TUAN HUNG NGUYENYin, LichangLichangYinTran, Phong DinhPhong DinhTranSaito, RiichiroRiichiroSaito2025-09-242025-09-242019https://www.scopus.com/inward/record.uri?eid=2-s2.0-85076821993&doi=10.1021%2Facs.jpcc.9b09325&partnerID=40&md5=d91ba2b0a8ceeb52253d04c21257204fhttps://scholars.lib.ntu.edu.tw/handle/123456789/732319Using the density functional theory (DFT) calculations, we investigate the molybdenum sulfide polymer (Mo<inf>3</inf>S<inf>11</inf>) as an electrode for the sodium-ion battery. The ionic ordering of Na<inf>x</inf>Mo<inf>3</inf>S<inf>11</inf> in the ground-state structures is determined by the DFT method. During the intercalation process of Na ions, we find that the Na<inf>x</inf>Mo<inf>3</inf>S<inf>11</inf> 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 (S<inf>2</inf>)2- → S2- (1 ? x ? 4) occurs, while in the second step, both anionic and cationic redoxes of (S<inf>2</inf>)2- → S2- and Mo4+ → Mo3+ (4 < x ? 17) occur simultaneously. In total, the Na<inf>x</inf>Mo<inf>3</inf>S<inf>11</inf> 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. Mo<inf>3</inf>S<inf>11</inf> thus is predicted to be a promising one-dimensional polymer electrode for the sodium-ion battery.Density Functional TheoryElectrodesGround StateMetal IonsMolybdenum CompoundsPolymersRedox ReactionsSodium-ion BatteriesGround-state StructuresIntercalation ProcessIonic OrderMolybdenum SulfideOne-dimensional PolymersPolymer ElectrodesSemiconductor-to-metal TransitionsTwo-step ReactionsSulfur Compounds[SDGs]SDG6journal article10.1021/acs.jpcc.9b093252-s2.0-85076821993