| Abstract Scope |
The practical implementation of Li-S batteries is severely limited by the polysulfide shuttle effect, sluggish redox kinetics, and rapid capacity fading. Here, we present a CeSe₂@TiSe₂-C composite, derived from Ti₃C₂Tₓ MXene, as an advanced separator coating designed to address these challenges. The composite integrates catalytically active CeSe₂ and TiSe₂ within a conductive carbon framework, effectively enhancing sulfur utilization, suppressing polysulfide diffusion, and accelerating electrochemical reaction kinetics. As a result, the CeSe₂@TiSe₂-C coating significantly reduces charge transfer resistance to 28.0 Ω, compared to 56.6 Ω in control cells, leading to an initial discharge capacity of 1651 mAh g⁻¹ at 0.2 C. Under high sulfur loading (5 mg cm⁻²) and lean electrolyte conditions, the coated separators enable a stable capacity retention of 404 mAh g⁻¹ after 100 cycles with nearly 100% Coulombic efficiency. |