Nanoscale coupling of MoS2 and graphene via rapid thermal decomposition of ammonium tetrathiomolybdate and graphite oxide for boosting capacity of Li-ion batteries

We report the MoS2/graphene coupling as the result of the decomposition of a mixture of ammonium tetrathiomolybdate and graphene oxide in thermal shock conditions. X-ray diffraction and Raman spectroscopy showed that the temperature of 400 degrees C is sufficient for the formation of MoS2 crystallites. High-resolution electron microscopy detected that nanoscale MoS2 crystallites are oriented along or perpendicular to the graphene surface or they are incorporated between the graphene layers. Electron energy loss C K-edge spectra confirmed a firm bonding between the components. Used as the electrodes of Li-ion batteries, the materials were able to sustain a specific capacity of 564 mAhg(-1) at a current density of 10 Ag-1 with gradual growth of the capacity up to similar to 1730 mAhg(-1) during next 425 operation cycles at 0.1 Ag-1. Our study revealed that rapid decomposition of the precursors creates defects in the graphene and MoS2 layers, short synthesis time enables the formation of few-layer MoS2 nanosheets, and high pressure, developed in the reactor, leads to covalent bonding between the components. These structural features ensure many sites for the adsorption of Li ions, fast transport of the ions, and high stability of the electrode during long-term operation of the battery. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

Our study revealed that rapid decomposition of the precursors creates defects in the graphene and MoS2 layers, short synthesis time enables the formation of few-layer MoS2 nanosheets, and high pressure, developed in the reactor, leads to covalent bonding between the components. These structural features ensure many sites for the adsorption of Li ions, fast transport of the ions, and high stability of the electrode during long-term operation of the battery.