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.