Bimetallic Sulfides Heterostructure Efficient Adsorption and Catalytic of Polysulfides for High-Performance Lithium-Sulfur Batteries

The large-scale commercial application of lithium-sulfur (Li-S) batteries is severely impacted by the sluggish reaction kinetics of polysulfides conversion and the low utilization rate of active substances. It has been proved that the introduction of functional interlayers between electrodes is an effective method to inhibit the shuttle effect of lithium polysulfides (LiPSs). Herein, FeS2-MnS heterostructure is combined with carbon materials and applied to Li-S batteries through the modifying commercial separator to accelerate the redox kinetics of LiPSs. The FeS2-MnS/C//PP modified separators achieve the chemical catalysis, adsorption, and physical confinement of LiPSs through well-dispersed FeS2-MnS heterostructure and carbon materials. Compared with single-metal sulfides, the FeS2-MnS heterostructure can considerably enhance the catalysis interface effect, rapidly adsorb and promote the conversion of LiPSs. As a result, the cell with FeS2-MnS/C//PP separator displays remarkable cyclic stability (768 mAh/g at 1.0C after 500cycles with a low capacity decay of merely 0.036% per cycle) and outstanding rate capacity (660 mAh/g at 5.0C). This work provides a reference for the use of heterostructure materials as separator modifiers for Li-S batteries.