Exploring hydrogen storage attributes of alkali metal XNH6 (X=Li, Na, K) perovskite hydrides using DFT calculations

초록

The global demand for green and sustainable energy solutions has fueled efforts to create effective hydrogen storage technology. By employing the first principles analysis, we have investigated the hydrogen storage and the physical attributes of XNH6 (X = Li, Na, K) using DFT. The structural integrity is assessed through the tolerance factors, volume optimization curves and computed formation energies. The lattice parameters for LiNH6, NaNH6, and KNH6 are obtained as 6.65 & Aring;, 6.80 & Aring;, and 7.19 & Aring;. The mechanical characteristic reveals the studied hydrides are brittle, hard, and stiff, whereas the Debye and melting temperatures disclose that these studied hydrides possess extraordinary endurance to the external temperatures. The materials' electrical band structure characteristics identified them as metallic, making the storage and release of hydrogen more efficient in terms of easy charge transfer. The optical examination of XNH6 (X = Li, Na, and K) reveals considerable polarization and absorption in the infrared area, as well as substantial peaks in the visible and ultraviolet regions, showing high optical activity throughout the spectrum. Furthermore, the hydrogen storage capacities revealed that the U.S department of energy's hydrogen storage material targets are achieved. XNH6 (X = Li, Na, K) shows potential hydrogen capabilities, with LiNH6 having the highest hydrogen weight percent of 18.18 and volumetric density of 68.27 gH2/L, making it a viable contender for the hydride exceptional choice for producing renewable energy.

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