High-performance lithium–sulfur batteries utilizing charged binder and solid-state ionogel electrolyte

Abstract

Lithium–sulfur (Li–S) batteries have garnered significant attention as next-generation energy storage devices owing to their eco-friendly nature and high theoretical energy density. However, the practical implementation of Li–S batteries faces several challenges, with the two primary issues being the shuttle effect caused by polysulfide dissolution and the slow reaction kinetics of sulfur. To address these challenges, we proposed the combination of a charged binder and a solid-state ionogel electrolyte. In this strategy, we employed charged poly(diallyldimethylammonium bis(trifluoromethylsulfonyl)imide) (PDDATFSI) as a binder to enhance the adsorption of polysulfides and facilitate the faster movement of lithium ions, thereby ensuring accelerated reaction kinetics. The ionogel further suppressed the shuttle effect owing to its low solubility in polysulfides, limited compatibility with the polymer host, and high viscosity. The resulting Li–S coin cells, using both the PDDATFSI binder and solid-state ionogel, exhibited a high initial discharge capacity of 1027 mAh/g at 0.1 °C, with superior discharge capacity retention exceeding 70% (750 mAh/g) after 100 cycles, maintaining 100% coulombic efficiency. Additionally, we successfully fabricated flexible pouch cells that powered a camp light and 100 LEDs in a bent state. These results highlight their significant potential as deformable and high-capacity energy storage devices in the future.

Graphic abstract

High-performance, flexible Lithium-sulfur (Li-S) batteries were fabricated using a charged binder and a solid-state ionogel electrolyte. Flexible Li-S cells successfully powered a camp light and 100 LEDs in a bent state, indicating their significant potential as next-generation, deformable, high-capacity energy storage devices.