Enhanced energy-storage properties and dielectric temperature stability of (Bi_0·5Na_0.5)_0.84Sr_0·16Ti_1-x(Y_0·5Nb_0.5)_xO₃ lead-free ceramics

A series of lead-free (Bi_0·5Na_0.5)_0.84Sr_0·16Ti_1-x(Y_0·5Nb_0.5)_xO₃ (abbreviated as BNST-100xYN) relaxor ferroelectric ceramics were prepared by solid state reaction sintering. The micro morphology, dielectric properties, and energy storage properties of the ceramics with increasing doping content were systematically studied, and their conductive mechanism was also studied. The perovskite structure was not significantly changed with the addition of (Y_0·5Nb_0.5)⁴⁺ complex ions, but it led to a certain amount of flake grains appear and element precipitation with increasing composition. And the larger dielectric breakdown strength (DBS) and lower remanent polarization (P_r) were attained with the recoverable energy storage density (W_rec) of ~1.0433 J/cm³ for x = 0.04 composition. In addition, it showed outstanding dielectric temperature stability and cycle stability. These results indicated that BNST-4YN ceramics are an excellent candidate for energy storage device and temperature-stable dielectric equipment.