Dielectric capacitors have drawn growing attention for their wide application in future high power and/or pulsed power electronic systems. However, the recoverable energy storage density ( W rec ) for dielectric ceramics is relatively low up to now, which largely restricts their actual application. Herein, the domain engineering is employed to construct relaxor antiferroelectric NaNbO 3 -BiFeO 3 bulk ceramics, which integrates the merits of antiferroelectrics and relaxors. It is revealed that the antiferroelectric phase transforms from orthorhombic P to R phase, and antiferroelectric domain evolves from micron-sized blocks to nanoscale clusters. Of particular importance is that the 0.90NaNbO 3 –0.10BiFeO 3 ceramic demonstrates ultrahigh W rec of 18.5 J cm −3 with giant electric breakdown strength of 99.5 kV mm −1 , which is superior than state-of-the-art bulk dielectric ceramics. Moreover, the 0.90NaNbO 3 –0.10BiFeO 3 ceramic exhibits superior frequency, cycling and thermal reliability, as well as the substantial current density (2140.6 A cm −2 ), ultrahigh power density (428.1 MW cm −3 ) and ultrafast discharge rate (14 ns). These results not only suggest that the NaNbO 3 -based relaxor antiferroelectric ceramics are promising candidates for advanced energy storage capacitors, but also provide feasible strategy of domain engineering to develop novel lead-free high-performance dielectric materials.
The ferroelectric domain plays an important role in determining the piezoelectric performance of ferroelectric ceramics . Herein, LiNbO 3 (LN) is used as an additive to tune the ferroelectric domain of 0.49Pb(Ni 1/3 Nb 2/3 )O 3 -0.2Pb(In 1/2 Nb 1/2 )O 3 -0.31PbTiO 3 (PNN-PIN-PT) ceramics. PNN-PIN-PT-0LN ceramic exhibits the ordered tetragonal phase (90 °) domain wall and rhombohedral phase (71 ° and 109 °) domain wall. Incorporating LN into the system leads to the transformation of the majority of structured macro-domains into random micro-domains with smaller sizes, which disrupt their long-range ordered ferroelectric domains, resulting in significant piezoelectric enhancement. Compared to PNN-PIN-PT-0LN ceramics, PNN-PIN-PT-1.8LN ceramics exhibit giant piezoelectric responses with d 33 = 1112 pC/N, d 31 =521 pC/N, d 33 * =1220 pm/V (@ E = 5 kV/cm), ε r = 12092. These findings shed light on a specific aspect of domain engineering in piezoelectric materials , thus contributing to a more comprehensive understanding of the underlying factors that give rise to the phenomenon of giant piezoelectricity .
危险品化学品经营许可证（带存储）