Energy storage performance of BaTiO3-based relaxor ferroelectric ceramics prepared through a two-step process

•BT-SBT-NdVPP ceramic achieved an ultrahigh Wrec of 4.2 J/cm3 under 460 kV/cm.•High Wrec of 2.6 J/cm3 at 30 ~ 100 °C and 10 ~ 400 Hz under 300 kV/cm.•Two-step strategy provides a universal way for fabricating energy storage ceramics. As the industrial pillar of electronic ceramics, BaTiO3 ceramic is difficult to achieve large energy storing performance due to its high Pr and low dielectric breakdown field strength, making it difficult to satisfy their development requirements of miniaturization and lightweight of power electronic equipment. Therefore, a two-step strategy including adjusting the ratio of chemical elements to modify the microstructures and optimizing the preparation process to enhance electric breakdown strength has been proposed to greatly enhance the energy storing performance of lead-free ferroelectric ceramics, whose effectiveness has been proved within this investigation. Especially, the (Ba0.65Sr0.245Bi0.07)0.99Nd0.01TiO3 (BT-SBT-NdVPP) ceramic prepared by this strategy obtains a superhigh energy storage density of 4.2 J/cm3 under 460 kV/cm, and its temperature (30 ~ 100 °C) and frequency (10 ~ 400 Hz) stabilities under 300 kV/cm are pretty good. In addition, this ceramic has excellent pulse performance under 350 kV/cm between 30 and 150 °C. Therefore, this two-step strategy put forward within this investigation not only significantly improves the energy storage performance of BT-based ceramics but also provides a reference for the preparation of dielectric ceramics with high quality, which could has great potential for the practical industrial application.