MoS2 spheres covered with a few layers of MXene as a high-performance anode for sodium-ion batteries

Abstract

As a kind of anode material with high theoretical sodium storage capacity for sodium-ion batteries (SIBs), MoS₂ has been widely studied. However, its low conductivity and large volume change hamper its application in SIBs. Herein, MoS₂ microspheres were first synthesized through the sulfidation of molybdenyl acetylacetonate via a solvothermal method and then successfully covered with a few layers of MXene nanosheets using the electrostatic assembly method. The ratio of MoS₂ to MXene was also investigated. The obtained MXene@MoS₂ composite has a large specific surface area due to its porous and non-stacked structure, which benefits the enhancement of ion and electron diffusion kinetics in SIBs. Therefore, the MXene@MoS₂ composite has a specific capacity of 257.8 mA h g⁻¹ after 1000 cycles at a current density of 1 A g⁻¹ with a capacity retention of 95.7% and excellent rate performance (220.8 mA h g⁻¹ at 5 A g⁻¹).