Fe3C-Decorated Folic Acid-Derived Graphene-like Carbon-Modified Separator as a Polysulfide Barrier for High-Performance Lithium-Sulfur Batteries

The lithium-sulfur (Li-S) battery has been regarded as an important candidate for the next-generation energy storage system due to its high theoretical capacity (1675 mAh g−1) and density (2600 Wh kg−1). However, shuttle effect of polysulfide seriously affects cycling stability Li-S battery. Here, a novel Fe3C-decorated folic acid-derived graphene-like N-doped carbon sheet (Fe3C@N-CS) was successfully prepared catalyst modify separator batteries. porous layered structures can capture physical barrier encapsulated Fe3C effectively trap catalyze conversion polysulfide, thus accelerating redox reaction kinetics. Together with highly conductive networks, cell Fe3C@N-CS-modified evinces superior 0.06% decay per cycle at 1 C rate over 500 cycles excellent specific initial 1260 g−1 0.2 C. Furthermore, sulfur loading 4.0 mg cm−2, batteries also express superb performance.