Glass modified barium strontium titanate ceramics for energy storage capacitor at elevated temperatures

Abstract

A glass with composition of B2O3-Bi2O3-SiO2-CaO-BaO-Al2O3-ZrO2 (BBSZ) modified BaxSr1-xTiO3 (BST, x = 0.3 and 0.4) ceramics were prepared by a conventional solid state reaction method abided by a formula of BST + y%BBSZ (y = 0, 2, 4, 7, and 10, in mass). The effect of BBSZ glass content on the structure, dielectric properties and energy storage characteristics of the ceramics was investigated. The dielectric constant reduced but the endurable electrical strength enhanced due to the BBSZ glass addition in BST ceramics. In particular, the dielectric loss of the ceramics at elevated temperature (e.g. 200 °C) can be strongly suppressed from tanδ>20% to tanδ<3% after BBSZ glass modification. For Ba0.3Sr0.7TiO3+2% BBSZ ceramics, an optimized energy storage density (γ = 0.63 J/cm3) and efficiency (η = 91.6%) under an applied electric field of 160 kV/cm was obtained at room temperature. Meanwhile, the temperature dependent polarization-electric field (P-E) hysteresis loops were measured to evaluate the energy storage characteristics of the ceramics potential for high voltage capacitor application at elevated temperatures. Keywords: Barium strontium titanate, Glass modification, Energy storage, Ceramic capacitor