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

Na2Zn2TeO6 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 Na2Zn2-xCaxTeO6 (x = 0-0.05) (NZTO-Cx) electrolytes have been investigated. The highest conductivity has been achieved 7.54 x 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-Cx are improved by Ca doping. Furthermore, the cycle stability of Na3V2(PO4)(3)/NZTO-Cx/Na solid-state batteries have been successfully increased by Ca doping. These advantages highly demonstrate good potential application prospect of NZTO-Cx in all-solid-state sodium-ion batteries. (C) 2018 Published by Elsevier Ltd.