Hydrogen Storage Properties of XFe 3 H 8 Hydrides: A First‐Principles Study
Wasif Abu Dujana, Md Saiduzzaman, Tasdid Bin Kabir, Tahani Mohammed Alrosaa, Reda A. Haggam, Raghad Radi Al Rasheed, Amani Mubarak Al‐Farhan, Zakia Hassan Alhashem, Mohammed Albossed, Shima Sadaf, Mir Waqas Alam, Noureddine ElboughdiriABSTRACT
The current work provides the first‐principles exploration of the XFe 3 H 8 (X = Li, Na, K, and Rb) perovskite hydrides series. The negative formation energies confirm the thermodynamic stability of the entire XFe 3 H 8 series. Electronic band structures and density of states (DOS) analyses reveal the metallic nature of all compounds for both GGA and HSE06 functionals. The dynamic stability is confirmed by the positive phonon curves. Elastic constants satisfy Born stability criteria, with mechanical analysis indicating that all four hydrides show ductile behavior that suggest potential use of the compounds in flexible devices. The XFe 3 H 8 (X = Li, Na, K, and Rb) hydrides' exhibit gravimetric H 2 storage capacities of 4.42, 4.06, 3.76, and 3.09 wt.%, respectively demonstrating that LiFe 3 H 8 provides the highest capacity and superior performance in the series. The resulting volumetric H 2 storage capacities are 207.92, 187.98, 167.09, and 156.11 gH 2 /L respectively for XFe 3 H 8 (X = Li, Na, K, and Rb) hydrides.