Novel 2D Layered Molybdenum Ditelluride Encapsulated in Few-Layer Graphene as High-Performance Anode for Lithium-Ion Batteries

Molybdenum ditelluride nanosheets encapsulated in few-layer graphene (MoTe2/FLG) are synthesized by a simple heating method using Te and Mo powder and subsequent ball milling with graphite. The as-prepared MoTe2/FLG nanocomposites as anode materials for lithium-ion batteries exhibit excellent electrochemical performance with a highly reversible capacity of 596.5 mAh g(-1) at 100 mA g(-1), a high rate capability (334.5 mAh g(-1) at 2 A g(-1)), and superior cycling stability (capacity retention of 99.5% over 400 cycles at 0.5 A g(-1)). Ex situ X-ray diffraction and transmission electron microscopy are used to explore the lithium storage mechanism of MoTe2. Moreover, the electrochemical performance of a MoTe2/FLG//0.35Li(2)MnO(3)center dot 0.65LiMn(0.5)Ni(0.5)O(2) full cell is investigated, which displays a reversible capacity of 499 mAh g(-1) (based on the MoTe2/FLG mass) at 100 mA g(-1) and a capacity retention of 78% over 50 cycles, suggesting the promising application of MoTe2/FLG for lithium-ion storage. First-principles calculations exhibit that the lowest diffusion barrier (0.18 eV) for lithium ions along pathway III in the MoTe2 layered structure is beneficial for improving the Li intercalation/deintercalation property.