Physico-Chemical Properties of NaV(3)O(8) Prepared by Solid-State Reaction

Sodium–vanadium oxide NaV(3)O(8) is synthesized via solid-state method and optimum synthesis conditions are chosen based on the data of DSC and TG analysis. The material synthesized is characterized by X-ray phase analysis, Raman spectroscopy and scanning electron microscopy. The ratio V(4+)/V(5+) in the sample obtained is determined by X-ray photoelectron spectroscopy. Conductivity of the material synthesized was measured by impedance spectroscopy, pulse potentiometry and DC method over the range RT–570 °C. It is shown that NaV(3)O(8) has rather high conductivity essentially electron in type (6.3 × 10(−2) at room temperature). AC and DC conductivity measurements are performed and cycling of symmetricNaV(3)O(8)|Na(3.85)Zr(1.85)Nb(0.15)Si(3)O(12)|NaV(3)O(8) cell in galvanostatic conditions. Thermal stability is studied across 25–570 °C temperature range. The results obtained are compared with the properties of NaV(3)O(8) produced via aqueous solution.