Polyaniline-Coated Cobalt-Iron Oxide Composites Modified Separator for High Performance Lithium-Sulfur Batteries

Lithium-sulfur (Li-S) batteries have a supreme theoretical energy density, which makes them a promising candidate for energy storage. However, the persistent challenge of polysulfide dissolution hinders their extensive adoption. In this study, we developed polyaniline-coated cobalt-iron oxide composites (CFOP) to embellish separators for Li-S batteries via a straightforward calcination, followed by an in situ oxidation polymerization technique. Owing to the synergistic impact of bimetallic oxides and PANi coating, the CFOP-modified separator exhibited improved electrical conductivity and polysulfide adsorption capabilities. At 0.1 C, the sulfur cathode with CFOP modified separator showed a high discharge capacity of 1489.4 mAh<middle dot>g(-1). For the electrode with high sulfur loading (>3 mg<middle dot>cm(-2)), it delivered an incipient capacity of 810.9 mAh<middle dot>g(-1) and sustained 498.1 mAh<middle dot>g(-1) after long cycles (300 cycles at 0.5 C). In summary, the CFOP-modified separator successfully mitigated polysulfide shuttling, leading to enhanced electrochemical performance. This research offers valuable views into Li-S battery separator modification.