High energy symmetric supercapacitor based on mechanically delaminated few-layered MoS2 sheets in organic electrolyte

Abstract

Electrochemical energy storage devices based on the two-dimensional metal chalcogenides have great interest due to their intriguing physical and chemical properties. In this work, we are reporting the high-performance supercapacitive properties of few-layered MoS2 (prepared via ball milling process) in an organic electrolyte. The physico-chemical characterizations such as X-ray diffraction, X-ray photoelectron spectroscopy, high-resolution transmission electron microscope, and laser Raman spectrum, confirms the formation of few-layered MoS2. The cyclic voltammetry and electrochemical impedance spectroscopy (Nyquist and Bode plots) studies of the MoS2 symmetric supercapacitor (SSC) reveals the presence of pseudocapacitive nature of charge-storage via ion-intercalation/de-intercalation process. The galvanostatic charge-discharge analysis shows that the MoS2 SSC device possesses a high specific capacitance of 14.75 F g−1 and an energy density of 18.43 Wh kg−1 (measured at a constant current density of 0.75 A g−1) with excellent cyclic stability over 5000 cycles. The experimental results suggest that the few-layered MoS2 SSC device might be the ideal choice in the development of next-generation energy devices.