Na10SnSb2S12: A nanosized air-stable solid electrolyte for all-solid-state sodium batteries

• Na 10 SnSb 2 S 12 with nanoscale particle size is synthetized by liquid phase process. • Na 10 SnSb 2 S 12 shows ion conductivity of 0.52 mS cm −1 . • Excellent air stability is achieved by replacing phosphorus with antimony. • All-solid-state sodium batteries display excellent cycling stability and rate capability. All-solid-state sodium batteries are attractive for large-scale energy storage due to their low cost, wide variety of cathode materials and high safety. And sulfide sodium solid electrolytes are key to enable room-temperature all-solid-state sodium batteries. Herein, we report the quaternary nanosized solid electrolyte Na 10 SnSb 2 S 12 synthetized through liquid phase process. The crystalline structure and diffusion path of Na 10 SnSb 2 S 12 are investigated through the first principles calculations. The Na 10 SnSb 2 S 12 electrolyte presents a room temperature conductivity of 0.52 mS cm −1 at 25 °C and very low activation energy of 0.23 eV as well as excellent air stability by replacing phosphorus with antimony. Moreover, the small particle size of the solid electrolytes enhances the contact between solid electrolyte and electrode, reducing the interfacial contact resistance. Consequently, the TiS 2 /Na 10 SnSb 2 S 12 /Na all-solid-state sodium batteries show excellent cycling stability and exhibit a capacity of 119.6 mAh g −1 after cycling for 100 cycles at 100 mA g −1 .