Synergistic effect of tubular amorphous carbon and polypyrrole on polysulfides in Li-S batteries

In order to explore a cathode material with high electrochemical performance for lithium-sulfur batteries (LSBs), a novel core-shell structured tubular amorphous carbon@sulfur@polypyrrole (TAC@S@PPy) composite with a dual-conductive layer is synthesized by in-situ chemical precipitation and chemical oxidation polymerization, including a TAC Conductive matrix layer, an intermediate sulfur layer, and an external PPy coating layer with a certain conductivity and adsorptivity for polysulfides. Compared to pure sulfur and TAC@S composite, the core shell structured TAC@S@PPy composite exhibits a higher discharge specific capacity of 1111 mAh g(-1), and still maintains at 731 mAh g(-1) after 100 cycles at a current density of 335 mA g(-1). Whereas, TAC@S composite and pure sulfur only retain 472 and 224 mAh g(-1) after 100 cycles at the same current density, respectively. Therefore, these results indicate that the core-shell structured TAC@S@PPy composite with a dual-conductive layer would be a promising cathode for LSBs.