MoO(3)@MoS(2) Core-Shell Structured Hybrid Anode Materials for Lithium-Ion Batteries

We explore a phase engineering strategy to improve the electrochemical performance of transition metal sulfides (TMSs) in anode materials for lithium-ion batteries (LIBs). A one-pot hydrothermal approach has been employed to synthesize MoS(2) nanostructures. MoS(2) and MoO(3) phases can be readily controlled by straightforward calcination in the (200–300) °C temperature range. An optimized temperature of 250 °C yields a phase-engineered MoO(3)@MoS(2) hybrid, while 200 and 300 °C produce single MoS(2) and MoO(3) phases. When tested in LIBs anode, the optimized MoO(3)@MoS(2) hybrid outperforms the pristine MoS(2) and MoO(3) counterparts. With above 99% Coulombic efficiency (CE), the hybrid anode retains its capacity of 564 mAh g(−1) after 100 cycles, and maintains a capacity of 278 mAh g(−1) at 700 mA g(−1) current density. These favorable characteristics are attributed to the formation of MoO(3) passivation surface layer on MoS(2) and reactive interfaces between the two phases, which facilitate the Li-ion insertion/extraction, successively improving MoO(3)@MoS(2) anode performance.