In situ synthesis of homogeneous Ce2S3/MoS2 composites and their electrochemical performance for lithium ion batteries

Abstract

Homogeneous Ce₂S₃/MoS₂ composite have been fabricated via an in situ sulfurization method and their structure, morphology and electrochemical properties are researched systematically for the first time. Ce₂S₃/MoS₂ composite present spherical secondary particles of 0.5–1 μm in diameter. The cycling performance and rate property of Ce₂S₃/MoS₂ composite are better than those of Ce₂S₃ and MoS₂ as anode materials for lithium ion batteries. Among them, Ce₂S₃/MoS₂ composite (cationic ratio of Ce : Mo in 4 : 1) have an initial discharge capacity of 225.5 mA h g⁻¹, a coulombic efficiency of 99.1% and a reversible capacity as high as 661.7 mA h g⁻¹, a coulombic efficiency of 99.7% after 500 cycles at a current density of 100 mA g⁻¹ and the highest discharge capacity of 285.6 mA h g⁻¹ at a high current density of 1000 mA g⁻¹, showing the best cycling performance and rate capability among the as-prepared Ce₂S₃/MoS₂ composite. The reason is that the compositing between MoS₂ and Ce₂S₃ can maintain the stability of the structure during the charge/discharge process and the existence of Ce₂S₃ enhances the electrical conductivity of Ce₂S₃/MoS₂ composite and further improves the reversible capacities and rate performance of Ce₂S₃/MoS₂ composite.