High energy storage properties of Nd(Mg_2/3Nb_1/3)O₃ modified Bi_0.5Na_0.5TiO₃ lead-free ceramics

This study proposes an optimization strategy to improve the energy storage performance of Bi_0.5Na_0.5TiO₃ (BNT)-based ceramics. The strategy is to reduce the grain size, break the long-range polar ordering, form disordered polar nanoregions (PNRs), and increase the breakdown field strength (E_b). The (1-x)Bi_0.5Na_0.5TiO₃-xNd(Mg_2/3Nb_1/3)O₃ ((1-x)BNT-xNMN, x = 0.05, 0.10, 0.15 and 0.20) ceramics were prepared using this optimization strategy, and an ultrahigh recoverable energy storage density of 2.72 J/cm³ and an efficiency of 91.74% were obtained. Notably, this marks a several times increase in energy storage density compared to pure BNT ceramics. The energy storage density exhibits excellent electrical stability in the temperature range of 20–160 °C and frequency range of 1–200 Hz. Additionally, the power density (P_D) of the ceramic reaches 19.74 MW/cm³ at an electric field of 180 kV/cm. These findings hold great promise as to pave the way for the development of cutting-edge energy storage solutions and high-performance capacitor materials.