Zn–V-MOF-Derived Hierarchical Zn3V2O8 Modified Separator for Synergistic Polysulfide Trapping and Catalytic Conversion in High-Energy Lithium–Sulfur Batteries

Lithium–sulfur batteries (LSBs) are recognized as promising candidates for next-generation high-energy-density energy storage technologies due to their exceptionally high theoretical energy density (2600 Wh kg –1 ), low cost, and environmental sustainability. However, several challenges, including the polysulfide(LiPS) shuttle effect, the low conductivity of the sulfur cathode, and lithium dendrite growth, have significantly impeded their practical application. In this research, we developed a hierarchical porous Zn 3 V 2 O 8 (ZVO) modified separator through the high-temperature calcination of a Zn–V-MOF precursor to effectively mitigate LiPS shuttle effects via a dual mechanism. The porous architecture of ZVO facilitates efficient adsorption and rapid conversion of polysulfides through both physical confinement and catalytic activity arising from vanadium’s multivalent states. Additionally, the nitrogen-doped carbon network enhances electrode conductivity while strengthening polysulfide anchoring. The performance of the ZVO-modified separator reveals an initial discharge capacity of 882.9 mAh g –1 at 0.5C with a sulfur loading of 2.8 mg cm –2, demonstrating retention at 541.2 mAh g –1 after 500 cycles-yielding a capacity retention rate of 61.3%. Notably, under commercially viable conditions (5 mg cm –2 sulfur loading and 0.1C), the battery exhibits stable cycling performance, underscoring the potential applicability of ZVO-based separators in practical high-energy-density LSB systems.