Energy storage performance of SrSc_0.5Nb_0.5O₃ modified (Bi,Na)TiO₃-based ceramic under low electric fields

Dielectric ceramics with a high recoverable energy density (W_rec) and high efficiency are desirable for the development of pulsed power capacitors under low electric fields. In this study, through the introduction of SrSc_0.5Nb_0.5O₃ into (Bi_0.5Na_0.5Ti_0.95Al_0.025Nb_0.025O₃) [(1-x)BNTA-xSSN], a considerable recoverable energy storage density (W_rec) of approximately 2.7 J/cm³ and energy storage efficiency (η) of approximately 76 % at 210 kV/cm are achieved at x =.1; additionally, η is further improved to 85 % at x =.2. Moreover, η and W_rec of.9BNTA-.1SSN exhibit outstanding stability (thermal and frequency stability) at 150 kV/cm, which is superior to that of other lead-free ceramics. The excellent energy storage performance is attributed to the increased relaxation degree and the formation of ferroelectric nanodomains, whereas the enhanced E_b is ascribed to the increased electrical resistivity and decreased grain size upon modification. These results indicate the potential of (1-x)BNTA-xSSN as an ideal candidate for energy-storage applications.