Energy Storage Performance of Na 0.5 Bi 0.5 TiO 3 -Based Relaxor Ferroelectrics with Wide Temperature Range

Bi 0.5 Na 0.5 TiO 3 -based ceramics play a pivotal role in energy storage applications due to their significant attributes, such as large maximum polarization. However, the considerable remnant polarization limits its application impulse capacitor applications. To address this limitation, we conceived and synthesized lead-free relaxor ferroelectric ceramics with the composition (1 − x)(Bi 0.5 Na 0.5 )TiO 3 − xSr(Ti 0.5 Zr 0.5 )O 3 (BNT-SZT). By incorporating Sr(Ti 0.5 Zr 0.5 )O 3 , we enhanced the energy storage characteristics by inducing relaxor behavior and improving the dielectric breakdown strength. Notably, the 0.7BNT-0.3SZT ceramics exhibited a substantial recoverable energy storage density of 3.79 J/cm 3 at 260 kV/cm. Furthermore, these ceramics demonstrated remarkable temperature stability, manifesting a consistent W rec within the range of 1.41 to 1.59 J/cm 3 across a broad temperature span of 20 to 160 °C at 150 kV/cm. Additionally, the 0.7BNT-0.3SZT ceramic displayed exceptional energy release properties, characterized by a high discharge energy density ( W d = 1.17 ~ 1.42 J/cm 3 ) and rapid discharge time ( t 0.9 ~ 0.259 μs). These discernible outcomes underscore the potential of BNT-SZT ceramics as a promising lead-free material for energy storage applications.