Structural, elastic, optic, electronic, phonon, thermodynamic, and hydrogen storage properties of bialkali alanates M2LiAlH6 (M = Na, K)
     
Yazarlar (2)
Çağatay Yamçıçıer
Osmaniye Korkut Ata University, Türkiye
Prof. Dr. Cihan KÜRKÇÜ Kırşehir Ahi Evran Üniversitesi, Türkiye
Makale Türü Özgün Makale (SSCI, AHCI, SCI, SCI-Exp dergilerinde yayınlanan tam makale)
Dergi Adı International Journal of Hydrogen Energy (Q1)
Dergi ISSN 0360-3199 Wos Dergi Scopus Dergi
Dergi Tarandığı Indeksler SCI-Expanded
Makale Dili İngilizce Basım Tarihi 06-2025
Cilt / Sayı / Sayfa 135 / 1 / 440–456 DOI 10.1016/j.ijhydene.2025.04.445
Makale Linki https://doi.org/10.1016/j.ijhydene.2025.04.445
Özet
In this study, the structural, elastic, optical, electronic, phonon, thermodynamic, and hydrogen storage properties of bialkali alanates M2LiAlH6 (M = Na, K) were systematically investigated using density functional theory (DFT). The compounds crystallize in a cubic structure and exhibit mechanical and thermodynamic stability, as evidenced by their negative formation enthalpies and positive cohesive energies. Elastic constant calculations revealed that both materials are mechanically stable yet brittle. Optical analyses indicated strong absorption and reflectivity in the ultraviolet region, while electronic band structure results showed that the materials are wide-bandgap semiconductors with direct transitions. Phonon dispersion confirmed the dynamic stability of K2LiAlH6, while Na2LiAlH6 exhibited imaginary frequencies indicating instability. Thermodynamic properties, including Debye temperature, melting point, and minimum thermal conductivity, support the suitability of these compounds for thermal applications. Furthermore, Na2LiAlH6 demonstrated a higher hydrogen storage capacity, both gravimetric (3.42 wt%) and volumetric (100.63 gH2L−1), meeting the U.S. Department of Energy's volumetric target for 2025.
Anahtar Kelimeler
Elastic properties | Electronic properties | Hydrogen storage | Optical properties | Phonon and thermal properties