Understanding the effects of binder dissolution dynamics on the chemistry and performance of lithium–sulfur batteries

Abstract

Lithium–sulfur batteries (LSBs) are promising next-generation energy storage devices due to their higher theoretical specific energy and lower cost compared to conventional Lithium-ion batteries. However, their practical implementation has been hindered by severe performance degradation during extended cycling, primarily driven by shuttling of soluble sulfur discharge products (polysulfides) between the cathode and anode leading to capacity loss. In this work, we investigate the impact of selected binders and solvents, highlighting the effect of the dissolution process of the binder in solvent, on the structural properties and electrochemical performance of sulfur cathode. It is demonstrated for a variety of binders that tailoring the dissolution process of binders within solvents can result in a specific binder morphology around sulfur particles that aids in trapping the polysulfides, controlling the shuttling phenomenon. The best combination of binder and solvent with optimized dissolution process results in outstanding capacity retention of 84% retention over 1000 cycles at C/10.