Lead-free X8R-type 0.92Ba0.8Sr0.2TiO3-0.08Bi(Mg0.5Zr0.5)O3 dielectric energy-storage ceramics for pulsed power capacitors

Dielectric ceramic capacitors, as one kind of important electrical energy-storage device, have been widely used because of their high-power density and low cost. It is a key challenge and of great significance to develop dielectric ceramic capacitors with high energy-storage density within a wide operate temperature range. In this work, the effect of the Bi(Mg0.5Zr0.5)O3 addition on the dielectric and energy-storage properties of lead-free Ba0.8Sr0.2TiO3 ceramics was systematically studied. It can be found that with increasing Bi(Mg0.5Zr0.5)O3 content, an increase in dielectric temperature stability as a result of the addition of Bi(Mg0.5Zr0.5)O3 can accompany the formation of the long-range ordered ferroelectric domain into polar nanoregions and also conform to a decrease in remanent polarization and an increase in energy-storage properties. As a result, for the composition 0.92Ba0.8Sr0.2TiO3-0.08Bi(Mg0.5Zr0.5)O3, a stable dielectric constant in a temperature range of −100–151 °C was achieved. Furthermore, a large recoverable energy-storage density value (3.44 J/cm3) and a high-power density value (541 MW/cm3) were obtained simultaneously in the above ceramic composition. All these features suggest that the 0.92Ba0.8Sr0.2TiO3-0.08Bi(Mg0.5Zr0.5)O3 ceramics might be ideal materials for potential applications of high energy-storage capacitors.