High ionic conductivity and UV blocking in nanosized Li3 (1−x)Na3x VO4 superionic conductors

Abstract

The effect of alkali metal doping on the electrical conductivity of Li3(1−x)Na3x VO4 (x = 0.0, 0.2, 0.4 and 0.6) is the axiom of this paper. The samples are synthesized using the conventional solid-state reaction technique. The X-ray diffraction results show the polycrystalline behavior of alkali-doped lithium vanadate (Li3VO4). It was also observed that sodium (Na+) ions have not shown their presence in the diffraction pattern, which indicates that alkali metal ions were well substituted in the interstitials and did not disturb the crystal planes of the lithium vanadate matrix. The X-ray diffraction studies also suggest an increment in the crystallite size of the prepared samples. The optical study shows excellent absorbance in UV range (200–300 nm) and also that with an increase in the alkali-doping concentration, shifts absorbance peaks slightly toward higher wavelengths, suggesting enhancement in the particle size. In these alkali-doped samples, it was observed that ionic conductivity decreases, and conversely, the dielectric constant and loss tangent increase subsequently with an increase in the sodium doping concentration due to the ionic radius of the dopant metal. High ionic conductivity within the range 1.1374 × 102–7.9326 × 100 Ω−1 m−1 (99.98% of total conductivity) is obtained in superionic phase of the material. These materials can be utilized in field of capacitors, transparent battery and electrode for batteries.