Temperature-stable dielectric and energy storage properties of (1-x)(0.94Bi0.5Na0.5TiO3-0.09BiAlO3)-xSrTiO3 ceramics

The increasing demand of high-temperature and high-power electronics has triggered intensive research on capacitors with operation temperature up to 300 degrees C. In this work, dielectric properties of (1-x)[0.91Bi(0.5)Na(0.5)TiO(3)-0.09BiAlO(3)]-xSrTiO(3) (BNT-9BA-100xST) ceramics are studied. BNT-9BA-15ST has a stable permittivity between 96.7 degrees C and 396.8 degrees C and the dielectric loss is below 0.02 in the temperature range of 132.8 degrees C-391.8 degrees C. Furthermore, frequency dependent conductivities of BNT-BA-100xST are analyzed by a universal dynamic response (UDR) and nearly constant loss (NCL) behavior. Besides, the energy storage properties are studied and the recoverable energy storage density of BNT-9BA-15ST (W-rec) is 0.84 J/cm(3) at room temperature under the electric field of 90 kV/cm. And the variance of W-rec is smaller than +/- 15% in the temperature range of 20 degrees C-180 degrees C. Thus, this work provides a new candidate of dielectrics used for capacitors at high temperature. (C) 2019 Elsevier B.V. All rights reserved.