Engineering MoO₃-MoS₂ heter-nanorods as a multi-functional separator for synergistic adsorption-catalysis in Li S batteries

Boasting a superior theoretical energy density, lithium–sulfur (Li S) batteries hold great promise for surpassing conventional lithium-ion technology. Their commercialization, however, is impeded by critical issues including the polysulfide shuttle effect and sluggish reaction kinetics. Herein, we demonstrate a MoO₃–MoS₂ heterostructure nanorod coating on a separator to simultaneously address these challenges. This design not only chemically anchors polysulfides but also catalytically accelerates their redox kinetics. The assembled Li S battery thus delivers outstanding performance: a reversible capacity of 768 mAh g −1 after 400 cycles at 1C, corresponding to a minimal fade rate of 0.06% per cycle, and a capacity of 681 mAh g −1 at 3C. This study provides a strategic design of functional separators through heterostructure catalysis, paving the way for long-life Li S batteries. • A MoO₃–MoS₂ heterostructure is constructed for separator modification. • The built-in electric field promotes polysulfide trapping and conversion. • Capacity retention of 768 mAh g −1 after 400 cycles with 0.06% decay per cycle. • High rate capability is maintained even at 3C current density.