(Bi0.5Na0.5)TiO3-based relaxor ferroelectrics with enhanced energy-storage density and efficiency under low/moderate-fields via average ionic polarizability design

作者：Wang, Zepeng; Zhang, Lixue^*; Kang, Ruirui^*; Yang, Weijie; He, Liqiang; Mao, Pu; Lou, Xiaojie; Zhang, Lin; Wang, Jiping^*

来源：Chemical Engineering Journal, 2022, 431: 133716.

DOI：10.1016/j.cej.2021.133716

• Average ionic polarizability
• Bi1/2Na1/2TiO3-based ceramics
• Relaxor ferroelectrics
• Energy-storage properties
• Low/moderate electric fields

Electrostatic capacitors are promising candidates in the application of pulse-power systems due to their high power density and fast charge-discharge rate. However, the insufficient recoverable energy density (W-rec) and energy efficiency (eta) under low/moderate electric field is still the bottleneck for their applications in miniaturized equipment and portable devices. In this work, we utilize an average ionic polarizability design strategy to enhance W-rec by sustaining the high-polarization gene of the system and simultaneously improve eta by disrupting the polar order in (1-x)[0.7Bi(0.5)Na(0.5)TiO(3)-0.3Sr0.7Bi0.2TiO3]-xSr(Zn-1/3(Nb0.85Ta0.15)(2/3))O-3 ceramics. As a result, excellent energy-storage properties have been achieved both in low-field (Wrec -2.7 J/cm(3) and high eta -93% at 200 kV/cm) and moderate-field (W-rec -5.2 J/cm(3) and eta -91% at 330 kV/cm) for x = 0.12 sample. Additionally, the x = 0.12 sample exhibits good thermal stability (-50 -200 celcius), frequency stability (0.5 -500 Hz) and cycle stability (10(5) cycles). Hence, the current work may provide some novel perspectives for improving the W-rec and eta of dielectric capacitors under low/moderate electric fields.

• 单位
  西安交通大学; 南昌航空大学