Abundant nanodomains in Bi0.48Na0.48Ba0.04TiO3-based ceramics induced by phase transformation for excellent energy storage properties

In light of the mounting environmental challenges, there is a pressing need to investigate the development of a lead-free energy storage solution with excellent energy storage properties. Herein, lead-free dielectric energy storage ceramics, namely (1−x)Bi_0.48Na_0.48Ba_0.04TiO₃₋xLa_1/3NbO₃ (BNBT-LN), are synthesized using a traditional solid-phase method. The incorporation of LN into BNBT ceramics led to the observation of rhombohedral and tetragonal phase transitions at room temperature, while randomly distributed nanodomains were induced. The charge mismatch induced by heterovalent cation doping alters the dielectric anomaly peaks, resulting in the ceramics remaining highly polarized. Furthermore, the enhancement of grain boundary density optimizes the ceramic breakdown electric field. As a result, the 0.91BNBT-0.9LN ceramics obtain excellent energy storage properties (W_rec = 7.7 J cm⁻³, \(\eta\) = 73.8%, E = 560 kV cm⁻¹), along with good frequency stability, temperature stability, and discharge performance. This work proposes a novel strategy to develop environmentally friendly dielectric capacitors with superior energy density.