Heterogeneous Polarization Configuration Regulated by Core‐Multi‐Shells Structure Enabled Superior Energy Storage in BNT‐Based Ceramics

ABSTRACT Environmental concerns have driven widespread research into energy storage for new energy development. Despite Bi _0.5 Na _0.5 TiO ₃ ‐based ceramics offer high power density, fast charging/discharging, and good temperature stability, a major challenge of low energy density resulting from low breakdown strength and polarization hysteresis, limits their practical use despite other advantageous properties. In this work, a novel core‐multi‐shells structure, coupling the anti‐ferroelectrics core, relaxor ferroelectrics inner shell, and linear dielectrics outer shell together, is constructed. This core‐multi‐shells structure induces multilevel lattice distortions, which facilitate quick polarization responses and effectively hinder the formation of long‐range polar order, thus delays polarization saturation and weakens hysteresis. Beneficial from this heterogeneous polarization configuration, a remarkable discharge energy storage density of 11.05 J/cm ³ at 790 kV/cm is achieved, together with good temperature stability and frequency stability, demonstrating the great application potential of this design.