Sulfurized-Poly(acrylonitrile) Coated C/S Composite Cathode Materials for Rechargeable Lithium-Sulfur Batteries

Lithium-sulfur batteries (Li–S) received growing attention owing to the high theoretical energy density of 2600 Wh kg−1 along with the high theoretical specific capacity of 1675 mAh g-1, low cost, and natural abundance of elemental sulfur. However, dissolution of polysulfides, shuttling effect, and short cycle life are still challenges which limit the practical applications of Li–S batteries. Sulfurized-poly(acrylonitrile) composite cathode materials provide high specific capacity and decipher polysulfide dissolution though active materials loading and rate performance are remaining unsatisfactory. Here, we synthesize a sulfurized-poly(acrylonitrile) coated C/S composite using a dissolution-reprecipitation method followed by the thermal treatment. The dissolution-reprecipitation of SP@PAN boost the surface area of the composite that hold high active sulfur, enhance the composite-electrolyte contact and improve the conductivity of the cathode. Consequently, the prepared sulfurized-poly(acrylonitrile) coated C/S composite cathode materials yield excellent cyclability and high rate capability of 492 mAh g-1 at a high C-rate of 10 C with a high active sulfur loading of 54.5 wt%.