Boosting Solid–Solid Conversion Kinetics via Electron‐Pinned Interface Engineering for High‐Energy‐Density Li‐S Batteries

Abstract

ABSTRACT The pursuit of high‐energy‐density lithium–sulfur (Li–S) batteries necessitates the use of lean electrolyte conditions. However, this goal is severely hampered by the sluggish kinetics of the sulfur reduction reaction (SRR), especially in the “solid–solid” conversion stage, where each step requires distinct active sites with specific electron‐donating capabilities. Herein, we report a catalyst architecture that integrates “long‐range order” with “local disorder”, creating gradient‐ordered active sites through amorphous nanodomain modification and precise local electronic structure regulation. This catalyst, termed an electron‐pinned interface catalyst (EPIC) and denoted as a ‐FeOOH@Fe/AlO x , exhibits synergistic catalytic enhancement via multi‐level electronic interactions. Operando studies and DFT simulations reveal that the catalyst establishes conductive pathways facilitated by its gradient electron‐donating properties, thereby decoupling the SRR process and significantly enhancing the “solid–solid” conversion efficiency. Under lean electrolyte conditions, this catalyst achieves a high areal capacity of 10.7 mAh·cm −2 at a sulfur loading of 10.2 mg·cm −2 , exhibits 94.2% capacity retention after 150 cycles in a pouch cell, and enables stable operation of a 3.6 Ah pouch cell with an energy density of 418.6 Wh·kg −1 . This strategy effectively overcomes the reaction kinetic limitations in lean electrolyte conditions, providing valuable insights and a novel design paradigm for future high‐energy‐density Li–S batteries.