High energy storage performance obtained by adjusting the polarization ability of NaNbO3 based ceramics

Linear dielectric-modified NaNbO3 ceramics exhibit decent energy storage efficiency and breakdown field strength, however, their practical application is hindered by the inherently low Pmax values, which lead to a reduction in Wrec, constituting a significant pain point in this field. In this paper, we propose a novel (1-x) (0.90NaNbO3-0.10Sm(Mg0.5Zr0.5)O3) -xBi0.5Na0.5TiO3 (x = 0.20, 0.25, 0.30, and 0.35) ceramic composition. This composition is designed by incorporating Bi0.5Na0.5TiO3 ceramics, which have enhanced polarization behavior, into 0.90NaNbO3-0.10Sm(Mg0.5Zr0.5)O3 ceramics that possess high breakdown field strength and small domain size. This strategic addition effectively elevated the Pmax value. Furthermore, we mitigated the dielectric loss of the ceramics by constructing relaxor ferroelectrics. As a result, under a breakdown field strength of 575 kV/cm, the 0.70[0.90NaNbO3-0.10Sm(Mg0.5Zr0.5)O3]-0.30Bi0.5Na0.5TiO3 ceramic composition achieved ultrahigh energy storage performance of 10.2 J/cm3 and a high energy storage efficiency of 85.7 %. In practical charge-discharge tests, the 0.30BNT ceramic also demonstrated high charge-discharge density (CD) of 1348 A/ cm2 and power density (PD) of 148 MW/cm3. This study conducted a comprehensive investigation into the phase structure, microstructure, and related electrical properties of NaNbO3-based ceramics.