Synthesis of hierarchical MoS2 and its electrochemical performance as an anode material for lithium-ion batteries

A facile process is developed to synthesize MoS2 in basic solutions via a hydrothermal route by employing ammonium heptamolybdate and thiourea as starting materials and post-annealing in a N-2 atmosphere at 450 degrees C for 5 h. The morphologies of the MoS2 products can be tuned from porous flowers to dense spheres by addition of NaOH. Experimental results show that the MoS2 products have good crystallinity. A formation mechanism of the MoS2 is proposed in which the dense MoS2 spheres are evolved from the porous MoS2 flowers through growth along the < 00l > direction of the nanosheets. Based on the growth mechanism, the microstructure of MoS2 can be successfully controlled by adjustment of the S/Mo ratio or addition of a surfactant in the recipe. Electrochemical measurements demonstrate that the flower-like MoS2 shows better electrochemical performance than MoS2 spheres as anode materials for Li-ion batteries, which deliver a high reversible capacity of 900 mA h g(-1) at a current density of 100 mA g(-1), excellent cycling stability and rate capability.