Novel 2D Sb₂S₃ Nanosheet/CNT Coupling Layer for Exceptional Polysulfide Recycling Performance

2D layer-structured materials are considered a promising candidate as a coupling material in lithium sulfur batteries (LSBs) due to their high surface-volume ratio and abundant active binding sites, which can efficiently mitigate shuttling of soluble polysulfides. Herein, an electrochemical Li intercalation and exfoliation strategy is used to prepare 2D Sb₂S₃ nanosheets (SSNSs), which are incorporated onto a separator in LSBs as a new 2D coupling material for the first time. The cells containing a rationally designed separator which is coated with an SSNS/carbon nanotube (CNT) coupling layer deliver a much improved specific capacity with a remarkable 0.05% decay rate for over 200 cycles at a current density of 2 C. The capability of the SSNSs to entrap polysulfides through their favorable interfacial functionality and the high electrical conductivity of the CNT network facilitates recycling of active materials. The first-principle calculations verify the important roles of SSNSs, which demonstrate ideal binding strengths (1.33–2.14 eV) to entrap Li₂S_x as well as a low-energy barrier (189 meV) for Li diffusion. These findings offer new insights into discovering novel coupling layers for high-performance LSBs and shed new light on the application of 2D layer-structured materials in energy storage systems.