A TiS2/Celgard separator as an efficient polysulfide shuttling inhibitor for high-performance lithium–sulfur batteries

Abstract

The rapid capacity loss caused by the shuttling effect of polysulfides is one of the great challenges of Li–S batteries. In this work, we adopted a simple solid-phase sintering method to synthesize titanium disulfide (TiS₂) and further demonstrated it as a superior modifier of separators for Li–S batteries. Two commonly adopted modification processes of separators, including vacuum filtration (VF) and slurry casting (SC) have been used to prepare TiS₂/Celgard separators. TiS₂-VF/Celgard can better restrain the polysulfide shuttling effect compared with TiS₂-SC/Celgard. A TiS₂-VF/Celgard-based Li–S battery has a reversible capacity of 771.6 mA h g⁻¹, with a capacity retention of 645.6 mA h g⁻¹ after 500 cycles at 2.0 C, corresponding to a capacity fading rate of ∼0.033% per cycle. This study has shown the potential of TiS₂ as a multifunctional modifier of separators for high performance and long cycle life Li–S batteries.