Relaxor ferroelectrics based on sodium bismuth titanate (Bi_0.5Na_0.5TiO₃, BNT) have attracted more interest recently as potential ecologically acceptable materials for pulse power technology because of their excellent full-energy storage capabilities. This paper formed (1 − x){0.97[0.98(BNT-ST)-0.02CN]-0.03AlN}-xNN ceramics through a traditional solid-state reaction process. It was noted that the incorporation of NaNbO₃ enhances the property of energy storage by elevating the breakdown strength and causing the creation of an ergodic relaxation state. The effective energy storage density (W_rec) and the energy storage efficiency (η) are 1.09 J/cm³ and 85%, respectively. The breakdown field strength E_b reached 155 kV/cm at x = 40%. These ceramics have excellent temperatures and frequency stabilities from 0.5 to 50 Hz and 20 to 60 °C.

Dielectric capacitors with a high density of recoverable energy storage are extremely desirable for a variety of uses. However, these capacitors often exhibit lower breakdown strengths and energy efficiency compared to other materials, which poses significant challenges for their practical use. We report on a novel antiferroelectric ceramic system in the present study, (1 − x){0.97[0.985(0.93Bi_0.5Na_0.5TiO₃–0.07BaTiO₃)–0.015Er)]–0.03AlN}–xNaNbO₃ (x = 0, 10 wt%, 20 wt%, 30 wt%, and 40 wt%), synthesized via a conventional solid-state reaction approach. Here, (Bi_0.5Na_0.5TiO₃–BaTiO₃) is denoted as BNT–BT. We observed that varying the NaNbO₃ (NN) content gradually refined the grain size of the ceramics, narrowed their hysteresis loops, and transformed their phase structure from antiferroelectric to relaxor ferroelectric. These changes enhanced breakdown strength (E_b), thus increasing the performance of energy storage. Specifically, the recoverable energy density (W_rec) and energy storage efficiency (η), respectively, reached 0.67–1.06 J/cm³ and 44–88% at electric fields of 110–155 kV/cm, with the highest performance observed at 30 wt% NN doping. Additionally, over a broad range of temperature and frequency, the 70 wt% {0.97[0.985(BNT–BT)–0.015Er]–0.03AlN}–30 wt% NN ceramic demonstrated exceptional stability in energy storage. These results demonstrate the significant potential of lead-free(1 − x)({0.97[0.985(BNT–BT)–0.015Er]–0.03AlN}–xNN ceramics for the applications of high-performance energy storage.

(Bi_0.5Na_0.5)TiO₃-based lead-free ferroelectric ceramics are among the most extensively researched energy storage materials today. In this paper, (1 − x)Bi_0.46Sr_0.06Na_0.5TiO_3−xCaTiO₃ ceramics were synthesized through a solid-phase sintering method by synergistically adjusting CaTiO₃ components after introducing Sr²⁺ 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 CaTiO₃ 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 CaTiO₃ addition, the samples obtained a maximum breakdown field strength of 260 kV/cm and corresponding saturation polarization strength of 32.80 μC/cm² and thereby exhibited a reversible energy storage density valued 3.52 J/cm³. 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/cm² and a maximum power density of 18.90 MW/cm³ for their charge–discharge performance, all of which makes them suitable for pulse system applications.