Stable cycling of lithium-sulfur battery enabled by a reliable gel polymer electrolyte rich in ester groups

Gel polymer electrolyte (GPE) is promising to accomplish high energy density and high safe lithium-sulfur (Li-S) batteries owing to their higher ionic conductivity than solid electrolyte and lower mobility than liquid electrolyte. Herein, a novel polyethylene (PE) separator supported GPE rich in ester groups was synthesized via in-situ polymerized pentaerythritol tetraacrylate (PETEA) with divinyladipate (Ester) on PE separator. This novel PE supported GPE (PEGPE) achieved a decent ionic conductivity of 2.8 × 10−4 S cm−1 at room temperature and exhibited a wide electrochemical window up to 4.75 V vs Li/Li+. The assembled Li-S battery using this novel PEGPE delivered better rate capability and cycling stability than liquid electrolyte. Our work presents a reliable and efficient GPE enabling high energy density and high safe Li-S batteries, which would boost the practical application of Li-S batteries.