Solid polymer electrolytes from double-comb Poly(methylhydrosiloxane) based on quaternary ammonium moiety-containing crosslinking system for Li/S battery

The synthesis, characterization, and electrochemical cell performance of a double-comb poly (siloxane) solid polymer electrolyte (SPE) for Li-S battery application is reported. The SPE is designed with different degrees of chemical crosslinking via quaternary ammonium moieties. The chemical crosslinking enhanced dimensional stability and quaternization raised the dielectric constant of SPE. The SPE with 3% crosslinking ratio shows the highest Li⁺ ion conductivity of 6.6 × 10^-4 Scm^-1 at 30 °C. The electrochemical studies reveal a high specific capacity value of 1082 mAhg^-1 with good capacity retention over several cycles. The SPE demonstrate excellent performance in Li-S battery even with high sulfur loading and varied electrochemical stability with good lithium plating/stripping performance.