Remarkable energy storage properties in (Bi0.5Na0.5)TiO3-based quasilinear relaxor ferroelectrics via superparaelectric regulation

The utilization of electrostatic energy storage technology, which relies on dielectrics, is of utmost importance in the realm of advanced electronics and high-power electrical systems. However, there is still a lack of a universally applicable method to simultaneously attain elevated recoverable energy density (Wrec) and high efficiency (η). Herein, based on the design of superparaelectric regulation, SmFeO3 was introduced into the typical 0.6Bi0.5Na0.5TiO3–0.4Sr0.7Bi0.2TiO3 relaxor. A nearly linear P–E loop with near-zero remanent polarization and excellent comprehensive performance were realized in the 0.9(0.6Bi0.5Na0.5TiO3–0.4Sr0.7Bi0.2TiO3) –0.1SmFeO3 ceramic. A remarkable Wrec value of 7.2 J⋅cm−3 together with a high η of 86 % was obtained at an improved Weibull breakdown electric field (Eb) of 430 kV⋅cm−1. Wherein the ultra-small nanodomain size and the increased linearity of the P–E loop based on superparaelectric regulation strategy at largely enhanced Eb are responsible for the improvement of Wrec and η. Therefore, the method of superparaelectric regulation realized on relaxor ferroelectrics opens a new avenue for the progress of cutting-edge ceramic capacitors.