Nitrogen doped sulfide solid electrolytes with enhanced air stability and lithium metal compatibility

Abstract

Compared with oxide, halide, and polymer‐based solid electrolytes, Li‐ion conducting sulfide solid electrolytes exhibit remarkable ionic conductivity, electronic conductivity, and exceptional thermal and mechanical properties. Despite these advantages, the susceptibility of sulfide electrolytes to air and the formation of lithium dendrites on the anode hinder their large‐scale commercial application. In this study, we propose a doping strategy involving the nitrogen (N) element in sulfide electrolyte Li5.5PS4.5Cl1.5 (LPSCl) with inherently high ionic conductivity. We have successfully synthesized Li5.5+xPS4.5−xNxCl1.5(x = .025, .05, .07, .10) solid electrolytes by enhancing their air stability through doping. The modified electrolyte material demonstrates stable cycling performance exhibiting superior air stability compared to Li5.5PS4.5Cl1.5. The results indicate that the doped sulfide solid electrolyte effectively suppresses the growth of lithium dendrites, thereby enhancing the compatibility between the lithium metal anode and sulfide solid electrolyte.