FeCoNiCuPt High‐Entropy Alloy as a Robust Catalytic Shield Against Polysulfide Shuttling in Li–S Batteries

ABSTRACT Efficient catalytic materials are vital for addressing the polysulfide shuttle and sluggish redox kinetics in lithium–sulfur batteries. Herein, we report a facile sugar‐blowing method to prepare porous carbon‐supported FeCoNiCuPt high‐entropy alloy (HEA) nanospheres with abundant lattice defects in a single crystalline phase. The multiple constituent metals endow the HEA catalyst with moderate polysulfide adsorption and enhanced catalytic activity, which favors suppressing polysulfide migration, accelerating sulfur redox reactions, and reducing activation energies of Li 2 S oxidation. Consequently, the battery with HEA‐modified separator delivers a high initial capacity of 1429 mAh g −1 at 0.1C and maintains exceptional cycling stability at 0.5C. Remarkably, under a sulfur loading of 4.32 mg cm −2 , a superior capacity above 700 mAh g −1 is achieved after 60 cycles. Density functional theory calculations confirm the strong binding of polysulfides on the HEA surface and the reduced conversion barriers. This work establishes HEAs as a robust catalytic shield to effectively address polysulfide adsorption‐conversion.