Ethylene glycol solvent induced expansion of interplanar spacing and 2H-1T phase transformation of molybdenum disulfide nanocomposites for enhanced lithium storage capability

Molybdenum disulfide (MoS2), has aroused people's much research interest as an anode candidate for next generation of Li-ion batteries because of special layered structure and high theoretical capacity. However, MoS2 suffers from a poor cycling stability and an inferior rate capability upon charge/discharge processes. So we have successfully synthesized a more stable expanded nanocomposite with superior electrical conductivity by intercalating moderate amorphous carbon between two adjacent S-Mo-S interlayer via a simple method which exhibits excellent lithium storage performance with high capacity (858.9 mA h g(-1) at 1 A g(-1) for 1000 cycles), and superior rate capability (518 mA h g(-1) at 4 A g(-1)). This superior electrochemical performance is attributed to the special structure (few layers, 2H phase, expanded interlayer spacing, amorphous carbon between S-Mo-S layers, C-O-Mo bond in the layer), small size and evenly distributed MoS2 nanosheets. Besides, we study the 2H-1T phase transformation mechanism by controlling the ratio of ethylene glycol to water and O-C=O bond plays an important role in promoting 2H-1T phase transformation. (C) 2019 Elsevier B.V. All rights reserved.