Electrical and optical properties of Li3NbO4 material

Abstract

Rechargeable lithium batteries have rapidly risen to prominence as fundamental devices for green and sustainable energy development. They are now used as power sources for electric vehicles. However, material innovations are still needed to meet the growing demand for increasing the energy density of lithium batteries. This study explores new electrode materials, specifically Li₃NbO₄-based electrode for high-energy rechargeable lithium batteries.

Li3NbO4 ceramics has been prepared using the solid-state reaction method and sintered at approximately 1203 K. The materials were examined using X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), optical analysis and impedance spectroscopy. The X-ray powder diffraction (XRPD) data confirmed the formation of a single phase with a cubic type of structure. The compound's semiconductor characteristics were verified by the optical measurement, indicating a direct band-gap value of about 2.52 eV. Additionally, impedance spectroscopy was employed to investigate the properties of this material, across a frequency range of 10⁻¹ Hz–10⁶ Hz and at temperatures ranging from 443 K to 633 K. The frequency behavior of AC conductivity, σ_ac, was analyzed using the universal Jonscher law.

Charge transport studies indicated that Li3NbO4 adheres to the correlated barrier hopping (CBH) model. A correlation between ionic conductivity and crystal structure was discussed. The modulus analysis highlighted thermally activated relaxation processes, with high-frequency charge carrier movement across short distances and low-frequency movement across longer distances. highlighted thermally activated relaxation processes, with high-frequency charge carrier movement across short distances and low-frequency movement across longer distances.