Defect-rich molybdenum dioxide cluster coupled hierarchical carbon toward advanced Na–S batteries

We report a hierarchical carbon host decorated with defect-rich MoO₂ clusters (MoO_2-<i>x</i>/NC) for room-temperature Na-S batteries. The defect-enhanced MoO_2-<i>x</i> clusters, coupled with conductive carbon, not only chemically anchor polysulfides <i>via</i> Mo-S bonds but also catalyze their conversion. The resulting MoO_2-<i>x</i>/NC@S cathode delivers a remarkable capacity retention of 331 mAh g^-1 after 2000 cycles at 5 C, outperforming most reported Na-S cathodes. This work demonstrates the efficacy of defect-rich cluster catalysts in enabling long-lasting and high-rate sulfur electrochemistry.