(337cd) Improving Interfacial Stability of Argyrodite Sulfide-Based Solid Electrolytes and Lithium Electrodes Via CO2 Treatment

Metal/ion Batteries, Catalysis Reaction, Materials Characterization

Abstract

Argyrodite sulfide-based solid electrolyte Li6PS5Cl (LPSC) exhibits promising potential for solid-state battery applications due to its comparable ion conductivity to liquid electrolytes. However, the interfacial instability between LPSC and Li during cycling, leading to battery polarization, remains a persistent issue. In this study, we demonstrate the significant role of CO2 adsorption in improving both interfacial and electrochemical stability between lithium and LPSC. By investigating the formation of the S-CO2 bond using various analytical techniques, we gain insights into modifying interfacial behavior and enhancing stability. The Li|CO2@LPSC|LTO system exhibits remarkable performance, with 62% capacity retention and an ultra-high coulombic efficiency of 99.91% after 1000 cycles. Interestingly, we extend this concept to the sulfide-based superionic conductor Li10GeP2S12 (LGPS) system, which shares the (PS4)3- moiety, and observe enhanced stability at the lithium and LGPS interface. This work opens new avenues for reducing interfacial resistance in sulfide-based solid electrolytes, thereby increasing the potential for sulfide-based all-solid-state lithium metal batteries.