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

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 Na10SnSb2S12 synthetized through liquid phase process. The crystalline structure and diffusion path of Na10SnSb2S12 are investigated through the first principles calculations. The Na10SnSb2S12 electrolyte presents a room temperature conductivity of 0.52 mS cm(-1) at 25 degrees 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 TiS2/Na10SnSb2S12/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).

Automated summary

All-solid-state sodium batteries are promising for large-scale energy storage due to their low cost, wide variety of cathode materials and high safety, with sulfide sodium solid electrolytes playing a key role in enabling room-temperature operation. The quaternary nanosized solid electrolyte Na10SnSb2S12 synthesized through a liquid phase process exhibits high room-temperature conductivity, low activation energy, and excellent air stability by replacing phosphorus with antimony. The small particle size of the solid electrolytes enhances contact between the electrolyte and electrode, reducing interfacial contact resistance and leading to excellent cycling stability and high capacity in TiS2/Na10SnSb2S12/Na all-solid-state sodium batteries.