Synthesis of Polypyrrole Coated RGO/S Composite as a Cathode material for Enhanced Lithium-Sulfur Batteries

摘要

Lithium-sulfur (Li-S) batteries have been widely studied in recent years, but the utilization of sulfurcathode is still limited by the low conductivity of cathode material and dissolution of polysulfides. Apolypyrrole (PPy) coated reduced graphene oxide/S (RGO/S@PPy) material was synthesized in thisstudy. It is shown that sulfur is uniformly distributed on RGO sheets, and a PPy layer ishomogeneously coated on the surface of the RGO/S composite. The PPy coating relieves thedissolution of polysulfides and improves the utilization of active sulfur. As a result, a dischargecapacity of 631 mA h g-1after 300 cycles at 0.2C and an excellent rate capability are obtained..