Modified relaxor ferroelectrics in BiFeO3-(Ba,Sr)TiO3-BiScO3 ceramics for energy storage applications

Environmental-friendly relaxor ferroelectrics is deemed as one of the most promising and ultimate candidates for energy storage. Here the relaxor ferroelectrics 0.20BiFeO3-(0.30-x)BaTiO3-xBiScO3–0.50SrTiO3 (0.05 ≤ x ≤ 0.25, denoted as 0.20BFO-(0.30-x)BTO-xBSO-0.50STO) with outstanding energy storage performances were extensively characterized by structural and morphological studies and dielectric and polarization measurements. The dielectric properties display frequency dispersion characteristics with diffusion index (γ) between 1.48 and 1.85. The BSO addition significantly increases the largest Pmax (33.90 μC/cm2) compared to that of the BSO-free ternary system (Pmax = 26.39 μC/cm2). Ultimately, a high recoverable energy density Wrec (~ 3.4 J/cm3) with high efficiency η (~85.6%) was attained in x = 0.25, which also exhibits frequency-insensitive characteristic and satisfactory stability over a wide temperature range of 30–120 °C. These findings reveal that the BSO-modified relaxor ferroelectric ceramics is an ideal lead-free candidate for pulsed power systems.