High Energy Storage Performance in Bi0.46Sr0.06Na0.5TiO3/CaTiO3 Relaxor Ferroelectric Ceramics

(Bi 0.5 Na 0.5 )TiO 3 -based lead-free ferroelectric ceramics are among the most extensively researched energy storage materials today. In this paper, (1 − x)Bi 0.46 Sr 0.06 Na 0.5 TiO 3−x CaTiO 3 ceramics were synthesized through a solid-phase sintering method by synergistically adjusting CaTiO 3 components after introducing Sr 2+ at the A-site. The XRD patterns revealed that all samples formed a single perovskite solid solution, with the 111 and 200 peaks shifting to higher levels as the CaTiO 3 increased, indicating a gradual decrease in cell volume. The SEM images exhibited dense crystals without any apparent porosity, which were formed by the different components of the ceramics. Through energy storage, dielectric, and charge–discharge performance tests, it was found that with a 10%mol CaTiO 3 addition, the samples obtained a maximum breakdown field strength of 260 kV/cm and corresponding saturation polarization strength of 32.80 μC/cm 2 and thereby exhibited a reversible energy storage density valued 3.52 J/cm 3 . In addition, the dielectric constant varied by less than 10% within the temperature range of 63.7 °C to 132.7 °C and presented good frequency (10–250 Hz) stability at 180 kV/cm. Moreover, the ceramics demonstrated a maximum current density reaching 349.58 A/cm 2 and a maximum power density of 18.90 MW/cm 3 for their charge–discharge performance, all of which makes them suitable for pulse system applications.