Ultrathin MoS2@C layered structure as an anode of lithium ion battery

Abstract

We report a simple and scalable process to synthesize the core-shell nanostructure of MoS2@N-doped carbon nanosheets (MoS2@C), in which polydopamine is coated on the MoS2 surface and then carbonized. Transmission electron microscopy reveals that the as-synthesized MoS2@C possesses a nanoscopic and ultrathin layer of MoS2 sheets with a thin and conformal coating of carbon layers (similar to 5 nm). The MoS2@C demonstrates a superior electrochemical performance as an anode material for lithium ion batteries compared to exfoliated MoS2 sample. This unique core-shell structure is capable of excellent delivery of Li+ ion in charging-discharging process: a specific capacity as high as 1239 mA h g(-1), a high rate of charging-discharging capability even at a high current rate of 10 A g(-1) while retaining 597 mA h g(-1), and a good cycle stability over 70 cycles at a high current rate of 2 A g(-1).