Solvent‐Free Dry‐Process Enabling High‐Areal Loading Selenium‐Doped SPAN Cathodes Toward Practical Lithium–Sulfur Batteries

Abstract In this study, a selenium‐doped sulfurized polyacrylonitrile (Se‐SPAN) cathode fabricated by a dry process with multi‐walled carbon nanotubes (MWCNT) and a polytetrafluoroethylene (PTFE) binder is proposed to address issues in currently developed dry‐processed cathodes. The dry‐processed Se‐SPAN (D/Se‐SPAN) is characterized by a dense, robust, and uniform structure that successfully resists the internal stress evolution caused by significant volume variations of the Se‐SPAN under high‐loading conditions. Understanding these architectural advantages in D/Se‐SPAN, the unrivaled potential of D/Se‐SPAN compared with traditional slurry‐processed Se‐SPAN cathodes (S/Se‐SPAN) is established through a series of in‐depth electrochemical‐mechanical investigations. As a result, the D/Se‐SPAN recorded ≈31.8 mAh cm −2 of reversible areal capacities under ultra‐high‐loading conditions (64.2 mg Se‐SPAN cm −2 ) and exhibited remarkable cycle stability. Based on this study, vital design guidelines are provided for developing high‐loading S‐based dry cathodes crucial for realizing cost‐effective and eco‐friendly battery production.