Simultaneous Anionic and Cationic Redox in the Mo3S11 Polymer Electrode of a Sodium-Ion Battery
Journal
Journal of Physical Chemistry C
Journal Volume
123
Journal Issue
51
Start Page
30856
End Page
30862
ISSN
19327455
19327447
Date Issued
2019
Author(s)
Abstract
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.
Subjects
Density Functional Theory
Electrodes
Ground State
Metal Ions
Molybdenum Compounds
Polymers
Redox Reactions
Sodium-ion Batteries
Ground-state Structures
Intercalation Process
Ionic Order
Molybdenum Sulfide
One-dimensional Polymers
Polymer Electrodes
Semiconductor-to-metal Transitions
Two-step Reactions
Sulfur Compounds
SDGs
Publisher
American Chemical Society
Type
journal article