Sandwiched Cathodes Assembled from CoS₂ -Modified Carbon Clothes for High-Performance Lithium-Sulfur Batteries

Structural design of advanced cathodes is a promising strategy to suppress the shuttle effect for lithium-sulfur batteries (LSBs). In this work, the carbon cloth covered with CoS₂ nanoparticles (CC-CoS₂ ) is prepared to function as both three-dimensional (3D) current collector and physicochemical barrier to retard migration of soluble lithium polysulfides. On the one hand, the CC-CoS₂ film works as a robust 3D current collector and host with high conductivity, high sulfur loading, and high capability of capturing polysulfides. On the other hand, the 3D porous CC-CoS₂ film serves as a multifunctional interlayer that exhibits efficient physical blocking, strong chemisorption, and fast catalytic redox reaction kinetics toward soluble polysulfides. Consequently, the Al@S/AB@CC-CoS₂ cell with a sulfur loading of 1.2 mg cm^-2 exhibits a high rate capability (≈823 mAh g^-1 at 4 C) and delivers excellent capacity retention (a decay of ≈0.021% per cycle for 1000 cycles at 4 C). Moreover, the sandwiched cathode of CC-CoS₂ @S/AB@CC-CoS₂ is designed for high sulfur loading LSBs. The CC-CoS₂ @S/AB@CC-CoS₂ cells with sulfur loadings of 4.2 and 6.1 mg cm^-2 deliver high reversible capacities of 1106 and 885 mAh g^-1 , respectively, after 100 cycles at 0.2 C. The outstanding electrochemical performance is attributed to the sandwiched structure with active catalytic component.