Study on hydrogen absorption and surface properties of TiZrVNbCr high entropy alloy

High-entropy hydrides for fast and reversible hydrogen storage at room temperature: Binding-energy engineering via first-principles calculations and experiments

“…HEAs are the most recent alloys which have been explored for hydrogen storage [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. The presence of multi-principal elements in the lattice of these alloys makes it possible to tune their electronic structures, crystal structures and physical properties in a much more straightforward way as compared to conventional alloys and intermetallics [7].…”

“…Atomic displacements are often considered to reflect the local lattice distortion in a HEA [74,75]. The variation of atomic displacements and lattice distortion in a HEA is particularly correlated with the magnitude of solid solution strengthening [76,77], although such distortions can also influence the functional properties of HEAs such as their activity for hydrogen storage [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. Here, we quantify the atomic displacements from the ideal lattice sites for the TixZr2-xCrMnFeNi alloys and TixZr2-xCrMnFeNiH6 hydrides (x = 0.5, 1.0 and 1.5) by ab initio DFT calculations.…”

“…The presence of several elements in a single phase allows to manipulate the electronic structure, hydrogen binding energy and accordingly hydrogen storage temperature and pressure by careful selection of principal elements and their concentrations [7]. TiVZrNbHf [8][9][10], TiVCrNbMo [8], TiVCrNbTa [8], Ti0.2Zr0.2Hf0.2Mo0.1Nb0.3 [11], Ti0.2Zr0.2Hf0.2Mo0.2Nb0.2 [11], Ti0.2Zr0.2Hf0.2Mo0.3Nb0.1 [11], TiZrVNbCr [12], V30Ti30Cr25Fe10Nb5 [13], V35Ti30Cr25Fe5Mn5 [13], Mg0.10Ti0.30V0.25Zr0.10Nb0.25 [14], TiZrNbFeNi [15], TiZrNbCrFe [16], MgAlTiFeNi [17], Al0.10Ti0.30V0.25Zr0.10Nb0.25 [18], Mg12Al11Ti33Mn11Nb33 [19], MgVAlCrNi [20], MgVTiCrFe [21], AlCrFeMnNiW [22], TiZrHfScMo [23], MgZrTiFe0.5Co0.5Ni0.5 [24] and LaNiFeVMn [25] are some of the HEAs which have been investigated for hydrogen storage. However, as discussed in a recent review paper [7], these HEAs have drawbacks such as either high-temperature requirement for hydrogen storage, poor hydrogen storage reversibility, poor activation, or high storage pressure [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]…”

“…TiVZrNbHf [8][9][10], TiVCrNbMo [8], TiVCrNbTa [8], Ti0.2Zr0.2Hf0.2Mo0.1Nb0.3 [11], Ti0.2Zr0.2Hf0.2Mo0.2Nb0.2 [11], Ti0.2Zr0.2Hf0.2Mo0.3Nb0.1 [11], TiZrVNbCr [12], V30Ti30Cr25Fe10Nb5 [13], V35Ti30Cr25Fe5Mn5 [13], Mg0.10Ti0.30V0.25Zr0.10Nb0.25 [14], TiZrNbFeNi [15], TiZrNbCrFe [16], MgAlTiFeNi [17], Al0.10Ti0.30V0.25Zr0.10Nb0.25 [18], Mg12Al11Ti33Mn11Nb33 [19], MgVAlCrNi [20], MgVTiCrFe [21], AlCrFeMnNiW [22], TiZrHfScMo [23], MgZrTiFe0.5Co0.5Ni0.5 [24] and LaNiFeVMn [25] are some of the HEAs which have been investigated for hydrogen storage. However, as discussed in a recent review paper [7], these HEAs have drawbacks such as either high-temperature requirement for hydrogen storage, poor hydrogen storage reversibility, poor activation, or high storage pressure [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25], which limit their applications. Although the research on high-entropy hydrogen storage materials is still in its early stages, designing these alloys by theoretical and com...…”

Significance of interphase boundaries on activation of high-entropy alloys for room-temperature hydrogen storage

“…This study not only introduces a new strategy for the activation of HEAs but also suggests that interphase boundaries are likely responsible for the high activity of some high-entropy hydrogen storage materials reported earlier [5,24,38]. By considering the growing significance of hydrogen storage [1] and by considering the fast development of HEAs for storing hydrogen [5][6][7][8][9][10][11][12][13][14][52][53][54][55][56][57][58], the current study can contribute to the design of new highentropy hydrogen storage materials. Despite these positive findings, future studies using in-situ synchrotron and neutron diffraction methods are required to clarify the exact effect of interphase boundaries on the process of hydrogen storage from diffusion to nucleation and growth.…”