Superior energy storage properties in SrTiO₃-based dielectric ceramics through all-scale hierarchical architecture

The restricted energy density in dielectric ceramic capacitors is challenging for their integration with advanced electronic systems. Numerous strategies have been proposed to boost the energy density at different scales or combine those multiscale effects. Herein, guided by all-scale synergistic design, we fabricated Sr_0.7Bi_0.2TiO₃ ceramics doped with (Bi_0.5Na_0.5)(Zr_0.5Ti_0.5)O₃ by sintering the nanopowders by solution combustion synthesis, which demonstrate exceptional energy storage performance (ESP). Notably, an ultrahigh recoverable energy density of 11.33 J cm^-3, accompanied by an impressive energy efficiency of 89.30%, was achieved at an extremely high critical electric field of 961 kV cm^-1. These primary energy storage parameters outperform those of previously reported ceramic capacitors based on SrTiO₃. Additionally, an excellent comprehensive performance is also realized, including a substantial power density of 156.21 MW cm^-3 (at 300 kV cm^-1), an extraordinarily short discharge time of 97 ns, a high Vickers hardness rating of approximately 8.23 GPa, and outstanding thermal and frequency stability. This enhancement can be attributed to the synergistic effect at all scales from atomic substitution, polar nano regions, submicrometer grain, and sample thickness. Consequently, this panoscopic approach has effectively demonstrated the potential to enhance the ESP of dielectric ceramics.