Development of Sodium–Ion Conducting Sulfide Electrolytes

All-solid-state sodium batteries are promising rechargeable batteries owing to their safety, cost effectiveness, long cycle life, and high gravimetric energy density. To realize these batteries, a key material is a sodium-ion-conducting solid electrolyte with high Na + ion conductivity, appropriate mechanical properties, and moderate chemical and electrochemical properties. Sulfide electrolytes are currently the best choice for balancing these requirements. Na3PS4 and Na3BS3 glass-based electrolytes and W-doped Na3SbS4 crystalline electrolytes with high capacities and long cycle lives were developed for application in all-solid-state Na/S batteries.