Lithium-Cation Conductivity of Solid Solutions in Li6-xZr2-xAxO7 (A = Nb, Ta) Systems

Georgiy Sh Shekhtman; Anastasia V Kalashnova; Boris D Antonov

doi:10.3390/ma14226904

Lithium-Cation Conductivity of Solid Solutions in Li_6-xZr_2-xA_xO₇ (A = Nb, Ta) Systems

Materials (Basel). 2021 Nov 16;14(22):6904. doi: 10.3390/ma14226904.

Authors

Georgiy Sh Shekhtman¹, Anastasia V Kalashnova¹, Boris D Antonov¹

Affiliation

¹ Institute of High Temperature Electrochemistry, Ural Branch, Russian Academy of Sciences, 20 Akademicheskaya St., 620990 Ekaterinburg, Russia.

Abstract

Li_6-xZr_2-xAxO₇ (A = Nb; Ta) system with 0 < x < 0.30 is synthesized by glycine-nitrate method. Boundaries of solid solutions based on monoclinic Li₆Zr₂O₇ are determined; temperature (200-600 °C) and concentration dependences of conductivity are investigated. It is shown that monoclinic Li₆Zr₂O₇ exhibits better transport properties compared to its triclinic modification. Li_5.8Zr_1.8Nb(Ta)_0.2O₇ solid solutions have a higher lithium-cation conductivity at 300 °C compared to solid electrolytes based on other lithium zirconates due the "open" structure of monoclinic Li₆Zr₂O₇ and a high solubility of the doping cations.

Keywords: crystal structure; glycine-nitrate synthesis; heterovalent doping; lithium cation conductivity; lithium zirconates; solid electrolytes.