Superior Electrostatic Storage Energy Under Moderate Electric Field of Superparaelectrics with Highly Polarizable Clusters

Abstract Despite the widespread research of relaxor ferroelectrics in pulsed power capacitors, achieving both high recoverable energy density ( W _rec ) and efficiency ( η ) under moderate electric field range is still challenged because domain miniaturization required to enhance η generally leads to the delayed polarization saturation and the reduced spontaneous polarization. Here, highly polarizable clusters of superparaelectrics with locally coexisted multiphase are demonstrated by introducing Bi _0.5 Li _0.5 ZrO ₃ into the BaTiO ₃ matrix. The synergistic introduction of additional A‐site polarization contribution, the miniaturization of domains into polar clusters, and the local multiphase coexistence enable both the high maximal polarization ( P _max ) at the moderate electric field and the extremely low polarization hysteresis. As a result, the combined effects of heterogeneous cations with A‐site driven ferroelectricity, A‐site valence state difference, and A‐ and B‐sites ionic radius difference lead to both giant W _rec of ≈9.11 J cm ⁻³ and high η of ≈95.3% concurrently under a moderate electric field of 47 kV mm ⁻¹ . This work demonstrates that modulating the polarization characteristic of relaxor ferroelectric ceramics can achieve low electric field driven superior energy‐storage performances.