Lead‐free high‐energy‐storage performance ternary Bi _0.5 Na _0.5 TiO ₃ ‐BaTiO ₃ ‐Nd(Mg _0.5 Hf _0.5 )O ₃ relaxor ferroelectric ceramics

Abstract Dielectric energy‐storage ceramics capacitors have shown remarkable application potential in pulsed power systems. However, their energy‐storage density remains substantially lower than required for next‐generation power electronics applications, thereby restricting their widespread adoption in electric vehicle drive systems. In this study, the energy‐storage properties were significantly improved through the strategic incorporation of Nd(Mg 0.5 Hf 0.5 )O 3 as a ternary component into the 0.94Bi 0.5 Na 0.5 TiO 3 ‐0.06BaTiO 3 binary lead‐free ceramics system. The prepared (1 – x )(0.94Bi 0.5 Na 0.5 TiO 3 ‐0.06BaTiO 3 )‐ x Nd(Mg 0.5 Hf 0.5 )O 3 ternary lead‐free ceramics were comprehensively evaluated with regard to their structural characteristics, dielectric properties, and energy‐storage capabilities. Systematic characterization revealed that Nd(Mg 0.5 Hf 0.5 )O 3 doping effectively tailored electrical properties by reducing remnant polarization while enhancing breakdown strength, synergistically boosting recoverable energy‐storage density W rec . The optimized 0.85(0.94Bi 0.5 Na 0.5 TiO 3 ‐0.06BaTiO 3 )‐0.15Nd(Mg 0.5 Hf 0.5 )O 3 composition demonstrated superior energy‐storage performance: a high W rec of 6.1 J/cm 3 with moderate efficiency ~ 75.4% at 580 kV/cm, accompanied by exceptional thermal stability (20–100°C) and frequency stability (1–1000 Hz). Notably, superior power density (~352 MW/cm 3 ) and ultrafast discharge time (~45 ns) were simultaneously achieved. These enhancements originate from Nd(Mg 0.5 Hf 0.5 )O 3 ‐induced refined grain morphology, widened bandgap, and improved electrical homogeneity. This work establishes an effective strategy for developing BNT‐based ceramics, offering a sustainable solution for next‐generation pulsed power capacitor applications.