L-Cysteine-Assisted Synthesis of Layered MoS2/Graphene Composites with Excellent Electrochemical Performances for Lithium Ion Batteries

A facile process was developed to synthesize layered MoS2/graphene (MoS2/G) composites by an L-cysteine-assisted solution-phase method, in which sodium molybdate, as-prepared graphene oxide (GO), and L-cysteine were used as starting materials. As-prepared MoS2/G was then fabricated into layered MoS2/G composites after annealing in a H-2/N-2 atmosphere at 800 degrees C for 2 h. The samples were systematically investigated by X-ray diffraction, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and high-resolution transmission electron microscopy. Electrochemical performances were evaluated In two-electrode cells versus metallic lithium. It Is demonstrated that the obtained MoS2/G composites show three-dimensional architecture and excellent electrochemical performances as anode materials for U-ion batteries. The MoS2/G composite with a Mo:C molar ratio of 1:2 exhibits the highest specific capacity of similar to 1100 mAh/g at a current of 100 mA/g, as well as excellent cycling stability and high-rate capability. The superior electrochemical performances of MoS2/G composites as U-Ion battery anodes are attributed to their robust composite structure and the synergistic effects between layered MoS2 and graphene.