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Pulse ceramic capacitors that request particularly high reliability and long lifetime forbid over-applied electric field, hence demanding high energy density (W re) and energy storage efficiency (η) at low electric field. In this work, we investigated a lead lanthanum zirconate titanate (PLZT) ceramic featuring both of tetragonal antiferroelectric phase (AFE T) and relaxor characteristic, which emerge in converged area of PLZT phase diagram (mole ratio of La reaches ~10%). Temperature dependent permittivity and XRD analysis proves the crossover trait in this structure. In this special relaxor-like AFE T structure, decent W re (1.2–1.3 J cm−3) and η (86–90%) are achieved at 12 V μ m−1. Equivalent dielectric constant (ε eq) is also introduced to illustrate nonlinear energy storage performance at different electric field. Compared to common dielectric materials, tunable ε eq in relaxor-like AFE T structure shows advantages of excellent low-field energy density and wide working span, leading to the convenience in size design of capacitors. Finally, good energy storage stability under various external field was verified: ~1.00 J cm−3 in W re and ~92% in η were stabilized under varied frequency (< ± 8.9%, 0.01–2000 Hz), temperature (< ± 9.8%, −60 to 120 ℃) and fatigue loading (< ± 9.8%, >108 times) at ~10 V μ m−1. [ABSTRACT FROM AUTHOR]

Antiferroelectrics (AFE) are considered a promising energy storage material for components that require nanosecond-level discharge. Pb(Yb 1/2 Nb 1/2)O 3 (PYN) is an AFE material with potential energy storage applications. However, the unmatched critical phase transition field (E F) and breakdown electric field (E B) conceal most of energy storage capacitance. This work is aimed to settle imbalanced E F / E B via a compositional design strategy. E F and E B were tuned in order to obtain 5.18 J cm−3 in recoverable energy density, 65% energy efficiency, and thermal and frequency stability varying within 15%, producing excellent comprehensive energy storage properties. A modified kinetic model of energetic path was used to understand the mechanism governing the variation of E F. We expect our work to contribute to further development of novel AFE materials for energy storage. [ABSTRACT FROM AUTHOR]

Ag 1− x K x NbO 3 (AKN x (x ≤ 0.12) ceramics were prepared to understand the relationship of structure-properties driven by compositions and temperatures. The results suggested that this binary system possessed a morphotropic phase boundary (MPB) consisted of ferrielectric and ferroelectric phases with iso-symmetry at room temperature, in which domains switching together with electric-field-induced irreversible phase transition achieved a much higher electrostrain (S max = 0.4%) than other compositions. But this MPB was destroyed after poling, leading to inferior piezoelectricity. A phase diagram was drawn after analyzing in situ XRD and dielectric data, where an almost vertical ferrielectric/antiferroelectric ↔ polymorphic ferroelectric MPB line starting from a triple point was proposed. As temperature increased, the piezoelectricity significant enhanced near ferroelectric orthorhombic ↔ monoclinic phase boundary, while the highest piezoelectricity was achieved near the monoclinic ↔ paraelectric phase boundary with d 33 = 200 pC/N. The enhanced piezoelectricity is intimately related to the ferroelectric monoclinic possessing Pm symmetry. [ABSTRACT FROM AUTHOR]