Ionic‐Liquid‐Triggered Amorphization Engineers Symmetry‐Breaking <i>p</i> ‐Block Bismuth Oxides with Electric Dipole Domains for Practical Lithium‐Sulfur Batteries

Abstract

ABSTRACT The practical application of lithium‐sulfur batteries is severely hindered by the sluggish sulfur redox kinetics and the notorious lithium polysulfides (LiPSs) shuttle effect. Herein, we report a strategy utilizing an Fe‐based ionic liquid to trigger amorphization, engineering symmetry‐breaking p ‐block bismuth oxides on carbon nanofibers (CNFs) with electric dipole domains and asymmetric Fe 1 ‐O‐Bi electronic bridges (Fe 1 ⊂A/C‐Bi 2 O 3 @CNFs). The amorphous phase induces significant electronic delocalization, facilitating substantial orbital overlap and creating electron transport channels for rapid redox of LiPSs. Specifically, the asymmetric Fe 1 ‐O‐Bi electron bridges lower the p ‐band center through 3 d ‐2 p ‐6 p multi‐orbital coupling, optimizing the chemical adsorption of LiPSs and preventing active site poisoning. The electronic dipole domain functions as an electron/Li + “pump” to enhance charge transfer and Li + diffusion. In addition, the electric dipole domain induces dipole‐dipole interactions, facilitating Li─S bond polarization and cleavage. As a result, the Fe 1 ⊂A/C‐Bi 2 O 3 ‐based cell achieved a cyclability of 698 mAh g −1 at 1.0 C over 1000 cycles with a degradation rate of 0.026% per cycle, and a high areal capacity of 6.8 mAh cm −2 under a sulfur loading of 7.4 mg cm −2 . The strategy of constructing an electronic dipole domain through amorphization provides a new direction for the rational design of efficient catalysts for sulfur redox reactions.