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

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.