Significantly improved recoverable energy density and ultrafast discharge rate of Na0.5Bi0.5TiO3-based ceramics

Thermal stability of capacitors with both superior recoverable energy density (W-rec) and efficiency (eta) have recently attracted great research interest for application in the pulse power systems. Here, high-quality lead-free relaxor-ferroelectric (RFE) (1-x)Bi0.5Na0.5TiO3-x(Na0.73Bi0.09)NbO3 [(1-x)BNT-xNBN, x = 0.10-0.18] ceramics are fabricated through solid-state reaction method. The NBN substitution of NBT ceramics could improve effecitively breakdown strength (BDS), energy storage performances, and the thermal stability. Especially, excellent recoverable energy density (W-rec similar to 2.41 J/cm(3)) and efficiency (eta similar to 81.6%) could be achieved synchronously in 0.84BNT-0.14NBN ceramic. Moreover, the good thermal stability (20 degrees C similar to 140 degrees C), frequency stability (1-1000 Hz), and fatigue endurance (10(4) cycles) are also obtained in the composition of x = 0.14 ceramic. Particularly, corresponding ceramic shows high current density (similar to 817 A/cm(2)), discharge energy density (similar to 0.729 J/cm(3)), extremely short discharge rate ( < 50 ns), and power density (similar to 49 MW/cm(3)) from 20 to 140 degrees C. This research provides a creative method for preparing high-performance capacitors in high-temperature applications.