A multi-functional separator for quasi-solid-state lithium-sulfur batteries: simultaneously driving in-situ polymerization and capturing polysulfides

• • Ionic conductivity of 7.2 × 10−4 S cm−1 at 30 °C enables efficient charge transport, matching liquid electrolyte performance while eliminating leakage risks. • • Electrochemical window up to 4.7 V allows compatibility with high-voltage cathodes, potentially increasing energy density by >20% compared to conventional 4.2 V systems. • • Lithium-ion transference number of 0.7 reduces concentration polarization, enabling stable cycling at 0.5 C with 613 mAh g−1 retention after 500 cycles (98.5% coulombic efficiency). • • Thermal stability up to 200 °C for MoS2/PP separator with GPE mitigates thermal runaway, a critical safety threshold for EV and grid storage applications.