Realizing Li-S Batteries with Efficient Polysulfide Trapping and Conversion by using a High-Nitrogen-Content-Doped Fe-N-C Porous Carbon Nanosheet-Modified Separator

Lithium-sulfur (Li-S) batteries with high theoretical energy density have earned much attention in recent years. Nevertheless, the shuttle effect and tardy conversion of polysulfides severely hinder their practical applications. Herein, the high-nitrogen-doped Fe-N-C porous carbon nanosheets (denoted as AT-Fe-N-C-Me) were synthesized and coated on separator as an effective electrocatalyst for Li-S batteries. Benefiting from the hierarchical porous carbon structure and rich Fe-N-x catalytic sites, the AT-Fe-N-C-Me coating layer can effectively suppress the polysulfides shuttling and promote their redox conversion simultaneously. As a result, the Li-S batteries with AT-Fe-N-C-Me modified separators deliver superior rate capability (785.5 mAh g(-1) at 4.0 C) and cycling stability (capacity decay rate of 0.065 % per cycle over 1000 cycles at 1.0 C). This work provides a new strategy to design efficient electrocatalyst with high-surface-area porous structure for high-performance Li-S batteries.