Scalable synthesis of high-performance molybdenum diselenide-graphite nanocomposite anodes for lithium-ion batteries

摘要

Molybdenum diselenide-based carbon composites were prepared by a high-energy mechanical milling (HEMM) for anodes in lithium-ion batteries. In this paper, we have reported the effect of the type of carbonaceous matrix, for example, 2D graphite, 1D carbon nanotube, and 0D amorphous carbon, on the performance of MoSe2-carbon nanocomposite anodes. The combination of MoSe2 and graphite showed the best electrochemical performance in terms of cycling stability and rate capability. This improvement is associated with the increased surface area along both lateral and vertical directions of MoSe2, and effective mixing between MoSe2 and graphite due to HEMM. The facile exfoliation, size reduction, and homogeneous mixing of MoSe2 upon the addition of graphite, were characterized by XRD, Raman spectroscopy, BET, SEM, and TEM. The MoSe2-graphite nanocomposite ((2D)MoSe2@(2D)Gr) exhibited enhanced Li storage (a reversible discharge capacity of 909 mAh g(-1) at 100 mA g(-1) after 200 cycles) and rate performance (611 mAh g(-1) at a current density of 3 A g(-1)) as compared to other MoSe2-carbon nanocomposites, as well as pure MoSe2. The reduced charge transfer resistance, increased diffusivity, and improved mechanical stability as confirmed by electrochemical impedance spectroscopy (EIS) and ex-situ SEM, further served to demonstrate the superiority of the (2D)MoSe2 @(2D)Gr electrode.