Enhanced energy storage property in Bi _0.5 Na _0.5 TiO ₃ ‐based ceramics by composition modulation and grain refinement

Abstract High energy density ( W rec ) dielectrics with excellent efficiency ( η ) and thermal stability are crucial in high‐power energy storage applications. In this work, we introduce Ba(Zr 0.2 Ti 0.8 )O 3 (BZT) into Bi 0.5 Na 0.5 TiO 3 (BNT) to delay saturation polarization and refine grain sizes for enhancing energy storage performance. BZT diffusing into BNT lattice not only increases electronegativity between A‒O/B‒O bond and the relaxor, but also is beneficial for refining grain sizes and suppressing the development of local electric branches. Therefore, high P max with moderate P r and improved breakdown strength is achieved in BNT‒ x BZT ceramics with x = 0.6 mol. Additionally, BNT‒0.60BZT ceramics demonstrate enhanced recoverable energy storage density of 4.1 J cm −3 with high energy storage efficiency of 91%, along with favorable overdamped charge‒discharge properties including a maximum current, discharge energy density, and discharge time of 10 A, 2.4 J cm −3 , and 150 ns, respectively.