Structural, morphological, and electric study of doped- Na2Zn2TeO6 family in a wide range of temperatures

SALGADO, R.; TERNY, S.; FRECHERO, M.A.

MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY

ELSEVIER SCIENCE BV

Año: 2025 vol. 312

0921-5107

Nowadays Sodium solid conductors are intensely studied to develop electrochemical energy storage devices toboost the development of sodium ion batteries. The Na2Zn2TeO6 (NZTO) has been stablished as a 2D Na-ionconductor with excellent performance at low temperature. In this work four doped-NZTO have been synthesized by solid state reaction. The metal cations incorporated were: Ba2+, Nb5+, Mo6+, W6+. Their structures werecharacterized by XRD as a function of the temperature, and the Rietveld and Le Bail refinement were applied.Also, the thermal stability was studied by DSC technique between − 40 ◦C to 400 ◦C. SEM, EDS and densitymeasurement complement the information on structural features. The electrical conductivity, studied byimpedance spectroscopy and DC polarization, confirmed that it is possible to minimize the inherent electronicconductivity and that the material?s best performance, as a pure sodium conductor, was achieved at low temperature Moreover, this technique confirmed that the presence of a reversible order/disorder transition of sodium ions /vacancies in the structure has an important effect on the total conductivity. Additionally, it wasanalyzed how to minimize the sodium loss during the sintering process to diminish the secondary phaseformation.