A/B-sites disorder-induced relaxor phase transition and inhibit the grain size of BaTiO₃ ceramic to enhance energy storage properties

The present study introduces a strategy for improving the energy storage performance (ESPs) and enhancing the dielectric breakdown strength (DBSs) of BaTiO 3 (BT) via breaking the domain structure caused by A/B –sites cations disorder. Lead-free [(Ba 0.85 Bi 0.06 Mg 0.06 )(Ti 1−x Zr x )O 3 ] (abbreviate BT-BMZ) (x = 0.0, 0.025, 0.05, and 0.075) ceramics were used in this study. The substitution of isovalent (Ba 2+ ) by trivalent (Bi 3+ ) in the A-site of BT lattice induced charge misfit and cations disorder. It was balanced by creating barium ion vacancies in the A-site. Replacing Ti 4+ with Zr 4+ at the B-site of the lattice reduces the tolerance factor ( τ ), enhances the degree of relaxor phase, and subsequently enhances the DBSs values due to the larger ionic radius of (Zr 4+ = 0.72 Å, CN = 6) compared to (Ti 4+ = 0.6 Å, CN = 6). Furthermore, the maximum difference polarization (ΔP = P max —P r ) is enhanced by the hybridization between Bi 3+ 6 P and O 2− 2 P instead of Ba 2+ 5d and O 2− 2 P. [(Ba 0.85 Bi 0.06 Mg 0.06 )(Ti 0.95 Zr 0.05 )O 3 ] (BT-BMZ 0.05 ) ceramic (BT-BMZ 0.05 ) exhibit highest recoverable energy storage density (W rec ∼ 8 J cm −3 ), energy storage efficiency ( η = 86%) and (E b ∼ 700 kV cm −1 ). Furthermore, the samples showed wide range stability in the temperature range (25 °C–150 °C ) and the frequency range (2–20 Hz). BT-BMZ 0.05 ceramic has significant potential as a viable alternative dielectric for advanced pulsed power capacitors.