Multifaceted ethylenediamine and hydrothermal assisted optimum reduced GO-nanosulfur composite as high capacity cathode for lithium-sulfur batteries

Abstract

A high specific capacity conducting reduced graphene oxide nanosulfur nanocomposite (RGOSNC) cathode is synthesized via deposition of nanosulfur on graphene oxide (GO) through the hydrothermal treatment in the presence of multifaceted ethylenediamine (EDA) for improving the performance of lithium-sulfur battery (LiSB). The maximum utilization of active material (sulfur) is facilitated by the attachment of nanosulfur to GO via EDA, and further, optimum reduction of GO into conducting, porous and interconnected RGO is performed via hydrothermal treatment in the available solution having residual EDA. Therefore, GO is reduced in highly conducting RGO without the use of any external reducing agent; minimizing the chance of impurity in the synthesized RGOSNC. A three-dimensional interconnected porous conducting architecture with nitrogen (heteroatom) doping in RGO of RGOSNC with conductivity ∼1.83 S/cm assists easy electron transportation through conducting RGO network and stabilizes intermediate polysulfide to prevent loss of active material during the electrochemical performance. The synthesized RGOSNC cathode material delivers high initial specific capacities 1448 and 1040 mAh/g at 0.1 and 0.5 C, respectively. Prepared LiSB maintains ∼741 mAh/g retention over 100 cycles at 0.5 C with excellent Coulombic efficiency (∼99%).