Freestanding Bamboo‐Like Nitrogen‐Doped Carbon Nanofibers/PANI Dual‐Conductive Cathodes via Interfacial Engineering for High‐Performance Lithium–Sulfur Batteries

ABSTRACT Lithium–sulfur (Li–S) batteries are fascinating next‐generation energy storage devices because of their high energy density, but they face problems such as polysulfide (LiPS) shuttling and sluggish reaction kinetics. Herein, a freestanding film consisting of ultralong bamboo‐like nitrogen‐doped carbon nanofibers (BNCFs) is developed using melamine as a raw material and aluminum foil as a catalyst to form Al ₄ C ₃ nanoparticles via a vapor‐liquid‐solid growth process at high temperature. Subsequently, the BNCFs are combined with sulfur and in situ coated with polyaniline (PANI) to form a freestanding binder‐free cathode (BNCFs/S/PANI). The freestanding and binder‐free BNCFs film creates orderly channels for polysulfide adsorption, volume buffering, and efficient Li ⁺ /electron transport. The PANI coating chemically connects LiPSs, enhances uniform lithium deposition, and elevates redox activity via its quinonediimine and phenylenediamine units. This synergistic effect endows the cathode with superior cycling stability, leading to a minimal capacity decay rate of merely 0.047% per cycle over 500 cycles at 1.0 A g ⁻¹ . This research presents a new cathode design for high‐energy‐density Li–S batteries.