CaXH ₃ (X = Mn, Fe, Co) perovskite‐type hydrides for hydrogen storage applications

Abstract

Summary Hydrogen storage is one of the attractive research interests in recent years due to the advantages of hydrogen to be used as energy source. The studies on hydrogen storage applications focus mainly on investigation of hydrogen storage capabilities of newly introduced compounds. The present paper aims at characterization of CaXH3 (X: Mn, Fe, or Co) perovskite‐type hydrides for the first time to understand their potential contribution to the hydrogen storage applications. CaXH3 compounds have been investigated by density functional theory studies to reveal their various characteristics and hydrogen storage properties. CaXH3 compounds have been optimized in cubic crystal structure and the lattice constants of studied compounds have been obtained as 3.60, 3.50, and 3.48 Å for X: Mn, Fe, and Co compounds, respectively. The optimized structures have negative formation enthalpies pointing out that studied compounds are thermodynamically stable and could be synthesized experimentally. The gravimetric hydrogen storage densities of X: Mn, Fe, and Co compounds were found in as 3.09, 3.06, and 2.97 wt%, respectively. The revealed values for hydrogen storage densities indicate that CaXH3 compounds may be potential candidates for hydrogen storage applications. Moreover, various mechanical parameters of interest compounds like elastic constants, bulk modulus, and Poisson's ratio have been reported throughout the study. These compounds were found mechanically stable with satisfying Born stability criteria. Further analyses based on Cauchy pressure and Pugh criterion, showed that they have brittleness nature and relatively hard materials. In addition, the electronic characteristics, band structures, and associated partial density of states of CaXH3 hydrides have been revealed. The dynamic stability behavior of them was verified based on the phonon dispersion curves.

Morphological, Structural and Hydrogen Storage Properties of LaCrO3 Perovskite-Type Oxides

“…Besides, hydrogen storage capacity varies from 1.4 wt% at room temperature to almost 4 wt% at 333 K (60 • C), which shows the ability of this oxide to store hydrogen at a very moderate temperature. The storage capacity is comparable to that of perovskite hydrides, such as CaCoH 3 (2.97 wt%), CaFeH 3 (3.06 wt%), CaMnH 3 (3.09 wt%), MgCuH 3 (3.32 wt%) and MgNiH 3 (3.51 wt%) [45,46]. Additionally, compared to some other hydrides of the AB and AB 5 families used for solid hydrogen storage, LaCrO 3 perovskite oxides present better storage capacities, which allowed to promote their use for future transportation applications.…”

First‐principle investigation of XSrH3 (X = K and Rb) perovskite‐type hydrides for hydrogen storage

“…To recognize the possible adoption in hydrogen storage applications, we have calculated gravimetric hydrogen storage capacities ( C w% ) of XSrH 3 (X = K and Rb) by using the following formula [ 41 ] : …”

“…It is also used to check the stability of the compound. The formation enthalpies of XSrH 3 (X = K and Rb) are calculated by using the following formula [ 41 ] : …”

Structural, electronics, magnetic, optical, mechanical and hydrogen storage properties of Ga‐based hydride‐perovskites X GaH 3 ( X = K, Li)

“…The gravimetric hydrogen storage capacity is calculated for KGaH 3 and LiGaH 3 by using the following relation. 52,53 C wt…”