Liquid-electrolyte sodium-sulfur battery operated at room temperature is encountering challenges brought by the complex sulfur redox reactions, including (i) the dissolved polysulfide intermediates trigger serious side reactions on Na anode surface; (ii) the short-chain sulfide precipitation exhibits sluggish kinetics and the sulfur utilization is generally below 50% with unclear reasons. In this work, employing an ion selective polybenzimidazole-based separator we successfully suppress the polysulfide corrosion on the Na anode, which allows the investigation of the precipitation reaction. Combining DFT calculation and characterization techniques, we determine Na₂S₂ particles as the final discharge product and reveal that Na₂S₂ passivation is the predominant attributes of large polarization and capacity fading. To address these issues, we present the use of a bifunctional NaI-P₂S₅ based electrolyte additive, which (i) improves the Na₂S₂ precipitation kinetics by forming soluble Na₂S₂-P₂S₅ complex and (ii) promotes the dissolution of Na₂S₂ by the chemical mediation of I⁻/ $I_3^{-}$ . As a result, a much improved capacity retention (92.9% for 50 cycles at 0.2C) is attained, which sheds light on enabling the stable operation of sodium-sulfur batteries via combining advanced separator and electrolyte engineering strategies.

在室温下运行的液体电解质钠硫电池面临着复杂的硫氧化还原反应带来的挑战，其中包括：（i）溶解的多硫化物中间体会在钠阳极表面引发严重的副反应；（ii）短链硫化物沉淀表现出缓慢的动力学，并且由于不清楚的原因，硫的利用率通常低于50％。在这项工作中，采用基于离子选择性聚苯并咪唑的隔膜，我们成功地抑制了Na阳极上的多硫化物腐蚀，从而可以研究沉淀反应。结合DFT计算和表征技术，我们确定Na ₂ S ₂颗粒为最终放电产物，并揭示了Na ₂ S ₂钝化是大极化和容量衰减的主要属性。为了解决这些问题，我们提出了使用基于双功能NaI-P ₂ S ₅的电解质添加剂，该添加剂（i）通过形成可溶性Na ₂ S ₂ -P ₂ S _5配合物来改善Na ₂ S ₂沉淀动力学。）促进钠的溶出₂小号₂由I的化学调解^- /${\mathrm{一世}}_3^{-}$。结果，获得了大大提高的容量保持率（0.2C下50个循环为92.9％），这通过结合使用先进的隔板和电解质工程策略，使钠硫电池能够稳定运行，显得尤为重要。