Mild-method synthesised rGO–TiO2 as an effective Polysulphide–Barrier for Lithium–Sulphur batteries

Abstract

Abstract Reduced graphene oxide–TiO2 (rGO–TiO2) composites prepared via low-temperature hydrolysis and reduction process were used to modify the separator of lithium–sulphur (Li–S) batteries. Integrating the visible-light-absorption experiments, X-ray photoelectron spectroscopy (XPS) observations, and current–voltage (I–V) measurements, the rGO–TiO2 composites have been demonstrated to possess the advantages of both rGO and TiO2, i.e., superior conductivity from rGO and strong ability of anchoring polysulphides from TiO2. These advantages can reduce the polarisation voltage and enhance the capacity performance of the corresponding cells. Consequently, the cells display the initial capacity of 1145 mA h/g and reversible capacity of 760 mA h/g after 100 cycles at 0.5C, and the latter is approximately 52% higher than that of the cells with pristine separators. In addition, the cells provide satisfactory rate capability and high sulphur areal-loading. The rGO–TiO2 separator exhibits significant potential to enhance the performance of Li–S batteries.