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 N2 atmosphere at 450 °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.