Using the density functional theory (DFT) calculations, we investigate the molybdenum sulfide polymer (Mo3S11) as an electrode for the sodium-ion battery. The ionic ordering of NaxMo3S11 in the ground-state structures is determined by the DFT method. During the intercalation process of Na ions, we find that the NaxMo3S11 structure exhibits a two-step reaction pathway involving both cationic and anionic redox reactions for Mo and S, respectively. In the first step, an initial anionic redox (S2)2- → S2- (1 ≤ x ≤ 4) occurs, while in the second step, both anionic and cationic redoxes of (S2)2- → S2- and Mo4+ → Mo3+ (4 < x ≤ 17) occur simultaneously. In total, the NaxMo3S11 electrode can store up to 17 Na ions with a predicted capacity of 711 mA h/g. Moreover, a semiconductor-to-metal transition is observed during the cationic/anionic redox due to the appearance of mid-gap states. Mo3S11 thus is predicted to be a promising one-dimensional polymer electrode for the sodium-ion battery.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films