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

Abstract

The present study introduces a strategy for improving the energy storage performance (ESPs) and enhancing the dielectric breakdown strength (DBSs) of BaTiO3 (BT) via breaking the domain structure caused by A/B –sites cations disorder. Lead-free [(Ba0.85Bi0.06Mg0.06)(Ti1-xZrx)O3] (abbreviate BT-BMZ) (x = 0.0, 0.025, 0.05, and 0.075) ceramics were used in this study. The substitution of isovalent (Ba2+) by trivalent (Bi3+) into the A-site of BT lattice induced charge misfit and cations disorder, which can be balanced by creating barium ions vacancies into the A-site. Replacing Ti4+ with Zr4+ 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 (Zr4+ = 0.72Å, CN = 6) compared to (Ti4+ = 0.6Å, CN = 6). Furthermore, the maximum difference polarization (ΔP = Pmax – Pr) is enhanced by the hybridization between Bi3+ 6P and O2- 2P instead of Ba2+ 5d and O2- 2P. [(Ba0.85Bi0.06Mg0.06)(Ti0.95Zr0.05)O3] (BT-BMZ0.05) ceramic (BT-BMZ0.05) exhibit highest recoverable energy storage density (Wrec ~ 8 J/cm3), energy storage efficiency (ƞ = 86%) and (Eb ~ 700 kV/cm). Furthermore, the samples showed wide range stability in the temperature range (25-150oC ) and the frequency range (2-20Hz). BT-BMZ0.05 ceramic has significant potential as a viable alternative dielectric for advanced pulsed power capacitors.

Simultaneously enhanced of energy storage and energy harvesting performances of [(Bi0.5Na0.5)TiO3–BaTiO3] ceramics by addition of SrTiO3

“…Further, the mixture was dried at 80 °C for 6 h to eliminate any adsorbed moisture, sieved using 100 μm mesh and then calcined at 850 °C for 2 h in air with 5 °C min −1 of heating/cooling rate in the muffle furnace [25]. The calcined powders were ground and combined with a small amount of PVA which is used as a binder and uniaxially pressed into discs of about ∼ 10 mm in diameter and ∼ 1 mm in thickness at a pressure of 180 MPa [26]. The pellets were sintered at 1130 °C for 2 h with a heating rate of 3 °C min −1 after burning the PVA at 400 °C for 4 h in platinum crucibles in order to prevent any contamination during a thermal processing.…”