Advanced Separator Engineering with MOF and Carbon Nanofiber Cathode for Suppressed Polysulfide Shuttling in Li-S...

Lithium-sulfur (Li-S) batteries offer high theoretical energy density but are limited by the lithium polysulfide (LiPS) shuttle effect, sluggish redox kinetics, and large volume changes during cycling. A dual-functional strategy is presented using an indium-doped copper-cobalt metal-organic framework (In-doped CuCoMOF) modified separator and a heteroatom-doped Co nanoparticle-embedded porous carbon nanofiber (Co@PCNF) cathode. The In-doped CuCoMOF on the Celgard separator improves lithium-ion transport and suppresses LiPS migration through strong chemical adsorption and catalytic conversion. The Co@PCNF cathode provides a conductive porous structure that accommodates volume variation, enhances sulfur utilization, and maintains electrode stability. The synergistic combination accelerates sulfur redox reactions and improves electrochemical performance. The assembled Li-S battery delivers a high specific capacity of 1145 mAh g^-1 at 1 C and retains 1100 mAh g^-1 after 500 cycles. A high areal capacity of 6.45 mAh cm^-2 is achieved at a sulfur loading of 5.5 mg cm^-2 under lean electrolyte conditions. This work demonstrates an effective and scalable approach for designing advanced separators and cathodes for high-performance Li-S batteries.