Li₇P₃S₁₁/poly(ethylene oxide) hybrid solid electrolytes with excellent interfacial compatibility for all-solid-state batteries

Low ionic conductivity and poor interfacial compatibility between lithium electrodes and Li₇P₃S₁₁ sulfide solid electrolytes are the greatest challenges for all-solid state lithium-sulfur batteries. Herein, we introduce a hybrid solid electrolyte with Li₇P₃S₁₁ being wrapped with polyethylene oxide-LiClO₄ (PEO-LiClO₄). As served as conductive bridge between Li₇P₃S₁₁ particles, PEO-LiClO₄ would provide Li⁺ transition paths between Li₇P₃S₁₁ particles, thus successfully improve its ionic conductivity. Moreover, the polymer layer of PEO-LiClO₄ can isolate lithium metal and Li₇P₃S₁₁ solid electrolyte, suppressing the reaction between lithium electrode and Li₇P₃S₁₁ electrolyte. Therefore, hybrid solid electrolyte Li₇P₃S₁₁-PEO-LiClO₄ shows excellent interfacial compatibility with lithium foil. Lithium-sulfur battery with the hybrid electrolyte Li₇P₃S₁₁-PEO-LiClO₄ exhibits much improved electrochemical performance with better cycling stability and higher Coulombic efficiency.