Synthesis of polyaniline nanowires wrapped yolk-shell structured S@RGO composite material and its improved lithium-storage performance

Abstract

To accommodate volume change of sulfur particles, confine lithium polysulfides (LiPSs) within conductive matrix, as well as accelerate transference of electrons/ions, the sulfur@reduced graphene oxide (S@RGO) yolk-shell particles wrapped by polyaniline (PANI) nanowires were prepared in this work. Meanwhile, PANI nanowires are synthesized by in situ polymerization of aniline monomers. Importantly, many nanoscale holes are generated on the RGO nanosheets forming three-dimensional channels for ion transportation within the obtained composite material. LiPSs can be firmly confined in the composite material by the polar oxygen-containing groups on the surface of the RGO shells and the protonated nitrogen-containing groups on the PANI nanowires. Benefiting from the unique structure, the S@RGO/PANI particles exhibit an improved electrochemical performance. It can deliver an initial capacity of 1021 mAh·g−1 at 0.1C rate and a high initial coulombic efficiency up to 95.4%. Even at 2.0C rate, a discharge capacity of 501 mAh·g−1 can be retained after 500 cycles. Results indicate that the S@RGO/PANI can be promisingly exploited as a kind of high-energy density cathode material for rechargeable lithium batteries.