Ultrahigh Energy Storage Density Achieved in Freestanding (Pb 0.98 La 0.02 )(Zr 0.85– x Sn x Hf 0.15 ) 0.995 O ₃ Antiferroelectric Thick Film Ceramics

Antiferroelectric ceramics exhibiting electric field-induced phase transitions are excellent candidates for applications in advanced pulse-power capacitors. In this work, Hf⁴⁺-doped (Pb0.98La0.02)(Zr0.85-xSnxHf0.15)0.995O₃ (PLZSH, where x = 0.40, 0.45, 0.50, and 0.55) antiferroelectric thick film ceramics were synthesized and characterized. The Rietveld refinement of X-ray diffraction (XRD) data indicates that all PLZSH ceramics show orthorhombic structures. Notably, the average electric displacement of B-site cations decreases with increasing Sn⁴⁺ content, suggesting more stable antiferroelectric phases. Furthermore, the selected area electron diffraction (SAED) revealed F-points associated with 1/2{ooo} superlattice diffraction spots and incommensurate modulation structure (IMS) related to the 1/n⟨110⟩ superlattice, revealing the obvious tilting of octahedra in the ceramics, resulting in slimmer hysteresis loops. In addition, the series phase transitions that occurred in the AFE ceramics indicate the higher dielectric breakdown strength (DBS), showing a strong nonlinear Wrec ∼ En relationship. An ultrahigh DBS of ∼1600 kV/cm is achieved in PLZSH (x = 0.55) thick film ceramics, while the highest Wrec of 19.2 J/cm³ and efficiency of 79.5% were obtained at 1360 kV/cm in PLZSH (x = 0.50) ceramics. The remarkable energy storage performances demonstrated by PLZSH ceramics emphasize their potentials for use in advanced energy storage capacitors for pulse-power electronic devices.