[Bi³⁺/Zr⁴⁺] induced ferroelectric to relaxor phase transition of BaTiO₃ ceramic for significant enhancement of energy storage properties and dielectric breakdown strength

The low breakdown strength and recoverable energy storage density of pure BaTiO₃ (BT) dielectric ceramics limits the increase in energy-storage density. This study presents an innovative strategy to improve the energy storage properties of BT by the addition of Bi₂O₃ and ZrO₂. The effect of Bi, Mg and Zr ions (abbreviate BMZ) on the structural, dielectric and energy storage properties of BaTiO₃ ceramic by synthesize (Ba_0.85Bi_0.06Mg_0.06)(Ti_0.95Zr_0.05)O₃ (abbreviation BT-BMZ) lead-free ceramics have been investigated. Ferroelectric to relaxor phase transition has been achieved at BT-based which attributed to the different ionic radius and valances of ions into both of A and B-sites of BT lattice. The permittivity diffusive phase transition (γ) was observed increased from 1.24 to 1.89 by addition of BMZ to BT-lattice. The BT-BMZ sample shown significant enhancement of recoverable energy density (W_rec = 8.1 J/cm³), energy storage efficiency (ƞ = 86%) and dielectric breakdown strength E_b = 700kV/cm. The enhancement of energy storage performance is due to the hybridization between Bi³⁺ 6Pand O²⁻ 2P instead of Ba²⁺ 4F and O²⁻ 2P orbitals. On the other hand, the substitution of iso-valence (Ba²⁺) by trivalent (Bi³⁺) lead to create barium vacancies into the A-sites of BT lattice subsequently reducing the remnant polarization (P_r). The thermal stability into (W_rec) and efficiency (η) were enhanced by introducing BMZ to BT-lattice in a wide range of temperature (25–175 °C) due to present the relaxor phase in a wide range of temperature. The BT-BMZ ceramics are promising candidate for advanced pulsed power technology and energy storage applications.