A Novel Sulfur-Based Terpolymer Cathode Material for Lithium–Sulfur Battery

Herein, the preparation and characterization of a novel sulfur-based terpolymer via inverse vulcanization and dynamic covalent polymerizations using the raw materials of elemental sulfur, styrene, and peanut oil are reported. The sulfur content of this terpolymer is about 72 wt%. As it is viscous but flowable at room temperature, it can be mixed with conductive graphene without binders. Poly(sulfur–styrene–peanut oil) (poly(S–Sty–P)) terpolymer is further successfully utilized as the active cathode material in Li–S batteries. The initial specific capacity of this kind of battery reaches 1008 mAh g⁻¹. After 100 cycles, the specific capacity keeps at 611 mAh g⁻¹ with the capacity retention rate above 60% and coulombic efficiency close to 100%. Compared with the traditional sulfur cathode material, this terpolymer cathode material exhibits higher capacity, better cycle performance, and superior high-rate performance. In addition, it can be directly coated on the aluminum foil collector without additional binders, which reduces the internal resistance effect from additional binders and simplifies the battery assembly process.