In the present work, (Bi0.3Na0.3Ba0.06Sr0.34)(Ti1−xLax)O3 (abbreviated BNBSTLx); (x = 0.0, 0.05, and 0.075) ceramics have been developed to enhance their energy storage performance via cation disorder and entropy strategies. The configurational entropy (ΔSconfig) increased from 1.25R (medium entropy) to 1.51R (high entropy), while the tolerance factor (τ) decreased from 0.994 to 0.975 as La-content increased from 0.0 to 0.075. This indicated that the long-range order (LRO) of ferroelectricity in Bi0.5Na0.5TiO3 (BNT) ceramics was being disrupted and that the material was creeping to a high degree of relaxor phase. Fully dense microstructure in all the present ceramics evidenced by SEM imaging and adding La3+ led to reduction in grain size from 1.17 μm to 0.49 μm. Wide dispersion of permittivity peaks cross wide temperature range confirmed by elevation the diffusive coefficient (γ) to 1.86 at La = 0.075. Furthermore, the addition of La3+ causes increasing the resistance of grains and the maximum value was achieved at 0.075 resulting in highest value of activation energy (Ea). At increased entropy, the mismatch between grain resistance (Rg) and grain boundary (Rgb) was totally suppressed. This cascade effects reduce localized charge carriers and interfacial polarization at BBNSTL0.075, ultimately achieving superior energy storage efficiency (ƞ), and bolstered dielectric breakdown strength (DBS) (to 310 kV/cm). Ultimately, the specimen x = 0.075 exhibited excellent frequency and temperature stability of energy storage characteristics (recoverable energy density) Wrec) = 0.86 J/cm3, η = 84%) in the temperature range of 25–150 °C under 100 kV/cm. This research presents an effective method for designing perovskite dielectric ceramics with ultra-high comprehensive energy storage performance.
Ali et al. (Thu,) studied this question.