Synergistically boosting reaction kinetics and suppressing polyselenide shuttle effect by Ti3C2Tx/Sb2Se3 film anode in high-performance sodium-ion batteries

Synergistically boosting reaction kinetics and suppressing polyselenide shuttle effect by Ti3C2Tx/Sb2Se3 film anode enables excellent sodium storage performance. [Display omitted] •A flexible film with unique structure of Sb2Se3 nanowires uniformly anchored between Ti3C2Tx nanosheets was successfully fabricated.•The improved electrochemical reaction kinetics and mechanism are systematically analysed by a series of ex-situ characterization techniques and DFT.•Superior cycling stability and remarkable rate capability are achieved as anode for sodium-ion half and full batteries. Antimony selenide (Sb2Se3), with rich resources and high electrochemical activity, including in conversion and alloying reactions, has been regarded as an ideal candidate anode material for sodium-ion batteries. However, the severe volume expansion, sluggish kinetics, and polyselenide shuttle of the Sb2Se3-based anode lead to serious pulverization at high current density, restricting its industrialization. Herein, a unique structure of Sb2Se3 nanowires uniformly anchored between Ti3C2Tx (MXene) nanosheets was prepared by the electrostatic self-assembly method. The MXene can impede the volume expansion of Sb2Se3 nanowires in the sodiation process. Moreover, the Sb2Se3 nanowires can reduce the restacking of Ti3C2Tx nanosheets and enhance electrolyte accessibility. Furthermore, density functional theory calculations confirm the increased reaction kinetics and better sodium storage capability through the composite of Ti3C2Tx with Sb2Se3 and the high adsorption capability of Ti3C2Tx to polyselenides. Therefore, the resultant Sb2Se3/Ti3C2Tx anodes show high rate capability (369.4 mAh/g at 5 A/g) and cycling performance (568.9 and 304.1 mAh/g at 0.1 A/g after 100 cycles and at 1.0 A/g after 500 cycles). More importantly, the full sodium-ion batteries using the Sb2Se3/Ti3C2Tx anode and Na3V2(PO4)3/carbon cathode exhibit high energy/power densities and outstanding cycle performance.