Edge-selective nitrogen engineering of carbon nanofibers by dye-induced self-etching for enhanced polysulfide adsorption and conversion in Li–S batteries

Lithium–sulfur (Li–S) batteries are regarded as candidates for next-generation batteries attributed to low cost of sulfur resources and high energy density. Despite these advantages, their practical implementation is hampered by intrinsically insulating sulfur property, slow redox kinetics, and migration of dissolved lithium polysulfides (LiPSs), inducing rapid capacity fading. Herein, we report edge-N-enriched carbon nanofibers (EN-CNFs) enabled by a dye-induced selective etching strategy. The use of tartrazine enables in-situ chemical etching during thermal treatment, generating abundant defect and edge sites that promote selective formation of pyridinic and pyrrolic nitrogen while suppressing graphitic nitrogen. Notably, this approach allows decoupling of surface chemistry from bulk structural evolution, enabling selective enrichment of edge-type nitrogen without significantly alterin…