2,5-Dimercapto-1,3,4-thiadiazole-modified gel electrolyte for reduced shuttle effect and enhanced redox kinetics of lithium-sulfur batteries

The safety risks of liquid electrolyte leakage in conventional batteries have prompted intensive research on solid electrolytes for enhanced safety and energy density. Here, we report a novel PVDF gel electrolyte (GE) by incorporating 2,5-dimercapto-1,3,4-thiadiazole (DMcT). By virtue of the active thiol groups (S-H), DMcT can function as a difunctional mediator to suppress the shuttle effect and accelerate the redox kinetics of Li-S batteries, thereby enabling boosted rate performances and enhanced cycling stability of Li-S batteries. At 1C, the Li-S battery retains 180.5 mA h g^-1, outperforming control cells. At 0.5C, it exhibits an ultralow decay rate (0.13% per cycle) with 99% coulombic efficiency. This work presents a novel strategy to address the shuttle effect and improve the rate performance in gel electrolyte Li-S batteries, paving the way for safer high-energy battery systems.