Sulfur Nested with Mixture of MnO2/AB Composite as Efficient Host for High-Performance Li–S Batteries

Abstract

Lithium–sulfur (Li–S) batteries have established a tremendous interest in recent years because of their high specific capacity (1675 mAh g−1) and energy density (2600 Wh kg−1). In the present work, the electrode comprising carbon source viz., Acetylene Black (AB) and Manganese Oxide (MnO2) to serve as an efficient sulfur host in two different ratios (MnO2:AB as 10:20 (M1) and 20:10 (M2)) for Li/dissolved polysulfide batteries. The composite was characterized and studied by X-ray diffraction (XRD), Raman Spectroscopy, Nitrogen adsorption/desorption measurements, High-resolution transmission electron microscopy (HRTEM), X-ray photon spectroscopy (XPS), Thermogravimetric analysis (TGA) and electrochemical performance such as cyclic voltammetry (CV) and charge–discharge (C/D) tests. It shows good cycle performance and exhibits an initial capacity of 1540 mAh/g at 0.1 C between 1.5 and 3.0 V for MnO2 rich sample. Performance enhancement was also brought about by the adsorptive properties of MnO2 which help in locking the polysulfide discharge products within the cathode structure.