5Fe40Ni15 high entropy alloys (HEAs) were studied. These alloys were designed with the aid of thermodynamic calculations using the CALPHAD method due to their tendency to form single C14 Laves phase, a phase desirable for room-temperature hydrogen storage. The alloys, which were synthesized by arc melting, showed a dominant presence of C14 Laves phases with the (Zr, Ti)1(Fe, Ni, Nb, Ti)2 constitution and small amounts of cubic phases (<1.4 wt%), in good agreement with the thermodynamic predictions. Hydrogen storage properties, examined at room temperature without any activation procedure, revealed that a maximum hydrogen storage capacity was reached for the equiatomic alloy in comparison to the non-equiatomic alloy (1.64 wt% vs 1.38 wt%) in the first cycle; however, the non-equiatomic alloy presented superior reversibility of 1.14 wt% of hydrogen. Such differences on reversibility and capacity among the two alloys were discussed based on the chemical fluctuations of hydride-forming and non-hydride-forming elements, the volume per unit cell of the C14 Laves phases and the distribution of valence electrons.
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U2 - 10.1016/j.ijhydene.2020.09.047
DO - 10.1016/j.ijhydene.2020.09.047
M3 - Article
AN - SCOPUS:85092218880
SN - 0360-3199
VL - 45
SP - 33759
EP - 33770
JO - International Journal of Hydrogen Energy
JF - International Journal of Hydrogen Energy
IS - 58
ER -
