Enhanced electrical properties and energy storage performances of NBT-ST Pb-free ceramics through glass modification

In the current study, a strategy incorporating with glass addition has been employed to enhance the energy storage performance of 0.5(Na0.5Bi0.5TiO3)-0.5SrTiO3 Pb-free bulk ceramics through a traditional electroceramic processing route. The strategy is to introduce liquid sintering to dielectric ceramics, and hence lower the sintering temperature, finally resulting in refined grains and enhanced electrical properties. The detailed impacts of different additive contents on the phases, microstructure, electrical properties and energy storage and release of NBT-ST specimens were deeply and systemically studied. The results indicate as the glass content increases, the grains of NBT-ST-xBBZ ceramics are remarkably refined, and the dielectric constant and loss decrease. After glass addition, the breakdown strength of ceramics is nearly doubled. When the doping content of the glass is 1 wt%, the energy density reaches 1.67 J/cm3 under an electric field strength of 200 kV/cm. After further testing of NBT-ST-0.01BBZ ceramic, it exhibits good temperature (from 30 to 150 °C), frequency (0.2–100 Hz) and cycle (104) stability. •A strategy incorporating with glass addition has been employed to enhance the energy storage performance.•Glass addition can introduce liquid sintering, lower the sintering temperature, refine the grain, and improve BDS.•With Glass addition, the energy storage density is significantly enhanced (nearly twice).•Sample with 0.01 glass content shows relatively good temperature and frequency stability.