Ca-doped Na2Zn2TeO6 layered sodium conductor for all-solid-state sodium-ion batteries

Abstract Na 2 Zn 2 TeO 6 is a potential sodium solid electrolyte of all-solid-state sodium-ion batteries. In this work, Na + ion conductivity and electrochemical performance of layered Ca-doped Na 2 Zn 2- x Ca x TeO 6 ( x  = 0–0.05) (NZTO-C x ) electrolytes have been investigated. The highest conductivity has been achieved 7.54 × 10 −4  S cm −1 in NZTO-Cx at x  = 0.02, at room temperature due to grain-boundary modification and interlayer-interface elimination. Meanwhile, chemical stability with metallic Na anode and electrochemical window of NZTO-C x are improved by Ca doping. Furthermore, the cycle stability of Na 3 V 2 (PO 4 ) 3 /NZTO-C x /Na solid-state batteries have been successfully increased by Ca doping. These advantages highly demonstrate good potential application prospect of NZTO-C x in all-solid-state sodium-ion batteries.