Ti3C2Tx MXenes bonded MoS2 nanosheets for superior sodium-ion batteries

Abstract

Sodium-ion batteries (SIBs) have evolved into the most potential alternatives to lithium-ion batteries (LIBs) especially for large-scale energy storage applications. However, the large radius of sodium ion inevitably causes large volume change and sluggish ion diffusion kinetics. Molybdenum disulfide (MoS2) as a rising star of anode for SIBs has raised concern because of its high theoretical capacity. Nevertheless, MoS2 suffers from low electronic conductivity and serious re-stacking, resulting in declined cycling stability and poor rate capability. Herein, we reported an electrostatic self-assembly process to synthesize three-dimensional (3D) crumpled MXene-bonded MoS2 nanosheets. The MoS2/MXene heterostructure not only avoids the serious self-aggregation of MoS2 nanoparticles but only maintains the chemical and mechanical stability of MoS2/MXene hybrids during sodiation and desodiation. Strong chemical interactions were validated on the interface of MXene and MoS2, favoring fast charge transfer kinetics and durable structural stability. The developed MoS2/MXene electrode exhibits a high specific capacity (509 mAh g−1 at 0.05 A g−1) and considerable cyclability (326 mAh g−1 at 1 A g−1 after 900 cycles), manifesting a promising application prospect for SIBs. Our work can provide a rational strategy for the electrode design strategy for SIBs.