Achieving ultrahigh energy storage performance over a broad temperature range in (Bi0.5Na0.5)TiO3-based eco-friendly relaxor ferroelectric ceramics via multiple engineering processes

The development of ABO(3) perovskite-structured dielectric materials with high recoverable energy storage density (W-rec) and power density (P-D) is crucial for the downsizing of pulsed power devices. Despite several research efforts, achieving a high W-rec over a wide working temperature range in an environmentally benign system remains a difficulty. A synergistic design strategy is given here, which includes concurrently doping at the A- and B-site to achieve a spread and depressed dielectric response, adding sintering aids, and employing advanced viscous polymer rolling technology for dense and ultra-thin ceramic samples, respectively. Finally, at a relatively low electric field of 380 kV/cm, an ultrahigh W-rec of 6.57 J/cm(3) is realized in (Bi0.5Na0.5)(0.93)Ca0.07Ti0.85Zr0.15O3-0.5 wt% Li2CO3 component, which benefits from gentle polarization saturating and improved breakdown strength. The W-rec can be maintained above 6 J/cm(3) while maintaining strong thermal stability (variation <= +/- 3%) over a temperature range of 30-150 degrees C. Because BNT-based materials have such high energy storage performance and temperature stability, they are not only a promising candidate for replacing lead-based dielectrics, but also a valuable guide for developing new highperformance ferroelectric materials for future energy storage devices in the pulsed power system. (C) 2021 Elsevier B.V. All rights reserved.