Antiferroelectric ceramics are recently, a research hotspot for electrostatic energy storage because of their large electric-field induced polarization. Lead-free sodium niobate (NaNbO₃)-based ceramics are one of the emerging antiferroelectric counterparts. However, the unstable antiferroelectric phase seriously restricts the further improvement of energy density and efficiency. In this work, by introducing binary perovskite end-member BiFeO₃–BaTiO₃ with lower tolerance factor and average electronegativity into NaNbO₃ ceramics, the stablized antiferroelectric phase with improved relaxation characteristic is identified by slim double-like polarization-electric field (P–E) loops and four-peak current–electric field (I–E) curves. Meanwhile, the antiferroelectric P to R phase transition is verified through Raman spectra, X-ray diffraction (XRD) patterns, and dielectric performance. In particular, the enhanced electric breakdown strength E_b is achieved by synergic contributions from ultralow dielectric loss, reduced grain size, and so on. Consequently, the sample with optimized composition displays ultrahigh recoverable energy storage density (W_rec) of 14.5 J cm⁻³ and satisfied efficiency (η) of 83.9%, which shows the superiority in the state-of-the-art dielectric ceramics. These results provide a feasible route by regulating the relationship between antiferroelectric structure and properties to explore high-performance dielectrics for electrostatic energy storage applications.

中文翻译：

---

用于静电储能应用的无铅铌酸钠基弛豫反铁电陶瓷提高能量密度和效率

反铁电陶瓷因其电场感应极化大而成为近年来静电储能的研究热点。基于无铅铌酸钠 (NaNbO ₃ ) 的陶瓷是新兴的反铁电材料之一。然而，不稳定的反铁电相严重制约了能量密度和效率的进一步提高。在这项工作中，通过将具有较低容差因子和平均电负性的二元钙钛矿端元 BiFeO ₃ –BaTiO ₃引入 NaNbO ₃陶瓷中，通过细长类双极化电场 ( P–乙) 循环和四峰值电流-电场 ( I-E ) 曲线。同时，通过拉曼光谱、X 射线衍射 (XRD) 图案和介电性能验证了反铁电P到R相变。特别地，增强的电击穿强度Eb是通过超低介电损耗、减小的_晶粒尺寸等的协同作用实现的。因此，具有优化成分的样品显示出14.5 J cm ^-3的超高可恢复储能密度 ( W _{rec )}令人满意的效率 (η) 为 83.9%，这显示了在最先进的介电陶瓷中的优越性。这些结果为通过调节反铁电结构和性质之间的关系来探索用于静电储能应用的高性能电介质提供了一条可行的途径。