Regulating p‐Band Center of Sulfur in Li‐Argyrodite to Stabilize Dual Solid–Solid Interface for Robust All‐Solid‐State Lithium–Sulfur Battery

Abstract All‐solid‐state lithium‐sulfur batteries (ASSLSBs) are garnering significant interest due to their high energy density and safety. Nevertheless, the interfacial instability, particularly with sulfide‐based solid electrolytes, poses a formidable challenge to their widespread application. Herein, to adjust the p‐band center of the tetrahedron in Li₆PS₅Cl is proposed to alleviate undesirable reactions at anode and cathode interfaces via facile Sb/O co‐doping. The incorporation of Sb into Li₆PS₅Cl forms an SbS₄ tetrahedron, resulting in the downward shift of the S‐p band center. This benefits the acquisition of electrons from Li to in situ forming stable Li_xSb_yS_z interphase at the Li/LPSC‐SbO interface. The Li symmetric cell endows a high stability for over 4000 h. Moreover, the lower p‐band center of the S‐p band also strengthens the interaction of the SbS₄ tetrahedron with surrounding Li atoms, impeding charge transfer to S₈ and mitigating interfacial side reactions on the sulfur cathode. Additionally, O doping enhances the air stability of the electrolyte. The ASSLSBs with LPSC‐SbO achieve a high specific capacity of 932.6 mAh g⁻¹ at 0.1 C with 83.7% capacity retention over 150 cycles. Furthermore, the practical all‐solid‐state pouch cell demonstrates stable cycling performance and anticipated safety. This work provides insights into constructing stable dual solid–solid interfaces for sulfide‐based room‐temperature high‐performance ASSLSBs.