Structure, dielectric, and relaxor properties of BaTiO3-modified high- entropy (Bi0.2Na0.2K0.2Ba0.2Ca0.2)TiO3 ceramics for energy storage applications

High-entropy (1-x)Bi0.5Na0.5K0.5Ba0.5Ca0.5TiO3-xBaTiO3 (BNKBCT-BT, x = 0.02, 0.06, 0.10, 0.14 and 0.20) ceramics are successfully prepared via the solid-state reaction method. The XRD and Raman analyses reveal that all samples exhibit a pseudo-cubic phase structure. With increasing x, the a is gradually increased, resulting in the expansion of unit cell volume. A strong frequency dispersion appeared around Tm, de-monstrating that the as-prepared ceramics is a relaxor ferroelectric. Owing to the increase in the degree of lattice disorder, as well as relaxation and thermal evolution of PUs, the as-prepared ceramics exhibit a broad relaxor behavior. The Delta P is effectively increased by doping BT, which is conducive to achieving excellent energy storage properties. Moreover, Wrec of all samples is more than 1.31 J/cm3 and, at x = 0.20, Wrec reaches the maximum value of 2.24 J/cm3 at 140 kV/cm. These results indicate that high-entropy (1-x) BNKBCT-xBT ceramics are promising materials for energy storage applications. (c) 2023 Elsevier B.V. All rights reserved.

Automated summary

High-entropy (1-x) BNKBCT-xBT ceramics with various doping concentrations of BT were successfully prepared and showed promising energy storage properties. The XRD and Raman analyses revealed a pseudo-cubic phase structure for all samples. The as-prepared ceramics exhibited a relaxor ferroelectric behavior due to the increase in lattice disorder and the thermal evolution of polarization units. The increase in ΔP and the high Wrec values indicated the potential of these ceramics for energy storage applications.