Exploring thermally stable dielectric and energy storage response of Bi-based ceramics for renewable energy storage applications

Abstract

Renewable energy is accelerating rapidly, driven by the urgent need to mitigate environmental depletion, which has intensified the demand to produce environment-friendly perovskite materials. Among the promising candidates, undoped bismuth sodium titanate-strontium titanate 0.74Bi_0.5Na_0.5TiO₃–0.26SrTiO₃ (BNST) ceramics and niobium-doped BNST (BNST–Nb) ceramics have emerged as innovative materials that were prepared using mixed oxide solid-state synthesis. The X-ray diffraction (XRD) confirmed the phase structure of BNST–Nb, while the dense microstructure with equiaxed grain size was confirmed by scanning electron microscopy (SEM). The electrochemical impedance spectroscopy (EIS) confirmed that electrical microstructure explained the grain and grain boundary contribution. Increasing temperature, with increased Nb content in BNST, predicts a dielectric constant (ε_r ̴ 3000), and curie temperature (T_c ̴ 250 ℃) for 0.5% Nb. It has an energy density (W) of 0.6 J/cm³ and an efficiency (η) of 93% was observed. Niobium-doped BNST ceramics have specific benefits over other materials, especially for high-temperature applications at 500 ℃. Unlike many typical ceramics, which deteriorate at high temperatures, BNST-Nb retains and even improves its dielectric characteristics. The investigation of charge conduction and polarization at high temperatures yields novel insights, making BNST–Nb a viable material for advanced thermal and electrical applications.