Bimetallic Sulfide/Sulfur Doped T3C2TA:MXene Nanocomposites as High-performance Anode Materials for Sodium-ion Batteries

摘要

The application of transition metal dichalcogenides(TMDs)as anode materials in sodium-ion batteries(SIBs) has been hindered by low conductivity and poor cyclability.Herein,we report the synthesis of CoxFe1-xS2 bimetallic sulfide/sulfur-doped Ti3C2 MXene nanocomposites(CoxFe1-xS2@S-Ti3C2)by a facile co-precipitation process and thermal-sulfurization reaction.The interconnected 3D frameworks consisting of MXene nanosheets can effectively buffer the volume change and enhance the charge transfer.In particular,sulfur-doped MXene nanosheets provide rich active sites for sodium storage and restrain sulfur loss during charging/discharging processes,leading the increase of specific capacity and cycling the stability of anode materials.As a result,CoxFe1-xS2@S-Ti3C2 anodes exhibited high capacity,high rate capability and long cycle life(399mA·h/g at 5A/g with an 94% capacity retention after 600 cycles).