Constructing MoO2/Mo2C heterointerfaces on N-doped carbon microspheres for synergistic adsorption-catalysis of polysulfides in Lithium-Sulfur batteries

The practical implementation of lithium‑sulfur (Li S) batteries is severely hindered by the polysulfide shuttle effect and sluggish conversion kinetics. Herein, we designed and fabricated a heterostructured MoO 2 /Mo 2 C composite anchored on N-doped carbon microspheres (MoO 2 /Mo 2 C@NC) as a multifunctional separator coating. The built-in electric field formed at the MoO 2 /Mo 2 C interface drives electron redistribution, which not only strengthens the chemical anchoring of polysulfides on the polar MoO 2 surfaces but also accelerates their catalytic conversion on the conductive Mo 2 C domains. This synergistic adsorption-catalysis mechanism effectively suppressed shuttle behavior and enhanced liquid-to-solid transformation kinetics. As a result, Li S batteries equipped with the MoO 2 /Mo 2 C@NC-modified separator exhibited remarkable rate capability (670 mAh g −1 at 2C) and long-term cycling stability (approximately 515 mAh g −1 after 1000 cycles). This work elucidates the critical role of interfacial electronic modulation in polysulfide regulation and provides a rational heterostructure design strategy for high-energy-density Li S batteries.