2D NANOMATERIALS AS HIGH-PERFORMANCE ELECTRODES FOR ADVANCED ENERGY STORAGE.

Abstract

There is an increasing need for electrode materials having high specific capacitance, fast ion movement ability, and good cycling stability in the development of next-generation energy storage systems. In this research paper, the synthesis, characterization, and electrochemical properties of graphene oxide-based 2D nanostructured electrode material have been discussed for application in supercapacitors. Graphene oxide (GO) was prepared by modifying the conventional Hummers' process and was fabricated on nickel foam substrates. Material characterization through XRD, FTIR, SEM, Raman spectroscopy, and BET measurement confirmed that the resulting electrode had high porosity, wrinkled sheet structure, oxygen-rich functional groups, and a large specific surface area. Electrochemical characterization in the three-electrode cell test using 1 M Na₂SO₄ as electrolyte showed that the material has an electric double layer capacitor with good reversibility. It displayed high specific capacitance, symmetrical triangular charge-discharge curve during cyclic voltammetry, and low equivalent series and charge transfer resistances obtained from EIS measurement. Importantly, it retained more than 90% capacitance after 5000 charging and discharging cycles with Coulombic efficiency above 99%. The mechanism of charge storage involved cooperative contribution from electric double layer capacitance and pseudo-capacitance from functional groups on the surface