Effect of surface modification and exfoliation of molybdenum disulfide for application in batteries and supercapacitors

Abstract

Molybdenum disulfide (MoS2) flakes, a semiconductor-like material having high surface area and versatile electronic structure finds application in numerous electrochemical energy storage devices. Boosting its surface properties improves the overall storage performance to a greater extent. This present research work focuses on the surface modification of MoS2 using Lithium stearate (LiC18H35O2). The LiC18H35O2 modification supports lithium intercalation between the layers of MoS2 thereby facilitating the exfoliation process and simultaneous modification of the flakes. The resultant samples were characterized using X-ray powder diffraction (XRD), Raman spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, Thermogravimetric analysis (TGA), Scanning electron microscopy (SEM) and Energy dispersive x-ray (EDAX) analysis. EDAX results revealed that the stearate surface treated MoS2 samples exhibited larger increase in Carbon and Oxygen elemental concentrations, which further confirms modification. The modifier and the material itself have good lubricant properties suggesting lithium stearate assisted modification and exfoliation of MoS2 as a better choice to make composites with enhanced electrical and chemical properties suitable for energy storage applications in batteries and supercapacitors.