Lithium–sulfur (Li–S) batteries possess excessive theoretical particular vitality however endure from lithium polysulfide (LiPS) shuttling and sluggish response kinetics. Catalysts in Li–S batteries are deemed as a cornerstone for bettering the sluggish kinetics and concurrently mitigating the LiPS shuttling. Herein, a cheap hexagonal close-packed (hcp)-phase Fe–Ni alloy is proven to function an environment friendly electrocatalyst to advertise the LiPS conversion response in Li–S batteries. Importantly, the electrocatalysis mechanisms of Fe–Ni towards LiPS conversion is totally revealed by coupling electrochemical outcomes and submit mortem transmission electron microscopy, X-ray photoelectron spectroscopy, and in situ X-ray diffraction characterization. Benefiting from the great catalytic property, the Fe–Ni alloy permits an extended lifespan (over 800 cycles) and excessive areal capability (6.1 mA h cm–2) Li–S batteries beneath lean electrolyte circumstances with a excessive sulfur loading of 6.four mg cm–2. Impressively, pouch cells fabricated with the Fe–Ni/S cathodes obtain secure biking efficiency beneath virtually mandatory circumstances with a low electrolyte/sulfur (E/S) ratio of four.5 μL mg–1. This work is anticipated to design extremely environment friendly, cost-effective electrocatalysts for high-performance Li–S batteries.