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Na 0.5 Bi 0.5 TiO 3 (NBT) ceramic is a potential dielectric material for the manufacture of high-performance dielectric ceramic capacitors due to its high polarization and environmentally friendly characteristics. In this work, (1– x)(0.70Na 0.5 Bi 0.5 TiO 3 –0.30SrTiO 3)– x Bi(Ni 0.5 Hf 0.5)O 3 (NBST– x BNH) ceramics have been prepared based on the strategy of refining grain size and inducing polar nano-regions (PNRs). As a result, the NBST–0.15BNH ceramic achieved large energy density and efficiency (W rec = 4.11 J/cm3, η = 82.1%) at a low electric field of 240 kV/cm. This performance is outstanding compared to existing reports at similar breakdown electric fields. The introduction of Sr2+ enabled the NBST to have a high relaxation property, and the introduction of BNH induced PNRs, which ensured the high energy storage efficiency of the ceramics. BNH doping refined grain size, which contributed to the large breakdown electric field strength of the ceramics. In addition, stability tests showed that the NBST–0.15BNH ceramic had excellent thermal and frequency stability. The ceramic also demonstrated a fast discharge rate (t 0.9 = 148 ns) in the charge-discharge test. [Display omitted] [ABSTRACT FROM AUTHOR]

Na 0.5 Bi 0.5 TiO 3 (NBT) ceramic is a potential dielectric material for the manufacture of high-performance dielectric ceramic capacitors due to its high polarization and environmentally friendly characteristics. In this work, (1– x)(0.70Na 0.5 Bi 0.5 TiO 3 –0.30SrTiO 3)– x Bi(Ni 0.5 Hf 0.5)O 3 (NBST– x BNH) ceramics have been prepared based on the strategy of refining grain size and inducing polar nano-regions (PNRs). As a result, the NBST–0.15BNH ceramic achieved large energy density and efficiency (W rec = 4.11 J/cm3, η = 82.1%) at a low electric field of 240 kV/cm. This performance is outstanding compared to existing reports at similar breakdown electric fields. The introduction of Sr2+ enabled the NBST to have a high relaxation property, and the introduction of BNH induced PNRs, which ensured the high energy storage efficiency of the ceramics. BNH doping refined grain size, which contributed to the large breakdown electric field strength of the ceramics. In addition, stability tests showed that the NBST–0.15BNH ceramic had excellent thermal and frequency stability. The ceramic also demonstrated a fast discharge rate (t 0.9 = 148 ns) in the charge-discharge test. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • The 0.85NN-0.15BM 5 ceramic achieves 5.11 J/cm3 energy density and 77 % efficiency, outperforming previous studies. • Bi3+ ions and BM 5 inclusion augments polarization, stabilizes ferroelectric phase, and improves energy storage. • The 0.85NN-0.15 BM 5 ceramic shows superior stability, offering a reliable energy storage solution. NaNbO 3 (NN) ceramics have emerged as a significant lead-free dielectric material for pulsed power systems. This study introduces a pioneering NN- x BM 5 ceramic, crafted through a high-entropy method and compositional optimization strategy. By hybridizing the O2– 2p and Bi3+ 6p orbitals, the long-range order within the ceramic is disrupted, leading to enhanced relaxation properties and polarizability. The ceramic displayed an impressive breakdown electric field of 300 kV/cm, a substantial recoverable energy storage density of 5.11 J/cm3, and an impressive energy storage efficiency of 77 %. XRD and XPS analyses have validated the successful integration of BM 5 into the NN ceramics, effectively diminishing the occurrence of OV s, thereby aiding in reducing P r. SEM and TEM assessments reveal that the introduction of BM 5 results in a reduction in grain size and encourages the formation of PNRs, providing the ceramics with enhanced BDS and P m. Dielectric assessments illustrate that BM 5 doping enhances the temperature stability of the dielectric constant while upholding excellent relaxation properties (γ ≥ 1.7), suggesting heightened η in the ceramics. Furthermore, results for E a and E c derived from fitting the Arrhenius formula signify that the ceramics exhibit increased energy storage efficiency. The E a and E c outcomes suggest that the presence of OV s and the relaxation process in all samples are governed by the dipole conduction mechanism. This study implies that this approach can successfully design high-performance lead-free dielectric capacitors for forthcoming practical applications. [ABSTRACT FROM AUTHOR]