Synthesis and characterization of nano-material for supercapacitor application

Abstract

With the constantly increasing worldwide need for energy, fossil-based fuels (coal, petroleum, and natural gas) as our main energy sources are rapidly decreasing, while their combustion is increasing the output of greenhouse gases and other pollutants in our environment. Therefore, there is an urgent need to seek renewable clean energy sources like, solar energy, wind energy etc. as alternatives. Energy storage devices are employed to reduce the rate of mismatch between energy source and energy demand. Although great efforts have been made on development of high performance Li-ion batteries and fuel cells in the past, high maintenance cost and the slow power capability have kept them away from applications. Recently, supercapacitors have drawn attention because of their high charge storage capacity, long life cycle andoutstanding power density. Thus considering the importance of the supercapacitors as energy storage devices, in the present project proposal, it is aimed to focus on the synthesis and characterization of nanostructured materials for the supercapacitor applications. Electrode materials possessing the high capacity, long cycling stability, and excellent rate capability are highly desirable, also surface area plays a very crucial role since charges are stored on the surface. The aim of this project is to obtain nanomaterial of high surface area with controlled surface morphology for supercapacitor application.Here we report the synthesis and supercapacitive property of Nickel sulphide, Cobalt sulphide and Manganese Sulphide (NiCoMnS) composite nanostructure synthesized by fast, cost-effective and facile electrochemical technique. Physio-chemical characterizations were carried out such as; X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy(TEM) for phase purity, surface morphology of electrode material and particle size distribution. The electrochemical measurements were carried out by cyclic voltammetry (CV), galvanostatic charging-discharging (GCD), electrochemical impedance spectroscopy (EIS). The synthesized material exhibits enhanced electrochemical performance in 2M KOH electrolyte, CV exhibits the specific capacitance of 5420 Fg−1 at 1 mVs−1 scan rate and GCD exhibits 5008.08 Fg−1 at a current density of 5Ag−1. The material shows an excellent stability and capacitive retention of 48% after 3500 cycles at a current density of 100 Ag−1. Moreover, excellent energy density of 36 Wh/kg and power density of 24975 W/kg has been calculated. Hence these electrochemical results of NiCoMnS nanostructured composite demonstrate its application for energy storage devices at high current density.