Synthesis and Investigation of Reduced Graphene Oxide - Sulfur Composite Electrode for Lithium-Sulfur Battery

Abstract

Lithium sulfur (Li-S) batteries have become one of the promising rechargeable storage devices due to its abundancy, low cost, non-toxicity, environmental friendliness and high theoretical specific capacity. However, the insulating nature of sulfur and the shuttling effect of polysulfides have limited their applications. In order to alleviate these problems and make Li-S batteries more promising, we have synthesized a composite of reduced graphene oxide and sulfur (rGO-S) as electrode material for these batteries. In this paper, graphite oxide was prepared from graphite powder by Improved Hummer’s method followed by ultrasonic exfoliation to make Graphene Oxide (GO). The GO suspension was hydrothermally reduced and heated in a hot air oven at 150 °C for 4 hours followed by the addition of sulfur (S) in a ratio of 0.1:1 and 1:1 by mass and heated again at 180 °C for another 4 hours to make a composite of rGO-S. The electrode of the rGO-S composite was prepared by making a slurry of active material, carbon black and polyvinylidene fluoride (PVDF). The sample of GO and rGO were analyzed using Ultraviolet (UV)-Visible and Fourier Transform Infrared (FTIR) spectroscopy. The composite material was analyzed using X-Rays Powder Diffraction (XRD) while the energy density and charge discharge curves of the electrode were analyzed using cyclic voltammetry (CV).