Tungsten and Boron Codoping toward High Ionic Conductivity and Stable Sodium Solid Electrolyte for All-Solid-State Sodium Batteries
Lan Wang, Gaozhan Liu, Yunming Li, Wei Weng, Xing Xin, Xiayin Yao
Abstract
Sodium solid electrolytes with high ionic conductivity and good interfacial stability with sodium metal are crucial to realize high-performance all-solid-state sodium batteries. In this work, W and B-codoped Na 3 Sb 1– x W x S 4– x B x solid electrolytes are prepared by melt-quenching with further annealing. The synthesized Na 3 Sb 0.95 W 0.05 S 3.95 B 0.05 solid electrolyte possesses a high ionic conductivity of 11.06 mS cm –1 under 25 °C and shows significantly improved interface compatibility with metal sodium. Specifically, Na/Na 3 Sb 0.95 W 0.05 S 3.95 B 0.05 /Na symmetric cell can stable cycle for 500 h under a current density of 0.05 mA cm –2 . In addition, the resultant TiS 2 /Na 3 Sb 0.95 W 0.05 S 3.95 B 0.05 /Na battery exhibits an initial charge capacity of 164.1 mAh g –1 at 0.1 C with a capacity retention of 76.4% after 100 cycles. This work provides a new strategy to realize the high ionic conductivity of sodium solid electrolytes with improved interfacial stability with sodium anode.