Enabling Efficient Polysulfide Conversion by Self‐Assembled Co‐CoP@MXene for Li‐S Batteries

Abstract Lithium‐sulfur (Li‐S) batteries exhibit substantial potential as next‐generation energy storage devices due to their high theoretical capacity (1675 mAh g − 1 ), low cost, and environmental friendliness. However, the practical application is hindered by the insulating nature of sulfur/lithium sulfide (Li 2 S) and the polysulfide shuttle effect. Herein, hollow‐structured Co‐CoP (Co‐CoP@HNC)and intercalated is successfully fabricated it into the interlayer spacing of 2D MXene(MX) nanosheets (Co‐CoP@MX) to modify the separator for Li‐S batteries. The Co‐CoP@HNC intercalation expands the MX interlayer spacing, facilitating lithium ions (Li + ) transport, while the polar Co‐CoP@HNC acts as a catalytic center to accelerate polysulfide conversion. In addition, the built‐in electric field (BIEF) between Co and CoP drives the directional transfer of adsorbed polysulfides from the CoP (strong adsorption) to the Co (high catalytic activity), thereby accelerating their conversion. Therefore, the battery with the Co‐CoP@MX modified separator exhibits an initial capacity of 1356.77 mAh g −1 at 0.2 C, maintains 979.77 mAh g −1 at 1 C with a minimal capacity decay rate of 0.078% per cycle in 500 cycles, and achieves a high initial capacity of 751.08 mAh g −1 under high sulfur loading of 8.36 mg cm −2 .