Stable immobilization of lithium polysulfides using three-dimensional ordered mesoporous Mn₂O₃ as the host material in lithium–sulfur batteries

Lithium–sulfur batteries (LSBs) have drawn significant attention owing to their high theoretical discharge capacity and energy density. However, the dissolution of long-chain polysulfides into the electrolyte during the charge and discharge process (“shuttle effect”) results in fast capacity fading and inferior electrochemical performance. In this study, Mn₂O₃ with an ordered mesoporous structure (OM-Mn₂O₃) was designed as a cathode host for LSBs via KIT-6 hard templating, to effectively inhibit the polysulfide shuttle effect. OM-Mn₂O₃ offers numerous pores to confine sulfur and tightly anchor the dissolved polysulfides through the combined effects of strong polar–polar interactions, polysulfides, and sulfur chain catenation. The OM-Mn₂O₃/S composite electrode delivered a discharge capacity of 561 mA h g⁻¹ after 250 cycles at 0.5 C owing to the excellent performance of OM-Mn₂O₃. Furthermore, it retained a discharge capacity of 628 mA h g⁻¹ even at a rate of 2 C, which was significantly higher than that of a pristine sulfur electrode (206 mA h g⁻¹). These findings provide a prospective strategy for designing cathode materials for high-performance LSBs.