A 3D network-structured gel polymer electrolyte with soluble starch for enhanced quasi-solid-state lithium-sulfur batteries

The polysulfide shuttling effect and safety concerns associated with liquid electrolytes impede the commercialization of lithium-sulfur (Li-S) batteries. We report a novel gel polymer electrolyte (GPE) denoted as "PTPHS" prepared via facile ultraviolet polymerization of pentaerythritol tetrakis (3-mercaptopropionate) (PETT) and pentaerythritol tetraacrylate (PETEA) with poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) as the polymer matrix. Soluble starch (SST) is incorporated as an interacting filler to construct a 3D network structure with intermolecular hydrogen bonds. This unique architecture not only ensures high ionic conductivity and mechanical robustness but also effectively mitigates the polysulfide shuttling effect, thereby improving cycling stability. The PTPHS-based Li-S cell exhibits stable cycling over 150 cycles at 0.2 C with 87.6 % capacity retention. This strategy provides insights into material development and structural design of GPEs for high-performance quasi-solid-state Li-S batteries.