P(VDF-HFP)-poly(sulfur-1,3-diisopropenylbenzene) functional polymer electrolyte for lithium–sulfur batteries

Abstract Lithium–sulfur (Li–S) battery as a high-energy density electrochemical energy storage system has attracted many researchers’ attention. However, the shuttle effect of Li–S batteries and the challenges associated with lithium metal anode caused poor cycle performance. In this work, the organosulfide poly(sulfur-1,3-diisopropenylbenzene) (PSD) was prepared as cathode material and additive of P(VDF-HFP) polymer electrolyte (P(VDF-HFP)). It was verified that P(VDF-HFP) polymer electrolyte with 10% PSD (P(VDF-HFP)-10%PSD) showed a higher ionic conductivities than that of liquid electrolyte up to 2.27 × 10−3 S cm−1 at room temperature. The quasi-solid-state Li−S batteries fabricated with organosulfide cathode material PSD and P(VDF-HFP) based functional polymer electrolyte delivered good cycling stability (780 mAh g−1 after 200th cycle at 0.1 C) and rate performance (613 mAh g−1 at 1 C). The good cycling performance could be attributed to the synergistic effect of components, including the interaction between polysulfides and polymer main chain in the organosulfide cathode, the sustained organic/inorganic hybrid stable SEI layer formed by polymer electrolyte additive PSD, the improved cathode/electrolyte interface and the good affinity between P(VDF-HFP) based functional polymer electrolyte and Li metal surface. This strategy herein may provide a new route to fabricate high-performance Li–S batteries through the organosulfide cathode and functional polymer electrolyte.