(Bi0.5Na0.5)TiO3-based relaxor ferroelectrics with simultaneous high energy storage properties and remarkable charge-discharge performances under low working electric fields for dielectric capacitor applications

High energy storage and charge-discharge performances under low electric field are desirable for lead-free dielectric materials because of environmental hazards, the risk of high voltage and the high cost of insulation technology. Herein, lead-free ceramics based on 0.6BNT-0.4Sr0.775Bi0.15TiO3 (BNT-SBT) were designed, which simultaneously achieves a large energy storage density (Wrec- 2.41 J/cm3) and a high efficiency (eta-87.5%) under a low electric field of 190 kV/cm due to enhanced dielectric properties and the relaxation response. Moreover, the energy storage properties of the BNT-SBT ceramic exhibit moderate temperature stability, excellent frequency dependence, and cycling reliability. Furthermore, the charge-discharge performance simultaneously features a high power density (PD-51.4 MW/cm3), an ultrafast discharge speed (t0.9-77 ns), and remarkable stability against temperature and cycling. This study exploits a high-efficiency BNT-related ceramics with concurrently high energy storage and charge-discharge performances under low electric fields, which provides great potential in practical dielectric capacitor applications.

Automated summary

Lead-free ceramics based on 0.6BNT-0.4Sr0.775Bi0.15TiO3 were designed with high energy storage density and efficiency under low electric fields, showing moderate temperature stability, excellent frequency dependence, and cycling reliability. The ceramics also exhibit high power density, ultrafast discharge speed, and stability against temperature and cycling, making them suitable for practical dielectric capacitor applications.