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

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)).