Improvement of dielectric and energy storage properties in Sr0.85Bi0.1ZrO3 modified (Bi0.5Na0.5)0.7Sr0.3TiO3 lead-free ceramics

Abstract

In recent years, with the rapid development of electronic components industry, higher requirements are put forward for energy storage density and efficiency of pulse power capacitors. In this work, the improved energy storage density and efficiency of (Bi 0.5 Na 0.5 ) 0.7 Sr 0.3 TiO 3 (BNST)-based ceramics have been obtained by introducing the Sr 0.85 Bi 0.1 ZrO 3 (SBZ). The addition of SBZ reduced phase transition temperature to about 50 ºC, accompanied by relaxation enhancement. A high recoverable energy density ( W rec = 3.53 J/cm 3 ) and energy efficiency ( η = 87.15%) were synchronously achieved in 0.875BNST-0.125SBZ ceramic under 270 kV/cm. Moreover, excellent temperature stability (20–120 ºC) and frequency stability (5–200 Hz) for energy storage have been achieved at 150 kV/cm. A power density ( P D ) of 7.32 MW/cm 3 and the transitory discharge time ( t 0.9 = 0.86 μs) were achieved for 0.875BNST-0.125SBZ ceramics under 120 kV/cm. These characteristics indicate that 0.875BNST-0.125SBZ ceramic is expected to be applied in high-power equipment. • The addition of SBZ reduced phase transition temperature to about 50 ℃, accompanied by relaxation enhancement. • 0.875BNST-0.125SBZ ceramic possesses a high recoverable energy density of 3.53 J/cm³ and efficiency of 87.15%. • 0.875BNST-0.125SBZ ceramic exhibits good electrical stability in wide frequency (5–200 Hz) and temperature range (20–120 ℃). • A high power density ( P D ) of 7.32 MW/cm 3 and a transitory discharge time ( t 0.9 ~0.86 µs) can be achieved.