Sodium storage performance and mechanism of rGO-wrapped nanorod vanadium sulfide as an anode material for sodium ion batteries

• Published in: Solid state ionics Vol. 327; pp. 129 - 135
• Main Authors: Zhu, Liya, Li, Yanan, Wang, Jing, Zhu, Xianjun
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.12.2018; Elsevier BV
• Subjects: Anode; Anodes; Batteries; Chemical synthesis; Discharge; Efficiency; Electrochemical analysis; Electrode materials; Graphene; Nanorods; rGO; Sodium; Sodium ion battery; Sodium sulfide; Sodium-ion batteries; Vanadium; Vanadium sulfide; Voltammetry; Sodium ion battery; rGO; Anode; Vanadium sulfide
• ISSN: 0167-2738; 1872-7689
• DOI: 10.1016/j.ssi.2018.10.022

Nanorod vanadium sulfide wrapped by reduced graphene oxide (rGO) composite is synthesized by a facile solvothermal reaction. Nanorod vanadium sulfide is uniformly distributed on the surface of rGO nanosheets. As an anode for sodium ion batteries, the composite with 13 wt% rGO has 1203.8 and 781.4 mAh g−1 specific capacities for the first discharge and charge, respectively, with 64.9% of Coulombic efficiency, higher than that of pure vanadium sulfide submicrospheres. The sodiation/desodiation mechanism is investigated by cyclic voltammetry, electrochemical impedance spectrum and discharging-charging measurement. The results show that the vanadium sulfide/rGO composite can convert to sodium sulfide + vanadium/rGO composite after the first cycle, and the rGO can inhibit the dissolution of polysulfide while metal vanadium increases electrode conductivity, resulting in the enhanced electrochemical performance. •VS4/rGO can deliver a reversible capacity of 781.4 mAh g-1.•The mechanism of storage sodium for VS4/rGO is investigated.