Facile synthesis of hetero-structured few-layer MoS2-coated MoO2 as superior anode materials of lithium ion batteries

A hetero-structured few-layer MoS 2 -coated MoO 2 (MoS 2 @MoO 2 ) has been fabricated and applied as an anode material for LIBs . The MoS 2 @MoO 2 was synthesized via two-step fire process: reducing MoO 3 vapor with H 2 for producing Mo powder, and oxidizing-sulfurizing Mo powder with SO 2 . With the aid of thermodynamic computations, it is found that Mo oxidation under SO 2 atmosphere produces limited amounts of S 2 vapor, which will locally sulfurize the particles nearby, resulting in finite and even sulfurization. The as-prepared MoS 2 @MoO 2 includes few-layer MoS 2 (about 3 nm thick) covering the surface, which serves a well-spreading and active material that synergizes with inner MoO 2 to boost the performance for LIBs. Thus, the MoS 2 @MoO 2 could deliver a high reversible specific capacity of 1263 mA h g −1 after 40 cycles at 0.1 A g −1 , and maintain a specific capacity of 1052 mA h g −1 after 150 cycles at 0.2 A g −1 . Even at 0.5 A g −1 , the specific capacity could still keep above 650 mA h g −1 for over 500 cycles. The new method for MoS 2 @MoO 2 synthesis is facile and effective, and may be extended to produce hybrids composed of other transition metal oxides and sulfides.