Ti3C2Tx MXenes bonded MoS2 nanosheets for superior sodium-ion batteries

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 con-siderable 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.(c) 2023 Elsevier B.V. All rights reserved.

Automated summary

Sodium-ion batteries have emerged as the most potential alternatives to lithium-ion batteries, especially for large-scale energy storage applications. However, the large size of sodium ions leads to significant volume change and slow ion diffusion. Molybdenum disulfide has shown promise as an anode material for sodium-ion batteries due to its high theoretical capacity, but it suffers from low electronic conductivity and stacking issues, resulting in decreased cycling stability and rate capability. In this study, a self-assembly process was used to synthesize crumpled MXene-bonded MoS2 nanosheets, which exhibited improved cycling performance and capacity. The findings provide a rational strategy for the design of electrodes for sodium-ion batteries.