Enhanced comprehensive energy storage properties in Bi0.5Na0.5TiO3-based relaxor ferroelectric ceramics under a moderate electric field

Bismuth sodium titanate (Bi0.5Na0.5TiO3)-based relaxor ferroelectric ceramics have received ever-increasing interest for their potential application in dielectric capacitors owing to their sterling energy storage capability. Herein, the perovskite end-member Ba(Fe0.5Nb0.5)O3 (BFN) was incorporated into 0.7Bi0.5Na0.5TiO3-0.3SrTiO3 (0.7BNT-0.3ST) ceramics to improve the relaxor characteristics and refine the grain, leading to slim polarization–electric field (P–E) hysteresis loops and enhanced electric breakdown strength. Particularly, the 0.85(0.7BNT-0.3ST)-0.15BFN ceramics achieved a high recoverable energy density of 5.7 J/cm3 and a high energy storage efficiency of 86.4% under a moderate electric field of 390 kV/cm. Additionally, remarkable stability in frequency, cycling, and temperature and excellent charge/discharge behavior were achieved at the same time. The above findings reveal that BFN-modified BNT-ST ceramics display greatly improved comprehensive energy storage properties, making them promising candidates in the field of electrostatic energy storage.