Relaxor ferroelectric ceramics with excellent energy storage density obtained from BT-based ceramics

Abstract

Lead-free energy storage ceramic capacitors which have high-power density and ultrafast discharge time are widely used in electronic systems. However, lead-free energy storage ceramic materials still suffer from low energy storage density and poor stability. In this study, the synergistic optimization of polarization and electric field breakdown strength (Eb) is realized by doping with highly polarized Bi0.5Na0.5TiO3 (Ps > 42 μC/cm2) in BaTiO3-based ceramics, thereby optimizing the energy storage density. 0.15BNT ceramics have a large ΔP (Pmax-Pr) of 29 μC/cm2 under Eb of 525 kV/cm, resulting in excellent total energy storage density (Wtotal = 5.4 J/cm3), large recoverable energy storage density (Wrec = 4.8 J/cm3) and high energy storage efficiency (η = 89%). In particular, 0.15BNT ceramics also exhibit a high-power density (PD = 80 MW/cm3), a large discharge density (Wdis = 1.9 J/cm3), and an ultrafast discharge time (t0.9 = 37 ns). In addition, 0.15BNT ceramics also show excellent frequency stability (1–120 Hz) and temperature stability (25–200 °C). These excellent properties establish that 0.15BNT ceramics are promising material candidates for applications.