GROWTH AND CHARACTERIZATION OF MoS2@METAL OXIDE BASED NANOCOMPOSITES FOR SUPERCAPACITOR APPLICATIONS

Abstract

Energy is a basic requirement for the well growth of human civilization. The industrial revolution and economic prosperity of a Nation directly depend on its energy resources. Recently, Supercapacitor, an electrochemical energy storage device, has drawn tremendous research attention due to their unique properties such as long cycle stability, high specific capacitance, high power density, low cost, easy handling, and eco-friendly nature. In supercapacitor application, both the electrolytes and electrode materials play a very important role to deliver improved energy storage performance. 2D materials, for example, graphene and transition metal dichalcogenides (TMDCs) are used to design high-performance supercapacitors. Among TMDCs, MoS2 has gained special attention as electrode material for supercapacitor, due to its sheet-like layered structure, high surface area, and high electrical conductivity. MoS2 reveals high specific capacitance as a result of non-faradaic reactions and some redox reactions at lower scan rates due to the diffusion of electrolyte ions into the layered electrode structure. In this thesis work, our main focus is concentrated on MoS2 owing to the above mentioned properties. Further, to get the improved electrochemical behavior of MoS2, it is planned to synthesize MoS2 based nanocomposites. In this regard, we choose Mn-based compound after doing a deep literature survey. Generally, Mn-based oxide materials are promising candidates for supercapacitor electrodes among the most admirable electrode materials due to their huge abundance, low-cost, and eco-friendly nature. Further, Manganese dioxide (MnO2) is used as favorable electrode material for SCs due to its low cost, abundance, rich redox activity, non-toxic nature, and high theoretical specific capacitance (~1232 F g-1). With the above discussed advantages, there are some factors that limit the practical utilizations of MnO2 such as low experimental specific capacitance and poor cycling ability which can be attributed to its poor electrical conductivity. Therefore, it was planned to synthesize nanocomposites of MnO2 with MoS2 material, so that enhanced electrochemical properties can be achieved.