Dopamine-derived N-doped carbon-encapsulated MoS2 microspheres as a high-performance anode for sodium-ion batteries

Two-dimensional lamellar MoS2 has been widely studied as an anode material for sodium-ion batteries. However, MoS2 exhibits low electrical conductivity and large volume change during the electrochemical charge-discharge process, resulting in poor electrochemical performance. In this work, the dopamine-derived N-doped carbon-encapsulated MoS2 microsphere (MoS2@NC) composite material was synthesized and employed as anode material for sodium-ion batteries (SIBs). As-prepared MoS2@NC composites exhibited an excellent cycle performance with high specific capacity of 480 mAh g(-1) at a current density of 100 mA g(-1) after 100 cycles and outstanding rate capability (the capacities of 484, 456, 425, 408, and 393 mAh g(-1) at 0.1, 0.2, 0.5, 1, and 2 A g(-1), respectively). The good electrochemical sodium storage performance for MoS2@NC is probably attributed to N-doped carbon layer on the surface of MoS2, which can effectively suppress the volume expansion of MoS2, increase the electric conductivity and limit contact with electrolyte.