Improved energy storage performances of lead-free BiFeO3-based ceramics via doping Sr0.7La0.2TiO3

Abstract Substantial attention for dielectric ceramic capacitors toward lead-free has been driven by the enhanced awareness of environmental protection. However, the unsatisfying breakdown strength (Eb) and comparatively low efficiency (η) becomes an obstacle for their widespread application. Here, environment-friendly lead-free relaxor ferroelectric (1-x) (0.67BiFeO3-0.33Ba0.8Sr0.2TiO3) -xSr0.7La0.2TiO3+0.1 wt.% MnO2 (BFO-BST-SLT) ceramic is reported as an efficient route to possess excellent Eb and high η simultaneously. The doping of SLT can significantly suppress the grain growth, improve the relaxation behavior, and thus increasing the Eb and η of the ceramics. Consequently, the corresponding ceramics with x=0.3 achieves good discharged energy density of ~ 2.55 J/cm3 and ultrahigh η of ~ 92%. Notably, it presents outstanding charging/discharging performances with fast charging/discharging time (~ 0.0266 μs), power density (~ 28.11 MW/cm3) along with current density (~ 468.5 A/cm2). Together with great temperature stability, frequency stability and cycle stability, this contributes provides a crucial way to prepare lead-free dielectrics for next-generation pulsed power capacitor applications.