Giant comprehensive energy storage performance in Pb-doped Bi0.25Na0.25Sr0.5TiO3 ceramics via multiscale regulation of grain size and relaxation behavior

Abstract

Developed ceramic capacitors with excellent recoverable energy storage density (Wrec) and efficiency (η) are greatly desired for next-generation pulsed power devices but challenge as well. Herein, outstanding Wrec of 5.2 J/cm3 and η of 82% are achieved in the PbO-doped fine grain Bi0.25Na0.25Sr0.5TiO3 (BNST-P) based relaxor ferroelectric ceramics. The corresponding mechanism is that A-site Pb-doping increases maximum polarization and breakdown strength, and suppresses remnant polarization simultaneously. Meanwhile, the energy storage property possesses excellent temperature and frequency stability, and the variation of Wrec and η is less than 5% within the range of 25–100 °C and 2–100 Hz. Encouragingly, superior charge-discharge performance with fast discharge speed t0.9 of 24 ns and high power density PD of 296 MW/cm3 is obtained. These striking comprehensive results suggest BNST-P ceramics possess potential prospects for applications.