BS_0.5BNT-based relaxor ferroelectric ceramic/glass-ceramic composites for energy storage

Relaxor ferroelectric ceramics have very high dielectric constant (epsilon(r)) but relatively low electrical breakdown strength (E-b), while glass-ceramics exhibit higher E-b due to the more uniformly dispersed amorphous phases and submicrocrystals/nanocrystals inside. How to effectively combine the advantages of both relaxor ferroelectric ceramics and glass-ceramics is of great significance for the development of new dielectric materials with high energy storage performance. In this work, we firstly prepared BaO-SrO-Bi2O3-Na2O-TiO2-Al2O3-SiO2 (abbreviated as GS) glass powders, and then fabricated (Ba0.3Sr0.7)(0.5)(Bi0.5Na0.5)(0.5)TiO3 + x wt% GS ceramic composites (abbreviated as BS0.5BNT-xGS, x = 0, 2, 6, 10, 14, 16, and 18). Submicrocrystals/nanocrystals with a similar composition to BS0.5BNT were crystalized from the glass, ensuring the formation of uniform core-shell structure in BS0.5BNT-xGS relaxor ferroelectric ceramic/glass-ceramic composites. When the addition amount of GS was 14 wt%, the composite possessed both high epsilon(r) (> 3200 at 1 kHz) and high E-b (approximate to 170 kV/cm) at room temperature, and their recoverable energy storage density and efficiency were W-rec = 2.1 J/cm(3) and eta = 65.2%, respectively. The BS0.5BNT-14GS composite also had several attractive properties such as good temperature, frequency, cycle stability, and fast charge-discharge speed. This work provides insights into the relaxor ceramic/glass-ceramic composites for pulsed power capacitors and sheds light on the utilization of the hybrid systems.