Fig. 5.

Structural characterization and electrochemical performance analysis of TMD (MoS₂) as an electrode material in SIB: a, b HRTEM images of exfoliated MoS₂ nanosheets obtained after treatment with a superacid. c Selected area diffraction pattern for the MoS₂ nanosheet imaged in Fig. b. d, e SEM images of the top and cross-sectional view of the 60 MoS₂ sample (60 wt% MoS₂-40 wt% rGO), respectively. e TEM image of SAED pattern (in the inset) of the same 60 MoS₂ sample. g Graphical representation of the total interaction potential (VT), repulsion (V_DLVO), and attraction energy (V_vdW) versus greater sheet separation. h Raman spectra of the MoS₂ samples, in bulk (black) and after exfoliation (red) by acid treatment. i XRD spectra of the bulk (black) and exfoliated MoS₂ (red) sample, indicating the peak shift and the broadening of the consequent increase in the interlayer distance of the exfoliated sample. j XRD pattern of pristine MoS₂-rGO (60 MoS₂) electrode (blue) and the same after one discharge cycle (black). Considerable peak broadening is observed due to sodiation. k First discharge graph of the 60 MoS₂ electrode, also showing the formation of nanocrsytallites along the process from the TEM images and SAED patterns in the inset. l 1st (black)- and 2nd-cycle (red) GCD curves for the 60 MoS2 sample. m Differential capacity curves for the first two cycles demonstrating the redox voltages. n Charging capacity and Coulombic efficiency values for the different composite and bare rGO sample performed at a current density of 25 mA g⁻¹. o Charge capacity, coulombic efficiency, and rate capability of 60 MoS₂ sample [83]. Copyright 2014 American Chemical Society. Scale bar for d, e is 10 μm and for f is 100 nm. (Color figure online)