Realizing Enhanced Energy Storage and Hardness Performances in 0.90NaNbO3-0.10Bi(Zn0.5Sn0.5)O3 Lead-Free Ceramics

Relaxor behavior has been demonstrated responsible for excellent energy storage characteristics in dielectric materials owing to the fast polarization response, and an ultrahigh energy storage density can also be induced in NaNbO3 (NN)-based ceramics via combining antiferroelectric and relaxor features. Most of the existing reports lead-free dielectric ceramics, nevertheless, are still lacking of the relevant research among domain evolution and relaxor behavior. Herein, a novel lead-free solid solution, (1-x)NaNbO3-xBi(Zn0.5Sn0.5)O3 [xBZS, x = 0.05, 0.10, 0.15, and 0.20] ceramics are designed to further illustrate the above issues. Domain evolutions in xBZS ceramics confirm the contribution of relaxor behavior to the excellent energy storage characteristics, owning to fast polarization rotation based on the low energy barrier of polar nanoregions (PNRs). Consequently, a high energy storage density of 3.14 J/cm3 and energy efficiency of 83.30% are simultaneously available at 0.10BZS ceramics, together with the stabilities of energy storage properties in large temperature range (20-100 °C) and wide frequency range (1-200 Hz). Additionally, for practical applications, the 0.10BZS ceramics display a great discharge energy storage density (Wdis ~1.05 J/cm3), fast discharge rate (t0.9 ~60.60 ns), and high hardness (H ~5.49 GPa). These results indicate that this study may provide a considerable new light on the mechanism of high performance lead-free dielectric energy storage materials.