Electrochemically Self‐Driven Interfacial Selenium Transfer Reshapes Sulfur Redox Pathway in Lithium–Sulfur Batteries

ABSTRACT Sulfur redox in lithium–sulfur (Li–S) batteries is governed by a multistep liquid–solid conversion network involving soluble polysulfide intermediates and continuously evolving solid–liquid interfaces. Here we identify an electrochemically self‐driven interfacial anion‐transfer process at a CoPSe‐based catalytic interface that reshapes sulfur redox pathway. During discharge, selenium released from the catalyst surface becomes incorporated into sulfur intermediates, redirecting sulfur reduction toward Se‐containing species that facilitate bond cleavage, favor shorter‐chain intermediates, and accelerate Li 2 S formation. Meanwhile, partial selenium extraction generates Se‐deficient catalytic sites with enhanced polysulfide affinity, promoting intermediate anchoring and liquid‐to‐solid conversion. Through this coupled evolution of sulfur species and catalytic sites, the interface operates in an operando adaptive mode rather than merely accelerating conventional polysulfide conversion. The resulting Li–S cells deliver 703 mAh g– 1 at 5 C with a capacity decay of 0.016% per cycle over 1,000 cycles at 2 C. This work establishes interfacial anion transfer as a route to pathway‐level sulfur‐redox regulation and adaptive catalyst evolution as a design principle for multistep electrochemical reactions.