The polysulfide shuttle effect is a significant challenge for the operation of lithium-sulfur batteries, causing the battery’s overall performance and capacity to decrease over time. In the present study, we exploited random copolymer single ion conductors (XPEGMA-Li) combined with TEGDME (tetraethylene glycol dimethyl ether, G4) as quasi-solid polymer electrolytes. The PEGMA backbone provides the electrolyte’s mechanical robustness, while the crosslinker PEGDMA offers further elasticity to prevent the volume expansion of the sulfur particles. The single ion conductor XPEGMA-Li was expected to impair sulfide dissolution during cycling significantly. At the same time, the XPEGMA-Li affords a sufficiently high ionic conductivity of 0.06 (25°C) and 0.23 mS cm-1 (60°C), respectively, rendering it suitable for various electrochemical storage devices. The limiting current density of XPEGMA-Li exceeds values of 1.2 mAh cm-1, indicating robust interfaces with Lithium metal anodes. After 100 cycles, the cycling performance shows a more stable capacity retention (83.1%) than the liquid electrolyte and pristine G4 oligomer reference cells. This study suggests that cycling-induced volume change can cause S particle pulverization, which can be prevented by in-situ polymerization. Significantly, the XPEGMALi quasi-solid enables efficient charge transfer at the sulfur particles interface, ensuring the reversibility of the polysulfides is not hindered. This observation manifests that the contact loss of sulfur particles and dissolution of polysulfide shuttle into the electrolyte is successfully mitigated, allowing for future fabrication of high energy density Li-S batteries.