Rice‐like Sulfur/Polyaniline Nanorods Wrapped with Reduced Graphene Oxide Nanosheets as High‐Performance Cathode for Lithium–Sulfur Batteries

Abstract

AbstractBy rational design, rice‐like sulfur/polyaniline nanorods wrapped with reduced graphene oxide nanosheets (designated rGO:S:PANI) were successfully synthesized through emulsification–polymerization followed by a hydrothermal process. In the rice‐like S:PANI nanoparticles, the sulfur active material is uniformly distributed among the PANI polymer network. PANI not only provides a flexible matrix for accommodating volume changes in the active sulfur upon lithium insertion/extraction, the conducting polymer chains also provide high conductivity paths for effective charge transport. Benefiting from the electrostatic interaction between GO and PANI, the sulfur/polyaniline nanorods (designated S:PANI) can be well wrapped by the rGO nanosheets after the hydrothermal process, which can further increase the conductivity of the composite and prevent the polysulfide from dissolving upon cycling. When evaluated as a cathode for lithium–sulfur batteries, the rGO:S:PANI material exhibits a high specific capacity of 1240 mAh g−1 at a current density of 0.1 Ag−1, and a capacity of approximately 500 mAh g−1 (ca. 77 % retention) even at a high current rate of 1.5 Ag−1.